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Sample records for lizard island great

  1. Nephtyidae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Murray, Anna; Wong, Eunice; Hutchings, Pat

    2015-01-01

    Seven species of the family Nephtyidae are recorded from Lizard Island, none previously reported from the Great Barrier Reef. Two species of Aglaophamus, four species of Micronephthys, one new and one previously unreported from Australia, and one species of Nephtys, were identified from samples collected during the Lizard Island Polychaete Workshop 2013, as well as from ecological studies undertaken during the 1970s and deposited in the Australian Museum marine invertebrate Collections. A dichotomous key to aid identification of these species newly reported from Lizard Island is provided. PMID:26624076

  2. Nereididae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Glasby, Christopher J

    2015-01-01

    Nereididae is one of the most ubiquitous of polychaete families, yet knowledge of their diversity in the northern Great Barrier Reef is poor; few species have been previously reported from any of the atolls or islands including Lizard Island. In this study, the diversity of the family from Lizard Island and surrounding reefs is documented based on museum collections derived from surveys conducted mostly over the last seven years. The Lizard Island nereidid fauna was found to be represented by 14 genera and 38 species/species groups, including 11 putative new species. Twelve species are newly reported from Lizard Island; four of these are also first records for Australia. For each genus and species, diagnoses and/or taxonomic remarks are provided in addition to notes on their habitat on Lizard Island, and general distribution; the existence of tissue samples tied to vouchered museum specimens is indicated. Fluorescence photography is used to help distinguish closely similar species of Nereis and Platynereis. A key is provided to facilitate identification and encourage further taxonomic, molecular and ecological studies on the group. PMID:26624071

  3. Serpulidae (Annelida) of Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Kupriyanova, Elena K; Sun, Yanan; Hove, Harry A Ten; Wong, Eunice; Rouse, Greg W

    2015-01-01

    Serpulidae are obligatory sedentary polychaetes inhabiting calcareous tubes that are most common in subtropical and tropical areas of the world. This paper describes serpulid polychaetes collected from Lizard Island, Great Barrier Reef, Australia in 1983-2013 and deposited in Australian museums and overseas. In total, 17 serpulid genera were recorded, but although the study deals with 44 nominal taxa, the exact number of species remains unclear because a number of genera (i.e., Salmacina, Protula, Serpula, Spirobranchus, and Vermiliopsis) need world-wide revisions. Some species described herein are commonly found in the waters around Lizard Island, but had not previously been formally reported. A new species of Hydroides (H. lirs) and two new species of Semivermilia (S. annehoggettae and S. lylevaili) are described. A taxonomic key to all taxa found at Lizard Island is provided. PMID:26624073

  4. Six genetically distinct clades of Palola (Eunicidae, Annelida) from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Schulze, Anja

    2015-01-01

    A total of 36 lots of Palola spp. (Eunicidae, Annelida) were collected during the Lizard Island Polychaete Workshop on Lizard Island, Great Barrier Reef, Queensland, Australia. Of these, 21 specimens were sequenced for a portion of the mitochondrial cytochrome c oxidase I gene. These sequences were analysed in conjunction with existing sequences of Palola spp. from other geographic regions. The samples from Lizard Island form six distinct clades, although none of them can clearly be assigned to any of the nominal species. Four of the six Lizard Island clades fall into species group A and the remaining two into species group B (which also includes the type species, Palola viridis). All sequenced specimens were characterized morphologically as far as possible and a dichotomous key was assembled. Based on this key, the remaining samples were identified as belonging to one of the clades. PMID:26624083

  5. Syllidae (Annelida: Phyllodocida) from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Aguado, M Teresa; Murray, Anna; Hutchings, Pat

    2015-01-01

    Thirty species of the family Syllidae (Annelida, Phyllodocida) from Lizard Island have been identified. Three subfamilies (Eusyllinae, Exogoninae and Syllinae) are represented, as well as the currently unassigned genera Amblyosyllis and Westheidesyllis. The genus Trypanobia (Imajima & Hartman 1964), formerly considered a subgenus of Trypanosyllis, is elevated to genus rank. Seventeen species are new reports for Queensland and two are new species. Odontosyllis robustus n. sp. is characterized by a robust body and distinct colour pattern in live specimens consisting of lateral reddish-brown pigmentation on several segments, and bidentate, short and distally broad falcigers. Trypanobia cryptica n. sp. is found in association with sponges and characterized by a distinctive bright red colouration in live specimens, and one kind of simple chaeta with a short basal spur. PMID:26624065

  6. Neosabellides lizae, a new species of Ampharetidae (Annelida) from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Alvestad, Tom; Budaeva, Nataliya

    2015-01-01

    Neosabellides lizae, a new species of Ampharetidae, is described from the intertidal zone off Lizard Island, Great Barrier Reef, Queensland, Australia. The new species is referred to the genus Neosabellides based on the shape of the prostomium, three pairs of branchiae, 14 thoracic segments with notopodia, 12 thoracic uncinigerous segments, and the first two pairs of abdominal uncinigers of thoracic type. The new species differs from all known species of Neosabellides in having 14 abdominal uncinigerous segments. PMID:26624066

  7. Joeropsididae Nordenstam, 1933 (Crustacea, Isopoda, Asellota) from the Lizard Island region of the Great Barrier Reef, Queensland, Australia

    PubMed Central

    Bruce, Niel L.

    2015-01-01

    Abstract The marine isopod family Joeropsididae (Asellota) is documented for the Lizard Island region of the Great Barrier Reef, Australia. Fifteen species of Joeropsis are recorded, including ten new species; descriptive notes are provided for five species that lacked adequate material for description. A revised family and genus diagnosis is presented together with comments on the most useful characters for species identification and a key to Joeropsis of the Lizard Island region. PMID:25878536

  8. Community calcification in Lizard Island, Great Barrier Reef: A 33 year perspective

    NASA Astrophysics Data System (ADS)

    Silverman, J.; Schneider, K.; Kline, D. I.; Rivlin, T.; Rivlin, A.; Hamylton, S.; Lazar, B.; Erez, J.; Caldeira, K.

    2014-11-01

    Measurements of community calcification (Gnet) were made during September 2008 and October 2009 on a reef flat in Lizard Island, Great Barrier Reef, Australia, 33 years after the first measurements were made there by the LIMER expedition in 1975. In 2008 and 2009 we measured Gnet = 61 ± 12 and 54 ± 13 mmol CaCO3 m-2·day-1, respectively. These rates are 27-49% lower than those measured during the same season in 1975-76. These rates agree well with those estimated from the measured temperature and degree of aragonite saturation using a reef calcification rate equation developed from observations in a Red Sea coral reef. Community structure surveys across the Lizard Island reef flat during our study using the same methods employed in 1978 showed that live coral coverage had not changed significantly (∼8%). However, it should be noted that the uncertainty in the live coral coverage estimates in this study and in 1978 were fairly large and inherent to this methodology. Using the reef calcification rate equation while assuming that seawater above the reef was at equilibrium with atmospheric PCO2 and given that live coral cover had not changed Gnet should have declined by 30 ± 8% since the LIMER study as indeed observed. We note, however, that the error in estimated Gnet decrease relative to the 1970's could be much larger due to the uncertainties in the coral coverage measurements. Nonetheless, the similarity between the predicted and the measured decrease in Gnet suggests that ocean acidification may be the primary cause for the lower CaCO3 precipitation rate on the Lizard Island reef flat.

  9. Sphaerodoridae (Annelida) from Lizard Island, Great Barrier Reef, Australia, including the description of two new species and reproductive notes.

    PubMed

    Capa, María; Rouse, Greg W

    2015-01-01

    Sphaerodorids are scarce at Lizard Island archipelago and other localities in the Great Barrier Reef, Australia. Intensive collections at a variety of habitats within the Lizard Island archipelago over the last four decades have resulted in a total of just 11 specimens. Nevertheless, they represent two new species and a new record for Lizard Island. Sphaerodoropsis aurantica n. sp. is characterised by nine longitudinal rows of sessile and spherical dorsal macrotubercles, arranged in a single transverse row per segment; parapodia with around 10 spherical papillae; and compound chaetae with thin shafts and long blades. Sphaerodoropsis plurituberculata n. sp. is characterised by more than 12 more or less clearly arranged longitudinal rows of sessile spherical dorsal tubercles (variable in size), in four transverse rows per segment; parapodia lacking papillae; and semi-compound chaetae with distally enlarged shaft and short blades. Ephesiella australiensis is reported for the first time in Lizard Island. Laboratory observations of live specimens of Sphaerodoropsis plurituberculata n. sp., revealed the use of spermatophores by males. These were found attached externally to the body surface of both sexes, indicating pseudo-copulation. PMID:26624069

  10. Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Hutchings, Pat; de Matos Nogueira, João Miguel; Carrerette, Orlemir

    2015-01-01

    In a survey of the polychaetes of the Lizard Island region, six species of polychaetes belonging to the families Telothelepodidae Nogueira, Fitzhugh & Hutchings, 2013, Thelepodidae Hessle, 1917 and Trichobranchidae Malmgren, 1866 were found, from material collected during the Lizard Island Polychaete Taxonomic Workshop, and material collected by previous projects undertaken by the Australian Museum. This material includes one new species of Rhinothelepus Hutchings, 1974 (Telothelepodidae); one new species of each of the genera, Euthelepus McIntosh, 1885, Streblosoma Sars, 1872, and Thelepus Leuckart, 1849 (Thelepodidae); and one new species of Terebellides Sars, 1835 and another of Trichobranchus Malmgren, 1866 (Trichobranchidae). Keys for identification of these species are provided, together with full descriptions for all species, as well as comparisons with the morphologically most similar congeners. PMID:26624072

  11. Glyceriformia Fauchald, 1977 (Annelida: "Polychaeta") from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Böggemann, Markus

    2015-01-01

    Eight species of Glyceridae (Glycera brevicirris, Glycera cf. lapidum, Glycera onomichiensis, Glycera sagittariae, Glycera tesselata, Glycera tridactyla, Glycerella magellanica, Hemipodia cf. simplex) and six species of Goniadidae (Goniada antipoda, Goniada cf. brunnea, Goniada echinulata, Goniada emerita, Goniada grahami, Goniada paucidens) have been collected during several expeditions to the vicinity of Lizard Island (Australia, Queensland). An identification key to the Glyceriformia that inhabit the region is presented. Detailed and illustrated morphological descriptions are given for all investigated species. PMID:26624067

  12. A new species of gnathiid (Crustacea: Isopoda) parasitizing teleosts from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Ferreira, Maryke L; Smit, Nico J; Grutter, Alexandra S; Davies, Angela J

    2009-10-01

    During March 2002 and November 2005, teleost fishes were collected at Lizard Island, Great Barrier Reef (GBR), Australia. Gnathiid isopod juveniles were allowed to detach from these host fishes and were maintained in fresh seawater until they molted into adults. Adult males emerged 5 days post-detachment (d.p.d.) and females 10 d.p.d. of juveniles from host fish. The adults and juveniles were identified as new to science and described as Gnathia aureamaculosa n. sp. The species description is based on brightfield and scanning electron microscopy observations primarily of males, since the taxonomy of gnathiids is based on male morphology. This species has been widely employed in various studies on the Great Barrier Reef, from its involvement in feeding patterns in reef fish to its role in transmitting blood parasites, and has been referred to as Gnathia sp. A. Distinctive features of the male include gold-spotted pigmentation on the dorsal pereon of live specimens, a cephalosome with a conical superior fronto-lateral process, an inferior and conical medio-frontal process, and mandibles, each with an armed carina and an internal lobe. The female is characterized by its broad, rounded shape and cephalosome setae. The mandible of the third stage juvenile has 2 small teeth on the tip and 7 large teeth on the mesial margin. Differential pigmentation occurs in live male and female third-stage juveniles; females have greenish-yellow spots distributed over the pereon and males have white blotches and light brown and yellow spots on the pereon. PMID:19895161

  13. New and previously known species of Oenonidae (Polychaeta: Annelida) from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Zanol, Joana; Ruta, Christine

    2015-01-01

    The family Oenonidae consists of Eunicida species with prionognath jaws. Its Australian fauna had been reported to comprise six species belonging to Arabella, Drilonereis, and Oenone. This study provides descriptions for four new species, redescriptions for three species (two previously recorded and a new record, Drilonereis cf. logani) and diagnoses for the genera recorded from Australia. Currently, eleven species of oenonids, distributed in three genera, are known for the Australian coast. On Lizard Island, this family shows low abundance (19 specimens collected) and high richness (seven species). Our results suggest that despite the increasing accumulation of information, the biodiversity of the family is still poorly estimated. PMID:26624086

  14. Orbiniidae (Annelida: Errantia) from Lizard Island, Great Barrier Reef, Australia with notes on orbiniid phylogeny.

    PubMed

    Zhadan, Anna; Stupnikova, Alexandra; Neretina, Tatiana

    2015-01-01

    The fauna of Orbiniidae (Annelida: Errantia) from the Lizard Island has been studied. Five species were found and each was redescribed and illustrated using light microscopy and SEM. Scoloplos acutissimus Hartmann-Schröder, 1991 and Scoloplos dayi Hartmann-Schröder, 1980 collected for the first time since their original descriptions and confirmed through re-examination of their type materials. Molecular analyses were carried out using nuclear 18S rDNA and mitochondrial 16S rDNA and CO1 gene sequences with evolutionary distances and the Neighbor-Joining Method. The molecular analyses did not support the monophyly of the genera Scoloplos, Leitoscoloplos, Leodamas, and Naineris, and its results are incongruent with morphological data. PMID:26624087

  15. Spionidae (Annelida) from Lizard Island, Great Barrier Reef, Australia: the genera Aonides, Dipolydora, Polydorella, Prionospio, Pseudopolydora, Rhynchospio, and Tripolydora.

    PubMed

    Radashevsky, Vasily I

    2015-01-01

    Nineteen species in seven genera of spionid polychaetes are described and illustrated based on new material collected from the intertidal and shallow waters around the Lizard Island Group, northern Great Barrier Reef. Only one of these species had been previously reported from the Reef. Six species are described as new to science, and the taxonomy of seven species should be clarified in the future. Prionospio sensu lato is the most diverse group with 11 species identified in the present study. One species is identified in each of the genera Dipolydora, Polydorella, Rhynchospio and Tripolydora, and two species are identified in each of the genera Aonides and Pseudopolydora. The fauna of spionid polychaetes of the Great Barrier Reef seems to be more diverse than previously described and more species are expected to be found in the future. An identification key is provided to 16 genera of Spionidae reported from or likely to be found on the Great Barrier Reef. PMID:26624082

  16. A taxonomic guide to the fanworms (Sabellidae, Annelida) of Lizard Island, Great Barrier Reef, Australia, including new species and new records.

    PubMed

    Capa, María; Murray, Anna

    2015-01-01

    This comprehensive taxonomic work is the result of the study of fan worms (Sabellidae, Annelida) collected over the last 40 years from around the Lizard Island Archipelago, Great Barrier Reef, Australia. Some species described herein are commonly found in Lizard Island waters but had not previously been formally reported in the literature. Most species appear to be not particularly abundant, and few specimens have been collected despite the sampling effort in the area over this time period. After this study, the overall sabellid diversity of the archipelago has been greatly increased (by more than 650%). Before this revision, only four sabellid species had been recorded for Lizard Island, and in this paper we report 31 species, 13 of which belong to nominal species, six are formally described as new species (Euchone danieloi n. sp., Euchone glennoi n. sp., Jasmineira gustavoi n. sp., Megalomma jubata n. sp., Myxicola nana n. sp., and Paradialychone ambigua n. sp.), and the identity of 12 species is still unknown (those referred as cf. or sp.). Two species are newly recorded in Australia and two in Queensland. The invasive species Branchiomma bairdi is reported for the first time at Lizard Island. The genus Paradialychone is reported for Australia for the first time. Standardised descriptions, general photographs of live and/or preserved specimens and distribution data are provided for all species. New species descriptions are accompanied by detailed illustrations and exhaustive morphological information. A dichotomous key for sabellid identification is also included. PMID:26624068

  17. Changes in coral assemblages during an outbreak of Acanthaster planci at Lizard Island, northern Great Barrier Reef (1995-1999)

    NASA Astrophysics Data System (ADS)

    Pratchett, M. S.

    2010-09-01

    Population outbreaks of crown-of-thorns starfish ( Acanthaster planci L.) represent one of the most significant biological disturbances on tropical coral reefs and have the potential to devastate coral communities, thereby altering the biological and physical structure of reef habitats. This study reports on changes in area cover, species diversity and taxonomic composition of corals during an outbreak of A. planci at Lizard Island, in the northern Great Barrier Reef, Australia. Mean coral cover declined by 28.8% across ten locations studied. However, densities of A. planci, and their effects on local coral assemblages, were very patchy. Declines in coral cover were mostly due to the selective removal of certain coral taxa (mainly Acropora and Pocilloporidae corals); such that the greatest coral loss occurred at locations with highest initial cover of preferred coral prey. Most notably, coral assemblages in back-reef locations were transformed from topographically complex staghorn Acropora-dominated habitats, to relatively depauperate assemblages dominated by alcyonacean soft corals. Although coral loss was greatest among formerly dominant taxa (especially Acropora), effects were sufficiently widespread across different coral taxa, such that overall coral diversity tended to decline. Clearly, moderate outbreaks of A. planci have the potential to greatly alter community structure of coral communities even if they do not devastate live corals. Recovery in this instance is expected to be very rapid given that all coral taxa persisted, and effects were greatest among fast growing corals.

  18. Six new species of the genus Armandia Filippi, 1861 (Polychaeta, Opheliidae) from Lizard Island (Great Barrier Reef, Australia).

    PubMed

    Parapar, Julio; Moreira, Juan

    2015-01-01

    From the study of the material collected during the Polychaete Workshop held in Lizard Island (Great Barrier Reef, Australia) in August 2013, six species belonging to the genus Armandia (Polychaeta, Opheliidae) are newly described. Armandia bifida n. sp. is characterised by the bifid shape of the prechaetal lobe in CH1-CH3, A. dolio n. sp. by the barrel-shaped anal (=pygidial) tube (=funnel), A. filibranchia n. sp. by the extremely long and thin branchiae, A. laminosa n. sp. by the foliose shape and large size of the prechaetal lobe in CH1-CH3, A. paraintermedia n. sp. by the squared-shaped anal tube and size and shape of anal cirri, and A. tubulata n. sp. by the tubular shape of the anal tube. All species are fully described and illustrated, and compared with similar species. Several body characters of taxonomic relevance (e.g., anal tube and parapodia shape) are studied based on SEM micrographs. A key of the Armandia species hitherto described or reported in South-East Asia and Australasia is provided based on features of the anal tube. PMID:26624079

  19. A new gnathiid (Crustacea: Isopoda) parasitizing two species of requiem sharks from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Coetzee, Maryke L; Smit, Nico J; Grutter, Alexandra S; Davies, Angela J

    2008-06-01

    Third-stage juveniles (praniza 3) of Gnathia grandilaris n. sp. were collected from the gill filaments and septa of 5 requiem sharks, including a white tip reef shark, Triaenodon obesus, and 4 grey reef sharks, Carcharhinus amblyrhynchos, at Lizard Island, Great Barrier Reef, Australia, in March 2002. Some juvenile gnathiids were then maintained in fresh sea water until they molted to adults. Adult males appeared 19 days following detachment of juveniles from host fishes, but no juveniles molted successfully into females. The current description is based, therefore, on bright field and scanning electron microscopy observations of adult males and third-stage juveniles. Unique features of the male include the triangular-shaped inferior medio-frontal process, 2 areolae on the dorsal surface of the pylopod, and a slender pleotelson (twice as long as wide) with lateral concavities. The third-stage juvenile has distinctive white pigmentation on the black pereon when alive, while the mandible has 9 triangular backwardly directed teeth. This species has the largest male and third-stage juvenile of any Gnathia spp. from Australia and of any gnathiid isopods associated with elasmobranchs. PMID:18605791

  20. New records of Pectinariidae (Polychaeta) from Lizard Island, Great Barrier Reef, Australia and the description of two new species.

    PubMed

    Wong, Eunice; Hutchings, Pat

    2015-01-01

    Five species of Pectinariidae have previously been reported from Australia. This study documents the first records of this family from the Lizard Island region: Pectinaria antipoda is recorded, in addition to its already currently wide Australian distribution; two new species, Amphictene lizardensis n. sp. and Pectinaria carnosus n. sp. were also discovered and described. A key to all Australian species of Pectinariidae is provided. PMID:26624085

  1. Spionidae (Annelida: 'Polychaeta': Canalipalpata) from Lizard Island, Great Barrier Reef, Australia: the genera Malacoceros, Scolelepis, Spio, Microspio, and Spiophanes.

    PubMed

    Meißner, Karin; Götting, Miriam

    2015-01-01

    Seven species belonging to the spionid genera Malacoceros, Scolelepis, Spio, Microspio, and Spiophanes were found during the polychaete workshop on Lizard Island in August 2013. One species is new to science and named Scolelepis inversa n. sp., another Scolelepis species is probably also a new species but was represented in our samples by only a single specimen and not formally described. All other species have been reported previously from Australia. Species diagnoses of all species found during the workshop and of Scolelepis balihaiensis Hartmann-Schröder, 1979, Microspio microcera (Dorsey, 1977) and M. minuta (Hartmann-Schröder, 1962) have been critically reviewed and amended based on the study of type material. The potential synonymy of Microspio minuta (Hartmann-Schröder, 1962) and M. microcera (Dorsey, 1977) is discussed. The new combination Spio jirkovi (Sikorski, 1992) proposed by Sikorski (2013) is returned to Malacoceros. We added DNA barcodes for five species collected in the Lizard Island area to public databases which will be useful in future phylogenetic and phylogeographic studies. For Microspio we provide the first sequence data for this genus. PMID:26624075

  2. Impact Of Coral Structures On Wave Directional Spreading Across A Shallow Reef Flat - Lizard Island, Northern Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Leon, J. X.; Baldock, T.; Callaghan, D. P.; Hoegh-guldberg, O.; Mumby, P.; Phinn, S. R.; Roelfsema, C. M.; Saunders, M. I.

    2013-12-01

    Coral reef hydrodynamics operate at several and overlapping spatial-temporal scales. Waves have the most important forcing function on shallow (< 5 m) reefs as they drive most ecological and biogeochemical processes by exerting direct physical stress, directly mixing water (temperature and nutrients) and transporting sediments, nutrients and plankton. Reef flats are very effective at dissipating wave energy and providing an important ecosystem service by protecting highly valued shorelines. The effectiveness of reef flats to dissipate wave energy is related to the extreme hydraulic roughness of the benthos and substrate composition. Hydraulic roughness is usually obtained empirically from frictional-dissipation calculations, as detailed field measurements of bottom roughness (e.g. chain-method or profile gauges) is a very labour and time-consuming task. In this study we measured the impact of coral structures on wave directional spreading. Field data was collected during October 2012 across a reef flat on Lizard Island, northern Great Barrier Reef. Wave surface levels were measured using an array of self-logging pressure sensors. A rapid in situ close-range photogrammetric method was used to create a high-resolution (0.5 cm) image mosaic and digital elevation model. Individual coral heads were extracted from these datasets using geo-morphometric and object-based image analysis techniques. Wave propagation was modelled using a modified version of the SWAN model which includes the measured coral structures in 2m by 1m cells across the reef. The approach followed a cylinder drag approach, neglecting skin friction and inertial components. Testing against field data included bed skin friction. Our results show, for the first time, how the variability of the reef benthos structures affects wave dissipation across a shallow reef flat. This has important implications globally for coral reefs, due to the large extent of their area occupied by reef flats, particularly, as

  3. The Oweniidae (Annelida; Polychaeta) from Lizard Island (Great Barrier Reef, Australia) with the description of two new species of Owenia Delle Chiaje, 1844.

    PubMed

    Parapar, Julio; Moreira, Juan

    2015-01-01

    Study of the Oweniidae specimens (Annelida; Polychaeta) from Lizard Island (Great Barrier Reef, Australia) stored at the Australian Museum, Sydney and newly collected in August 2013 revealed the presence of three species, namely Galathowenia quelis Capa et al., 2012 and two new species belonging to the genus Owenia Delle Chiaje, 1844. Owenia dichotoma n. sp. is characterised by a very short branchial crown of about 1/3 of thoracic length which bears short, dichotomously-branched tentacles provided with the major division close to the base of the crown. Owenia picta n. sp. is characterised by a long branchial crown of about 4/5 of thoracic length provided with no major divisions, ventral pigmentation on thorax and the presence of deep ventro-lateral groove on the first thoracic chaetiger. A key of Owenia species hitherto described or reported in South East Asia and Australasia regions is provided based on characters of the branchial crown. PMID:26624080

  4. Quantifying Water Flow within Aquatic Ecosystems Using Load Cell Sensors: A Profile of Currents Experienced by Coral Reef Organisms around Lizard Island, Great Barrier Reef, Australia

    PubMed Central

    Johansen, Jacob L.

    2014-01-01

    Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (<$150) to provide a detailed current velocity profile of the coral-reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient current velocity of 99%. Each instrument is able to continuously record current velocities to >500 cms−1 and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.). Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm−2 allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: Currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms−1, while tidal currents rarely exceed 5.5 cms−1. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats. PMID:24421878

  5. Sabellariidae from Lizard Island, Great Barrier Reef, including a new species of Lygdamis and notes on external morphology of the median organ.

    PubMed

    Capa, María; Faroni-Perez, Larisse; Hutchings, Pat

    2015-01-01

    We document herein the occurrence of three species of Sabellariidae at Lizard Island, Great Barrier Reef, including a new Lygdamis species. Sabellaria lungalla, described from Northern Territory, is reported for Queensland for the first time. The genus Gesaia, represented by a planktonic larva collected in shallow waters of the Archipelago, is a new record for Australia. Lygdamis nasutus n. sp. is characterised by one of the most conspicuous median organ described in the family (cylindrical, distally pigmented and is provided with a flattened, teardrop corona), its paleae morphology (with straight paleae, outer ones with asymmetrical pointed tips and subtle thecal sculpture and inner paleae with blunt tips and smooth surface), three lateral lobes on chaetiger 2, abdominal chaetigers with two type of neurochaetae, and notopodial uncini with 1-4 longitudinal rows of teeth. Comparison of the external morphology of the medial organ and median ridge of several species has been undertaken. Even though its function remains uncertain, the median organ morphology seems species specific and may provide relevant information about the evolutionary history and adaptations of sabellariids. PMID:26624070

  6. Seven new species of Paleanotus (Annelida: Chrysopetalidae) described from Lizard Island, Great Barrier Reef, and coral reefs of northern Australia and the Indo-Pacific: two cryptic species pairs revealed between western Pacific Ocean and the eastern Indian Ocean.

    PubMed

    Watson, Charlotte

    2015-01-01

    Morphological investigation into the paleate genus Paleanotus Schmarda 1861 of the family Chrysopetalidae from northern Australian coral reefs, primarily Lizard Island and outlying reefs, included a complex of very small, slender individuals (length < 5 mm). This complex resolved into 7 new species, described herein: Paleanotus inornatus n. sp., P. adornatus n. sp., P. chrysos n. sp., P. aquifolia n. sp., P. latifolia n. sp., P. silus n. sp., and P. silopsis n. sp. A key is provided to the new species and Paleanotus distinguished from Treptopale and Hyalopale, two closely related genera. Diagnostic features of the apical structure and shape of the notochaetal main paleae plus median paleae shape and raised rib pattern, differentiates each species from the other. Gametous states are described. Two cryptic species pairs (Paleanotus silopsis n. sp. and P. silus n. sp.; Paleanotus aquifolia n. sp. and P. latifolia n. sp.) were identified. In each case one species is restricted to either the NE or NW Australian coast. In each pair the most eastern point for the NW Australian species range occurs at Darwin, western Arnhemland, Northern Territory. Additional material for each species pair extends their respective ranges northwards: NW Australia to Thailand, Andaman Sea, eastern Indian Ocean or NE Australia, Great Barrier Reef to the Philippines, western Pacific Ocean. Cryptic morphology and potential genetic diversity is discussed in Paleanotus inornatus n. sp. and P. adornatus n. sp. that possess overlapping widespread distribution patterns across northern Australia and Indo-Pacific reefs. The smallest bodied taxon, Paleanotus chrysos n. sp. is the only species with a Coral Sea range encompassing Lizard Island, Heron Island and New Caledonia. PMID:26624084

  7. Status of the Island Night Lizard and Two Non-Native Lizards on Outlying Landing Field San Nicolas Island, California

    USGS Publications Warehouse

    Fellers, Gary M.; Drost, Charles A.; Murphey, Thomas

    2008-01-01

    More than 900 individually marked island night lizards (Xantusia riversiana) were captured on San Nicolas Island, California, between 1984 and 2007 as part of an ongoing study to monitor the status of this threatened species. Our data suggest that at least a few lizards are probably more than 20 years old, and one lizard would be 31.5 years old if it grew at an average rate for the population. Ages of 20 and 30 years seem reasonable given the remarkably slow growth during capture intervals of more than a decade for five of the lizards which we estimated to be 20 or more years old. Like other lizards, island night lizard growth rates vary by size, with larger lizards growing more slowly. In general, growth rates were somewhat greater on San Nicolas Island (compared with Santa Barbara Island), and this increase was sustained through all of the intermediate size classes. The higher growth rate may account for the somewhat larger lizards present on San Nicolas Island, although we cannot discount the possibility that night lizards on San Nicolas are merely living longer. The high percentage of small lizards in the Eucalyptus habitat might seem to reflect a healthy population in that habitat, but the high proportion of small lizards appears to be caused by good reproduction in the 1900s and substantially poorer reproduction in subsequent years. The Eucalyptus habitat has dried quite a bit in recent years. Night lizards in the Haplopappus/Grassland habitat have shown an increase in the proportion of larger lizards since 2000. There has also been an increase in the proportion of large lizards in the Rock Cobble habitat at Redeye Beach. However, there are has been some change in habitat with more elephant seals occupying the same area just above the high tide as do the night lizards. Southern alligator lizards and side-blotched lizards are both non-native on San Nicolas Island. Neither lizard causes obvious harm to island night lizards, and management time and effort should

  8. Lizard Island Polychaete Workshop: sampling sites and a checklist of polychaetes.

    PubMed

    Ribas, Julia; Hutchings, Pat

    2015-01-01

    In August 2013, a two week polychaete workshop was held at Lizard Island, Great Barrier Reef. Twenty-one sites representing 121 collection events were sampled for polychetes around Lizard and on the Outer Barrier. Workshop participants sorted polychaetes to family and each participant received on loan selected families to work up. This Zootaxa monograph describes 91 new species, 67 new records for Lizard Island, and 19 for Australia. Details regarding the habitats and locations are provided in Table 2 together with two maps (Figs 1, 2) showing sampling locations. In this paper we also list previously collected polychaete material from the region together with any published records for families which are not included in this volume. PMID:26624064

  9. Microhabitat choice in island lizards enhances camouflage against avian predators.

    PubMed

    Marshall, Kate L A; Philpot, Kate E; Stevens, Martin

    2016-01-01

    Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation. PMID:26804463

  10. Microhabitat choice in island lizards enhances camouflage against avian predators

    PubMed Central

    Marshall, Kate L. A.; Philpot, Kate E.; Stevens, Martin

    2016-01-01

    Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation. PMID:26804463

  11. The blue lizard spandrel and the island syndrome

    PubMed Central

    2010-01-01

    Background Many small vertebrates on islands grow larger, mature later, lay smaller clutches/litters, and are less sexually dimorphic and aggressive than their mainland relatives. This set of observations is referred to as the 'Island Syndrome'. The syndrome is linked to high population density on islands. We predicted that when population density is low and/or fluctuating insular vertebrates may evolve correlated trait shifts running opposite to the Island Syndrome, which we collectively refer to as the 'reversed island syndrome' (RIS) hypothesis. On the proximate level, we hypothesized that RIS is caused by increased activity levels in melanocortin receptors. Melanocortins are postranslational products of the proopiomelanocortin gene, which controls pleiotropically pigmentation, aggressiveness, sexual activity, and food intake in vertebrates. Results We tested the RIS hypothesis performing a number of behavioral, genetic, and ontogenetic tests on a blue colored insular variant of the Italian Wall lizard Podarcis sicula, living on a small island off the Southern Italian coast. The population density of this blue-colored variant was generally low and highly fluctuating from one year to the next. In keeping with our predictions, insular lizards were more aggressive and sexually dimorphic than their mainland relatives. Insular males had wide, peramorphic heads. The growth rate of insular females was slower than growth rates of mainland individuals of both sexes, and of insular males. Consequently, size and shape dimorphism are higher on the Island. As predicted, melanocortin receptors were much more active in individuals of the insular population. Insular lizards have a higher food intake rate than mainland individuals, which is consistent with the increased activity of melanocortin receptors. This may be adaptive in an unpredictable environment such as Licosa Island. Insular lizards of both sexes spent less time basking than their mainland relatives. We suspect this

  12. New records of Cotylea (Polycladida, Platyhelminthes) from Lizard Island, Great Barrier Reef, Australia, with remarks on the distribution of the Pseudoceros Lang, 1884 and Pseudobiceros Faubel, 1984 species of the Indo-Pacific Marine Region.

    PubMed

    Marquina, Daniel; Aguado, M Teresa; Noreña, Carolina

    2015-01-01

    In the present work eleven polyclad species of Lizard Island are studied. Seven of them are new records for this locality of the Australian coral reef and one is new to science, Lurymare clavocapitata n. sp. (Family Prosthiostomidae). The remaining recorded species belong to the genera Pseudoceros (P. bimarginatus, P. jebborum, P. stimpsoni, P. zebra, P. paralaticlavus and P. prudhoei) and Pseudobiceros (Pb. hancockanus, Pb. hymanae, Pb. flowersi and Pb. uniarborensis). Regardless of the different distribution patterns, all pseudocerotid species show brilliant colours, but similar internal morphology. Furthermore, differences in the form and size of the stylet are characteristic, because it is a sclerotic structure that is not affected during fixation. In Pseudoceros, the distance between the sucker and the female pore also differs among species. These features do not vary enough to be considered as diagnostic, but they provide information that can help to disentangle similarly coloured species complexes. A key of the genera Pseudoceros and Pseudobiceros of the Indo-Pacific region is provided, in order to facilitate the identification of species from this area. PMID:26624074

  13. Geological history and within-island diversity: a debris avalanche and the Tenerife lizard Gallotia galloti.

    PubMed

    Brown, Richard P; Hoskisson, Paul A; Welton, John-Henry; Báez, Marcos

    2006-10-01

    Several processes have been described that could explain geographical variation and speciation within small islands, including fragmentation of populations through volcanic eruptions. Massive landslides, or debris avalanches, could cause similar effects. Here we analyse the potential impact of the 0.8 million-year-ago (Ma) Güimar valley debris avalanche on the phylogeography of the lizard Gallotia galloti on the Canary Island of Tenerife. Distributions of mitochondrial DNA lineages (based on cytochrome b sequences) were analysed on a 60-km southeastern coast transect centred on this area. Three main clades were detected, which can be divided into northern (one clade) and southern (two clades) groups that introgress across the valley. Maximum-likelihood estimates of migration rates (scaled for mutation rate) revealed highly asymmetric patterns, indicating that long-term gene flow into this region from both the northern and the southern populations greatly exceeded that in the opposite directions, consistent with recolonization of the area. The ancestral Tenerife node on the G. galloti tree is estimated at 0.80 Ma, matching closely with the geological estimate for the debris avalanche. Morphological variation (body dimensions and scalation) was also analysed and indicated a stepped cline in female scalation across the valley, although the patterns for male scalation and male and female body dimensions were not as clear. Together these findings provide support for the hypothesis that the debris avalanche has shaped the phylogeography of G. galloti and may even have been a primary cause of the within-island cladogenesis through population fragmentation and isolation. Current estimates of timing of island unification mean that the original hypothesis that within-island diversity is explained by the secondary contact of populations from the two ancient precursor islands of Teno and Anaga is less plausible for this and some other Tenerife species. Large-scale landslides

  14. Watch out where you sleep: nocturnal sleeping behaviour of Bay Island lizards.

    PubMed

    Mohanty, Nitya Prakash; Harikrishnan, Surendran; Vasudevan, Karthikeyan

    2016-01-01

    Sleeping exposes lizards to predation. Therefore, sleeping strategies must be directed towards avoiding predation and might vary among syntopic species. We studied sleeping site characteristics of two syntopic, congeneric lizards-the Bay Island forest lizard, Coryphophylax subcristatus and the short-tailed Bay Island lizard, C. brevicaudus and evaluated inter-specific differences. We measured structural, microclimatic and potential predator avoidance at the sleeping perches of 386 C. subcristatus and 185 C. brevicaudus. Contrary to our expectation, we found similar perch use in both species. The lizards appeared to use narrow girth perch plants and accessed perches by moving both vertically and horizontally. Most lizards slept on leaves, with their heads directed towards the potential path of a predator approaching from the plant base. There was no inter-specific competition in the choices of sleeping perches. These choices indicate an anti-predator strategy involving both tactile and visual cues. This study provides insight into a rarely studied behaviour in reptiles and its adaptive significance. PMID:27168958

  15. Ecological explanations to island gigantism: dietary niche divergence, predation, and size in an endemic lizard.

    PubMed

    Runemark, Anna; Sagonas, Kostas; Svensson, Erik I

    2015-08-01

    Although rapid evolution of body size on islands has long been known, the ecological mechanisms behind this island phenomenon remain poorly understood. Diet is an important selective pressure for morphological divergence. Here we investigate if selection for novel diets has contributed to the multiple independent cases of island gigantism in the Skyros wall lizard (Podarcis gaigeae) and if diet, predation, or both factors best explain island gigantism. We combined data on body size, shape, bite force, and realized and available diets to address this. Several lines of evidence suggest that diet has contributed to the island gigantism. The larger islet lizards have relatively wider heads and higher bite performance in relation to mainland lizards than would be expected from size differences alone. The proportions of consumed and available hard prey are higher on islets than mainland localities, and lizard body size is significantly correlated with the proportion of hard prey. Furthermore, the main axis of divergence in head shape is significantly correlated with dietary divergence. Finally, a model with only diet and one including diet and predation regime explain body size divergence equally well. Our results suggest that diet is an important ecological factor behind insular body size divergence, but could be consistent with an additional role for predation. PMID:26405734

  16. Watch out where you sleep: nocturnal sleeping behaviour of Bay Island lizards

    PubMed Central

    Mohanty, Nitya Prakash; Harikrishnan, Surendran

    2016-01-01

    Sleeping exposes lizards to predation. Therefore, sleeping strategies must be directed towards avoiding predation and might vary among syntopic species. We studied sleeping site characteristics of two syntopic, congeneric lizards—the Bay Island forest lizard, Coryphophylax subcristatus and the short-tailed Bay Island lizard, C. brevicaudus and evaluated inter-specific differences. We measured structural, microclimatic and potential predator avoidance at the sleeping perches of 386 C. subcristatus and 185 C. brevicaudus. Contrary to our expectation, we found similar perch use in both species. The lizards appeared to use narrow girth perch plants and accessed perches by moving both vertically and horizontally. Most lizards slept on leaves, with their heads directed towards the potential path of a predator approaching from the plant base. There was no inter-specific competition in the choices of sleeping perches. These choices indicate an anti-predator strategy involving both tactile and visual cues. This study provides insight into a rarely studied behaviour in reptiles and its adaptive significance. PMID:27168958

  17. Ecology of Great Salt Pond, Block Island

    EPA Science Inventory

    Great Salt Pond is an island of estuarine water on Block Island, which sits in the middle of the Northwest Atlantic Continental Shelf. When the last continental glaciers retreated, they left a high spot on a terminal moraine. The rising sea from melting glaciers formed two island...

  18. Simulating reef response to sea-level rise at Lizard Island: A geospatial approach

    NASA Astrophysics Data System (ADS)

    Hamylton, S. M.; Leon, J. X.; Saunders, M. I.; Woodroffe, C. D.

    2014-10-01

    Sea-level rise will result in changes in water depth over coral reefs, which will influence reef platform growth as a result of carbonate production and accretion. This study simulates the pattern of reef response on the reefs around Lizard Island in the northern Great Barrier Reef. Two sea-level rise scenarios are considered to capture the range of likely projections: 0.5 m and 1.2 m above 1990 levels by 2100. Reef topography has been established through extensive bathymetric profiling, together with available data, including LiDAR, single beam bathymetry, multibeam swath bathymetry, LADS and digitised chart data. The reef benthic cover around Lizard Island has been classified using a high resolution WorldView-2 satellite image, which is calibrated and validated against a ground referencing dataset of 364 underwater video records of the reef benthic character. Accretion rates are parameterised using published hydrochemical measurements taken in-situ and rules are applied using Boolean logic to incorporate geomorphological transitions associated with different depth ranges, such as recolonisation of the reef flat when it becomes inundated as sea level rises. Simulations indicate a variable platform response to the different sea-level rise scenarios. For the 0.5 m rise, the shallower reef flats are gradually colonised by corals, enabling this active geomorphological zone to keep up with the lower rate of rise while the other sand dominated areas get progressively deeper. In the 1.2 m scenario, a similar pattern is evident for the first 30 years of rise, beyond which the whole reef platform begins to slowly drown. To provide insight on reef response to sea-level rise in other areas, simulation results of four different reef settings are discussed and compared at the southeast reef flat (barrier reef), Coconut Beach (fringing reef), Watson's Bay (leeward bay with coral patches) and Mangrove Beach (sheltered lagoonal embayment). The reef sites appear to accrete upwards

  19. A fossil Diploglossus (Squamata, Anguidae) lizard from Basse-Terre and Grande-Terre Islands (Guadeloupe, French West Indies).

    PubMed

    Bochaton, Corentin; Boistel, Renaud; Casagrande, Fabrice; Grouard, Sandrine; Bailon, Salvador

    2016-01-01

    Today, Diploglossine lizards (Anguidae) are common on the Greater Antillean Islands (West Indies), where they are represented by many endemic species. However these lizards are very rare on the Lesser Antillean Islands, where they are only represented by a single species, the Montserrat galliwasp (Diploglossus montisserrati). Here, we show that diploglossine lizards were present in the past on other Lesser Antillean islands, by reporting the discovery of Anguidae fossil remains in two Amerindian archaeological deposits and in a modern deposit. These remains are compared to skeletons of extant diploglossine lizards, including D. montisserrati, using X-ray microtomography of the type specimen of this critically endangered lizard. We also conducted a histological study of the osteoderms in order to estimate the putative age of the specimen. Our results show that the fossil specimens correspond to a member of the Diploglossus genus presenting strong similarities, but also minor morphological differences with D. montisserrati, although we postulate that these differences are not sufficient to warrant the description of a new species. These specimens, identified as Diploglossus sp., provide a new comparison point for the study of fossil diploglossine lizards and reflect the historical 17(th) century mentions of anguid lizards, which had not been observed since. PMID:27354326

  20. A fossil Diploglossus (Squamata, Anguidae) lizard from Basse-Terre and Grande-Terre Islands (Guadeloupe, French West Indies)

    PubMed Central

    Bochaton, Corentin; Boistel, Renaud; Casagrande, Fabrice; Grouard, Sandrine; Bailon, Salvador

    2016-01-01

    Today, Diploglossine lizards (Anguidae) are common on the Greater Antillean Islands (West Indies), where they are represented by many endemic species. However these lizards are very rare on the Lesser Antillean Islands, where they are only represented by a single species, the Montserrat galliwasp (Diploglossus montisserrati). Here, we show that diploglossine lizards were present in the past on other Lesser Antillean islands, by reporting the discovery of Anguidae fossil remains in two Amerindian archaeological deposits and in a modern deposit. These remains are compared to skeletons of extant diploglossine lizards, including D. montisserrati, using X-ray microtomography of the type specimen of this critically endangered lizard. We also conducted a histological study of the osteoderms in order to estimate the putative age of the specimen. Our results show that the fossil specimens correspond to a member of the Diploglossus genus presenting strong similarities, but also minor morphological differences with D. montisserrati, although we postulate that these differences are not sufficient to warrant the description of a new species. These specimens, identified as Diploglossus sp., provide a new comparison point for the study of fossil diploglossine lizards and reflect the historical 17th century mentions of anguid lizards, which had not been observed since. PMID:27354326

  1. Intraspecific Colour Variation among Lizards in Distinct Island Environments Enhances Local Camouflage

    PubMed Central

    Marshall, Kate L. A.; Philpot, Kate E.; Damas-Moreira, Isabel; Stevens, Martin

    2015-01-01

    Within-species colour variation is widespread among animals. Understanding how this arises can elucidate evolutionary mechanisms, such as those underlying reproductive isolation and speciation. Here, we investigated whether five island populations of Aegean wall lizards (Podarcis erhardii) have more effective camouflage against their own (local) island substrates than against other (non-local) island substrates to avian predators, and whether this was linked to island differences in substrate appearance. We also investigated whether degree of local substrate matching varied among island populations and between sexes. In most populations, both sexes were better matched against local backgrounds than against non-local backgrounds, particularly in terms of luminance (perceived lightness), which usually occurred when local and non-local backgrounds were different in appearance. This was found even between island populations that historically had a land connection and in populations that have been isolated relatively recently, suggesting that isolation in these distinct island environments has been sufficient to cause enhanced local background matching, sometimes on a rapid evolutionary time-scale. However, heightened local matching was poorer in populations inhabiting more variable and unstable environments with a prolonged history of volcanic activity. Overall, these results show that lizard coloration is tuned to provide camouflage in local environments, either due to genetic adaptation or changes during development. Yet, the occurrence and extent of selection for local matching may depend on specific conditions associated with local ecology and biogeographic history. These results emphasize how anti-predator adaptations to different environments can drive divergence within a species, which may contribute to reproductive isolation among populations and lead to ecological speciation. PMID:26372454

  2. The lizard fauna of Guam's fringing islets: Island biogeography, phylogenetic history, and conservation implications

    USGS Publications Warehouse

    Perry, G.; Rodda, G.H.; Fritts, T.H.; Sharp, T.R.

    1998-01-01

    We sampled the lizard fauna of twenty-two small islets fringing the Pacific island of Guam and used these data to shed light on the processes responsible for present-day diversity. Habitat diversity, measured by islet area and vegetation complexity, was significantly correlated with the number of species found on an islet. However, islet distance and elevation were not significant predictors of diversity. Distribution patterns were slightly different for the two major families in our sample, Scincidae and Gekkonidae: skinks needed larger islets to maintain a population than did geckos. Presence/absence patterns were highly and significantly nested, and population density was correlated with the number of islets on which a species was found. An area cladogram was poorly supported and showed no faunal similarity between nearby islands. These patterns indicate that extinctions on most islets were due mostly to non-catastrophic, long-acting biological causes. The presence on the islets of species extirpated on Guam and the lack of significant nestedness on islands with greater maximum elevation highlight the impact that predators (primarily brown treesnakes) can have. Our findings also show that small reserves will not suffice to protect endangered lizard faunas, and that the islets may serve as a short-term repository of such species until snake-free areas can be established on Guam.

  3. New host and distributional records for Cryptosporidium sp. (Apicomplexa: Cryptosporidiidae) from lizards (Sauria: Gekkonidae, Scincidae) from the Cook Islands and Vanuatu, South Pacific

    USGS Publications Warehouse

    McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.

    2013-01-01

    Between 1991 and 1993, 295 lizards, comprising 21 species in 2 families (Gekkonidae, Scincidae) from the Cook Islands, Fiji, Palau, Takapoto, and Vanuatu in the South Pacific, were examined for Cryptosporidium oocysts. Only 6 lizards (2%) were found to be passing Cryptosporidium oocysts in their feces, including 2 of 30 (7%) Oceania geckos, Gehyra oceanica, from Rarotonga, Cook Islands, and 4 of 26 (15%) Pacific blue-tailed skinks, Emoia caeruleocauda, from Efate Island, Vanuatu. This represents the largest survey for Cryptosporidium in Pacific island lizards, and we document 2 new host and 2 new locality records for this parasite genus.

  4. Stable isotopes document mainland-island divergence in resource use without concomitant physiological changes in the lizard Liolaemus pictus.

    PubMed

    Vidal, Marcela A; Sabat, Pablo

    2010-05-01

    Shifts in feeding ecology are believed to promote island-mainland divergence. The lizard Liolaemus pictus has several different subspecies on Chilean islands and mainland. These subspecies inhabit contrastingly different habitats both in different islands and mainland, which suggests the potential for habitat related dietary variation. We investigated the dietary habits of L. pictus by both stomach content analyses and by nitrogen stable isotope analyses (delta(15)N), which we used as a proxy variable for trophic level. We also compared the morphology of the digestive tract and the activity of intestinal digestive enzymes of mainland and island lizards. We hypothesized differences in diet and trophic level among populations and that these differences would predict the expression of the morphological and biochemical features of the digestive tract. More specifically, we predicted shorter intestines and higher levels of peptidases in more insectivorous than in more frugivorous/herbivorous lizards. The diet of L. pictus was characterized by the consumption of a wide diversity of food types, including fruit and insects, in all populations. Stable isotopes revealed higher trophic level, and hence probably higher protein intake, in mainland than in island populations, but contrary to our prediction, they had shorter intestines and higher relative activity of intestinal peptidases than mainland lizards. Furthermore, the proportion of fruit items in the stomach content was higher in the population that exhibited the lowest tropic level. These results suggest that morphological and physiological differences among populations of L. pictus are not correlated with feeding ecology, suggesting that the lizard's first responses to the selective pressure represented by a diet shift are behavioral. PMID:20172042

  5. Equilibrium speciation dynamics in a model adaptive radiation of island lizards

    PubMed Central

    Rabosky, Daniel L.; Glor, Richard E.

    2010-01-01

    The relative importance of equilibrium and nonequilibrium processes in shaping patterns of species richness is one of the most fundamental questions in biodiversity studies. If equilibrium processes predominate, then ecological interactions presumably limit species diversity, potentially through diversity dependence of immigration, speciation, and extinction rates. Alternatively, species richness may be limited by the rate at which diversity arises or by the amount of time available for diversification. These latter explanations constitute nonequilibrium processes and can apply only to biotas that are unsaturated or far from diversity equilibria. Recent studies have challenged whether equilibrium models apply to biotas assembled through in situ speciation, as this process may be too slow to achieve steady-state diversities. Here we demonstrate that speciation rates in replicate Caribbean lizard radiations have undergone parallel declines to equilibrium conditions on three of four major islands. Our results suggest that feedback between total island diversity and per-capita speciation rates scales inversely with island area, with proportionately greater declines occurring on smaller islands. These results are consistent with strong ecological controls on species richness and suggest that the iconic adaptive radiation of Caribbean anoles may have reached an endpoint. PMID:21135239

  6. Development and characterization of 12 microsatellite markers for the Island Night Lizard (Xantusia riversiana), a threatened species endemic to the Channel Islands, California, USA

    USGS Publications Warehouse

    O'Donnell, Ryan P.; Drost, Charles A.; Mock, Karen E.

    2014-01-01

    The Island Night Lizard is a federally threatened species endemic to the Channel Islands of California. Twelve microsatellite loci were developed for use in this species and screened in 197 individuals from across San Nicolas Island, California. The number of alleles per locus ranged from 6 to 21. Observed heterozygosities ranged from 0.520 to 0.843. These microsatellite loci will be used to investigate population structure, effective population size, and gene flow across the island, to inform protection and management of this species.

  7. Molecular detection of invertebrate prey in vertebrate diets: trophic ecology of Caribbean island lizards.

    PubMed

    Kartzinel, Tyler R; Pringle, Robert M

    2015-07-01

    Understanding community assembly and population dynamics frequently requires detailed knowledge of food web structure. For many consumers, obtaining precise information about diet composition has traditionally required sacrificing animals or other highly invasive procedures, generating tension between maintaining intact study populations and knowing what they eat. We developed 16S mitochondrial DNA sequencing methods to identify arthropods in the diets of generalist vertebrate predators without requiring a blocking primer. We demonstrate the utility of these methods for a common Caribbean lizard that has been intensively studied in the context of small island food webs: Anolis sagrei (a semi-arboreal 'trunk-ground' anole ecomorph). Novel PCR primers were identified in silico and tested in vitro. Illumina sequencing successfully characterized the arthropod component of 168 faecal DNA samples collected during three field trips spanning 12 months, revealing 217 molecular operational taxonomic units (mOTUs) from at least nine arthropod orders (including Araneae, Blattodea, Coleoptera, Hemiptera, Hymenoptera, Isoptera, Lepidoptera and Orthoptera). Three mOTUs (one beetle, one cockroach and one ant) were particularly frequent, occurring in ≥50% of samples, but the majority of mOTUs were infrequent (180, or 83%, occurred in ≤5% of samples). Species accumulation curves showed that dietary richness and composition were similar between size-dimorphic sexes; however, female lizards had greater per-sample dietary richness than males. Overall diet composition (but not richness) was significantly different across seasons, and we found more pronounced interindividual variation in December than in May. These methods will be generally useful in characterizing the diets of diverse insectivorous vertebrates. PMID:25545675

  8. Cryptic extinction of a common Pacific lizard Emoia impar (Squamata, Scincidae) from the Hawaiian Islands.

    USGS Publications Warehouse

    Fisher, Robert; Ineich, Ivan

    2012-01-01

    Most documented declines of tropical reptiles are of dramatic or enigmatic species. Declines of widespread species tend to be cryptic. The early (1900s) decline and extinction of the common Pacific skink Emoia impar from the Hawaiian Islands is documented here through an assessment of literature, museum vouchers and recent fieldwork. This decline appears contemporaneous with the documented declines of invertebrates and birds across the Hawaiian Islands. A review of the plausible causal factors indicates that the spread of the introduced big-headed ant Pheidole megacephala is the most likely factor in this lizard decline. The introduction and spread of a similar skink Lampropholis delicata across the islands appears to temporally follow the decline of E. impar, although there is no evidence of competition between these species. It appears that L. delicata is spreading to occupy the niche vacated by the extirpated E. impar. Further confusion exists because the skink E. cyanura, which is very similar in appearance to E. impar, appears to have been introduced to one site within a hotel on Kaua'i and persisted as a population at that site for approximately 2 decades (1970s–1990s) but is now also extirpated. This study highlights the cryptic nature of this early species extinction as evidence that current biogeographical patterns of non-charismatic or enigmatic reptiles across the Pacific may be the historical result of early widespread invasion by ants. Conservation and restoration activities for reptiles in the tropical Pacific should consider this possibility and evaluate all evidence prior to any implementation.

  9. OFF THE SAND AND ONTO THE ASPHALT: DOES THE URBAN HEAT ISLAND INFLUENCE DESERT LIZARDS?

    EPA Science Inventory

    Lower lizard diversity and potential activity likely will be found at hotter sites in summer, with higher potential lizard activity at hotter sites in winter.

    Potential to Further Environmental/Human Health Protection

    This study will i...

  10. Phylogeography and conservation genetics of the common wall lizard, Podarcis muralis, on islands at its northern range.

    PubMed

    Michaelides, Sozos; Cornish, Nina; Griffiths, Richard; Groombridge, Jim; Zajac, Natalia; Walters, Graham J; Aubret, Fabien; While, Geoffrey M; Uller, Tobias

    2015-01-01

    Populations at range limits are often characterized by lower genetic diversity, increased genetic isolation and differentiation relative to populations at the core of geographical ranges. Furthermore, it is increasingly recognized that populations situated at range limits might be the result of human introductions rather than natural dispersal. It is therefore important to document the origin and genetic diversity of marginal populations to establish conservation priorities. In this study, we investigate the phylogeography and genetic structure of peripheral populations of the common European wall lizard, Podarcis muralis, on Jersey (Channel Islands, UK) and in the Chausey archipelago. We sequenced a fragment of the mitochondrial cytochrome b gene in 200 individuals of P. muralis to infer the phylogeography of the island populations using Bayesian approaches. We also genotyped 484 individuals from 21 populations at 10 polymorphic microsatellite loci to evaluate the genetic structure and diversity of island and mainland (Western France) populations. We detected four unique haplotypes in the island populations that formed a sub-clade within the Western France clade. There was a significant reduction in genetic diversity (HO, HE and AR) of the island populations in relation to the mainland. The small fragmented island populations at the northern range margin of the common wall lizard distribution are most likely native, with genetic differentiation reflecting isolation following sea level increase approximately 7000 BP. Genetic diversity is lower on islands than in marginal populations on the mainland, potentially as a result of early founder effects or long-term isolation. The combination of restriction to specific localities and an inability to expand their range into adjacent suitable locations might make the island populations more vulnerable to extinction. PMID:25659074

  11. Phylogeography and Conservation Genetics of the Common Wall Lizard, Podarcis muralis, on Islands at Its Northern Range

    PubMed Central

    Michaelides, Sozos; Cornish, Nina; Griffiths, Richard; Groombridge, Jim; Zajac, Natalia; Walters, Graham J.; Aubret, Fabien; While, Geoffrey M.; Uller, Tobias

    2015-01-01

    Populations at range limits are often characterized by lower genetic diversity, increased genetic isolation and differentiation relative to populations at the core of geographical ranges. Furthermore, it is increasingly recognized that populations situated at range limits might be the result of human introductions rather than natural dispersal. It is therefore important to document the origin and genetic diversity of marginal populations to establish conservation priorities. In this study, we investigate the phylogeography and genetic structure of peripheral populations of the common European wall lizard, Podarcis muralis, on Jersey (Channel Islands, UK) and in the Chausey archipelago. We sequenced a fragment of the mitochondrial cytochrome b gene in 200 individuals of P. muralis to infer the phylogeography of the island populations using Bayesian approaches. We also genotyped 484 individuals from 21 populations at 10 polymorphic microsatellite loci to evaluate the genetic structure and diversity of island and mainland (Western France) populations. We detected four unique haplotypes in the island populations that formed a sub-clade within the Western France clade. There was a significant reduction in genetic diversity (HO, HE and AR) of the island populations in relation to the mainland. The small fragmented island populations at the northern range margin of the common wall lizard distribution are most likely native, with genetic differentiation reflecting isolation following sea level increase approximately 7000 BP. Genetic diversity is lower on islands than in marginal populations on the mainland, potentially as a result of early founder effects or long-term isolation. The combination of restriction to specific localities and an inability to expand their range into adjacent suitable locations might make the island populations more vulnerable to extinction. PMID:25659074

  12. Revealing Beta-Diversity Patterns of Breeding Bird and Lizard Communities on Inundated Land-Bridge Islands by Separating the Turnover and Nestedness Components

    PubMed Central

    Si, Xingfeng; Baselga, Andrés; Ding, Ping

    2015-01-01

    Beta diversity describes changes in species composition among sites in a region and has particular relevance for explaining ecological patterns in fragmented habitats. However, it is difficult to reveal the mechanisms if broad sense beta-diversity indices (i.e. yielding identical values under nestedness and species replacement) are used. Partitioning beta diversity into turnover (caused by species replacement from site to site) and nestedness-resultant components (caused by nested species losses) could provide a unique way to understand the variation of species composition in fragmented habitats. Here, we collected occupancy data of breeding birds and lizards on land-bridge islands in an inundated lake in eastern China. We decomposed beta diversity of breeding bird and lizard communities into spatial turnover and nestedness-resultant components to assess their relative contributions and respective relationships to differences in island area, isolation, and habitat richness. Our results showed that spatial turnover contributed more to beta diversity than the nestedness-resultant component. The degree of isolation had no significant effect on overall beta diversity or its components, neither for breeding birds nor for lizards. In turn, in both groups the nestedness-resultant component increased with larger differences in island area and habitat richness, respectively, while turnover component decreased with them. The major difference among birds and lizards was a higher relevance of nestedness-resultant dissimilarity in lizards, suggesting that they are more prone to local extinctions derived from habitat fragmentation. The dominance of the spatial turnover component of beta diversity suggests that all islands have potential conservation value for breeding bird and lizard communities. PMID:25992559

  13. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  14. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  15. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  16. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  17. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  18. Diversification and Demography of the Oriental Garden Lizard (Calotes versicolor) on Hainan Island and the Adjacent Mainland

    PubMed Central

    Huang, Yong; Guo, Xianguang; Ho, Simon Y. W.; Shi, Haitao; Li, Jiatang; Li, Jun; Cai, Bo; Wang, Yuezhao

    2013-01-01

    The Oriental garden lizard (Calotes versicolor) is one of the few non-gekkonid lizards that are geographically widespread in the tropics. We investigated its population dynamics on Hainan Island and the adjacent mainland of China and Vietnam, focusing on the impact of cyclic upheaval and submergence of land bridges during the Pleistocene. Our Bayesian phylogenetic analysis reveals two mitochondrial lineages, A and B, which are estimated to have coalesced about 0.26 million years ago (95% credibility interval: 0.05–0.61 million years ago). Lineage A contains individuals mainly from central and southern Wuzhi Mountain on Hainan Island, whereas lineage B mainly comprises individuals from other sites on the island plus the adjacent mainland. The estimated coalescence times within lineages A (0.05 million years ago) and B (0.13 million years ago) fall within a period of cyclical land-bridge formation and disappearance in the Pleistocene. A spatial analysis of molecular variance identified two distinct population groupings: I, primarily containing lineage A, and II, mainly consisting of lineage B. However, haplotypes from lineages A and B occur sympatrically, suggesting that gene flow is ongoing. Neither Wuzhi Mountain nor Qiongzhou Strait and Gulf of Tonkin act as barriers to gene flow among C. versicolor populations. Analyses of the data using mismatch distributions and extended Bayesian skyline plots provide evidence of a relatively stable population size through time for Group I, and moderate population expansions and contractions during the end of the Pleistocene for Group II. We conclude that the phylogeographical patterns of C. versicolor are the combined product of Pleistocene sea-level oscillations and nonphysical barriers to gene flow. PMID:23840304

  19. Genetic Variation in the Green Anole Lizard (Anolis carolinensis) Reveals Island Refugia and a Fragmented Florida During the Quaternary

    PubMed Central

    Tollis, Marc; Boissinot, Stéphane

    2014-01-01

    The green anole lizard (Anolis carolinensis) is a model organism for behavior and genomics that is native to the southeastern United States. It is currently thought that the ancestors of modern green anoles dispersed to peninsular Florida from Cuba. However, the climatic changes and geological features responsible for the early diversification of A. carolinensis in North America have remained largely unexplored. This is because previous studies (1) differ in their estimates of the divergence times of populations, (2) are based on a single genetic locus and (3) did not test specific hypotheses regarding the geologic and topographic history of Florida. Here we provide a multi-locus study of green anole genetic diversity and find that the Florida peninsula contains a larger number of genetically distinct populations that are more diverse than those on the continental mainland. As a test of the island refugia hypothesis in Pleistocene Florida, we use a coalescent approach to estimate the divergence times of modern green anole lineages. We find that all demographic events occurred during or after the Upper Pliocene and suggest that green anole diversification was driven by population divergence on interglacial island refugia in Florida during the Lower Pleistocene, while the region was often separated from continental North America. When Florida reconnected to the mainland, two separate dispersal events led to the expansion of green anole populations across the Atlantic Seaboard and Gulf Coastal Plain. PMID:24379168

  20. Trapper readies trap for lizard

    NASA Technical Reports Server (NTRS)

    2000-01-01

    State-licensed animal trapper James Dean sets the open door of an animal trap on KSC. He hopes to catch a large monitor lizard spotted recently near S.R. 3, a route into the Center, by several area residents. The lizard is not a native of the area, and possibly a released pet. Dean is working with the cooperation of KSC and the Merritt Island National Wildlife Refuge.

  1. The 2006-2007 Kuril Islands great earthquake sequence

    USGS Publications Warehouse

    Lay, T.; Kanamori, H.; Ammon, C.J.; Hutko, Alexander R.; Furlong, K.; Rivera, L.

    2009-01-01

    The southwestern half of a ???500 km long seismic gap in the central Kuril Island arc subduction zone experienced two great earthquakes with extensive preshock and aftershock sequences in late 2006 to early 2007. The nature of seismic coupling in the gap had been uncertain due to the limited historical record of prior large events and the presence of distinctive upper plate, trench and outer rise structures relative to adjacent regions along the arc that have experienced repeated great interplate earthquakes in the last few centuries. The intraplate region seaward of the seismic gap had several shallow compressional events during the preceding decades (notably an MS 7.2 event on 16 March 1963), leading to speculation that the interplate fault was seismically coupled. This issue was partly resolved by failure of the shallow portion of the interplate megathrust in an MW = 8.3 thrust event on 15 November 2006. This event ruptured ???250 km along the seismic gap, just northeast of the great 1963 Kuril Island (Mw = 8.5) earthquake rupture zone. Within minutes of the thrust event, intense earthquake activity commenced beneath the outer wall of the trench seaward of the interplate rupture, with the larger events having normal-faulting mechanisms. An unusual double band of interplate and intraplate aftershocks developed. On 13 January 2007, an MW = 8.1 extensional earthquake ruptured within the Pacific plate beneath the seaward edge of the Kuril trench. This event is the third largest normal-faulting earthquake seaward of a subduction zone on record, and its rupture zone extended to at least 33 km depth and paralleled most of the length of the 2006 rupture. The 13 January 2007 event produced stronger shaking in Japan than the larger thrust event, as a consequence of higher short-period energy radiation from the source. The great event aftershock sequences were dominated by the expected faulting geometries; thrust faulting for the 2006 rupture zone, and normal faulting for

  2. Snake and Bird Predation Drive the Repeated Convergent Evolution of Correlated Life History Traits and Phenotype in the Izu Island Scincid Lizard (Plestiodon latiscutatus)

    PubMed Central

    Brandley, Matthew C.; Kuriyama, Takeo; Hasegawa, Masami

    2014-01-01

    Predation may create strong natural selection pressure on the phenotype and life history characteristics of prey species. The Izu scincid lizards (Plestiodon latiscutatus) that inhabit the four Japanese Izu Islands with only bird predators are drab brown, mature later, lay small clutches of large eggs, and hatch large neonates. In contrast, skinks on seven islands with both snake and bird predators are conspicuously colored, mature early, lay large clutches of small eggs, and hatch small neonates. We test the hypothesis that these suites of traits have evolved independently on each island via natural selection pressures from one of two predator regimes – birds-only and birds + snakes. Using two mtDNA genes and a nuclear locus, we infer a time-calibrated phylogeny of P. latiscutatus that reveals a basal split between Mikura and all islands south, and Miyake, all islands north, and the Izu Peninsula. Populations inhabiting Miyake, Niijima, Shikine, and Toshima are not monophyletic, suggesting either multiple colonizations or an artifact of incomplete lineage sorting (ILS). We therefore developed novel phylogenetic comparative analyses that assume either a multiple colonization or more restrictive single colonization ILS scenario and found 1) statistically significant support for the of different suites of phenotypic and life history characteristics with the presence of bird-only or bird + snake predator assemblages, and 2) strong phylogenetic support for at least two independent derivations of either the “bird-only” or “snakes + birds” phenotypes regardless of colonization scenario. Finally, our time-calibrated phylogeographic analysis supports the conclusion that the ancestor to modern Izu Island P. latiscutatus dispersed from the mainland to the Izu proto-islands between 3–7.6 million years ago (Ma). These lineages remained present in the area during successive formation of the islands, with one lineage re-colonizing the mainland 0.24-0.7 Ma. PMID

  3. 77 FR 45988 - Anchorage Regulations; Great Chebeague Island, ME

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-02

    ... Act notice regarding our public dockets in the January 17, 2008, issue of the Federal Register (73 FR... order moving counter-clockwise around the island starting at the west side of the northern tip of the... the point of beginning. This area is approximately 5,500 sq. yards, encompassing the...

  4. 77 FR 51552 - The Great Lakes Islands National Wildlife Refuges in Michigan and Wisconsin

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-24

    .../ Michigan Islands National Wildlife Refuges (northern section managed by Seney NWR), 1674 Refuge Entrance Rd... Fish and Wildlife Service The Great Lakes Islands National Wildlife Refuges in Michigan and Wisconsin... Wildlife Refuges (NWR) for public review and comment. The group of five national wildlife refuges...

  5. Source process of the great 1971 Solomon Islands doublet

    NASA Astrophysics Data System (ADS)

    Schwartz, Susan Y.; Lay, Thorne; Ruff, Larry J.

    1989-09-01

    Large underthrusting earthquakes in the Solomon Islands tend to occur as multiplets, separated by a few hours to several days in time and 30-100 km in space. The largest sequence, a doublet on July 14, 1971 ( Mw = 8.0) and July 26, 1971 ( Mw = 8.1), is particularly unusual in that it occured at the junction of two trenches, with the July 14 event in the Solomon Islands Trench preceding the July 26 rupture in the New Britain Trench. The location and large moment release of this doublet as well as an incompatibility of published body wave and surface wave focal mechanisms for the July 14 event, motivated a detailed study of the source process of the 1971 sequence. To satisfy both the surface wave and body wave data, we explored the possibility of a change in the faulting geometry during rupture for the July 14 event. A fault model that changes orientation from a northwest-southeast striking, shallow-dipping plane, similar to the mechanisms of neighboring underthrusting events in the Solomon Islands Trench, to a more north-south striking plane ˜ 70 s after rupture initiation is consistent with the observed Rayleigh and Love wave amplitude patterns. This change in mechanism is suggested by systematic variations in the mechanisms of smaller earthquakes near the cusp in the Solomon Islands plate. A simultaneous inversion of WWSSN P wave seismograms for the time, location, seismic moment and focal mechanism of individual subevents gives results in agreement with the surface wave model, although the precise change in mechanism is not well resolved. The spatiotemporal distribution of subevents reveals two major pulses of moment release. The first occurred on the initial fault near the epicenter at the origin time of the earthquake. The second occurred on the north-south striking fault, 50-70 km northwest of the epicenter ˜ 70 s after the origin time. The change in mechanism appears to reflect contortion of the slab near the trench junction. Inversion of WWSSN P wave

  6. Trappers set up trap for lizard

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In hope of catching a large monitor lizard seen in the area, state-licensed animal trappers Dewey Kessler and James Dean (at left), with Gary Povitch (kneeling) of the U.S. Wildlife and Dan Turner (standing) set up a trap on KSC. The lizard has been spotted recently near S.R. 3, a route into the Center, by several area residents. Turner is a monitor expert. The lizard is not a native of the area, and possibly a released pet. Dean is working with the cooperation of KSC and the Merritt Island National Wildlife Refuge.

  7. The importance of large benthic foraminifera to reef island sediment budget and dynamics at Raine Island, northern Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Dawson, John L.; Smithers, Scott G.; Hua, Quan

    2014-10-01

    Low-lying reef islands are among the most vulnerable environments on earth to anthropogenic-induced climate change and sea-level rise over the next century because they are low, composed of unconsolidated sediment that is able to be mobilised by waves and currents, and depend on sediments supplied by reef organisms that are particularly sensitive to environmental changes (e.g. ocean temperatures and chemistry). Therefore, the spatial and temporal links between active carbonate production and island formation and dynamics are fundamental to predicting future island resilience, yet remain poorly quantified. In this paper we present results of a detailed geomorphological and sedimentological study of a reef and sand cay on the northern Great Barrier Reef. We provide an empirical investigation of the temporal linkages between sediment production and reef island development using a large collection of single grain AMS 14C dates. Large benthic foraminifera (LBF) are the single most important contributor to contemporary island sand mass (47%; ranging from 36% to 63%) at Raine Island, reflecting rapid rates of sediment production and delivery. Standing stock data reveal extremely high production rates on the reef (1.8 kg m- 2 yr- 1), while AMS 14C dates of single LBF tests indicate rapid rates of sediment transferral across the reef. We also demonstrate that age is statistically related to preservation and taphonomic grade (severely abraded tests > moderately abraded tests > pristine tests). We construct a contemporary reef and island sediment budget model for Raine Island that shows that LBF (Baculogypsina, Marginopora and Amphistegina) contribute 55% of the sediment produced on the reef annually, of which a large proportion (54%) contribute to the net annual accretion of the island. The tight temporal coupling between LBF growth and island sediment supply combined with the sensitivity of LBF to bleaching and ocean acidification suggests that islands dominated by LBF are

  8. A new species of bunchgrass lizard (Squamata: Phrynosomatidae) from the southern sky islands of the Sierra Madre Occidental, Mexico.

    PubMed

    Grummer, Jared A; Bryson, Robert W

    2014-01-01

    A new species of bunchgrass lizard in the Sceloporus scalaris group is described from the southern portion of the Sierra Madre Occidental in Mexico. The new species, Sceloporus aurantius sp. nov., was previously confused with S. brownorum but differs from this and all but one species within the S. scalaris group by a lack of blue belly patches in males. It shares with S. chaneyi an absence of blue belly patches, but differs from this species in size, number of dorsal scales, number of scales around midbody, and presence of an un-patterned morph. The new species further differs from S. chaneyi, and all other species in the S. scalaris species group, by unique phylogenetic position revealed through species delimitation based on multi-locus nuclear DNA. Principal component analyses of 24 traditional morphological characters used to describe previous S. scalaris group taxa indicate that these characters may be of limited use to delineate species in this species group. However, male lateral and ventral coloration may still be an important character for diagnosing species. PMID:24869877

  9. Unprovoked fatal shark attack in Lifou Island (Loyalty Islands, New Caledonia, South Pacific) by a great white shark, Carcharodon carcharias.

    PubMed

    Clua, Eric; Séret, Bernard

    2010-09-01

    The case of a fatal, unprovoked shark attack is reported and analyzed. The incident took place on the 30th of September 2007, in the lagoon of Luengoni Bay, Lifou Island (Loyalty Islands, New Caledonia). A young French woman who was snorkeling was severely bitten on the right thigh and died of hemorrhage. An analysis based in particular on the size and color of the shark, the characteristics of the wounds, and the behavior of the shark before and after the bite suggests that the aggressor was a great white shark, Carcharodon carcharias. PMID:20606572

  10. Relationships of scincid lizards (Mabuya spp; Reptilia: Scincidae) from the Cape Verde islands based on mitochondrial and nuclear DNA sequences.

    PubMed

    Brehm, A; Jesus, J; Pinheiro, M; Harris, D J

    2001-05-01

    Partial DNA sequences from two mitochondrial (mt) and one nuclear gene (cytochrome b, 12S rRNA, and C-mos) were used to estimate the phylogenetic relationships among the six extant species of skinks endemic to the Cape Verde Archipelago. The species form a monophyletic unit, indicating a single colonization of the islands, probably from West Africa. Mabuya vaillanti and M. delalandii are sister taxa, as indicated by morphological characters. Mabuya fogoensis and M. stangeri are closely related, but the former is probably paraphyletic. Mabuya spinalis and M. salensis are also probably paraphyletic. Within species, samples from separate islands always form monophyletic groups. Some colonization events can be hypothesized, which are in line with the age of the islands. C-mos variation is concordant with the topology derived from mtDNA. PMID:11341812

  11. 78 FR 7907 - Endangered and Threatened Wildlife and Plants; Removing the Island Night Lizard From the Federal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... (61 FR 4722; February 7, 1996) and requesting that we delist the San Clemente and San Nicolas Island DPSs (Navy 2004, p. 12). In 2006, we published a 90-day finding (71 FR 48900) concluding that the Navy... temperatures, lower rainfall amounts, and rising sea level are important issues with potential effects to...

  12. 78 FR 16287 - Great Lakes Islands Refuges, MI and WI; Final Comprehensive Conservation Plan and Finding of No...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-14

    ... Federal Register (73 FR 76677) on December 17, 2008. The Great Lakes Islands Refuges are comprised of... and EA to the public, announcing and requesting comments in a notice of availability (77 FR 51552) on... Fish and Wildlife Service Great Lakes Islands Refuges, MI and WI; Final Comprehensive Conservation...

  13. Continuous resistivity profiling data from Great South Bay, Long Island, New York

    USGS Publications Warehouse

    Cross, V.A.; Bratton, J.F.; Kroeger, K.D.; Crusius, John; Worley, C.R.

    2013-01-01

    An investigation of submarine aquifers adjacent to the Fire Island National Seashore and Long Island, New York was conducted to assess the importance of submarine groundwater discharge as a potential nonpoint source of nitrogen delivery to Great South Bay. Over 200 kilometers of continuous resistivity profiling data were collected to image the fresh-saline groundwater interface in sediments beneath the bay. In addition, groundwater sampling was performed at sites (1) along the north shore of Great South Bay, particularly in Patchogue Bay, that were representative of the developed Long Island shoreline, and (2) at sites on and adjacent to Fire Island, a 50-kilometer-long barrier island on the south side of Great South Bay. Other field activities included sediment coring, stationary electrical resistivity profiling, and surveys of in situ pore water conductivity. Results of continuous resistivity profiling surveys are described in this report. The onshore and offshore shallow hydrostratigraphy of the Great South Bay shorelines, particularly the presence and nature of submarine confining units, appears to exert primary control on the dimensions and chemistry of the submarine groundwater flow and discharge zones. Sediment coring has shown that the confining units commonly consist of drowned and buried peat layers likely deposited in salt marshes. Low-salinity groundwater extends from 10 to 100 meters offshore along much of the north and south shores of Great South Bay based on continuous resistivity profiling data, especially off the mouths of tidal creeks and beneath shallow flats to the north of Fire Island adjacent to modern salt marshes. Human modifications of much of the shoreline and nearshore areas along the north shore of the bay, including filling of salt marshes, construction of bulkheads and piers, and dredging of navigation channels, has substantially altered the natural hydrogeology of the bay's shorelines by truncating confining units and increasing

  14. Flea (Siphonaptera) species richness in the Great Basin Desert and island biogeography theory.

    PubMed

    Bossard, Robert L

    2014-06-01

    Numbers of flea (Siphonaptera) species (flea species richness) on individual mammals should be higher on large mammals, mammals with dense populations, and mammals with large geographic ranges, if mammals are islands for fleas. I tested the first two predictions with regressions of H. J. Egoscue's trapping data on flea species richness collected from individual mammals against mammal size and population density from the literature. Mammal size and population density did not correlate with flea species richness. Mammal geographic range did, in earlier studies. The intermediate-sized (31 g), moderately dense (0.004 individuals/m(2)) Peromyscus truei (Shufeldt) had the highest richness with eight flea species on one individual. Overall, island biogeography theory does not describe the distribution of flea species on mammals in the Great Basin Desert, based on H. J. Egoscue's collections. Alternatively, epidemiological or metapopulation theories may explain flea species richness. PMID:24820569

  15. Foraging movements of great frigatebirds from Aldabra Island: Relationship with environmental variables and interactions with fisheries

    NASA Astrophysics Data System (ADS)

    Weimerskirch, Henri; Corre, Matthieu Le; Kai, Emilie Tew; Marsac, Francis

    2010-07-01

    Great Frigatebirds ( Fregata minor) are large tropical seabirds that rely primarily on sub-surface predators such as tunas or cetaceans to capture their prey. We studied the foraging movements of 14 Great Frigatebirds breeding on Aldabra Island (9.4°S, 46.4°E), the largest colony in the Indian Ocean. This colony is located at more than 500 km from the main fishing grounds of a very important industrial purse-seine fishery targeting surface-dwelling tunas. Despite their slow flight speeds (16 km h -1), frigatebirds are able to forage at more than 1000 km from the colonies when breeding, using 2500-4750 km long foraging loops over oceanic waters. All trips were directed to the north of the island up to the equator. Foraging bouts, indicated by reduced flight speeds, were rare and located throughout the trips. Foraging spots tended to be more frequent on higher surface chlorophyll concentration and in association with some cyclonic vortices. However, mesoscale activity is relatively weak between Aldabra and the equator and the chlorophyll variability is mostly the result of wind-mixing processes during the southwest monsoon. These results suggest that frigatebirds forage for widely distributed resources to the north of Aldabra. The northernmost foraging bouts were located in the vicinity of the purse-seine fishing grounds, but without a significant overlap between frigatebirds and tuna fleets. The results of the study are compared with those from another population at Europa Island (22.3°S, 40.3°E) where birds were foraging on predictable features, the edge of cyclonic eddies that are marked in the Mozambique Channel. We discuss the consequences of the reliance of populations on contrasted oceanographic conditions on foraging strategies and on the evolution of life histories in these long-lived animals in a changing climate, as well as the possible effects of overfishing on frigatebird populations.

  16. Assessment and conservation of the giant gomeran lizard (Gallotia bravoana).

    PubMed

    Hernandez-Divers, S J; Lafortune, M; Martínez-Silvestre, A; Pether, J

    2003-03-29

    In June 1999, a species of lizard previously considered extinct was rediscovered on the island of La Gomera, Spain. The giant gomeran lizard, Gallotia bravoana, is highly endangered and at risk of extinction by the feral cat population. A conservation effort to save the species was initiatived by the regional and central Spanish government and six lizards were captured and brought into captivity. This paper describes the results of the initial assessment of the health of the animals, by a physical examination and by haematological, biochemical, radiographical and coprological investigations. The methods used to maintain the animals in captivity are described and the first captive breeding success is reported. PMID:12696706

  17. Communication Signals in Lizards.

    ERIC Educational Resources Information Center

    Carpenter, Charles C.

    1983-01-01

    Discusses mechanisms and functional intent of visual communication signals in iguanid/agamid lizards. Demonstrated that lizards communicate with each other by using pushups and head nods and that each species does this in its own way, conveying different types of information. (JN)

  18. Coral community responses to declining water quality: Whitsunday Islands, Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    Thompson, Angus; Schroeder, Thomas; Brando, Vittorio E.; Schaffelke, Britta

    2014-12-01

    A five-year period (2002-2006) of below-median rainfall followed by a six-year period (2007-2012) of above-median rainfall and seasonal flooding allowed a natural experiment into the effects of runoff on the water quality and subsequent coral community responses in the Whitsunday Islands, Great Barrier Reef (Australia). Satellite-derived water quality estimates of total suspended solids (TSS) and chlorophyll- a (Chl) concentration showed marked seasonal variability that was exaggerated during years with high river discharge. During above-median rainfall years, Chl was aseasonally high for a period of 3 months during the wet season (February-April), while TSS was elevated for four months, extending into the dry season (March-June). Coinciding with these extremes in water quality was a reduction in the abundance and shift in the community composition, of juvenile corals. The incidence of coral disease was at a maximum during the transition from years of below-median to years of above-median river discharge. In contrast to juvenile corals, the cover of larger corals remained stable, although the composition of communities varied along environmental gradients. In combination, these results suggest opportunistic recruitment of corals during periods of relatively low environmental stress with selection for more tolerant species occurring during periods of environmental extremes.

  19. Haemoproteus iwa in Great Frigatebirds (Fregata minor) in the Islands of the Western Indian Ocean

    PubMed Central

    Bastien, Matthieu; Jaeger, Audrey; Le Corre, Matthieu; Tortosa, Pablo; Lebarbenchon, Camille

    2014-01-01

    Blood parasites of the sub-genus Haemoproteus have been reported in seabirds, in particular in species in the Suliformes order. These parasites are transmitted by hippoboscid flies of the genus Olfersia; strong specificity has been suggested between the vector and its vertebrate host. We investigated the prevalence of Haemoproteus infection in Suliformes and hippoboscid flies in two oceanic islands of the Western Indian Ocean: Europa and Tromelin. In total, 209 blood samples were collected from great frigatebirds (Fregata minor), masked boobies (Sula dactylatra) and red-footed boobies (Sula sula). Forty-one hippoboscid flies were also collected from birds. Seventeen frigatebirds and one fly collected on Europa tested positive for the presence of Haemoproteus parasites by polymerase chain reaction. Phylogenetic analyses based on partial sequences of the Cytochrome b gene showed that parasites were closely related to Haemoproteus iwa reported from frigatebirds in the Pacific Ocean and in the Caribbean. Plasmodium was also detected in a frigatebird on Europa; however, its placement on the phylogenetic tree could not be resolved. We provide strong support for transmission of blood parasites in seabirds in the Western Indian Ocean and suggest that migrations between the Pacific and the Indian oceans could favor the large-scale distribution of Haemoproteus iwa in frigatebird populations. PMID:24810172

  20. Climatic control of trophic interaction strength: the effect of lizards on spiders.

    PubMed

    Spiller, David A; Schoener, Thomas W

    2008-01-01

    We investigated how temporal variation in rainfall influences the impact of lizards on spiders inhabiting small islands in Abaco, Bahamas. Annual censuses of web spiders were conducted on nine lizard islands and on eight no-lizard islands 1994-2003. Repeated-measures ANOVA showed that annual variation in spider density (time) and in the lizard effect on spider density (lizard x time) were both significant. Correlation coefficients between the lizard effect (ln ratio of no-lizard to lizard spider densities) and number of rainfall days were generally negative, and strengthened with length of the time period during which rainfall was measured prior to annual spider censuses. Spider density was also negatively correlated with rainfall days and strengthened with length of the prior time period. Longer time intervals included the hurricane season, suggesting that the strong negative correlations were linked to high rainfall years during which tropical storms impacted the region and reduced spider and lizard densities. Split-plot ANOVA showed that rainfall during the hurricane season had a significant effect on the lizard effect and on spider density. Results in this study are opposite to those found in our previous 10-year study (1981-1990) conducted in the Exuma Cays, a moderately xeric region of the Bahamas, where the relation between rainfall and the lizard effect on spider density was positive. Combined data from the Exuma and Abaco studies produce a unimodal relation between trophic interaction strength and rainfall; we suggest that the negative effect of storms associated with rainfall was paramount in the present study, whereas the positive bottom-up effect of rainfall prevailed in our previous study. We conclude that climatic variability has a major impact on the trophic interaction and suggest that a substantial change in precipitation in either direction may weaken the interaction significantly. PMID:17972107

  1. Spatiotemporal patterns of coral disease prevalence on Heron Island, Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    Haapkylä, J.; Melbourne-Thomas, J.; Flavell, M.; Willis, B. L.

    2010-12-01

    Despite increasing research effort on coral diseases, little is known about factors driving disease dynamics on the Great Barrier Reef (GBR). This is the first study to investigate the temporal patterns of coral disease prevalence and potential drivers of disease around Heron Island, in the southern Capricorn Bunker sector of the GBR. Surveys were conducted in two austral summers and three winters between November 2007 and August 2009 on six sites around the island. Six diseases were detected: brown band syndrome (BrB), growth anomalies (GA), ulcerative white spots (UWS), white syndrome (WS), skeletal eroding band disease (SEB) and black band disease (BBD). The lowest overall mean disease prevalence was 1.87 ± 0.75% (mean ± SE) in November 2007 and the highest 4.22 ± 1.72% in August 2008. There was evidence of seasonality for two diseases: BrB and UWS. This is the first study to report a higher prevalence of BrB in the winter. BrB had a prevalence of 3.29 ± 0.58% in August 2008 and 1.53 ± 0.28% in August 2009, while UWS was the most common syndrome in the summer with a prevalence of 1.12 ± 0.31% in November 2007 and 2.67 ± 0.52% prevalence in January 2008. The prevalence of GAs and SEB did not depend on the season, although the prevalence of GAs increased throughout the study period. WS had a slightly higher prevalence in the summer, but its overall prevalence was low (<0.5%). Sites with high abundance of staghorn Acropora and Montipora were characterised by the highest disease prevalence (12% of Acropora and 3.3% of Montipora species were diseased respectively). These results highlight the correlations between coral disease prevalence, seasonally varying environmental parameters and coral community composition. Given that diseases are likely to reduce the resilience of corals, seasonal patterns in disease prevalence deserve further research.

  2. A new blue-tailed Monitor lizard (Reptilia, Squamata, Varanus) of the Varanus indicus group from Mussau Island, Papua New Guinea

    PubMed Central

    Weijola, Valter; Donnellan, Stephen C.; Lindqvist, Christer

    2016-01-01

    Abstract We describe a new species of Varanus from Mussau Island, north-east of New Guinea. The new species is a member of the Varanus indicus species group and is distinguished from all other members by both morphological and molecular genetic characters. It is the third species of Varanus reported from the Bismarck Archipelago and the first record of a yellow tongued member of the Varanus indicus species group from a remote oceanic island. The herpetofauna of Mussau Island has not been well studied but the discovery of this new species is in accordance with recent findings indicating that the island may harbor several unknown endemic vertebrates. The distribution of the closely related Varanus finschi is also discussed in the light of recent fieldwork and a review of old records. PMID:27103877

  3. Continuous seismic-reflection survey of the Great Salt Lake, Utah- east of Antelope and Fremont Islands

    USGS Publications Warehouse

    Lambert, P.M.; West, J.C.

    1989-01-01

    A continuous seismic-reflection survey of the Great Salt Lake, Utah, was conducted east of Fremont and Antelope Islands in 1984 by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources and produced data along approximately 80 miles of seismic lines. The survey was conducted to determine depth to consolidated rock, and definition and continuity of overlying basin fill under the lake. Interpretation of the data indicates the presence of faulted rock dipping away from Fremont and Antelope Islands. A north-south-trending consolidated-rock ridge is identified 200 ft below lake bottom, 275 miles east of Fremont Island. Shallow rock is also inferred 380 ft below lake bottom, near Hooper Hot Springs, and 520 ft below lake bottom approximately 4 miles east of the south end of Antelope Island. Interpretation of reflections from overlying basin fill indicates fine-grained, thinly-bedded deposits that become coarser with depth. Strong reflectors in the basin fill can be correlated with water-bearing strata penetrated by wells near the north end of Antelope Island and along the east shore of the lake. Many continuous, high-amplitude reflections can be identified in data from basin fill and may represent sedimentary sections or aquifer boundaries but cannot be defined because of a lack of subsurface control in the area. (USGS)

  4. The Great 2006 and 2007 Kuril Earthquakes, Forearc Segmentation and Seismic Activity of the Central Kuril Islands Region

    NASA Astrophysics Data System (ADS)

    Baranov, B. V.; Ivashchenko, A. I.; Dozorova, K. A.

    2015-12-01

    We present a structural study of the Central Kuril Islands forearc region, where the great megathrust tsunamigenic earthquake ( M w 8.3) occurred on November 15, 2006. Based on new bathymetry and seismic profiles obtained during two research cruises of R/V Akademik Lavrentiev in 2005 and 2006, ten crustal segments with along-arc length ranging from 30 to 100 km, separated by NS- and NW-trending transcurrent faults were identified within the forearc region. The transcurrent faults may serve as barriers impeding stress transfer between the neighboring segments, so that stress accumulated within separate forearc segments is usually released by earthquakes of moderate-to-strong magnitudes. However, the great November 15, 2006 earthquake ruptured seven of the crustal segments probably following a 226-year gap since the last great earthquake in 1780. The geographic extent of earthquake rupture zones, aftershock areas and earthquake clusters correlate well with forearc crustal segments identified using the geophysical data. Based on segmented structure of the Central Kuril Islands forearc region, we consider and discuss three scenarios of a great earthquake occurrence within this area. Although the margin is segmented, we suggest that a rupture could occupy the entire seismic gap with a total length of about 500 km. In such a case, the earthquake magnitude M w might exceed 8.5, and such an event might generate tsunami waves significantly exceeding in height to those produced by the great 2006-2007 Kuril earthquakes.

  5. Evolution of Anolis Lizard Dewlap Diversity

    PubMed Central

    Nicholson, Kirsten E.; Harmon, Luke J.; Losos, Jonathan B.

    2007-01-01

    Background The dewlaps of Anolis lizards provide a classic example of a complex signaling system whose function and evolution is poorly understood. Dewlaps are flaps of skin beneath the chin that are extended and combined with head and body movements for visual signals and displays. They exhibit extensive morphological variation and are one of two cladistic features uniting anoles, yet little is known regarding their function and evolution. We quantified the diversity of anole dewlaps, investigated whether dewlap morphology was informative regarding phylogenetic relationships, and tested two separate hypotheses: (A) similar Anolis habitat specialists possess similar dewlap configurations (Ecomorph Convergence hypothesis), and (B) sympatric species differ in their dewlap morphologies to a greater extent than expected by chance (Species Recognition hypothesis). Methodology/Principal Findings We found that dewlap configurations (sizes, patterns and colors) exhibit substantial diversity, but that most are easily categorized into six patterns that incorporate one to three of 13 recognizable colors. Dewlap morphology is not phylogenetically informative and, like other features of anoles, exhibits convergence in configurations. We found no support for the Ecomorph Convergence hypothesis; species using the same structural habitat were no more similar in dewlap configuration than expected by chance. With one exception, all sympatric species in four communities differ in dewlap configuration. However, this provides only weak support for the Species Recognition hypothesis because, due to the great diversity in dewlap configurations observed across each island, few cases of sympatric species with identical dewlaps would be expected to co-occur by chance alone. Conclusions/Significance Despite previous thought, most dewlaps exhibit easily characterizable patterns and colorations. Nevertheless, dewlap variation is extensive and explanations for the origin and evolution of this

  6. Long-term redevelopment of resource islands in shrublands of the Great Basin, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil resource availability in semi-arid and arid shrubland ecosystems is highly heterogeneous and includes patterns of resource accumulation primarily beneath shrubs as opposed to shrub interspaces. These resource islands contribute to ecosystem relience after natural disturbances such as fire, yet...

  7. Coseismic vertical deformation during the great 2007 Solomon Islands megathrust rupture

    NASA Astrophysics Data System (ADS)

    Briggs, R.; Taylor, F. W.; Frohlich, C.; Papabatu, A. K.; Billy, D.; Brown, A.; Meltzner, A. J.

    2007-12-01

    A joint US-Solomon Islands team visited the epicentral area of the 1 April 2007 Mw 8.1 Solomon Islands earthquake a few weeks after the event. We used coral microatolls, satellite imagery, and displaced geomorphic and cultural features to map the coseismic deformation pattern in the region directly above and adjacent to the subduction megathrust rupture. Among our main findings is that most slip occurred on the shallow portion of the megathrust and that slip appears to have reached the deformation front at Ranongga island, which was uplifted as much as ~2.5 m when the rupture propagated across the subducting Simbo ridge transform. Simbo island, which sits on the downgoing Australian plate and lies only 8 km across the plate boundary from uplifted Ranongga, subsided ~0.7 m coseismically and experienced only subdued ground motions. The line of zero vertical displacement (hingeline) runs closely along the southwestern coasts of Vella Lavella, Ghizo, and Parara islands, implying a persistent structural relationship between the downdip limit of coseismic slip and these coastlines. A broad, asymmetrical subsidence trough as deep as ~0.7 m extends across Vella Lavella, Kolombangara, Parara, and New Georgia. Uplift of ~0.35 m on the westermost tip of Rendova, along with overall subsidence of Rendova and Tetepare, place a firm limit on the southeastern extent of rupture. Uplift of Mono and subsidence of Fauro and the Shortlands, and no resolvable vertical change on Bougainville, define a rupture length of nearly 250 km between Rendova and the Woodlark rise.

  8. Effects of herring gulls and great black-backed gulls on breeding piping plovers, South Monomoy Island, Massachusetts. Final Report

    USGS Publications Warehouse

    Keane, S.E.; Fraser, J.D.; Buckley, P.A.

    2002-01-01

    The large population of breeding herring gulls and great black-backed gulls on South Monomoy Island, Cape Cod, Massachusetts has been thought to negatively affect the breeding success of the threatened piping plover. Following the Piping Plover Recovery Plan's call for gull colonies to be removed from piping plover breeding sites, in 1996, the USFWS conducted gull removal on part of South Monomoy Island. We determined relative gull abundance on South Monomoy Island from 1998-2000 by counting gulls within 100-m radius plots located on the shoreline. We quantified piping plover behavior and habitat use by conducting instantaneous and 5-minute behavioral observations. We quantified characteristics of piping plover nesting habitat by measuring characteristics along random transects. We measured gull abundance, beach width, and prey abundance, and then used logistic regression to determine what habitat characteristics influenced piping plover nesting area selection. We monitored piping plover reproductive success and population fluctuations on South Monomoy Island. Gull abundance in the gull-removal area was lower than gull abundance in the reference area throughout the piping plover breeding season. The difference in gull abundance between the areas did not affect piping plover behavior, nest success, chick survival, or productivity. We found that gull removal did not result in an increased piping plover population on the island. In both management areas, prenesting plovers preferred to forage in moist substrate habitats. Wide backshore and open vegetation habitats characterized nesting areas. Broods spent most of their time foraging and preferred moist substrate habitats when available. Plovers were not prevented from occupying more suitable habitat by large gulls. Fewer large gulls were observed near prenesting plovers, plover nests, and plover broods than near random plots. Fewer large gulls were observed in plover nesting areas than in unused areas when the nesting

  9. Tsunami Runup in the Middle Kuril Islands from the Great Earthquake of 15 Nov 2006

    NASA Astrophysics Data System (ADS)

    Bourgeois, J.; Pinegina, T.; Razhegaeva, N.; Kaistrenko, V.; Levin, B.; Macinnes, B.; Kravchunovskaya, E.

    2007-12-01

    Two expeditions to the middle Kuril Islands [IMGG FED RAS, NSF Kurils Biocomplexity Project] in the summer of 2007 yielded tsunami runup and inundation measurements from the 15 Nov 2006 Mw 8.3 subduction-zone earthquake, and possibly from the 13 Jan 2007 Mw 8.1 earthquake seaward of the subduction zone. Both earthquakes produced measurable tsunamis in the far field, the 13 Jan tsunami significantly smaller; the 15 Nov tsunami did some damage in the harbor of Crescent City, CA. Ours are the first near-source measurements because no one lives in the middle Kurils. Moreover, because KBP visited many of the same sites in summer of 2006, we have numerous before-and-after comparisons, including quantified erosion. We measured 120 profiles and made more than 300 runup measurements. We found dramatic tsunami effects of erosion and deposition, with widespread runup of 8-12 m, up to about 20 m, between and including Simushir and Matua islands. In most cases, we measured runup with a transit and surveying rod, producing a topographic profile from sea level to the slope above runup indicators; in some cases, we used a hand level and tape. Runup/inundation criteria were generally subhorizontal lines of floatable debris, typically wood, plastic, glass floats, and styrofoam. Single occurrences, e.g., of a plastic bottle were not considered adequate. Corroborative evidence, not used independently, included limits of consistently oriented stems of tall grasses and flowers, limit of sand and gravel deposits above turf and dead vegetation, and elevation of fresh erosion of turf from slopes landward of the beach plain. Currently we are compiling, correcting and vetting our measurements, which will be submitted to online databases. Topographic profiles obviously had an effect on the data, with short, steep profiles generating high runup and short inundation; most beach-ridge profiles had longer inundation and shorter runup. However, at Ainu Bay on Matua Island, we found as much as 18

  10. Evolutionary stasis and lability in thermal physiology in a group of tropical lizards

    PubMed Central

    Muñoz, Martha M.; Stimola, Maureen A.; Algar, Adam C.; Conover, Asa; Rodriguez, Anthony J.; Landestoy, Miguel A.; Bakken, George S.; Losos, Jonathan B.

    2014-01-01

    Understanding how quickly physiological traits evolve is a topic of great interest, particularly in the context of how organisms can adapt in response to climate warming. Adjustment to novel thermal habitats may occur either through behavioural adjustments, physiological adaptation or both. Here, we test whether rates of evolution differ among physiological traits in the cybotoids, a clade of tropical Anolis lizards distributed in markedly different thermal environments on the Caribbean island of Hispaniola. We find that cold tolerance evolves considerably faster than heat tolerance, a difference that results because behavioural thermoregulation more effectively shields these organisms from selection on upper than lower temperature tolerances. Specifically, because lizards in very different environments behaviourally thermoregulate during the day to similar body temperatures, divergent selection on body temperature and heat tolerance is precluded, whereas night-time temperatures can only be partially buffered by behaviour, thereby exposing organisms to selection on cold tolerance. We discuss how exposure to selection on physiology influences divergence among tropical organisms and its implications for adaptive evolutionary response to climate warming. PMID:24430845

  11. Evolutionary stasis and lability in thermal physiology in a group of tropical lizards.

    PubMed

    Muñoz, Martha M; Stimola, Maureen A; Algar, Adam C; Conover, Asa; Rodriguez, Anthony J; Landestoy, Miguel A; Bakken, George S; Losos, Jonathan B

    2014-03-01

    Understanding how quickly physiological traits evolve is a topic of great interest, particularly in the context of how organisms can adapt in response to climate warming. Adjustment to novel thermal habitats may occur either through behavioural adjustments, physiological adaptation or both. Here, we test whether rates of evolution differ among physiological traits in the cybotoids, a clade of tropical Anolis lizards distributed in markedly different thermal environments on the Caribbean island of Hispaniola. We find that cold tolerance evolves considerably faster than heat tolerance, a difference that results because behavioural thermoregulation more effectively shields these organisms from selection on upper than lower temperature tolerances. Specifically, because lizards in very different environments behaviourally thermoregulate during the day to similar body temperatures, divergent selection on body temperature and heat tolerance is precluded, whereas night-time temperatures can only be partially buffered by behaviour, thereby exposing organisms to selection on cold tolerance. We discuss how exposure to selection on physiology influences divergence among tropical organisms and its implications for adaptive evolutionary response to climate warming. PMID:24430845

  12. The Effect of the Great Barrier Reef on the Propagation of the 2007 Solomon Islands Tsunami Recorded in Northeastern Australia

    NASA Astrophysics Data System (ADS)

    Baba, Toshitaka; Mleczko, Richard; Burbidge, David; Cummins, Phil R.; Thio, Hong Kie

    2008-12-01

    The effect of offshore coral reefs on the impact from a tsunami remains controversial. For example, field surveys after the 2004 Indian Ocean tsunami indicate that the energy of the tsunami was reduced by natural coral reef barriers in Sri Lanka, but there was no indication that coral reefs off Banda Aceh, Indonesia had any effect on the tsunami. In this paper, we investigate whether the Great Barrier Reef (GBR) offshore Queensland, Australia, may have weakened the tsunami impact from the 2007 Solomon Islands earthquake. The fault slip distribution of the 2007 Solomon Islands earthquake was firstly obtained by teleseismic inversion. The tsunami was then propagated to shallow water just offshore the coast by solving the linear shallow water equations using a staggered grid finite-difference method. We used a relatively high resolution (approximately 250 m) bathymetric grid for the region just off the coast containing the reef. The tsunami waveforms recorded at tide gauge stations along the Australian coast were then compared to the results from the tsunami simulation when using both the realistic 250 m resolution bathymetry and with two grids having fictitious bathymetry: One in which the the GBR has been replaced by a smooth interpolation from depths outside the GBR to the coast (the “No GBR” grid), and one in which the GBR has been replaced by a flat plane at a depth equal to the mean water depth of the GBR (the “Average GBR” grid). From the comparison between the synthetic waveforms both with and without the Great Barrier Reef, we found that the Great Barrier Reef significantly weakened the tsunami impact. According to our model, the coral reefs delayed the tsunami arrival time by 5-10 minutes, decreased the amplitude of the first tsunami pulse to half or less, and lengthened the period of the tsunami.

  13. High antipredatory efficiency of insular lizards: a warning signal of excessive specimen collection?

    PubMed

    Delibes, Miguel; Blázquez, María del Carmen; Soriano, Laura; Revilla, Eloy; Godoy, José Antonio

    2011-01-01

    We live-captured lizards on islands in the Gulf of California and the Baja California peninsula mainland, and compared their ability to escape predation. Contrary to expectations, endemic lizard species from uninhabited islands fled from humans earlier and more efficiently than those from peninsular mainland areas. In fact, 58.2% (n=146) of the lizards we tried to capture on the various islands escaped successfully, while this percentage was only 14.4% (n=160) on the peninsular mainland. Separate evidence (e.g., proportion of regenerated tails, low human population at the collection areas, etc.) challenges several potential explanations for the higher antipredatory efficiency of insular lizards (e.g., more predation pressure on islands, habituation to humans on the peninsula, etc.). Instead, we suggest that the ability of insular lizards to avoid predators may be related to harvesting by humans, perhaps due to the value of endemic species as rare taxonomic entities. If this hypothesis is correct, predation-related behavioral changes in rare species could provide early warning signals of their over-exploitation, thus encouraging the adoption of conservation measures. PMID:22216244

  14. Legacy Pollutants are Declining in Great Skuas (Stercorarius skua) but Remain Higher in Faroe Islands than in Scotland.

    PubMed

    Hammer, Sjurdur; Nager, Ruedi G; Alonso, Sarah; McGill, Rona A R; Furness, Robert W; Dam, Maria

    2016-08-01

    To monitor environmental pollutants in Faroese biota, samples from a top predator were analysed and put into a spatial and temporal context. Analysis of 20 Great Skua eggs sampled in 2012 from the Faroe Islands showed >70 % lower concentrations of legacy persistent organic pollutants (POPs) than in samples analysed in 1977. The 2012 Faroese eggs showed higher concentrations than for eggs in Shetland from about the same period (2008). Eggshells were analysed for sub-lethal effects but there were no detectable effects of legacy POP levels on eggshell colour or thickness. A temporal decline in legacy POPs would indicate a reduction in the general pollutant levels present in the environment as has been shown in other areas of the North Atlantic, but there are significant geographic differences in POPs levels likely due to differences in diet resulting in significantly different exposures on a relatively limited spatial scale. PMID:27329112

  15. Sheet-gravel evidence for a late Holocene tsunami run-up on beach dunes, Great Barrier Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Nichol, Scott L.; Lian, Olav B.; Carter, Charles H.

    2003-01-01

    A semi-continuous sheet of granule to cobble-size clasts forms a distinctive deposit on sand dunes located on a coastal barrier in Whangapoua Bay, Great Barrier Island, New Zealand. The gravel sheet extends from the toe of the foredune to 14.3 m above mean sea level and 200 m landward from the beach. Clasts are rounded to sub-rounded and comprise lithologies consistent with local bedrock. Terrestrial sources for the gravel are considered highly unlikely due to the isolation of the dunes from hillslopes and streams. The only source for the clasts is the nearshore to inner shelf of Whangapoua Bay, where gravel sediments have been previously documented. The mechanism for transport of the gravel is unlikely to be storm surge due to the elevation of the deposit; maximum-recorded storm surge on this coast is 0.8 m above mean high water spring tide. Aeolian processes are also discounted due to the size of clasts and the elevation at which they occur. Tsunami is therefore considered the most probable mechanism for gravel transport. Minimum run-up height of the tsunami was 14.3 m, based on maximum elevation of gravel deposits. Optical ages on dune sands beneath and covering the gravel allow age bracketing to 0-4.7 ka. Within this time frame, numerous documented regional seismic and volcanic events could have generated the tsunami, notably submarine volcanism along the southern Kermadec arc to the east-southeast of Great Barrier Island where large magnitude events are documented for the late Holocene. Radiocarbon ages on shell from Maori middens that appear to have been reworked by tsunami run-up constrain the age of this event to post ca. 1400 AD. Regardless of the precise age of this event, the well-preserved nature of the Whangapoua gravel deposit provides for an improved understanding of the high degree of spatial variability in tsunami run-up.

  16. The impact of the introduction of the colubrid snake, Boiga irregularis, on Guam's lizards

    USGS Publications Warehouse

    Rodda, G.H.; Fritts, T.H.

    1992-01-01

    The extirpation of Guam's forest avifauna has been attributed to the accidental introduction and subsequent irruption of the brown tree snake, Boiga irregularis. However, recent dietary studies of this nocturnal arboreal snake indicate that it now preys primarily on lizards, not birds. We evaluated the effect the snake has had on Guam's lizards by contrasting lizard communities on Guam with those on adjacent snake-free islands and by comparing the extant lizard communities on Guam with those that were present before the snake arrived. Both comparisons revealed radical reductions in abundance of Guam's native nocturnal lizards and the extirpation of several species. The effect of the snake on diurnal lizards (skinks) is more equivocal. Skinks are still common on Guam, but several species no longer exist on the island. Identification of causes of these extirpations is complicated by the snake's elimination of an important avian skink predator, the concurrent irruption of a shrew, and the effects of predation and competition between the native skinks and an introduced skink.

  17. A population genetic assessment of coral recovery on highly disturbed reefs of the Keppel Island archipelago in the southern Great Barrier Reef

    PubMed Central

    Lukoschek, Vimoksalehi; Berkelmans, Ray; Peplow, Lesa M.; Jones, Alison M.

    2015-01-01

    Coral reefs surrounding the islands lying close to the coast are unique to the Great Barrier Reef (GBR) in that they are frequently exposed to disturbance events including floods caused by cyclonic rainfall, strong winds and occasional periods of prolonged above-average temperatures during summer. In one such group of islands in the southern GBR, the Keppel Island archipelago, climate-driven disturbances frequently result in major coral mortality. Whilst these island reefs have clearly survived such dramatic disturbances in the past, the consequences of extreme mortality events may include the loss of genetic diversity, and hence adaptive potential, and a reduction in fitness due to inbreeding, especially if new recruitment from external sources is limited. Here we examined the level of isolation of the Keppel Island group as well as patterns of gene flow within the Keppel Islands using 10 microsatellite markers in nine populations of the coral, Acropora millepora. Bayesian cluster analysis and assignment tests indicated gene flow is restricted, but not absent, between the outer and inner Keppel Island groups, and that extensive gene flow exists within each of these island groups. Comparison of the Keppel Island data with results from a previous GBR-wide study that included a single Keppel Island population, confirmed that A. millepora in the Keppel Islands is genetically distinct from populations elsewhere on the GBR, with exception of the nearby inshore High Peak Reef just north of the Keppel Islands. We compared patterns of genetic diversity in the Keppel Island populations with those from other GBR populations and found them to be slightly, but significantly lower, consistent with the archipelago being geographically isolated, but there was no evidence for recent bottlenecks or deviation from mutation-drift equilibrium. A high incidence of private alleles in the Keppel Islands, particularly in the outer islands, supports their relative isolation and contributes

  18. A population genetic assessment of coral recovery on highly disturbed reefs of the Keppel Island archipelago in the southern Great Barrier Reef.

    PubMed

    van Oppen, Madeleine J H; Lukoschek, Vimoksalehi; Berkelmans, Ray; Peplow, Lesa M; Jones, Alison M

    2015-01-01

    Coral reefs surrounding the islands lying close to the coast are unique to the Great Barrier Reef (GBR) in that they are frequently exposed to disturbance events including floods caused by cyclonic rainfall, strong winds and occasional periods of prolonged above-average temperatures during summer. In one such group of islands in the southern GBR, the Keppel Island archipelago, climate-driven disturbances frequently result in major coral mortality. Whilst these island reefs have clearly survived such dramatic disturbances in the past, the consequences of extreme mortality events may include the loss of genetic diversity, and hence adaptive potential, and a reduction in fitness due to inbreeding, especially if new recruitment from external sources is limited. Here we examined the level of isolation of the Keppel Island group as well as patterns of gene flow within the Keppel Islands using 10 microsatellite markers in nine populations of the coral, Acropora millepora. Bayesian cluster analysis and assignment tests indicated gene flow is restricted, but not absent, between the outer and inner Keppel Island groups, and that extensive gene flow exists within each of these island groups. Comparison of the Keppel Island data with results from a previous GBR-wide study that included a single Keppel Island population, confirmed that A. millepora in the Keppel Islands is genetically distinct from populations elsewhere on the GBR, with exception of the nearby inshore High Peak Reef just north of the Keppel Islands. We compared patterns of genetic diversity in the Keppel Island populations with those from other GBR populations and found them to be slightly, but significantly lower, consistent with the archipelago being geographically isolated, but there was no evidence for recent bottlenecks or deviation from mutation-drift equilibrium. A high incidence of private alleles in the Keppel Islands, particularly in the outer islands, supports their relative isolation and contributes

  19. Surf and turf: predation by egg-eating snakes has led to the evolution of parental care in a terrestrial lizard.

    PubMed

    Pike, David A; Clark, Rulon W; Manica, Andrea; Tseng, Hui-Yun; Hsu, Jung-Ya; Huang, Wen-San

    2016-01-01

    Animals display a great diversity of parental care tactics that ultimately enhance offspring survival, but how such behaviors evolve remains unknown for most systems. Here, we studied the evolution of maternal care, in the form of nest guarding, in a single population of long-tailed sun skink (Eutropis longicaudata) living on Orchid Island (Taiwan). This species typically does not provide protection to its offspring. Using a common garden experiment, we show that maternal care is genetically determined in this population. Through field manipulations, we demonstrate that care provides a significant increase in egg survival on Orchid Island by reducing predation from egg-eating snakes (Oligodon formosanus); this predator is not abundant in other populations of the lizard, which do not display parental care. Finally, using extensive field surveys, we show that the seasonal availability of green sea turtle (Chelonia mydas) nests is the cause for the high abundance of snake predators on Orchid Island, with the snakes consuming lizard eggs when green turtle eggs are not available. Together, these lines of evidence provide the first full demonstration of how predation can trigger the evolution of parental care in a species derived from a non-caring ancestor. PMID:26915464

  20. Surf and turf: predation by egg-eating snakes has led to the evolution of parental care in a terrestrial lizard

    PubMed Central

    Pike, David A.; Clark, Rulon W.; Manica, Andrea; Tseng, Hui-Yun; Hsu, Jung-Ya; Huang, Wen-San

    2016-01-01

    Animals display a great diversity of parental care tactics that ultimately enhance offspring survival, but how such behaviors evolve remains unknown for most systems. Here, we studied the evolution of maternal care, in the form of nest guarding, in a single population of long-tailed sun skink (Eutropis longicaudata) living on Orchid Island (Taiwan). This species typically does not provide protection to its offspring. Using a common garden experiment, we show that maternal care is genetically determined in this population. Through field manipulations, we demonstrate that care provides a significant increase in egg survival on Orchid Island by reducing predation from egg-eating snakes (Oligodon formosanus); this predator is not abundant in other populations of the lizard, which do not display parental care. Finally, using extensive field surveys, we show that the seasonal availability of green sea turtle (Chelonia mydas) nests is the cause for the high abundance of snake predators on Orchid Island, with the snakes consuming lizard eggs when green turtle eggs are not available. Together, these lines of evidence provide the first full demonstration of how predation can trigger the evolution of parental care in a species derived from a non-caring ancestor. PMID:26915464

  1. The western fence lizard Sceloporus occidentalis: evidence of field exposure to Borrelia burgdorferi in relation to infestation by Ixodes pacificus (Acari: Ixodidae).

    PubMed

    Manweiler, S A; Lane, R S; Tempelis, C H

    1992-09-01

    The role of the Western fence lizard Sceloporus occidentalis in the enzootiology of the Lyme disease spirochete Borrelia burgdorferi was evaluated in the Hopland and Ukiah areas of Mendocino County, California. In 1989, half of 74 lizards collected monthly from April to October at Hopland were infested by the immature western black-legged tick Ixodes pacificus at a mean intensity of 6.0 ticks per lizard. The prevalence of infestation of lizards by immature I. pacificus (36 of 73) at Ukiah was similar, but the mean intensity (12.9) was approximately twice as great. Overall, zero of 223 larvae and 2 (0.6%) of 330 nymphs from both sites were found to contain spirochetes by direct immunofluorescence. Larval and nymphal I. pacificus fit the negative binomial distribution in spring, and the prevalence and abundance of these stages were significantly greater in spring than in summer at both sites. Spirochetes were not visualized in thick blood films prepared from 133 lizards from both localities. Plasma antibodies against B. burgdorferi were detected in seven of 10 experimentally inoculated lizards, in five (8%) of 63 lizards from Hopland, and in 10 (14%) of 70 lizards from Ukiah. Adult lizards had a significantly greater tick burden and seropositivity rate than juvenile lizards only at Ukiah. In 1991, efforts to detect and culture spirochetes from the blood of 21 wild-caught lizards and from the tissues of 189 associated ticks that fed xenodiagnostically on them were unsuccessful.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1524146

  2. Molecular survey of Apicomplexa in Podarcis wall lizards detects Hepatozoon, Sarcocystis, and Eimeria species.

    PubMed

    Harris, D James; Maia, João P M C; Perera, Ana

    2012-06-01

    The occurrence of apicomplexan parasites in Podarcis sp. wall lizards from the Iberian Peninsula and Balearic islands was studied by amplification and sequencing of the 18S rRNA gene. Species from 3 genera, Hepatozoon , Sarcocystis , and Eimeria , were found. The phylogenetic analysis of the 18S rRNA gene provides unexpected insights into the evolutionary history of these parasites. All Hepatozoon spp. specimens were recovered as part of a clade already identified in lizards from North Africa. The Sarcocystis species, detected in Podarcis lilfordi from Cabrera Island in the Balearic Islands, appears related to Sarcocystis gallotiae , known only from endemic Gallotia sp. lizards from the Canary Islands. Based on the lack of snake predators on this island, this parasite presumably presents an atypical transmission cycle that uses the same host species as both intermediate and final host through cannibalism, like S. gallotiae . Eimeria sp. is reported for the first time from Podarcis spp. lizards. This study shows the power of detecting multiple different apicomplexan parasites through screening of tail tissue samples and blood drops that are often collected in reptiles for other purposes. PMID:22746392

  3. One Solution for Two Challenges: The Lizard Microlophus atacamensis Avoids Overheating by Foraging in Intertidal Shores

    PubMed Central

    Sepúlveda, Maritza; Sabat, Pablo; Porter, Warren P.; Fariña, José Miguel

    2014-01-01

    In lizards, one of the most important behavioral mechanisms to cope with spatial and temporal variations in thermal resources observed is activity time. The longer a lizard can maintain activity, the more time it has to forage and reach larger adult body size. We studied the behavioral adjustments to different climatic regimens on daily and seasonal scales in three natural populations of the lizard Microlophus atacamensis along a latitudinal temperature and rainfall gradient. We also used Niche Mapper to determinate the amount of thermally suitable time for activity for this species. Abundance and daily activity patterns varied greatly over the year for the three populations. In summer and spring, the daily activity times were greater, and were reduced in fall and winter seasons. In summer, when stressful heat loads should prohibit activity over a midday gap, lizards did not show bimodal patterns of activity. Instead, they move to the cooler intertidal habitat. Abundance and thermal quality in the southernmost coolest site was lower, and the potential annual activity time decreases with latitude. Contrary to expectations, lizards from this locality showed the largest body sizes possibly due to diet and/or time to sexual maturation. Our results indicate that the intertidal habitat is a key factor that influences daily and seasonal activity of M. atacamensis lizards. While this habitat is not climatically optimal for lizards, it allows them to behaviorally extend their activity window and gain access to food in the intertidal areas. PMID:24839969

  4. Genetic and biological characterization of Muko virus, a new distinct member of the species Great Island virus (genus Orbivirus, family Reoviridae), isolated from ixodid ticks in Japan.

    PubMed

    Ejiri, Hiroko; Lim, Chang-Kweng; Isawa, Haruhiko; Kuwata, Ryusei; Kobayashi, Daisuke; Yamaguchi, Yukie; Takayama-Ito, Mutsuyo; Kinoshita, Hitomi; Kakiuchi, Satsuki; Horiya, Madoka; Kotaki, Akira; Takasaki, Tomohiko; Maeda, Ken; Hayashi, Toshihiko; Sasaki, Toshinori; Kobayashi, Mutsuo; Saijo, Masayuki; Sawabe, Kyoko

    2015-12-01

    Among the tick-borne orbiviruses (genus Orbivirus, family Reoviridae), 36 serotypes are currently classified within a single virus species, Great Island virus. In this study, we report the first characterization of a tick-borne orbivirus isolated from the tick Ixodes turdus in Japan, which we identified as a new member of the species Great Island virus. The virus isolate, designated Muko virus (MUV), replicated and induced cytopathic effects in BHK-21, Vero E6, and CCL-141 cells and caused high mortality in suckling mice after intracerebral inoculation. Full genome sequence analysis showed that MUV shared the greatest phylogenetic similarity with Tribeč virus in terms of the amino acid sequences of all viral proteins except for outer capsid protein 1 (OC1; VP4 of MUV). Analysis of genome segment 9 in MUV detected an uninterrupted open reading frame that overlaps with VP6 (Hel), which putatively encodes a molecular and functional equivalent of NS4 from Great Island virus. Our study provides new insights into the geographic distribution, genetic diversity, and evolutionary history of the members of the species Great Island virus. PMID:26350980

  5. Palaeoecological evidence of a historical collapse of corals at Pelorus Island, inshore Great Barrier Reef, following European settlement

    PubMed Central

    Roff, George; Clark, Tara R.; Reymond, Claire E.; Zhao, Jian-xin; Feng, Yuexing; McCook, Laurence J.; Done, Terence J.; Pandolfi, John M.

    2013-01-01

    The inshore reefs of the Great Barrier Reef (GBR) have undergone significant declines in water quality following European settlement (approx. 1870 AD). However, direct evidence of impacts on coral assemblages is limited by a lack of historical baselines prior to the onset of modern monitoring programmes in the early 1980s. Through palaeoecological reconstructions, we report a previously undocumented historical collapse of Acropora assemblages at Pelorus Island (central GBR). High-precision U-series dating of dead Acropora fragments indicates that this collapse occurred between 1920 and 1955, with few dates obtained after 1980. Prior to this event, our results indicate remarkable long-term stability in coral community structure over centennial scales. We suggest that chronic increases in sediment flux and nutrient loading following European settlement acted as the ultimate cause for the lack of recovery of Acropora assemblages following a series of acute disturbance events (SST anomalies, cyclones and flood events). Evidence for major degradation in reef condition owing to human impacts prior to modern ecological surveys indicates that current monitoring of inshore reefs on the GBR may be predicated on a significantly shifted baseline. PMID:23135672

  6. Philopatry drives genetic differentiation in an island archipelago: comparative population genetics of Galapagos Nazca boobies (Sula granti) and great frigatebirds (Fregata minor)

    PubMed Central

    Levin, Iris I; Parker, Patricia G

    2012-01-01

    Seabirds are considered highly mobile, able to fly great distances with few apparent barriers to dispersal. However, it is often the case that seabird populations exhibit strong population genetic structure despite their potential vagility. Here we show that Galapagos Nazca booby (Sula granti) populations are substantially differentiated, even within the small geographic scale of this archipelago. On the other hand, Galapagos great frigatebird (Fregata minor) populations do not show any genetic structure. We characterized the genetic differentiation by sampling five colonies of both species in the Galapagos archipelago and analyzing eight microsatellite loci and three mitochondrial genes. Using an F-statistic approach on the multilocus data, we found significant differentiation between nearly all island pairs of Nazca booby populations and a Bayesian clustering analysis provided support for three distinct genetic clusters. Mitochondrial DNA showed less differentiation of Nazca booby colonies; only Nazca boobies from the island of Darwin were significantly differentiated from individuals throughout the rest of the archipelago. Great frigatebird populations showed little to no evidence for genetic differentiation at the same scale. Only two island pairs (Darwin – Wolf, N. Seymour – Wolf) were significantly differentiated using the multilocus data, and only two island pairs had statistically significant φST values (N. Seymour – Darwin, N. Seymour – Wolf) according to the mitochondrial data. There was no significant pattern of isolation by distance for either species calculated using both markers. Seven of the ten Nazca booby migration rates calculated between island pairs were in the south or southeast to north or northwest direction. The population differentiation found among Galapagos Nazca booby colonies, but not great frigatebird colonies, is most likely due to differences in natal and breeding philopatry. PMID:23170212

  7. Philopatry drives genetic differentiation in an island archipelago: comparative population genetics of Galapagos Nazca boobies (Sula granti) and great frigatebirds (Fregata minor).

    PubMed

    Levin, Iris I; Parker, Patricia G

    2012-11-01

    Seabirds are considered highly mobile, able to fly great distances with few apparent barriers to dispersal. However, it is often the case that seabird populations exhibit strong population genetic structure despite their potential vagility. Here we show that Galapagos Nazca booby (Sula granti) populations are substantially differentiated, even within the small geographic scale of this archipelago. On the other hand, Galapagos great frigatebird (Fregata minor) populations do not show any genetic structure. We characterized the genetic differentiation by sampling five colonies of both species in the Galapagos archipelago and analyzing eight microsatellite loci and three mitochondrial genes. Using an F-statistic approach on the multilocus data, we found significant differentiation between nearly all island pairs of Nazca booby populations and a Bayesian clustering analysis provided support for three distinct genetic clusters. Mitochondrial DNA showed less differentiation of Nazca booby colonies; only Nazca boobies from the island of Darwin were significantly differentiated from individuals throughout the rest of the archipelago. Great frigatebird populations showed little to no evidence for genetic differentiation at the same scale. Only two island pairs (Darwin - Wolf, N. Seymour - Wolf) were significantly differentiated using the multilocus data, and only two island pairs had statistically significant φ(ST) values (N. Seymour - Darwin, N. Seymour - Wolf) according to the mitochondrial data. There was no significant pattern of isolation by distance for either species calculated using both markers. Seven of the ten Nazca booby migration rates calculated between island pairs were in the south or southeast to north or northwest direction. The population differentiation found among Galapagos Nazca booby colonies, but not great frigatebird colonies, is most likely due to differences in natal and breeding philopatry. PMID:23170212

  8. Acoustical coupling of lizard eardrums.

    PubMed

    Christensen-Dalsgaard, Jakob; Manley, Geoffrey A

    2008-12-01

    Lizard ears are clear examples of two-input pressure-difference receivers, with up to 40-dB differences in eardrum vibration amplitude in response to ipsi- and contralateral stimulus directions. The directionality is created by acoustical coupling of the eardrums and interaction of the direct and indirect sound components on the eardrum. The ensuing pressure-difference characteristics generate the highest directionality of any similar-sized terrestrial vertebrate ear. The aim of the present study was to measure the gain of the direct and indirect sound components in three lizard species: Anolis sagrei and Basiliscus vittatus (iguanids) and Hemidactylus frenatus (gekkonid) by laser vibrometry, using either free-field sound or a headphone and coupler for stimulation. The directivity of the ear of these lizards is pronounced in the frequency range from 2 to 5 kHz. The directivity is ovoidal, asymmetrical across the midline, but largely symmetrical across the interaural axis (i.e., front-back). Occlusion of the contralateral ear abolishes the directionality. We stimulated the two eardrums with a coupler close to the eardrum to measure the gain of the sound pathways. Within the frequency range of maximal directionality, the interaural transmission gain (compared to sound arriving directly) is close to or even exceeds unity, indicating a pronounced acoustical transparency of the lizard head and resonances in the interaural cavities. Our results show that the directionality of the lizard ear is caused by the acoustic interaction of the two eardrums. The results can be largely explained by a simple acoustical model based on an electrical analog circuit. PMID:18648878

  9. Acoustical Coupling of Lizard Eardrums

    PubMed Central

    Manley, Geoffrey A.

    2008-01-01

    Lizard ears are clear examples of two-input pressure-difference receivers, with up to 40-dB differences in eardrum vibration amplitude in response to ipsi- and contralateral stimulus directions. The directionality is created by acoustical coupling of the eardrums and interaction of the direct and indirect sound components on the eardrum. The ensuing pressure-difference characteristics generate the highest directionality of any similar-sized terrestrial vertebrate ear. The aim of the present study was to measure the gain of the direct and indirect sound components in three lizard species: Anolis sagrei and Basiliscus vittatus (iguanids) and Hemidactylus frenatus (gekkonid) by laser vibrometry, using either free-field sound or a headphone and coupler for stimulation. The directivity of the ear of these lizards is pronounced in the frequency range from 2 to 5 kHz. The directivity is ovoidal, asymmetrical across the midline, but largely symmetrical across the interaural axis (i.e., front–back). Occlusion of the contralateral ear abolishes the directionality. We stimulated the two eardrums with a coupler close to the eardrum to measure the gain of the sound pathways. Within the frequency range of maximal directionality, the interaural transmission gain (compared to sound arriving directly) is close to or even exceeds unity, indicating a pronounced acoustical transparency of the lizard head and resonances in the interaural cavities. Our results show that the directionality of the lizard ear is caused by the acoustic interaction of the two eardrums. The results can be largely explained by a simple acoustical model based on an electrical analog circuit. PMID:18648878

  10. Will Coral Islands maintain their growth over the next century? A deterministic model of sediment availability at Lady Elliot Island, Great Barrier Reef.

    PubMed

    Hamylton, Sarah

    2014-01-01

    A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present), present and future (2010-2100) time periods. Reef platform sediment production is estimated at 569 m3 yr-1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate removal from the reef system. Key carbonate producers including hard coral, crustose coralline algae and Halimeda are mapped accurately (mean R2 = 0.81). Community net production estimates correspond closely to independent census-based estimates made in-situ (R2 = 0.86). Reef-scale outputs are compared with historic rates of production generated from (i) radiocarbon evidence of island deposition initiation around 3200 years ago, and (ii) island volume calculated from a high resolution island digital elevation model. Contemporary carbonate production rates appear to be remarkably similar to historical values of 573 m3 yr-1. Anticipated future seawater chemistry parameters associated with an RCP8.5 emissions scenario are employed to model rates of net community calcification for the period 2000-2100 on the basis of an inorganic aragonite precipitation law, under the assumption of constant benthic community character. Simulations indicate that carbonate production will decrease linearly to a level of 118 m3 yr-1 by 2100 and that by 2150 aragonite saturation levels may no longer support the positive budgetary status necessary to sustain island accretion. Novel aspects of this assessment include the development of rate law parameters to realistically represent the variable composition of coral reef benthic carbonate producers, incorporation of three dimensional rugosity of the entire reef platform and the coupling of model outputs with both historical radiocarbon dating evidence and forward hydrochemical projections to conduct an assessment of island evolution through time

  11. Will Coral Islands Maintain Their Growth over the Next Century? A Deterministic Model of Sediment Availability at Lady Elliot Island, Great Barrier Reef

    PubMed Central

    Hamylton, Sarah

    2014-01-01

    A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present), present and future (2010–2100) time periods. Reef platform sediment production is estimated at 569 m3 yr−1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate removal from the reef system. Key carbonate producers including hard coral, crustose coralline algae and Halimeda are mapped accurately (mean R2 = 0.81). Community net production estimates correspond closely to independent census-based estimates made in-situ (R2 = 0.86). Reef-scale outputs are compared with historic rates of production generated from (i) radiocarbon evidence of island deposition initiation around 3200 years ago, and (ii) island volume calculated from a high resolution island digital elevation model. Contemporary carbonate production rates appear to be remarkably similar to historical values of 573 m3 yr−1. Anticipated future seawater chemistry parameters associated with an RCP8.5 emissions scenario are employed to model rates of net community calcification for the period 2000–2100 on the basis of an inorganic aragonite precipitation law, under the assumption of constant benthic community character. Simulations indicate that carbonate production will decrease linearly to a level of 118 m3 yr−1 by 2100 and that by 2150 aragonite saturation levels may no longer support the positive budgetary status necessary to sustain island accretion. Novel aspects of this assessment include the development of rate law parameters to realistically represent the variable composition of coral reef benthic carbonate producers, incorporation of three dimensional rugosity of the entire reef platform and the coupling of model outputs with both historical radiocarbon dating evidence and forward hydrochemical projections to conduct an assessment of island evolution

  12. Chlorinated contaminants in chorio-allantoic membranes from great blue heron eggs at Whidbey Island Naval Air Station.

    PubMed

    Cobb, G P; Norman, D M; Miller, M W; Brewer, L W; Johnston, R K

    1995-01-01

    Chorio-allantoic membranes (CAMs) were collected and analyzed for chlorinated hydrocarbons as part of a wildlife toxicology demonstration project at Naval Air Station (NAS) Whidbey Island, Washington, USA. Concentrations of DDT, DDE, DDD, Aroclor 1254, and Aroclor 1260 were found at concentrations below 0.4 ppm for 13 of 14 samples. The low correlations among DDT and its metabolites in CAMs suggest herons are not being exposed to a consistent source of these compounds. Comparison of chlorinated hydrocarbon data for CAMs from three Puget Sound heron colonies, NAS Whidbey, Samish Island and Dumas Bay, indicates contaminant burdens in herons from NAS Whidbey and Samish Island are significantly lower than burdens in herons from Dumas Bay. PMID:7874465

  13. Conspicuous male coloration impairs survival against avian predators in Aegean wall lizards, Podarcis erhardii.

    PubMed

    Marshall, Kate L A; Philpot, Kate E; Stevens, Martin

    2015-09-01

    Animal coloration is strikingly diverse in nature. Within-species color variation can arise through local adaptation for camouflage, sexual dimorphism and conspicuous sexual signals, which often have conflicting effects on survival. Here, we tested whether color variation between two island populations of Aegean wall lizards (Podarcis erhardii) is due to sexual dimorphism and differential survival of individuals varying in appearance. On both islands, we measured attack rates by wild avian predators on clay models matching the coloration of real male and female P. erhardii from each island population, modeled to avian predator vision. Avian predator attack rates differed among model treatments, although only on one island. Male-colored models, which were more conspicuous against their experimental backgrounds to avian predators, were accordingly detected and attacked more frequently by birds than less conspicuous female-colored models. This suggests that female coloration has evolved primarily under selection for camouflage, whereas sexually competing males exhibit costly conspicuous coloration. Unexpectedly, there was no difference in avian attack frequency between local and non-local model types. This may have arisen if the models did not resemble lizard coloration with sufficient precision, or if real lizards behaviorally choose backgrounds that improve camouflage. Overall, these results show that sexually dimorphic coloration can affect the risk of predator attacks, indicating that color variation within a species can be caused by interactions between natural and sexual selection. However, more work is needed to determine how these findings depend on the island environment that each population inhabits. PMID:26442582

  14. Microgeographic variation in locomotor traits among lizards in a human-built environment

    PubMed Central

    2016-01-01

    Microgeographic variation in fitness-relevant traits may be more common than previously appreciated. The fitness of many vertebrates is directly related to their locomotor capacity, a whole-organism trait integrating behavior, morphology, and physiology. Because locomotion is inextricably related to context, I hypothesized that it might vary with habitat structure in a wide-ranging lizard, Podarcis erhardii, found in the Greek Cyclade Islands. I compared lizard populations living on human-built rock walls, a novel habitat with complex vertical structure, with nearby lizard populations that are naive to human-built infrastructure and live in flat, loose-substrate habitat. I tested for differences in morphology, behavior, and performance. Lizards from built sites were larger and had significantly (and relatively) longer forelimbs and hindlimbs. The differences in hindlimb morphology were especially pronounced for distal components—the foot and longest toe. These morphologies facilitated a significant behavioral shift in jumping propensity across a rocky experimental substrate. I found no difference in maximum velocity between these populations; however, females originating from wall sites potentially accelerated faster over the rocky experimental substrate. The variation between these closely neighboring populations suggests that the lizards inhabiting walls have experienced a suite of trait changes enabling them to take advantage of the novel habitat structure created by humans. PMID:26989616

  15. Successful Forecast of the Place of Great Solomon Islands Earthquake of April 1, 2007, Mw8.1

    NASA Astrophysics Data System (ADS)

    Purcaru, G.

    2007-12-01

    Predicting the large and great earhquakes proved to remain at present a complicated and most difficult problem, regarding the place and magnitude, and especially the time, on medium- or long-term interval, which is the principal component of any prediction. As a result a few (scientific) predictions are really successful, with a desired precision. False alarms and failures are by far dominant. However, the incresed number of higher accuracy data, advancements in the rupture- imaging at a smaller scale, seimotectonics details, increase of GPS data, different deterministic and probabilistic methods and numerical experimnts, retrospective predictions, etc. All these have to contribute, to increase a knowledge necessary to find better prediction-laws and methods in order to make particular earthquakes in specified regions more predictable. Along this view, we present a successful prediction (deterministic prediction) of a large earthquake in the Solomon Islands subduction zone: 154°E to 165°le E, where large earthquakes are occurring. We analized in detail historical earthquakes and aftershock areas (Kelleher et al, 1973, 1974; McCann et al 1979; Lay and Kanamori, 1980) of large events, their distribution and space and time, and the fluctuations of earthquake activity. We identified, in 1984, a seismic gap in the Central region of the subduction zone, with the boundary to No time prediction was made. The gap bundaries were fixed to NW at the SE-end of aftershock areas of the Jan - Feb. 1974 earthquake doublet (M7.0, M7.1) and to SE at the location of the Jan. 30, 1939 (Ms7.9-8.0) and its aftersock area was not known. The 2007 Solomon epicenter is well inside the gap. No evidence or rationale at that times would at least suggest that a future large earthquake in the gap will possibly rupture further to NW, and if the contrary than it is only a coincidence. Therefore the forecasted earthquake has closed very well the gap. The 6-days (also the 8-days) earthquake

  16. U-Th age distribution of coral fragments from multiple rubble ridges within the Frankland Islands, Great Barrier Reef: Implications for past storminess history

    NASA Astrophysics Data System (ADS)

    Liu, Entao; Zhao, Jian-xin; Feng, Yue-xing; Leonard, Nicole D.; Clark, Tara R.; Roff, George

    2016-07-01

    Prograded coral rubble ridges have been widely used as archives for reconstructing long-term storm or storminess history. Chronologies of ridge systems in previous studies are often based on a limited number of low-resolution radiocarbon or optically-stimulated luminescence (OSL) ages per ridge (usually only one age per ridge), which carry intrinsic age uncertainties and make interpretation of storm histories problematic. To test the fidelity of storm ridges as palaeo-storm archives, we used high-precision U-Th dating to examine whether different samples from a single ridge are temporally constrained. We surveyed three transects of ridge systems from two continental islands (Normanby Island and High Island) within the Frankland Islands, Great Barrier Reef (GBR), and obtained 96 U-Th dates from coral rubble samples collected from within and between different ridges. Our results revealed significant differences in age ranges between the two islands. The steeper and more defined rubble ridges present on Normanby Island revealed that the majority of U-Th ages (over 60%) from a single ridge clustered within a narrow age range (∼100 years). By contrast, the lower and less defined ridges on High Island, which were more likely formed during both storm and non-storm high-energy events, revealed significant scatter in age distribution (>>200 years) with no notable clustering. The narrower age ranges obtained from the steeper and more defined rubble ridges suggest that previous approaches of using either limited samples from a single ridge or low-precision dating methods to establish chronologies are generally valid at centennial to millennial timescales, although caution must be taken to use such approaches for storm history reconstruction on shorter timescales (e.g. decadal). The correlation between U-Th mortality ages of coral rubble and historical stormy periods highlights the possibility of using coral rubble age distribution from rubble ridges to reconstruct the long

  17. Comparison of Holocene With Coseismic Vertical Deformation Accompanying the Great 1 April 2007 Solomon Islands Megathrust Rupture

    NASA Astrophysics Data System (ADS)

    Taylor, F. W.; Briggs, R.; Frohlich, C.; Papabatu, A. K.; Billy, D.; Brown, A.; Meltzner, A. J.

    2007-12-01

    The 1 April 2007 Mw 8.1 earthquake in the western Solomons arc is the first major seismic rupture of this segment of plate boundary in historical times. A remarkable property of this region is the existence of coral- fringed islands located in a belt from ~90 km to as close as ~5 km from the trench. This setting provides a unique opportunity in which to measure forearc vertical movements using corals and other data to reveal relationships among coseismic vertical displacement, extremely rapid uplift of the outer forearc, and slower uplift of the main volcanic arc. The location of maximum coseismic uplift along a trench-parallel belt adjacent to the trench is consistent with the trench-parallel belt of maximum Holocene uplift rates. However, islands along the main volcanic arc lie in the swath of coseismic subsidence located arcward and parallel to the uplift zone. These islands typically have mean Holocene uplift rates up to ~1mm/yr. Thus, coseismic uplift correlates with rapid outer forearc Holocene uplift, but coseismic subsidence occurred throughout the more slowly uplifting volcanic arc. Using these observations, we can deconvolve and isolate the components of co- seismic, interseismic, and net vertical deformation and seek to address the underlying mechanisms. Interpretation is complicated by the late Quaternary history that includes subsidence of both the inner and outer arc islands prior to initiation of the ongoing net uplift since ~50 ka.

  18. Parrotfish predation on massive Porites on the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Bonaldo, R. M.; Bellwood, D. R.

    2011-03-01

    Parrotfish grazing scars on coral colonies were quantified across four reef zones at Lizard Island, Northern Great Barrier Reef (GBR). The abundance of parrotfish grazing scars was highest on reef flat and crest, with massive Porites spp . colonies having more parrotfish grazing scars than all other coral species combined. Massive Porites was the only coral type positively selected for grazing by parrotfishes in all four reef zones. The density of parrotfish grazing scars on massive Porites spp., and the rate of new scar formation, was highest on the reef crest and flat, reflecting the lower massive Porites cover and higher parrotfish abundance in these habitats. Overall, it appears that parrotfish predation pressure on corals could affect the abundance of preferred coral species, especially massive Porites spp , across the reef gradient. Parrotfish predation on corals may have a more important role on the GBR reefs than previously thought.

  19. Learning foraging thresholds for lizards

    SciTech Connect

    Goldberg, L.A.; Hart, W.E.; Wilson, D.B.

    1996-01-12

    This work gives a proof of convergence for a randomized learning algorithm that describes how anoles (lizards found in the Carribean) learn a foraging threshold distance. This model assumes that an anole will pursue a prey if and only if it is within this threshold of the anole`s perch. This learning algorithm was proposed by the biologist Roughgarden and his colleagues. They experimentally confirmed that this algorithm quickly converges to the foraging threshold that is predicted by optimal foraging theory our analysis provides an analytic confirmation that the learning algorithm converses to this optimal foraging threshold with high probability.

  20. Phenotypic shifts in urban areas in the tropical lizard Anolis cristatellus.

    PubMed

    Winchell, Kristin M; Reynolds, R Graham; Prado-Irwin, Sofia R; Puente-Rolón, Alberto R; Revell, Liam J

    2016-05-01

    Urbanization is an increasingly important dimension of global change, and urban areas likely impose significant natural selection on the species that reside within them. Although many species of plants and animals can survive in urban areas, so far relatively little research has investigated whether such populations have adapted (in an evolutionary sense) to their newfound milieu. Even less of this work has taken place in tropical regions, many of which have experienced dramatic growth and intensification of urbanization in recent decades. In the present study, we focus on the neotropical lizard, Anolis cristatellus. We tested whether lizard ecology and morphology differ between urban and natural areas in three of the most populous municipalities on the island of Puerto Rico. We found that environmental conditions including temperature, humidity, and substrate availability differ dramatically between neighboring urban and natural areas. We also found that lizards in urban areas use artificial substrates a large proportion of the time, and that these substrates tend to be broader than substrates in natural forest. Finally, our morphological data showed that lizards in urban areas have longer limbs relative to their body size, as well as more subdigital scales called lamellae, when compared to lizards from nearby forested habitats. This shift in phenotype is exactly in the direction predicted based on habitat differences between our urban and natural study sites, combined with our results on how substrates are being used by lizards in these areas. Findings from a common-garden rearing experiment using individuals from one of our three pairs of populations provide evidence that trait differences between urban and natural sites may be genetically based. Taken together, our data suggest that anoles in urban areas are under significant differential natural selection and may be evolutionarily adapting to their human-modified environments. PMID:27074746

  1. Temperature, activity, and lizard life histories

    SciTech Connect

    Adolph, S.C.; Porter, W.P. )

    1993-08-01

    Lizard life-history characteristics vary widely among species and populations. Most authors seek adaptive or phylogenetic explanations for life-history patterns, which are usually presumed to reflect genetic differences. However, lizard life histories are often phenotypically plastic, varying in response to temperature, food availability, and other environmental factors. Despite the importance of temperature to lizard ecology and physiology, its effects on life histories have received relatively little attention. The authors present a theoretical model predicting the proximate consequences of the thermal environment for lizard life histories. Temperature, by affecting activity times, can cause variation in annual survival rate and fecundity, leading to a negative correlation between survival rate and fecundity among populations in different thermal environments. Thus, physiological and evolutionary models predict the same qualitative pattern of life-history variation in lizards. They tested their model with published life-history data from field studies of the lizard Sceloporus undulatus, using climate and geographical data to reconstruct estimated annual activity seasons. Among populations, annual activity times were negatively correlated with annual survival rate and positively correlated with annual fecundity. Proximate effects of temperature may confound comparative analyses of lizard life-history variation and should be included in future evolutionary models. 125 refs., 6 figs., 1 tab.

  2. Lizard locomotion in heterogeneous granular media

    NASA Astrophysics Data System (ADS)

    Schiebel, Perrin; Goldman, Daniel

    2014-03-01

    Locomotion strategies in heterogeneous granular environments (common substrates in deserts), are relatively unexplored. The zebra-tailed lizard (C. draconoides) is a useful model organism for such studies owing to its exceptional ability to navigate a variety of desert habitats at impressive speed (up to 50 body-lengths per second) using both quadrapedal and bidepal gaits. In laboratory experiments, we challenge the lizards to run across a field of boulders (2.54 cm diameter glass spheres or 3.8 cm 3D printed spheres) placed in a lattice pattern and embedded in a loosely packed granular medium of 0.3 mm diameter glass particles. Locomotion kinematics of the lizard are recorded using high speed cameras, with and without the scatterers. The data reveals that unlike the lizard's typical quadrupedal locomotion using a diagonal gait, when scatterers are present the lizard is most successful when using a bipedal gait, with a raised center of mass (CoM). We propose that the kinematics of bipedal running in conjunction with the lizard's long toes and compliant hind foot are the keys to this lizard's successful locomotion in the presence of such obstacles. NSF PoLS

  3. Omnivory of an Insular Lizard: Sources of Variation in the Diet of Podarcis lilfordi (Squamata, Lacertidae)

    PubMed Central

    Pérez-Cembranos, Ana; León, Alicia; Pérez-Mellado, Valentín

    2016-01-01

    Through 17 years and from a sample of 7,790 faecal pellets and 26,346 prey items, we studied the diet of the Balearic lizard Podarcis lilfordi in Aire Island (Menorca, Balearic Islands, Spain). We analysed the diet in terms of prey frequencies, as well as by their volume and biomass contributions. The diet of the Balearic lizard was extremely variable through the years, months and areas under study. The dominance of small clumped prey, particularly ants, was confirmed. However, the main contribution by volume corresponded to beetles, with a relevant role for Diplopoda and terrestrial Isopoda during some months and at particular areas of the island. Several prey items were probably captured at the base of shrubs, under stones or inside rock crevices. Therefore, our estimations of electivity would only be reliable for epigeal and flying prey. The capacity of the Balearic lizard to include marine subsidies in its diet, such as coastal crustaceans, is noteworthy. Also, its consumption of carrion from carcasses of gulls and rabbits and leftovers from human visitors is remarkable. Juvenile conspecifics can also be a sporadic food resource, especially during the second half of summer, whereas the consumption of vegetal matter is constant for each whole year. The shifts of vegetal exploitation among areas of the island and months take place according to availability of different plant species at each area or during a given period. Thus, lizards are able to conduct a thorough monitoring of plant phenology, exploiting a large variety of plant species. Omnivory does not imply the indiscriminate inclusion of any edible food in its diet. Rather, the inclusion of several food items means the adoption of a wide range of foraging behaviours adapted to the exploitation of each food resource. PMID:26871439

  4. Omnivory of an Insular Lizard: Sources of Variation in the Diet of Podarcis lilfordi (Squamata, Lacertidae).

    PubMed

    Pérez-Cembranos, Ana; León, Alicia; Pérez-Mellado, Valentín

    2016-01-01

    Through 17 years and from a sample of 7,790 faecal pellets and 26,346 prey items, we studied the diet of the Balearic lizard Podarcis lilfordi in Aire Island (Menorca, Balearic Islands, Spain). We analysed the diet in terms of prey frequencies, as well as by their volume and biomass contributions. The diet of the Balearic lizard was extremely variable through the years, months and areas under study. The dominance of small clumped prey, particularly ants, was confirmed. However, the main contribution by volume corresponded to beetles, with a relevant role for Diplopoda and terrestrial Isopoda during some months and at particular areas of the island. Several prey items were probably captured at the base of shrubs, under stones or inside rock crevices. Therefore, our estimations of electivity would only be reliable for epigeal and flying prey. The capacity of the Balearic lizard to include marine subsidies in its diet, such as coastal crustaceans, is noteworthy. Also, its consumption of carrion from carcasses of gulls and rabbits and leftovers from human visitors is remarkable. Juvenile conspecifics can also be a sporadic food resource, especially during the second half of summer, whereas the consumption of vegetal matter is constant for each whole year. The shifts of vegetal exploitation among areas of the island and months take place according to availability of different plant species at each area or during a given period. Thus, lizards are able to conduct a thorough monitoring of plant phenology, exploiting a large variety of plant species. Omnivory does not imply the indiscriminate inclusion of any edible food in its diet. Rather, the inclusion of several food items means the adoption of a wide range of foraging behaviours adapted to the exploitation of each food resource. PMID:26871439

  5. Review Article: Potential geomorphic consequences of a future great (Mw = 8.0+) Alpine Fault earthquake, South Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Robinson, T. R.; Davies, T. R. H.

    2013-09-01

    The Alpine Fault in New Zealand's South Island has not sustained a large magnitude earthquake since ca. AD 1717. The time since this rupture is close to the average inferred recurrence interval of the fault (~300 yr). The Alpine Fault is therefore expected to generate a large magnitude earthquake in the near future. Previous ruptures of this fault are inferred to have generated Mw = 8.0 or greater earthquakes and to have resulted in, amongst other geomorphic hazards, large-scale landslides and landslide dams throughout the Southern Alps. There is currently 85% probability that the Alpine Fault will cause a Mw = 8.0+ earthquake within the next 100 yr. While the seismic hazard is fairly well understood, that of the consequential geomorphic activity is less well studied, and these consequences are explored herein. They are expected to include landsliding, landslide damming, dam-break flooding, debris flows, river aggradation, liquefaction, and landslide-generated lake/fiord tsunami. Using evidence from previous events within New Zealand as well as analogous international examples, we develop first-order estimates of the likely magnitude and possible locations of the geomorphic effects associated with earthquakes. Landsliding is expected to affect an area > 30 000 km2 and involve > 1billion m3 of material. Some tens of landslide dams are expected to occur in narrow, steep-sided gorges in the affected region. Debris flows will be generated in the first long-duration rainfall after the earthquake and will continue to occur for several years as rainfall (re)mobilises landslide material. In total more than 1000 debris flows are likely to be generated at some time after the earthquake. Aggradation of up to 3 m will cover an area > 125 km2 and is likely to occur on many West Coast alluvial fans and floodplains. The impact of these effects will be felt across the entire South Island and is likely to continue for several decades.

  6. Historical contingency and behavioural divergence in territorial Anolis lizards.

    PubMed

    Ord, T J

    2012-10-01

    The extent that evolution - including adaptation - is historically contingent (dependent on past events) has often been hotly debated, but is still poorly understood. In particular, there are little data on the degree that behaviour, an aspect of the phenotype that is strongly linked to contemporary environments (social or physical), retains the imprint of evolutionary history. In this study, I examined whether differences in the design of the territorial displays among species of Caribbean Anolis lizards reflect island-specific selection regimes, or historically contingent predispositions associated with different clade histories. Adult males advertise territory ownership using a series of headbobs and dewlap extensions, bouts of which vary in duration among species. When display durations were mapped onto the Anolis phylogeny, prominent differences between species belonging to the Western and Eastern Caribbean radiations were apparent. Statistical analyses confirmed that species differences in the duration of headbob displays, and to some extent the duration of dewlap extensions, were historically contingent. The unique evolutionary histories of each clade have seemingly had a profound effect on the subsequent direction of display evolution among descendent taxa. These results combined with those from previous studies on these lizards show that past history can have an important impact on the type of behaviour exhibited by species today, to the point that adaptive evolution can proceed quite differently in lineages originating from different evolutionary starting points. PMID:22862423

  7. Effects of insularity on digestion: living on islands induces shifts in physiological and morphological traits in island reptiles

    NASA Astrophysics Data System (ADS)

    Sagonas, Kostas; Pafilis, Panayiotis; Valakos, Efstratios D.

    2015-10-01

    Living on islands entails numerous challenges for animals, among which resource scarcity stands out. In order to survive, animals have to optimize energy acquisition. We examined the impact of insularity on digestion comparing a series of physiological and morphological traits of adult males between insular and mainland populations of the Balkan green lizard. Island lizards had longer gastrointestinal tracts and gut passage times and higher digestive efficiencies. The dissection of the hindgut revealed an unexpected finding, the presence of cecal valves that were more frequent in island lizards. Thanks to all above islanders retain food for longer periods and thus maximize energy income and increase the amount of the extracted nutrients. That way, they secure energy income from the limited, in time and quantity, food resources of the islands.

  8. Effect of colony size and surrounding substrate on corals experiencing a mild bleaching event on Heron Island reef flat (southern Great Barrier Reef, Australia)

    NASA Astrophysics Data System (ADS)

    Ortiz, J. C.; Gomez-Cabrera, M. Del C.; Hoegh-Guldberg, O.

    2009-12-01

    In January-May 2006, Heron Island in the Great Barrier Reef experienced a mild bleaching event. The effect of colony size, morphology and surrounding substrate on the extent of bleaching was explored. In contrast with previous studies, colony size did not influence bleaching sensitivity, suggesting that there may be a threshold of light and temperature stress beyond which size plays a role. Also contrasting with previous studies, massive corals were more affected by bleaching than branching corals. Massive corals surrounded by sand were more affected than the ones surrounded by rubble or dead coral. It is hypothesized that light reflectance from sand increases stress levels experienced by the colonies. This effect is maximized in massive corals as opposed to branching corals that form dense thickets on Heron Island. These results emphasize the importance of the ecological dynamics of coral communities experiencing low, moderate and high levels of bleaching for the understanding of how coral communities may change under the stress of climate change.

  9. Sand and nest temperatures and an estimate of hatchling sex ratio from the Heron Island green turtle ( Chelonia mydas) rookery, Southern Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Booth, David T.; Freeman, Candida

    2006-11-01

    Sand and nest temperatures were monitored during the 2002-2003 nesting season of the green turtle, Chelonia mydas, at Heron Island, Great Barrier Reef, Australia. Sand temperatures increased from ˜ 24°C early in the season to 27-29°C in the middle, before decreasing again. Beach orientation affected sand temperature at nest depth throughout the season; the north facing beach remained 0.7°C warmer than the east, which was 0.9°C warmer than the south, but monitored nest temperatures were similar across all beaches. Sand temperature at 100 cm depth was cooler than at 40 cm early in the season, but this reversed at the end. Nest temperatures increased 2-4°C above sand temperatures during the later half of incubation due to metabolic heating. Hatchling sex ratio inferred from nest temperature profiles indicated a strong female bias.

  10. Fish predation on sea urchins on the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Young, M. A. L.; Bellwood, D. R.

    2012-09-01

    Predators are important for regulating adult sea urchin densities. Here, we employ remote underwater video cameras to record diurnal predation on tethered sea urchins at Lizard Island on the Great Barrier Reef (GBR). We identified four fish predators of adult sea urchins ( Balistoides viridescens, Balistapus undulatus, Lethrinus atkinsoni and Choerodon schoenleinii). Predator activity appeared to be site-specific. Balistoides viridescens and B. undulatus (f: Balistidae) were the two most important predators of Echinometra mathaei with the former handling E. mathaei significantly faster (mean 0.7 min) than B. undulatus (5.2 min). Balistoides viridescens also successfully preyed on 70 % of detections, while C. schoenleinii, B. undulatus and L. atkinsoni preyed on just 33, 17 and <1 %, respectively. Additionally, B. viridescens were behaviourally dominant among predator species and were observed as aggressors in 30 encounters with B. undulatus and 8 encounters with L. atkinsoni. In only one encounter was B. viridescens the recipient of any aggression (from B. undulatus). In terms of relative vulnerability, of the three sea urchin species examined, E. mathaei were more vulnerable to predation than Diadema setosum or Echinothrix calamaris, with mean handling times of 1.2, 4.8 and 10.3 min, respectively. Balistoides viridescens and B. undulatus both appear to be able to play an important role as predators of sea urchins on the relatively intact coral reefs of Lizard Island. However, B. viridescens emerge as the most efficient predator in terms of handling speed and the proportion of detections preyed upon. They were also the behaviourally dominant predator. This preliminary study of the predators of sea urchins on the GBR highlights the potential significance of relatively scarce but functionally important species.

  11. Effect of immersion in seawater on egg survival in the lizard Anolis sagrei.

    PubMed

    Losos, Jonathan B; Schoener, Thomas W; Spiller, David A

    2003-11-01

    Studies on the lizard, Anolis sagrei, revealed that after Hurricane Floyd devastated the Bahamas in 1999, some populations consisted only of hatchlings. Because the storm surge of the hurricane completely inundated these islands, apparently for up to 6 h, survival of anole eggs in salt water for such periods is implied. To test this hypothesis directly, we placed A. sagrei eggs in saltwater for 3 or 6 h with unimmersed eggs serving as the control. Hatching success and incubation time did not differ among the three treatments. These findings help explain the persistence of anole populations on small islands vulnerable to hurricanes. PMID:12910410

  12. Anatomy, morphology and evolution of the patella in squamate lizards and tuatara (Sphenodon punctatus).

    PubMed

    Regnault, Sophie; Jones, Marc E H; Pitsillides, Andrew A; Hutchinson, John R

    2016-05-01

    The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary

  13. Enterobacteriaceae isolated from iguanid lizards of west-central Texas.

    PubMed Central

    Mathewson, J J

    1979-01-01

    The prevalence of members of the family Enterobacteriaceae in the intestines of seven species of iguanid lizards native to west-central Texas was determined. Of the 67 lizard specimens examined, 48.7% were infected with Salmonella and 9% were infected with Salmonella arizonae. Two lizard species (Sceloporus olivaceus and Crotaphytus collaris) were shown to have a 100% prevalence of Salmonella. PMID:533273

  14. Wall lizards display conspicuous signals to conspecifics and reduce detection by avian predators

    PubMed Central

    Stevens, Martin

    2014-01-01

    Visual signals are often under conflicting selection to be hidden from predators while being conspicuous to mates and rivals. Here, we investigated whether 3 different island populations of Aegean wall lizards (Podarcis erhardii) with variable coloration among diverse island habitats exhibit simultaneous camouflage and sexual signals. We examined whether signals appear better tuned to conspecific vision as opposed to that of avian predators, and whether background-matching camouflage and sexual signals are partitioned to specific body regions. This could facilitate both covert sexual signaling and camouflage according to the viewing perspectives of predators and conspecifics. We found that lizards typically appeared twice as conspicuous to conspecifics than to avian predators against the same visual background, largely due to lizards’ enhanced sensitivity to ultraviolet, suggesting that P. erhardii signals are tuned to conspecific vision to reduce detection by predators. Males were more conspicuous than females to both predators and conspecifics. In 2 populations, male backs were relatively more camouflaged to predators compared to signaling flanks, whereas in females, exposed and concealed surfaces were camouflaged to predators and generally did not differ in background matching. These findings indicate that lizard coloration evolves under the competing demands of natural and sexual selection to promote signals that are visible to conspecifics while being less perceptible to avian predators. They also elucidate how interactions between natural and sexual selection influence signal detectability and partitioning to different body regions, highlighting the importance of considering receiver vision, viewing perspectives, and signaling environments in studies of signal evolution. PMID:25419083

  15. High-intensity cardiac infections of Phthinomita heinigerae n. sp. (Digenea: Aporocotylidae) in the orangelined cardinalfish, Taeniamia fucata (Cantor), off Heron Island on the Great Barrier Reef.

    PubMed

    Nolan, Matthew J; Cantacessi, Cinzia; Cutmore, Scott C; Cribb, Thomas H; Miller, Terrence L

    2016-10-01

    We report a new species of aporocotylid trematode (Platyhelminthes: Digenea) from the heart of the orangelined cardinalfish, Taeniamia fucata (Cantor), from off Heron Island on the southern Great Barrier Reef. We used an integrated approach, analysing host distribution, morphology, and genetic data from the internal transcribed spacer 2 of the ribosomal DNA, to circumscribe Phthinomita heinigerae n. sp. This is the first species of Phthinomita Nolan & Cribb, 2006 reported from the Apogonidae; existing species and known 'types' are recorded from species of the Labridae, Mullidae, and Siganidae. The new species is distinguished from its 11 congeners in having a body 2977-3539 long and 16.5-22.4 times longer than wide, an anterior testis 6.2-8.2 times longer than wide and 8.3-13.0 times longer than the posterior testis, a posterior testis whose width is 35-56% of the body width, and an ovary positioned 11-13% of the body length from the posterior end, and is entirely anterior to the posterior margin of the anterior testis. In addition, 2-34 base differences (0.4-7.0% sequence divergence over 485 base positions) were detected among the ITS2 sequence representing P. heinigerae n. sp. and the 14 representing other Phthinomita species/molecular types. Prevalence and intensity of infection with P. heinigerae n. sp. was relatively high within the heart tissue of T. fucata, with 19 of 20 fish examined from off Heron Island infected (95%) with 7-25 adult worms (arithmetic mean 16.6). Infections by these parasites accounted for an occupation of 7-30% of the total estimated heart volume. PMID:27185234

  16. pH homeostasis during coral calcification in a free ocean CO2 enrichment (FOCE) experiment, Heron Island reef flat, Great Barrier Reef

    PubMed Central

    Georgiou, Lucy; Falter, James; Trotter, Julie; Kline, David I.; Holcomb, Michael; Dove, Sophie G.; Hoegh-Guldberg, Ove; McCulloch, Malcolm

    2015-01-01

    Geochemical analyses (δ11B and Sr/Ca) are reported for the coral Porites cylindrica grown within a free ocean carbon enrichment (FOCE) experiment, conducted on the Heron Island reef flat (Great Barrier Reef) for a 6-mo period from June to early December 2010. The FOCE experiment was designed to simulate the effects of CO2-driven acidification predicted to occur by the end of this century (scenario RCP4.5) while simultaneously maintaining the exposure of corals to natural variations in their environment under in situ conditions. Analyses of skeletal growth (measured from extension rates and skeletal density) showed no systematic differences between low-pH FOCE treatments (ΔpH = ∼−0.05 to −0.25 units below ambient) and present day controls (ΔpH = 0) for calcification rates or the pH of the calcifying fluid (pHcf); the latter was derived from boron isotopic compositions (δ11B) of the coral skeleton. Furthermore, individual nubbins exhibited near constant δ11B compositions along their primary apical growth axes (±0.02 pHcf units) regardless of the season or treatment. Thus, under the highly dynamic conditions of the Heron Island reef flat, P. cylindrica up-regulated the pH of its calcifying fluid (pHcf ∼8.4–8.6), with each nubbin having near-constant pHcf values independent of the large natural seasonal fluctuations of the reef flat waters (pH ∼7.7 to ∼8.3) or the superimposed FOCE treatments. This newly discovered phenomenon of pH homeostasis during calcification indicates that coral living in highly dynamic environments exert strong physiological controls on the carbonate chemistry of their calcifying fluid, implying a high degree of resilience to ocean acidification within the investigated ranges. PMID:26438833

  17. pH homeostasis during coral calcification in a free ocean CO2 enrichment (FOCE) experiment, Heron Island reef flat, Great Barrier Reef.

    PubMed

    Georgiou, Lucy; Falter, James; Trotter, Julie; Kline, David I; Holcomb, Michael; Dove, Sophie G; Hoegh-Guldberg, Ove; McCulloch, Malcolm

    2015-10-27

    Geochemical analyses (δ(11)B and Sr/Ca) are reported for the coral Porites cylindrica grown within a free ocean carbon enrichment (FOCE) experiment, conducted on the Heron Island reef flat (Great Barrier Reef) for a 6-mo period from June to early December 2010. The FOCE experiment was designed to simulate the effects of CO2-driven acidification predicted to occur by the end of this century (scenario RCP4.5) while simultaneously maintaining the exposure of corals to natural variations in their environment under in situ conditions. Analyses of skeletal growth (measured from extension rates and skeletal density) showed no systematic differences between low-pH FOCE treatments (ΔpH = ∼-0.05 to -0.25 units below ambient) and present day controls (ΔpH = 0) for calcification rates or the pH of the calcifying fluid (pHcf); the latter was derived from boron isotopic compositions (δ(11)B) of the coral skeleton. Furthermore, individual nubbins exhibited near constant δ(11)B compositions along their primary apical growth axes (±0.02 pHcf units) regardless of the season or treatment. Thus, under the highly dynamic conditions of the Heron Island reef flat, P. cylindrica up-regulated the pH of its calcifying fluid (pHcf ∼8.4-8.6), with each nubbin having near-constant pHcf values independent of the large natural seasonal fluctuations of the reef flat waters (pH ∼7.7 to ∼8.3) or the superimposed FOCE treatments. This newly discovered phenomenon of pH homeostasis during calcification indicates that coral living in highly dynamic environments exert strong physiological controls on the carbonate chemistry of their calcifying fluid, implying a high degree of resilience to ocean acidification within the investigated ranges. PMID:26438833

  18. Lizard-Skin Surface Texture

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1

    The south polar region of Mars is covered seasonally with translucent carbon dioxide ice. In the spring gas subliming (evaporating) from the underside of the seasonal layer of ice bursts through weak spots, carrying dust from below with it, to form numerous dust fans aligned in the direction of the prevailing wind.

    The dust gets trapped in the shallow grooves on the surface, helping to define the small-scale structure of the surface. The surface texture is reminiscent of lizard skin (figure 1).

    Observation Geometry Image PSP_003730_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 14-May-2007. The complete image is centered at -85.2 degrees latitude, 181.5 degrees East longitude. The range to the target site was 248.5 km (155.3 miles). At this distance the image scale is 24.9 cm/pixel (with 1 x 1 binning) so objects 75 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel . The image was taken at a local Mars time of 06:04 PM and the scene is illuminated from the west with a solar incidence angle of 69 degrees, thus the sun was about 21 degrees above the horizon. At a solar longitude of 237.5 degrees, the season on Mars is Northern Autumn.

  19. Phenotypic resonance from a single meal in an insectivorous lizard.

    PubMed

    Massot, Manuel; Aragón, Pedro

    2013-07-22

    Environmental variations are usually thought to require a nonanecdotal intensity or duration to have major effects on individuals and evolutionary outputs. However, environmental variations of weak intensity and short duration could be of major importance when they influence key targets or critical stages. Because conditions experienced early in life can be critical determinants of life history trajectories, especially early nutrition, we tested this hypothesis by experimentally manipulating the first meal of life in the lizard Zootoca vivipara. The species is a live-bearing lizard without parental care, and it consumes small arthropods. Neonates face a great challenge in acquiring their first meal, as is the case in many species that develop skills through learning to capture live prey. We show that this single meal had an overall and long-lasting impact. Effects on dispersal arose within 10 days, and we found effects 1-2 months later on growth, recapture probability, and juvenile survival. Interestingly, we detected effects on reproduction up to 2 years later. Such a "phenotypic resonance" reveals that the influence of small and ephemeral events should not be neglected by evolutionary biologists. PMID:23831289

  20. Species interactions mediate phylogenetic community structure in a hyperdiverse lizard assemblage from arid Australia.

    PubMed

    Rabosky, Daniel L; Cowan, Mark A; Talaba, Amanda L; Lovette, Irby J

    2011-11-01

    Evolutionary history can exert a profound influence on ecological communities, but few generalities have emerged concerning the relationships among phylogeny, community membership, and niche evolution. We compared phylogenetic community structure and niche evolution in three lizard clades (Ctenotus skinks, agamids, and diplodactyline geckos) from arid Australia. We surveyed lizard communities at 32 sites in the northwestern Great Victoria Desert and generated complete species-level molecular phylogenies for regional representatives of the three clades. We document a striking pattern of phylogenetic evenness within local communities for all groups: pairwise correlations in species abundance across sites are negatively related to phylogenetic similarity. By modeling site suitability on the basis of species' habitat preferences, we demonstrate that phylogenetic evenness generally persists even after controlling for habitat filtering among species. This phylogenetic evenness is coupled with evolutionary lability of habitat-associated traits, to the extent that closely related species are more divergent in habitat use than distantly related species. In contrast, lizard diets are phylogenetically conserved, and pairwise dietary overlap between species is negatively related to phylogenetic distance in two of the three clades. Our results suggest that contemporary and historical species interactions have led to similar patterns of community structure across multiple clades in one of the world's most diverse lizard communities. PMID:22030728

  1. A stem acrodontan lizard in the Cretaceous of Brazil revises early lizard evolution in Gondwana.

    PubMed

    Simões, Tiago R; Wilner, Everton; Caldwell, Michael W; Weinschütz, Luiz C; Kellner, Alexander W A

    2015-01-01

    Iguanians are one of the most diverse groups of extant lizards (>1,700 species) with acrodontan iguanians dominating in the Old World, and non-acrodontans in the New World. A new lizard species presented herein is the first acrodontan from South America, indicating acrodontans radiated throughout Gondwana much earlier than previously thought, and that some of the first South American lizards were more closely related to their counterparts in Africa and Asia than to the modern fauna of South America. This suggests both groups of iguanians achieved a worldwide distribution before the final breakup of Pangaea. At some point, non-acrodontans replaced acrodontans and became the only iguanians in the Americas, contrary to what happened on most of the Old World. This discovery also expands the diversity of Cretaceous lizards in South America, which with recent findings, suggests sphenodontians were not the dominant lepidosaurs in that continent as previously hypothesized. PMID:26306778

  2. A stem acrodontan lizard in the Cretaceous of Brazil revises early lizard evolution in Gondwana

    PubMed Central

    Simões, Tiago R.; Wilner, Everton; Caldwell, Michael W.; Weinschütz, Luiz C.; Kellner, Alexander W. A.

    2015-01-01

    Iguanians are one of the most diverse groups of extant lizards (>1,700 species) with acrodontan iguanians dominating in the Old World, and non-acrodontans in the New World. A new lizard species presented herein is the first acrodontan from South America, indicating acrodontans radiated throughout Gondwana much earlier than previously thought, and that some of the first South American lizards were more closely related to their counterparts in Africa and Asia than to the modern fauna of South America. This suggests both groups of iguanians achieved a worldwide distribution before the final breakup of Pangaea. At some point, non-acrodontans replaced acrodontans and became the only iguanians in the Americas, contrary to what happened on most of the Old World. This discovery also expands the diversity of Cretaceous lizards in South America, which with recent findings, suggests sphenodontians were not the dominant lepidosaurs in that continent as previously hypothesized. PMID:26306778

  3. Polycyclic aromatic hydrocarbons in clams, sediments, and seawater from the Great Barrier Reef region, Australia

    SciTech Connect

    Bagg, J.; Smith, J.D. )

    1988-09-01

    On the Great Barrier Reef actively growing organisms occur mainly in shallow water, between the low-water mark and about 5m depth. The effects of hydrocarbon pollution either from discharge into the sea or run-off from the shore might be expected to be most significantly at air/water or solid/water interfaces and so the earliest indications of contamination are likely to be found in species that live in this vulnerable zone. For this reason the clam Tridacna maxima which is found in the intertidal region was chosen to be analyzed for PAH content. This clam occurs in adequate numbers along the entire length of the Great Barrier Reef and yields enough tissue to permit detection of PAH at very low concentrations. In addition during collection their shells close so that the chance of significant contamination during transport is very small. Clams were taken from a number of sites including isolated reefs such as John Brewer Reef, the research stations, Heron and Lizard Islands, and a tourist resort, Green Island. At all these sites sediments were analyzed for PAH and at Green Island, in addition, seawater was analyzed.

  4. Synuclein expression in the lizard Anolis carolinensis.

    PubMed

    Toni, Mattia; Cioni, Carla; De Angelis, Federica; di Patti, Maria Carmela Bonaccorsi

    2016-08-01

    The synuclein (syn) family comprises three proteins: α-, β- and γ-syns. In humans, they are involved in neurodegenerative diseases such as Parkinson's disease and in tumors. Members of the syn family were sequenced in representative species of all vertebrates and the comparative analysis of amino acid sequences suggests that syns are evolutionarily conserved, but information about their expression in vertebrate lineages is still scarce and completely lacking in reptiles. In this study, the expression of genes coding for α-, β- and γ-syns was analyzed in the green lizard Anolis carolinensis by semiquantitative RT-PCR and Western blot. Results demonstrate good expression levels of the three syns in the lizard nervous system, similarly to human syns. This, together with the high identity between lizard and human syns, suggests that these proteins fulfill evolutionarily conserved functions. However, differences between lizard and humans in the expression of syn variants (two different variants of γ-syn were detected in A. carolinensis) and differences in some amino acids in key positions for the regulation of protein conformation and affinity for lipid and metal ions also suggest that these proteins may have acquired different functional specializations in the two lineages. PMID:27393691

  5. Great Minds? Great Lakes!

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Chicago, IL. Great Lakes National Program Office.

    This book contains lesson plans that provide an integrated approach to incorporating Great Lakes environmental issues into elementary subjects. The book is divided into three subject areas: (1) History, which includes the origins of the Great Lakes, Great Lakes people, and shipwrecks; (2) Social Studies, which covers government, acid rain as a…

  6. Rickettsia Detected in the Reptile Tick Bothriocroton hydrosauri from the Lizard Tiliqua rugosa in South Australia.

    PubMed

    Whiley, Harriet; Custance, Georgie; Graves, Stephen; Stenos, John; Taylor, Michael; Ross, Kirstin; Gardner, Michael G

    2016-01-01

    Rickettsiosis is a potentially fatal tick borne disease. It is caused by the obligate intracellular bacteria Rickettsia, which is transferred to humans through salivary excretions of ticks during the biting process. Globally, the incidence of tick-borne diseases is increasing; as such, there is a need for a greater understanding of tick-host interactions to create more informed risk management strategies. Flinders Island spotted fever rickettsioses has been identified throughout Australia (Tasmania, South Australia, Queensland and Torres Strait Islands) with possible identifications in Thailand, Sri Lanka and Italy. Flinders Island spotted fever is thought to be spread through tick bites and the reptile tick Bothriocroton hydrosauri has been implicated as a vector in this transmission. This study used qPCR to assay Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard) hosts on mainland South Australia near where spotted fever cases have been identified. We report that, although we discovered Rickettsia in all tick samples, it was not Rickettsia honei. This study is the first to use PCR to positively identify Rickettsia from South Australian Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard) hosts. These findings suggest that B. hydrosauri may be a vector of multiple Rickettsia spp. Also as all 41 tested B. hydrosauri ticks were positive for Rickettsia this indicates an extremely high prevalence within the studied area in South Australia. PMID:27338482

  7. Rickettsia Detected in the Reptile Tick Bothriocroton hydrosauri from the Lizard Tiliqua rugosa in South Australia

    PubMed Central

    Whiley, Harriet; Custance, Georgie; Graves, Stephen; Stenos, John; Taylor, Michael; Ross, Kirstin; Gardner, Michael G.

    2016-01-01

    Rickettsiosis is a potentially fatal tick borne disease. It is caused by the obligate intracellular bacteria Rickettsia, which is transferred to humans through salivary excretions of ticks during the biting process. Globally, the incidence of tick-borne diseases is increasing; as such, there is a need for a greater understanding of tick–host interactions to create more informed risk management strategies. Flinders Island spotted fever rickettsioses has been identified throughout Australia (Tasmania, South Australia, Queensland and Torres Strait Islands) with possible identifications in Thailand, Sri Lanka and Italy. Flinders Island spotted fever is thought to be spread through tick bites and the reptile tick Bothriocroton hydrosauri has been implicated as a vector in this transmission. This study used qPCR to assay Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard) hosts on mainland South Australia near where spotted fever cases have been identified. We report that, although we discovered Rickettsia in all tick samples, it was not Rickettsia honei. This study is the first to use PCR to positively identify Rickettsia from South Australian Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard) hosts. These findings suggest that B. hydrosauri may be a vector of multiple Rickettsia spp. Also as all 41 tested B. hydrosauri ticks were positive for Rickettsia this indicates an extremely high prevalence within the studied area in South Australia. PMID:27338482

  8. Aliphatic hydrocarbons in Great Barrier Reef organisms and environment

    NASA Astrophysics Data System (ADS)

    Coates, M.; Connell, D. W.; Bodero, J.; Miller, G. J.; Back, R.

    1986-07-01

    This investigation was undertaken to assess the chemical nature, occurrence, and possible origin of petroleum hydrocarbons in the Great Barrier Reef ecosystem. Aliphatic hydrocarbons in surface sediments, water, and a suite of seven species from widely separated coral reefs in the Great Barrier Reef area were analysed by gas chromatography, and by gas chromatography coupled with mass spectrometry. The hydrocarbons found were substantially of biogenic origin. The major components were n-pentadecane, n-heptadecane, pristane and mono-alkenes based on heptadecane, and were believed to originate from benthic algae and phytoplankton. There was no evidence to suggest that lipid content had any influence on hydrocarbon content. Hydrocarbons from the organisms and sediments have characteristic composition patterns which would be altered by the presence of petroleum hydrocarbons. An unresolved complex mixture, usually considered indicative of petroleum contamination, was found in greater than trace amounts only in Holothuria (sea cucumber) and Acropora (coral) from the Capricorn Group, and in some sediment samples from the Capricorn Group and Lizard Island area.

  9. The stinging Apidae and Vespidae (Hymenoptera: Apocrita) in Iranian islands, Qeshm, Abu-Musa, Great Tunb and Lesser Tunb on the Persian Gulf

    PubMed Central

    Khoobdel, Mehdi; Tavassoli, Maryam; Salari, Mehdi; Firozi, Fateme

    2014-01-01

    Objective To study the stinging flying Hymenoptera (Apidae and Vespidae) fauna in four Iranian Islands, Qeshm, Greater Tunb, Lesser Tunb and Abu-Musa on the Persian Gulf. Methods The flies were captured by used of Malaise trap, fly trap, bottle trap and insect net-hashing from March 2011 to July 2012. Results In this study, 11 species of stinging Hymenoptera were reported for the first time in Persian Gulf region. Conclusions Some of this species such as Vespa orientalis and Polistes olivaceus are more common in the Persian Gulf islands and can cause clinical problem to islands resident and travelers. PMID:25183092

  10. Habitat degradation may affect niche segregation patterns in lizards

    NASA Astrophysics Data System (ADS)

    Pelegrin, N.; Chani, J. M.; Echevarria, A. L.; Bucher, E. H.

    2013-08-01

    Lizards partition resources in three main niche dimensions: time, space and food. Activity time and microhabitat use are strongly influenced by thermal environment, and may differ between species according to thermal requirements and tolerance. As thermal characteristics are influenced by habitat structure, microhabitat use and activity of lizards can change in disturbed habitats. We compared activity and microhabitat use of two abundant lizard species of the Semi-arid Chaco of Argentina between a restored and a highly degraded Chaco forest, to determine how habitat degradation affects lizard segregation in time and space, hypothesizing that as activity and microhabitat use of lizards are related to habitat structure, activity and microhabitat use of individual species can be altered in degraded habitats, thus changing segregation patterns between them. Activity changed from an overlapped pattern in a restored forest to a segregated pattern in a degraded forest. A similar trend was observed for microhabitat use, although to a less extent. No correlation was found between air temperature and lizard activity, but lizard activity varied along the day and among sites. Contrary to what was believed, activity patterns of neotropical diurnal lizards are not fixed, but affected by multiple factors related to habitat structure and possibly to interspecific interactions. Changes in activity patterns and microhabitat use in degraded forests may have important implications when analyzing the effects of climate change on lizard species, due to synergistic effects.

  11. Patterns of coccidial prevalence in lizards of Mauritius.

    PubMed

    Leinwand, Ian; Kilpatrick, A Marm; Cole, Nik; Jones, Carl G; Daszak, Peter

    2005-10-01

    This paper reports prevalence of coccidial oocysts in fecal samples from 6 endemic and 2 introduced lizard species on Mauritius, an island nation in the Indian Ocean. Total coccidian prevalence was 54% (n = 341) for the endemic 'ornate day gecko,' Phelsuma ornata; 48% (n = 159) for the endemic 'Durrell's night gecko,' Nactus durrelli; 53% (n = 15) for the endemic 'Serpent Island night gecko,' N. serpensinsula; and 78% (n = 248) for the introduced gecko, Hemidactylus frenatus. These high prevalences may reflect lack of long-lasting immune response to coccidial infection. There were few significant differences in prevalence among age, island, sex, or body condition within species, suggesting that these coccidia are relatively nonpathogenic and have little effect on host fitness. Prevalence was higher in the dry season than the wet season. These data suggest other factors, such as low host immune response to reinfection, affect overall prevalence more significantly than the effect of humidity on oocyst survival on Mauritius. No coccidia were found in samples from the endemic 'Gunner's Quoin night gecko,' N. coindemirensis (n = 155), probably reflecting parasite extinction due to a host population bottleneck following historical introduction of rats. There was no evidence of competitive or facilitative interactions between Eimeria sp. and Isospora sp., but evidence of competition between 2 Eimeria species in the 'ornate day gecko,' Phelsuma ornata. No evidence was found of cross-species infection, suggesting that reptile coccidia have high host specificity and are, therefore, poor subjects for studies of parasite-mediated competition and the evolution of sex. PMID:16419754

  12. Adaptive color polymorphism and unusually high local genetic diversity in the side-blotched lizard, Uta stansburiana.

    PubMed

    Micheletti, Steven; Parra, Eliseo; Routman, Eric J

    2012-01-01

    Recently, studies of adaptive color variation have become popular as models for examining the genetics of natural selection. We examined color pattern polymorphism and genetic variation in a population of side-blotched lizards (Uta stansburiana) that is found in habitats with both dark (lava) and light colored (granite) substrates. We conducted a limited experiment for adult phenotypic plasticity in laboratory conditions. We recorded both substrate and lizard color patterns in the field to determine whether lizards tended to match their substrate. Finally we examined genetic variation in a gene (melanocortin 1 receptor) that has been shown to affect lizard color in other species and in a presumably neutral gene (mitochondrial cytochrome b). Populations were sampled in the immediate area of the lava flows as well as from a more distant site to examine the role of population structure. Our captive Uta did not change color to match their background. We show that side-blotched lizards tend to match the substrate on which it was caught in the field and that variation in the melanocortin 1 receptor gene does not correlate well with color pattern in this population. Perhaps the most remarkable result is that this population of side-blotched lizards shows extremely high levels of variation at both genetic markers, in the sense of allele numbers, with relatively low levels of between-allele sequence variation. Genetic variation across this small region was as great or greater than that seen in samples of pelagic fish species collected worldwide. Statistical analysis of genetic variation suggests rapid population expansion may be responsible for the high levels of variation. PMID:23133520

  13. Adaptive Color Polymorphism and Unusually High Local Genetic Diversity in the Side-Blotched Lizard, Uta stansburiana

    PubMed Central

    Micheletti, Steven; Parra, Eliseo; Routman, Eric J.

    2012-01-01

    Recently, studies of adaptive color variation have become popular as models for examining the genetics of natural selection. We examined color pattern polymorphism and genetic variation in a population of side-blotched lizards (Uta stansburiana) that is found in habitats with both dark (lava) and light colored (granite) substrates. We conducted a limited experiment for adult phenotypic plasticity in laboratory conditions. We recorded both substrate and lizard color patterns in the field to determine whether lizards tended to match their substrate. Finally we examined genetic variation in a gene (melanocortin 1 receptor) that has been shown to affect lizard color in other species and in a presumably neutral gene (mitochondrial cytochrome b). Populations were sampled in the immediate area of the lava flows as well as from a more distant site to examine the role of population structure. Our captive Uta did not change color to match their background. We show that side-blotched lizards tend to match the substrate on which it was caught in the field and that variation in the melanocortin 1 receptor gene does not correlate well with color pattern in this population. Perhaps the most remarkable result is that this population of side-blotched lizards shows extremely high levels of variation at both genetic markers, in the sense of allele numbers, with relatively low levels of between-allele sequence variation. Genetic variation across this small region was as great or greater than that seen in samples of pelagic fish species collected worldwide. Statistical analysis of genetic variation suggests rapid population expansion may be responsible for the high levels of variation. PMID:23133520

  14. Great Lakes: Great Gardening.

    ERIC Educational Resources Information Center

    New York Sea Grant Inst., Albany, NY.

    This folder contains 12 fact sheets designed to improve the quality of gardens near the Great Lakes. The titles are: (1) "Your Garden and the Great Lakes"; (2) "Organic Gardening"; (3) "Fruit and Vegetable Gardening"; (4) "Composting Yard Wastes"; (5) "Herbicides and Water Quality"; (6) "Watering"; (7) "Soil Erosion by Water"; (8) "Soil…

  15. Ecological release in White Sands lizards

    PubMed Central

    Roches, S Des; Robertson, J M; Harmon, L J; Rosenblum, E B

    2011-01-01

    Ecological opportunity is any change that allows populations to escape selection from competition and predation. After encountering ecological opportunity, populations may experience ecological release: enlarged population size, broadened resource use, and/or increased morphological variation. We identified ecological opportunity and tested for ecological release in three lizard colonists of White Sands, New Mexico (Sceloporus undulatus, Holbrookia maculata, and Aspidoscelis inornata). First, we provide evidence for ecological opportunity by demonstrating reduced species richness and abundance of potential competitors and predators at White Sands relative to nearby dark soils habitats. Second, we characterize ecological release at White Sands by demonstrating density compensation in the three White Sands lizard species and expanded resource use in White Sands S. undulatus. Contrary to predictions from ecological release models, we observed directional trait change but not increased trait variation in S. undulatus. Our results suggest that ecological opportunity and ecological release can be identified in natural populations, especially those that have recently colonized isolated ecosystems. PMID:22393523

  16. Coupled, Active Oscillators and Lizard Otoacoustic Emissions

    NASA Astrophysics Data System (ADS)

    Bergevin, Christopher; Velenovsky, David S.; Bonine, Kevin E.

    2011-11-01

    The present study empirically explores the relationship between spontaneous otoacoustic emissions (SOAEs) and stimulus-frequency emissions (SFOAEs) in lizards, an ideal group for such research given their relatively simple inner ear (e.g., lack of basilar membrane traveling waves), diverse morphology across species/families (e.g., tectorial membrane structure) and robust emissions. In a nutshell, our results indicate that SFOAEs evoked using low-level tones are intimately related to underlying SOAE activity, and appear to represent the entrained response of active oscillators closely tuned to the probe frequency. The data described here indicate several essential features that are desirable to capture in theoretical models for auditory transduction in lizards, and potentially represent generic properties at work in many different classes of "active" ears.

  17. A modern soft-bottom, shallow-water crinoid fauna (Echinodermata) from the Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    Messing, C. G.; Meyer, D. L.; Siebeck, U. E.; Jermiin, L. S.; Vaney, D. I.; Rouse, G. W.

    2006-03-01

    A recent preliminary survey revealed that 12 species of unstalked crinoids occur on a gentle sandy slope (12 18 m depth) at Lizard Island, Great Barrier Reef, Australia; five of which are also found on coral reefs. The other seven appear to constitute a unique assemblage restricted to unconsolidated substrates, where most cling to algae or hide beneath rubble or sponges. Members of this assemblage exhibit all of the basic feeding postures found among reef-dwelling species. However, Comatula rotalaria, which lacks anchoring cirri and bears uniquely differentiated short and long arms, exhibits a posture different from other living crinoids. Quantitative transects reveal apparent depth-related differences in species composition: C. rotalaria dominated the 12 transects in 12 13 m (84% of 82 specimens), while Comatella nigra, Comatula cf. purpurea, Amphimetra cf. tessellata and Zygometra microdiscus accounted for 96% of 54 specimens observed along 12 transects in 16 17 m.

  18. Predation-associated modulation of movement-based signals by a Bahamian lizard

    PubMed Central

    Steinberg, David S.; Losos, Jonathan B.; Schoener, Thomas W.; Spiller, David A.; Kolbe, Jason J.; Leal, Manuel

    2014-01-01

    Signaling individuals must effectively capture and hold the attention of intended conspecific receivers while limiting eavesdropping by potential predators. A possible mechanism for achieving this balance is for individuals to modulate the physical properties of their signals or to alter the proportion of time spent signaling, depending upon local levels of predation pressure. We test the hypothesis that prey can alter their visual signaling behavior to decrease conspicuousness and potentially limit predation risk via modulation of signal properties or display rate. To do so, we conducted a manipulative experiment in nature to evaluate the possible effect of predation pressure on the physical properties of movement-based signals and on the proportion of time spent signaling by using a well-understood predator–prey system in the Bahamas, the semiarboreal lizard Anolis sagrei, and one of its main predators, the curly-tailed lizard Leiocephalus carinatus. We find that on islands onto which the predator was introduced, male anoles reduce the maximum amplitude of head-bob displays but not the proportion of time spent signaling, in comparison with control islands lacking the predator. This reduction of amplitude also decreases signal active space, which might alter the reproductive success of signaling individuals. We suggest that future studies of predator–prey interactions consider the risk effects generated by changes in signals or signaling behavior to fully determine the influence of predation pressure on the dynamics of prey populations. PMID:24843163

  19. Polycyclic aromatic hydrocarbons in the clam Tridacna maxima from the Great Barrier Reef, Australia

    SciTech Connect

    Smith, J.D.; Bagg, J.; Bycroft, B.M.

    1984-05-01

    The concentrations of eight polycyclic aromatic hydrocarbons (PAH), anthracene, pyrene, chrysene, benzo(k)fluoranthene, benzo(a)pyrene, benzo(ghi)perylene, fluoranthene, and perylene, were measured in clams, Tridacna maxima, collected from sites on the Great Barrier Reef ranging in latitude from 14/sup 0/31'S to 23/sup 0/33' S. At most locations the concentrations of PAH were not significantly above the limit of detection, e.g., pyrene < 0.07 ..mu..g/kg wet weight, benzo(a)pyrene < 0.01 ..mu..g/kg, and chrysene < 0.07 ..mu..g/kg. These levels of PAH appear to be the lowest reported for clams anywhere in the world, indicating the pristine nature of the Great Barrier Reef at the present time. Concentrations significantly above detection levels were found at only two sites, Lizard Island First Beach (anthracene, 3.2 ..mu..g/kg; pyrene, 1.4 ..mu..g/kg) and Heron Island Harbour (pyrene, 1.2 ..mu..g/kg; benzo(a)pyrene, 0.02 ..mu..g/kg). Both sites are frequently visited by power boats which are the most likely source of hydrocarbon contamination. These low levels of contamination would not have been demonstrated by the measurement of only the most commonly studied PAH, benzo(a)pyrene. Simultaneous determination of several PAH was necessary to show clearly that some localized pollution had occurred.

  20. Interhabitat differences in energy acquisition and expenditure in a lizard

    SciTech Connect

    Karasov, W.H.; Anderson, R.A.

    1984-02-01

    Cnemidophorus hyperythrus, a small (approx. =4-g) teiid lizard, occurs along an elevational thorn scrub - thorn woodland - thorn forest habitat gradient in the cape region of Baja California. Body size, daily energy expenditure (DEE, measured with doubly labeled water), relative feeding rate (as reflected by H/sub 2/O influx rate), behavior, and abundance of this species at two sites along the gradient were compared. At the inland thorn woodland site C. hyperythrus were more abundant (approx. =100 lizards/ha) than at the thorn scrub site near the ocean (approx. =50 lizards/ha). Mean body mass of woodland site lizards was 13% greater than that of scrub lizards. The DEE of the thorn woodland lizards, 330 J x g/sup -1/ x d/sup -1/,> and their H/sub 2/O influx, 99 mm/sup 3/ x g/sup -1/ x d/sup -1/, were also higher than the thorn scrub lizards', 219 J x g/sup -1/ x d/sup -1/ and 52 mm/sup 3/ x g/sup -1/ x d/sup -1/. Diets at the two sites were similar. There were no differences between sexes in diet, DEE, or H/sub 2/O influx. Daily maintenance energy costs were calculated based upon laboratory measures of O/sub 2/ consumption of resting lizards at a series of temperatures that represented the daily range of body temperatures experienced by lizards in the field. Activity costs (=DEE minus maintenance) were three times higher in the woodland lizards. Behavioral observations showed that woodland lizards were active most of the day (approx. =9 h/d) whereas scrub lizards were active primarily in the morning (approx. =3.5 h/d). Thus, the higher activity cost, DEE, and feeding rate of woodland lizards can be explained by their longer daily activity period. Causal factors for the difference in daily activity period are suggested, and implications of length of daily foraging period for adult body, size, population density, and various life history parameters of lizards are discussed.

  1. Intersexual chemo-sensation in a “visually-oriented” lizard, Anolis sagrei

    PubMed Central

    Driessens, Tess; Van Damme, Raoul

    2016-01-01

    While the conspicuous visual displays of anoles have been studied in great depth, the possibility that these lizards may also interact through chemical signalling has received hardly any consideration. In this study, we observed the behaviour of male brown anoles (Anolis sagrei) when introduced into an environment previously inhabited by female conspecifics, and compared it to when they were introduced into an untreated environment. The males in our tests exhibited significantly more elaborate display behaviour (i.e., greater number of dewlap extensions and head-nods) and a significantly greater number of tongue extrusions while in the cage formerly occupied by females than when placed in the untreated, control cage. The absolute numbers of tongue extrusions, however, were relatively low in comparison to average tongue-flick rates of ‘true’ chemically-oriented lizards. Our results strongly suggest that the males were capable of detecting chemical cues left behind by the females. These observations provide the first evidence of intersexual chemo-sensation in an anole lizard. PMID:27069809

  2. Intersexual chemo-sensation in a "visually-oriented" lizard, Anolis sagrei.

    PubMed

    Baeckens, Simon; Driessens, Tess; Van Damme, Raoul

    2016-01-01

    While the conspicuous visual displays of anoles have been studied in great depth, the possibility that these lizards may also interact through chemical signalling has received hardly any consideration. In this study, we observed the behaviour of male brown anoles (Anolis sagrei) when introduced into an environment previously inhabited by female conspecifics, and compared it to when they were introduced into an untreated environment. The males in our tests exhibited significantly more elaborate display behaviour (i.e., greater number of dewlap extensions and head-nods) and a significantly greater number of tongue extrusions while in the cage formerly occupied by females than when placed in the untreated, control cage. The absolute numbers of tongue extrusions, however, were relatively low in comparison to average tongue-flick rates of 'true' chemically-oriented lizards. Our results strongly suggest that the males were capable of detecting chemical cues left behind by the females. These observations provide the first evidence of intersexual chemo-sensation in an anole lizard. PMID:27069809

  3. Lizards in the ecology of salmonellosis in Panama.

    PubMed Central

    Kourany, M; Telford, S R

    1981-01-01

    Enteropathogenic bacteria was isolated from 131 of 447 (29.4%) neotropical Panamanian lizards belonging to 34 species of seven families. Overall, 147 strains of bacteria were isolated comprising 26 Salmonella and 10 Arizona serotypes. Gymnopthalmus speciosus had the highest infection rate, 12 of 13 individuals (92.3%), whereas Gonatodes fuscus exhibited the lowest, 1 of 18 (5.6%). The highest infection was detected in lizards whose behavioral patterns were secretive (42.0%) and terrestrial (42.6%), whereas the lowest infection was among the scansorial lizards (17.5%). Rates were highest during the dry season, from January through April. Many neotropical Panamanian lizards were multiply infected by Salmonella an Arizona strains representing representing a wide range of serotypes. Infected lizards were distributed in areas varying from remote rural and forested regions to urban developments, offering a potentially important reservoir of enteropathogenic bacteria known to cause infection in man and domestic animals. PMID:7259156

  4. Salmonellosis in laboratory-housed iguanid lizards (Sceloporus spp.).

    PubMed

    Kalvig, B A; Maggio-Price, L; Tsuji, J; Giddens, W E

    1991-10-01

    Fifteen wild-caught iguanid lizards (14 Sceloporus variabilis and one S. malachiticus) were used in a 3 mo study on thermal acclimation. Over a 2 mo period, five of the lizards showed decreased activity, anorexia and enlarged joints, and were either found moribund or were euthanatized due to their poor condition. Specimens taken from lesions in four of the five lizards were cultured and were infected with Salmonella spp. Salmonella spp. was cultured from cloacal swabs in six of the 10 surviving lizards. Standard metabolic rates of those that were infected did not differ significantly from those that were not infected. We postulate that the lizards were inapparent carriers of Salmonella spp. at the time of capture and, as a result of stress, five developed active overwhelming systemic infections. PMID:1758020

  5. Great Minds? Great Lakes!

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Chicago, IL. Great Lakes National Program Office.

    This booklet introduces an environmental curriculum for use in a variety of elementary subjects. The lesson plans provide an integrated approach to incorporating Great Lakes environmental issues into the subjects of history, social studies, and environmental sciences. Each of these sections contains background information, discussion points, and a…

  6. Data use investigations for applications Explorer Mission A (Heat Capacity Mapping Mission): HCMM's role in studies of the urban heat island, Great Lakes thermal phenomena and radiometric calibration of satellite data. [Buffalo, Syracuse, and Rochester New York and Lake Ontario

    NASA Technical Reports Server (NTRS)

    Schott, J. R. (Principal Investigator); Schimminger, E. W.

    1981-01-01

    The utility of data from NASA'a heat capacity mapping mission satellite for studies of the urban heat island, thermal phenomena in large lakes and radiometric calibration of satellite sensors was assessed. The data were found to be of significant value in all cases. Using HCMM data, the existence and microstructure of the heat island can be observed and associated with land cover within the urban complex. The formation and development of the thermal bar in the Great Lakes can be observed and quantitatively mapped using HCMM data. In addition, the thermal patterns observed can be associated with water quality variations observed both from other remote sensing platforms and in situ. The imaging radiometer on-board the HCMM satellite is shown to be calibratible to within about 1.1 C of actual surface temperatures. These findings, as well as the analytical procedures used in studying the HCMM data, are included.

  7. Interhabitat differences in energy acquisition and expenditure in a lizard

    SciTech Connect

    Karasov, W.H.; Anderson, R.A.

    1984-02-01

    Cnemidophorus hyperythrus, a small (approx. =4-g) teiid lizard, occurs along an elevational thorn scrub-thorn woodland-thorn forest habitat gradient in the cape region of Baja California. The authors compared body size, daily energy expenditure (DEE, measured with double labeled water), relative feeding rate (as reflected by H/sub 2/O influx rate), behavior, and abundance of this species at two sites along the gradient. At the inland thorn woodland site C. hyperythrus were more abundant (approx. =50 lizards/ha.). Mean body mass of woodland site lizards was 13% greater than that of scrub lizards. The DEE of the thorn woodland lizards, 330 site J x g/sup -1/ x d/sup -1/, and their H/sub 2/O influx, 99 mm/sup 3/ x g/sup -1/ x d/sup -1/, were also higher than the thorn scrub lizards', 219 J x g/sup -1/ x d/sup -1/ and 52 mm/sup 3/ x g/sup -1/ x d/sup -1/. Diets at the two sites were similar. There were no differences between sexes in diet, DEE, or H/sub 2/ influx. Daily maintenance energy costs were calculated based upon laboratory measures of O/sub 2/ consumption of resting lizards at a series of temperatures that represented the daily range of body temperatures experienced by lizards in the field. Activity costs (=DEE minus maintenance) were three times higher in the woodland lizards. Behavioral observations showed that woodland lizards were active most of the day (approx. =9 h/d) whereas scrub lizards were active primarily in the morning (approx. =3.5 h/d). Thus, the higher activity cost, DEE, and feeding rate of woodland lizards can be explained by their longer daily activity period. We suggest causal factors for the difference in daily activity period, and discuss implications of length of daily forging period for adult body size, population density, and various life history parameters of lizards.

  8. Island biogeography of the Anthropocene.

    PubMed

    Helmus, Matthew R; Mahler, D Luke; Losos, Jonathan B

    2014-09-25

    For centuries, biogeographers have examined the factors that produce patterns of biodiversity across regions. The study of islands has proved particularly fruitful and has led to the theory that geographic area and isolation influence species colonization, extinction and speciation such that larger islands have more species and isolated islands have fewer species (that is, positive species-area and negative species-isolation relationships). However, experimental tests of this theory have been limited, owing to the difficulty in experimental manipulation of islands at the scales at which speciation and long-distance colonization are relevant. Here we have used the human-aided transport of exotic anole lizards among Caribbean islands as such a test at an appropriate scale. In accord with theory, as anole colonizations have increased, islands impoverished in native species have gained the most exotic species, the past influence of speciation on island biogeography has been obscured, and the species-area relationship has strengthened while the species-isolation relationship has weakened. Moreover, anole biogeography increasingly reflects anthropogenic rather than geographic processes. Unlike the island biogeography of the past that was determined by geographic area and isolation, in the Anthropocene--an epoch proposed for the present time interval--island biogeography is dominated by the economic isolation of human populations. PMID:25254475

  9. The Lizard Wireless Station of Guglielmo Marconi

    NASA Astrophysics Data System (ADS)

    Montstein, Christian

    2014-08-01

    During the vacation with my wife in Cornwall, we by chance were walking by the Lizard wireless station, originally installed by Guglielmo Marconi and recently refurbished by The National Trust/UK. Fortunately the shed was open for public visitors and a student was present telling stories about the station and its history. The historic equipment was demonstrated by sending some Morse codes. The high voltage sparks and its sound were quite impressive while in the background the Morse code receiver punched dots and dashes onto the strip chart.

  10. Bermuda as an evolutionary life raft for an ancient lineage of endangered lizards.

    PubMed

    Brandley, Matthew C; Wang, Yuezhao; Guo, Xianguang; Nieto Montes de Oca, Adrián; Fería Ortíz, Manuel; Hikida, Tsutomu; Ota, Hidetoshi

    2010-01-01

    Oceanic islands are well known for harboring diverse species assemblages and are frequently the basis of research on adaptive radiation and neoendemism. However, a commonly overlooked role of some islands is their function in preserving ancient lineages that have become extinct everywhere else (paleoendemism). The island archipelago of Bermuda is home to a single species of extant terrestrial vertebrate, the endemic skink Plestiodon (formerly Eumeces) longirostris. The presence of this species is surprising because Bermuda is an isolated, relatively young oceanic island approximately 1000 km from the eastern United States. Here, we apply Bayesian phylogenetic analyses using a relaxed molecular clock to demonstrate that the island of Bermuda, although no older than two million years, is home to the only extant representative of one of the earliest mainland North American Plestiodon lineages, which diverged from its closest living relatives 11.5 to 19.8 million years ago. This implies that, within a short geological time frame, mainland North American ancestors of P. longirostris colonized the recently emergent Bermuda and the entire lineage subsequently vanished from the mainland. Thus, our analyses reveal that Bermuda is an example of a "life raft" preserving millions of years of unique evolutionary history, now at the brink of extinction. Threats such as habitat destruction, littering, and non-native species have severely reduced the population size of this highly endangered lizard. PMID:20614024

  11. Prevalence of neutralising antibodies against adenoviruses in lizards and snakes.

    PubMed

    Ball, Inna; Ofner, Sabine; Funk, Richard S; Griffin, Chris; Riedel, Ulf; Möhring, Jens; Marschang, Rachel E

    2014-10-01

    Adenoviruses (AdVs) are relatively common in lizards and snakes, and several genetically distinct AdVs have been isolated in cell culture. The aims of this study were to examine serological relationships among lizard and snake AdVs and to determine the frequency of AdV infections in these species. Isolates from a boa constrictor (Boa constrictor), a corn snake (Pantherophis gutattus) and a central bearded dragon (Pogona vitticeps), and two isolates from helodermatid lizards (Heloderma horridum and H. suspectum) were used in neutralisation tests for the detection of antibodies in plasma from 263 lizards from seven families (including 12 species) and from 141 snakes from four families (including 28 species) from the USA and Europe. Most lizard and snake samples had antibodies against a range of AdV isolates, indicating that AdV infection is common among these squamates. Neutralisation tests with polyclonal antibodies raised in rabbits demonstrated serological cross-reactivity between both helodermatid lizard isolates. However, squamate plasma showed different reactions to each of these lizard isolates in neutralisation tests. PMID:25163614

  12. Occurrence and distribution of the exotic lizard Hemidactylus mabouia Moreau de Jonnès, 1818 in Ilha Grande, RJ, Brazil.

    PubMed

    Rocha, C F D; Bergallo, H G

    2011-05-01

    The gekkonid lizard Hemidactylus mabouia is an exotic species in Brazil and is found in different ecosystems. This species was recorded at Ilha Grande, RJ, one of the largest insular remains of the Atlantic Rainforest in Brazil. In this study, the occurrence of H. mabouia was determined throughout the island, including the rain forest, restinga and anthropic environments. We used the active search method in points along 19 trails that surround Ilha Grande. At each regular interval of 100 m, we searched for the presence of H. mabouia. The species was recorded in a total of 100 points among the 719 sampled and, in all cases, the occurrence of the lizard corresponded to points located in anthropic or perianthropic areas. As most of Ilha Grande is covered by dense tropical rain forest, we believe this has restricted the invasion of H. mabouia in natural environments within the island. PMID:21755162

  13. Distribution pattern and number of ticks on lizards.

    PubMed

    Dudek, Krzysztof; Skórka, Piotr; Sajkowska, Zofia Anna; Ekner-Grzyb, Anna; Dudek, Monika; Tryjanowski, Piotr

    2016-02-01

    The success of ectoparasites depends primarily on the site of attachment and body condition of their hosts. Ticks usually tend to aggregate on vertebrate hosts in specific areas, but the distribution pattern may depend on host body size and condition, sex, life stage or skin morphology. Here, we studied the distribution of ticks on lizards and tested the following hypothesis: occurrence or high abundance of ticks is confined with body parts with smaller scales and larger interscalar length because such sites should provide ticks with superior attachment conditions. This study was performed in field conditions in central Poland in 2008-2011. In total, 500 lizards (Lacerta agilis) were caught and 839 ticks (Ixodes ricinus, larvae and nymphs) were collected from them. Using generalised linear mixed models, we found that the ticks were most abundant on forelimbs and their axillae, with 90% of ticks attached there. This part of the lizard body and the region behind the hindlimb were covered by the smallest scales with relatively wide gaps between them. This does not fully support our hypothesis that ticks prefer locations with easy access to skin between scales, because it does not explain why so few ticks were in the hindlimb area. We found that the abundance of ticks was positively correlated with lizard body size index (snout-vent length). Tick abundance was also higher in male and mature lizards than in female and young individuals. Autotomy had no effect on tick abundance. We found no correlation between tick size and lizard morphology, sex, autotomy and body size index. The probability of occurrence of dead ticks was positively linked with the total number of ticks on the lizard but there was no relationship between dead tick presence and lizard size, sex or age. Thus lizard body size and sex are the major factors affecting the abundance of ticks, and these parasites are distributed nearly exclusively on the host's forelimbs and their axillae. PMID:26520053

  14. Phylogeny of Neotropical Cercosaura (Squamata: Gymnophthalmidae) lizards.

    PubMed

    Torres-Carvajal, Omar; Lobos, Simón E; Venegas, Pablo J

    2015-12-01

    Among Neotropical lizards, the geographically widespread gymnophthalmid Cercosaura as currently defined includes lowland and highland taxa from Panama to Argentina, with some species occurring in the northern Andes. In this study we analyze three mitochondrial (12S, 16S, ND4) and one nuclear (c-mos) gene using Bayesian methods to clarify the phylogenetic relationships among most species of Cercosaura based on a well-supported phylogenetic hypothesis that also includes a large sample of other taxa within Cercosaurini. The phylogenetic tree obtained in this paper shows that Cercosaura as currently defined is not monophyletic. Two species from the northern Andes (C. dicra and C. vertebralis) are nested within Pholidobolus, which has been formerly recognized as a major radiation along the Andes of Ecuador and Colombia. Therefore, Cercosaura has probably not diversified in the northern Andes, although the phylogenetic position of C. hypnoides from the Andes of Colombia remains unknown. Tree topology and genetic distances support both recognition of C. ocellata bassleri as a distinct species, C. bassleri, and recognition of C. argula and C. oshaughnessyi as two different species. In the interest of promoting clarity and precision regarding the names of clades of gymnophthalmid lizards, we propose a phylogenetic definition of Cercosaura. PMID:26256641

  15. Divergence in morphology, but not habitat use, despite low genetic differentiation among insular populations of the lizard Anolis lemurinus in Honduras

    USGS Publications Warehouse

    Logan, M.L.; Montgomery, Chad E.; Boback, Scott M.; Reed, R.N.; Campbell, J.A.

    2012-01-01

    Studies of recently isolated populations are useful because observed differences can often be attributed to current environmental variation. Two populations of the lizard Anolis lemurinus have been isolated on the islands of Cayo Menor and Cayo Mayor in the Cayos Cochinos Archipelago of Honduras for less than 15 000 y. We measured 12 morphometric and 10 habitat-use variables on 220 lizards across these islands in 2 y, 2008 and 2009. The goals of our study were (1) to explore patterns of sexual dimorphism, and (2) to test the hypothesis that differences in environment among islands may have driven divergence in morphology and habitat use despite genetic homogeneity among populations. Although we found no differences among sexes in habitat use, males had narrower pelvic girdles and longer toe pads on both islands. Between islands, males differed in morphology, but neither males nor females differed in habitat use. Our data suggest that either recent selection has operated differentially on males despite low genetic dill'erentiation, or that they display phenotypic plasticity in response to environmental variation. We suggest that patterns may be driven by variation in intrapopulation density or differences in predator diversity among islands.

  16. A New Eocene Casquehead Lizard (Reptilia, Corytophanidae) from North America.

    PubMed

    Conrad, Jack L

    2015-01-01

    A new fossil showing affinities with extant Laemanctus offers the first clear evidence for a casquehead lizard (Corytophanidae) from the Eocene of North America. Along with Geiseltaliellus from roughly coeval rocks in central Europe, the new find further documents the tropical fauna present during greenhouse conditions in the northern mid-latitudes approximately 50 million years ago (Ma). Modern Corytophanidae is a neotropical clade of iguanian lizards ranging from southern Mexico to northern South America. PMID:26131767

  17. A New Eocene Casquehead Lizard (Reptilia, Corytophanidae) from North America

    PubMed Central

    Conrad, Jack L.

    2015-01-01

    A new fossil showing affinities with extant Laemanctus offers the first clear evidence for a casquehead lizard (Corytophanidae) from the Eocene of North America. Along with Geiseltaliellus from roughly coeval rocks in central Europe, the new find further documents the tropical fauna present during greenhouse conditions in the northern mid-latitudes approximately 50 million years ago (Ma). Modern Corytophanidae is a neotropical clade of iguanian lizards ranging from southern Mexico to northern South America. PMID:26131767

  18. Variation in steroid hormone levels among Caribbean Anolis lizards: endocrine system convergence?

    PubMed

    Husak, Jerry F; Lovern, Matthew B

    2014-04-01

    Variation in aggression among species can be due to a number of proximate and ultimate factors, leading to patterns of divergent and convergent evolution of behavior among even closely related species. Caribbean Anolis lizards are well known for their convergence in microhabitat use and morphology, but they also display marked convergence in social behavior and patterns of aggression. We studied 18 Anolis species across six ecomorphs on four different Caribbean islands to test four main hypotheses. We hypothesized that species differences in aggression would be due to species differences in circulating testosterone (T), a steroid hormone implicated in numerous studies across vertebrate taxa as a primary determinant of social behavior; more aggressive species were expected to have higher baseline concentrations of T and corticosterone. We further hypothesized that low-T species would increase T and corticosterone levels during a social challenge. Within three of the four island assemblages studied we found differences in T levels among species within an island that differ in aggression, but in the opposite pattern than predicted: more aggressive species had lower baseline T than the least aggressive species. The fourth island, Puerto Rico, showed the pattern of baseline T levels among species we predicted. There were no patterns of corticosterone levels among species or ecomorphs. One of the two species tested increased T in response to a social challenge, but neither species elevated corticosterone. Our results suggest that it is possible for similarities in aggression among closely related species to evolve via different proximate mechanisms. PMID:24662425

  19. Postseismic gravity change after the 2006-2007 great earthquake doublet and constraints on the asthenosphere structure in the central Kuril Islands

    NASA Astrophysics Data System (ADS)

    Han, Shin-Chan; Sauber, Jeanne; Pollitz, Fred

    2016-04-01

    Large earthquakes often trigger viscoelastic adjustment for years to decades depending on the rheological properties and the nature and spatial extent of coseismic stress. The 2006 Mw8.3 thrust and 2007 Mw8.1 normal fault earthquakes of the central Kuril Islands resulted in significant postseismic gravity change in Gravity Recovery and Climate Experiment (GRACE) but without a discernible coseismic gravity change. The gravity increase of ~4 μGal, observed consistently from various GRACE solutions around the epicentral area during 2007-2015, is interpreted as resulting from gradual seafloor uplift by ~6 cm produced by postseismic relaxation. The GRACE data are best fit with a model of 25-35 km for the elastic thickness and ~1018 Pa s for the Maxwell viscosity of the asthenosphere. The large measurable postseismic gravity change (greater than coseismic change) emphasizes the importance of viscoelastic relaxation in understanding tectonic deformation and fault-locking scenarios in the Kuril subduction zone.

  20. Life-History Patterns of Lizards of the World.

    PubMed

    Mesquita, Daniel O; Costa, Gabriel C; Colli, Guarino R; Costa, Taís B; Shepard, Donald B; Vitt, Laurie J; Pianka, Eric R

    2016-06-01

    Identification of mechanisms that promote variation in life-history traits is critical to understand the evolution of divergent reproductive strategies. Here we compiled a large life-history data set (674 lizard populations, representing 297 species from 263 sites globally) to test a number of hypotheses regarding the evolution of life-history traits in lizards. We found significant phylogenetic signal in most life-history traits, although phylogenetic signal was not particularly high. Climatic variables influenced the evolution of many traits, with clutch frequency being positively related to precipitation and clutches of tropical lizards being smaller than those of temperate species. This result supports the hypothesis that in tropical and less seasonal climates, many lizards tend to reproduce repeatedly throughout the season, producing smaller clutches during each reproductive episode. Our analysis also supported the hypothesis that viviparity has evolved in lizards as a response to cooler climates. Finally, we also found that variation in trait values explained by clade membership is unevenly distributed among lizard clades, with basal clades and a few younger clades showing the most variation. Our global analyses are largely consistent with life-history theory and previous results based on smaller and scattered data sets, suggesting that these patterns are remarkably consistent across geographic and taxonomic scales. PMID:27172590

  1. Spatial patterns in the abundance of the coastal horned lizard

    USGS Publications Warehouse

    Fisher, R.N.; Suarez, A.V.; Case, T.J.

    2002-01-01

    Coastal horned lizards (Phrynosoma coronatum) have undergone severe declines in southern California and are a candidate species for state and federal listing tender the Endangered Species Act. Quantitative data on their habitat use, abundance, and distribution are lacking, however. We investigated the determinants of abundance for coastal horned lizards at multiple spatial scales throughout southern California. Specifically, we estimated lizard distribution and abundance by establishing 256 pitfall trap arrays clustered within 21 sites across four counties. These arrays were sampled bimonthly for 2-3 years. At each array we measured 26 "local" site descriptors and averaged these values with other "regional" measures to determine site characteristics. Our analyses were successful at identifying factors within and among sites correlated with the presence and abundance of coastal horned lizards. These factors included the absence of the invasive Argentine ant (Linepithema humile) (and presence of native ant species eaten by the lizards), the presence of chaparral community plants, and the presence of sandy substrates. At a regional scale the relative abundance of Argentine ants was correlated with the relative amount of developed edge around a site. There was no evidence for spatial autocorrelation, even at the scale of the arrays within sites, suggesting that the determinants of the presence or absence and abundance of horned lizard can vary over relatively small spatial scales (hundreds of meters). Our results suggest that a gap-type approach may miss some of the fine-scale determinants of species abundance in fragmented habitats.

  2. Ranavirus infections associated with skin lesions in lizards

    PubMed Central

    2013-01-01

    Ranaviral disease in amphibians has been studied intensely during the last decade, as associated mass-mortality events are considered to be a global threat to wild animal populations. Several studies have also included other susceptible ectothermic vertebrates (fish and reptiles), but only very few cases of ranavirus infections in lizards have been previously detected. In this study, we focused on clinically suspicious lizards and tested these animals for the presence of ranaviruses. Virological screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards. PMID:24073785

  3. Ranavirus infections associated with skin lesions in lizards.

    PubMed

    Stöhr, Anke C; Blahak, Silvia; Heckers, Kim O; Wiechert, Jutta; Behncke, Helge; Mathes, Karina; Günther, Pascale; Zwart, Peer; Ball, Inna; Rüschoff, Birgit; Marschang, Rachel E

    2013-01-01

    Ranaviral disease in amphibians has been studied intensely during the last decade, as associated mass-mortality events are considered to be a global threat to wild animal populations. Several studies have also included other susceptible ectothermic vertebrates (fish and reptiles), but only very few cases of ranavirus infections in lizards have been previously detected. In this study, we focused on clinically suspicious lizards and tested these animals for the presence of ranaviruses. Virological screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards. PMID:24073785

  4. Refuge sharing network predicts ectoparasite load in a lizard.

    PubMed

    Leu, Stephan T; Kappeler, Peter M; Bull, C Michael

    2010-09-01

    Living in social groups facilitates cross-infection by parasites. However, empirical studies on indirect transmission within wildlife populations are scarce. We investigated whether asynchronous overnight refuge sharing among neighboring sleepy lizards, Tiliqua rugosa, facilitates indirect transmission of its ectoparasitic tick, Amblyomma limbatum. We fitted 18 neighboring lizards with GPS recorders, observed their overnight refuge use each night over 3 months, and counted their ticks every fortnight. We constructed a transmission network to estimate the cross-infection risk based on asynchronous refuge sharing frequencies among all lizards and the life history traits of the tick. Although self-infection was possible, the network provided a powerful predictor of measured tick loads. Highly connected lizards that frequently used their neighbors' refuges were characterized by higher tick loads. Thus, indirect contact had a major influence on transmission pathways and parasite loads. Furthermore, lizards that used many different refuges had lower cross- and self-infection risks and lower tick loads than individuals that used relatively fewer refuges. Increasing the number of refuges used by a lizard may be an important defense mechanism against ectoparasite transmission in this species. Our study provides important empirical data to further understand how indirectly transmitted parasites move through host populations and influence individual parasite loads. PMID:20802788

  5. Conservation of sex chromosomes in lacertid lizards.

    PubMed

    Rovatsos, Michail; Vukić, Jasna; Altmanová, Marie; Johnson Pokorná, Martina; Moravec, Jiří; Kratochvíl, Lukáš

    2016-07-01

    Sex chromosomes are believed to be stable in endotherms, but young and evolutionary unstable in most ectothermic vertebrates. Within lacertids, the widely radiated lizard group, sex chromosomes have been reported to vary in morphology and heterochromatinization, which may suggest turnovers during the evolution of the group. We compared the partial gene content of the Z-specific part of sex chromosomes across major lineages of lacertids and discovered a strong evolutionary stability of sex chromosomes. We can conclude that the common ancestor of lacertids, living around 70 million years ago (Mya), already had the same highly differentiated sex chromosomes. Molecular data demonstrating an evolutionary conservation of sex chromosomes have also been documented for iguanas and caenophidian snakes. It seems that differences in the evolutionary conservation of sex chromosomes in vertebrates do not reflect the distinction between endotherms and ectotherms, but rather between amniotes and anamniotes, or generally, the differences in the life history of particular lineages. PMID:27037610

  6. Spatial memory: are lizards really deficient?

    PubMed Central

    LaDage, L. D.; Roth, T. C.; Cerjanic, A. M.; Sinervo, B.; Pravosudov, V. V.

    2012-01-01

    In many animals, behaviours such as territoriality, mate guarding, navigation and food acquisition rely heavily on spatial memory abilities; this has been demonstrated in diverse taxa, from invertebrates to mammals. However, spatial memory ability in squamate reptiles has been seen as possible, at best, or non-existent, at worst. Of the few previous studies testing for spatial memory in squamates, some have found no evidence of spatial memory while two studies have found evidence of spatial memory in snakes, but have been criticized based on methodological issues. We used the Barnes maze, a common paradigm to test spatial memory abilities in mammals, to test for spatial memory abilities in the side-blotched lizard (Uta stansburiana). We found the existence of spatial memory in this species using this spatial task. Thus, our study supports the existence of spatial memory in this squamate reptile species and seeks to parsimoniously align this species with the diverse taxa that demonstrate spatial memory ability. PMID:22933038

  7. Predictors of telomere content in dragon lizards

    NASA Astrophysics Data System (ADS)

    Ballen, Cissy; Healey, Mo; Wilson, Mark; Tobler, Michael; Olsson, Mats

    2012-08-01

    Telomeres shorten as a consequence of DNA replication, in particular in cells with low production of telomerase and perhaps in response to physiological stress from exposure to reactive oxygen species, such as superoxide. This process of telomere attrition is countered by innate antioxidation, such as via the production of superoxide dismutase. We studied the inheritance of telomere length in the Australian painted dragon lizard ( Ctenophorus pictus) and the extent to which telomere length covaries with mass-corrected maternal reproductive investment, which reflects the level of circulating yolk precursor and antioxidant, vitellogenin. Our predictors of offspring telomere length explained 72 % of telomere variation (including interstitial telomeres if such are present). Maternal telomere length and reproductive investment were positively influencing offspring telomere length in our analyses, whereas flow cytometry-estimated superoxide level was negatively impacting offspring telomere length. We suggest that the effects of superoxide on hatchling telomere shortening may be partly balanced by transgenerational effects of vitellogenin antioxidation.

  8. Islands in the ice stream: were spawning habitats for native salmonids in the Great Lakes created by paleo-ice streams?

    USGS Publications Warehouse

    Riley, Stephen; Binder, Thomas R.; Tucker, Taaja R.; Menzies, John; Eyles, Nick; Janssen, John; Muir, Andrew M.; Esselman, Peter C.; Wattrus, Nigel J.; Krueger, Charles C.

    2016-01-01

    Lake trout Salvelinus namaycush, lake whitefish Coregonus clupeaformis and cisco Coregonus artedi are salmonid fishes native to the Laurentian Great Lakes that spawn on rocky substrates in the fall and early winter. After comparing the locations of spawning habitat for these species in the main basin of Lake Huron with surficial substrates and the hypothesized locations of fast-flowing Late Wisconsinan paleo-ice streams, we hypothesize that much of the spawning habitat for these species in Lake Huron is the result of deposition and erosion by paleo-ice streams. This hypothesis may represent a new framework for the identification and protection of spawning habitat for these native species, some of which are currently rare or extirpated in some of the Great Lakes. We further suggest that paleo-ice streams may have been responsible for the creation of native salmonid spawning habitat elsewhere in the Great Lakes and in other glaciated landscapes.

  9. Genotoxicity induced by Roundup® (Glyphosate) in tegu lizard (Salvator merianae) embryos.

    PubMed

    Schaumburg, Laura G; Siroski, Pablo A; Poletta, Gisela L; Mudry, Marta D

    2016-06-01

    Environmental contaminants produce multiple adverse consequences at individual, population and ecosystem levels. High volumes of agrochemicals applied to great variety of crops, together with agricultural expansion, generate great concerns due to the impact for the environment and large risk implicated for wildlife. The lack of data on these threats is striking. The tegu lizard (Salvator merianae) is one of the species that live in environments under contaminant effects. Several characteristics allow proposing this species as a potential sentinel organism for the monitoring of pesticides in their habitat. The present study is the first report about genotoxicity in tegu lizard neonates after embryonic exposure to Roundup® (glyphosate 66.2%). The micronucleus test (MN), nuclear abnormalities (NAs) assay and comet assay (CA) were used as biomarkers of genotoxic effects induced in erythrocytes by topical exposure of the eggs to the glyphosate commercial formulation Roundup® (RU), in laboratory controlled conditions. A total of 96 eggs were distributed in six groups exposed to RU (50, 100, 200, 400, 800, 1600μg/egg), one positive control (PC; 200μg cyclophosphamide/egg) and one negative control (NC; distilled water). No teratogenic effects were observed in any of the exposed or control neonates. A significant increase in DNA damage was observed in all concentrations higher than 100μg/egg with respect to NC (p<0.05). However, no statistical differences were found in the frequencies of MN and NAs in any group exposed to RU compared to the NC. No statistically significant differences were found in the size of the lizards at birth or after six months post-exposure (p>0.05). Our results provide new information about the undesirable effects of the glyphosate-based herbicide formulations RU on this lizard species that inhabits areas permanently exposed to several pesticide formulations. We consider of utmost necessity a strict regulation of the agrochemical application

  10. Contrasting Selective Pressures on Seed Traits of Two Congeneric Species by Their Main Native Guilds of Dispersers on Islands

    PubMed Central

    Nogales, Manuel; González-Castro, Aarón; Marrero, Patricia; Bonnaud, Elsa; Traveset, Anna

    2013-01-01

    Many fleshy-fruited plants from the Mediterranean and Macaronesian islands are dispersed through endozoochory. In mainland Mediterranean areas, reciprocal adaptations have been found between plants and animals, although evidence is scarce. On small isolated oceanic islands, such reciprocal adaptations might well be more prevalent due to intrinsic island traits. Here we evaluate the existence of selective pressures exerted by two different disperser guilds (lizards and birds) on two seed traits (seed coat thickness and seed germination pattern) of two congeneric species present on Mediterranean and Macaronesian islands. In the continental Balearic Islands, Rubia peregrina has evolved mostly with birds, although frugivorous lizards are present in some of these islands and are known to eventually consume its fruits. By contrast, R. fruticosa, endemic to the Macaronesian archipelago, has evolved mostly interacting with lizards and only recently with birds. We hypothesized that R. fruticosa would be especially adapted to saurochory, with thicker seed coats and higher germination proportion, whereas R. peregrina would be more adapted to ornithocory, with thinner seed coats and showing a lower germination percentage after being ingested by lizards. Captivity experiments of seed ingestions by natural and non-natural dispersers (i.e., frugivores that have not evolved with those plants) were conducted. Results suggest that dispersers did not exert any strong enough selective pressure to induce changes in germination patterns. We attribute this to the fact that the Rubiaceae is an ancestral family in the Mediterranean (both on continent and islands) and thus probably interacted with lizards in the past. Lastly, although we hold that the seed coat structure of R. fruticosa is probably associated with its evolutionary success after a long interaction with insular lizards, our findings support the idea that the relationship between endozoochorous plants and the guild of

  11. 15. Photo copy of drawing, July 24, 1916. GREAT CAPTAIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Photo copy of drawing, July 24, 1916. GREAT CAPTAIN ISLAND LIGHT STATION. (Northwest and northeast elevations and basement floor plan). Drawing No. 5912, United States Coast Guard Civil Engineering Unit, Metro Center Boulevard, Warwick, RI - Great Captain Island Light, Great Captain Island, Greenwich, Fairfield County, CT

  12. 14. Photo copy of historic photograph, ca. 1964. GREAT CAPTAIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Photo copy of historic photograph, ca. 1964. GREAT CAPTAIN ISLAND LIGHTHOUSE, FOG SIGNAL BUILDING, AND OIL HOUSE, AND DOCK. United States Coast Guard Civil Engineering Unit, Metro Center Boulevard, Warwick, RI - Great Captain Island Light, Great Captain Island, Greenwich, Fairfield County, CT

  13. 16. Photo copy of drawing, May 19, 1934. GREAT CAPTAIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Photo copy of drawing, May 19, 1934. GREAT CAPTAIN ISLAND LIGHT STATION; ARRANGEMENT OF PIPING & MACHINERY FOR FOG SIGNAL INSTALLATION. Drawing No. 8075, United States Coast Guard Civil Engineering Unit, Metro Center Boulevard, Warwick, RI - Great Captain Island Light, Great Captain Island, Greenwich, Fairfield County, CT

  14. Lizard and Frog Prestin: Evolutionary Insight into Functional Changes

    PubMed Central

    Tang, Jie; Pecka, Jason L.; Fritzsch, Bernd

    2013-01-01

    The plasma membrane of mammalian cochlear outer hair cells contains prestin, a unique motor protein. Prestin is the fifth member of the solute carrier protein 26A family. Orthologs of prestin are also found in the ear of non-mammalian vertebrates such as zebrafish and chicken. However, these orthologs are electrogenic anion exchangers/transporters with no motor function. Amphibian and reptilian lineages represent phylogenic branches in the evolution of tetrapods and subsequent amniotes. Comparison of the peptide sequences and functional properties of these prestin orthologs offer new insights into prestin evolution. With the recent availability of the lizard and frog genome sequences, we examined amino acid sequence and function of lizard and frog prestins to determine how they are functionally and structurally different from prestins of mammals and other non-mammals. Somatic motility, voltage-dependent nonlinear capacitance (NLC), the two hallmarks of prestin function, and transport capability were measured in transfected human embryonic kidney cells using voltage-clamp and radioisotope techniques. We demonstrated that while the transport capability of lizard and frog prestin was compatible to that of chicken prestin, the NLC of lizard prestin was more robust than that of chicken’s and was close to that of platypus. However, unlike platypus prestin which has acquired motor capability, lizard or frog prestin did not demonstrate motor capability. Lizard and frog prestins do not possess the same 11-amino-acid motif that is likely the structural adaptation for motor function in mammals. Thus, lizard and frog prestins appear to be functionally more advanced than that of chicken prestin, although motor capability is not yet acquired. PMID:23342145

  15. Prey capture kinematics of ant-eating lizards.

    PubMed

    Meyers, Jay J; Herrel, Anthony

    2005-01-01

    While morphological and behavioral feeding specializations are obvious in many vertebrate groups, among lizards there appear to be few dietary specialists. By comparing the prey capture kinematics and overall feeding behavior in two highly specialized ant-eating lizards (Moloch horridus and Phrynosoma platyrhinos) with those of two closely related dietary generalists (Pogona vitticeps and Uma notata), we investigate whether dietary specialization has been accompanied by changes in the function and use of the feeding system. We quantified kinematic variables from high-speed video recordings (200-250 frames s(-1)) of each species feeding on ants. Prey capture was strikingly different in M. horridus to that of other species, being characterized by a suite of unusual behaviors including the lack of a body lunge, faster tongue protrusion, reduced prey processing and, most notably, the ability to modulate the slow open phase of the gape cycle. In concert, these traits make a single feeding event in M. horridus faster than that in any other iguanian lizard studied to date. Prey capture behavior in P. platyrhinos is kinematically more similar to U. notata and P. vitticeps than to M. horridus, but the ant specialists are similar in that both lack distinct prey processing behaviors, resulting in faster overall capture and feeding events. While ant feeding in P. vitticeps is faster than feeding on other prey, the duration of a single feeding event is still four times longer than in either ant specialist, because of extensive prey processing. Additionally, a phylogenetic comparison of ant specialist lizards with dietary generalists revealed that ant-eating lizards require significantly less time to capture and process prey. Thus there are not only significant behavioral modifications in these ant-eating lizards, but also multiple strategies among specialists, suggesting differing selective pressures or phylogenetic constraints in the evolution of ant eating in lizards. PMID

  16. Lizard and frog prestin: evolutionary insight into functional changes.

    PubMed

    Tang, Jie; Pecka, Jason L; Fritzsch, Bernd; Beisel, Kirk W; He, David Z Z

    2013-01-01

    The plasma membrane of mammalian cochlear outer hair cells contains prestin, a unique motor protein. Prestin is the fifth member of the solute carrier protein 26A family. Orthologs of prestin are also found in the ear of non-mammalian vertebrates such as zebrafish and chicken. However, these orthologs are electrogenic anion exchangers/transporters with no motor function. Amphibian and reptilian lineages represent phylogenic branches in the evolution of tetrapods and subsequent amniotes. Comparison of the peptide sequences and functional properties of these prestin orthologs offer new insights into prestin evolution. With the recent availability of the lizard and frog genome sequences, we examined amino acid sequence and function of lizard and frog prestins to determine how they are functionally and structurally different from prestins of mammals and other non-mammals. Somatic motility, voltage-dependent nonlinear capacitance (NLC), the two hallmarks of prestin function, and transport capability were measured in transfected human embryonic kidney cells using voltage-clamp and radioisotope techniques. We demonstrated that while the transport capability of lizard and frog prestin was compatible to that of chicken prestin, the NLC of lizard prestin was more robust than that of chicken's and was close to that of platypus. However, unlike platypus prestin which has acquired motor capability, lizard or frog prestin did not demonstrate motor capability. Lizard and frog prestins do not possess the same 11-amino-acid motif that is likely the structural adaptation for motor function in mammals. Thus, lizard and frog prestins appear to be functionally more advanced than that of chicken prestin, although motor capability is not yet acquired. PMID:23342145

  17. The Ins & Outs of Developing a Field-Based Science Project: Learning by Lassoing Lizards

    ERIC Educational Resources Information Center

    Matthews, Catherine E.; Huffling, Lacey D.; Benavides, Aerin

    2014-01-01

    We describe a field-based lizard project we did with high school students as a part of our summer Herpetological Research Experiences. We describe data collection on lizards captured, identified, and marked as a part of our mark-recapture study. We also describe other lizard projects that are ongoing in the United States and provide resources for…

  18. Artificial Water Point for Livestock Influences Spatial Ecology of a Native Lizard Species

    PubMed Central

    Leu, Stephan T.; Bull, C. Michael

    2016-01-01

    Pastoralism is a major agricultural activity in drier environments, and can directly and indirectly impact native species in those areas. We investigated how the supply of an artificial watering point to support grazing livestock affected movement and activity patterns of the Australian sleepy lizard (Tiliqua rugosa) during a drought year. We observed 23 adult lizards; six had access to a dam, whereas 17 lizards did not. Lizards with access to the dam had larger home ranges, were substantially active on more days (days with >100 steps), and moved more steps per day compared to lizards that did not have access to the dam, both during the early and late period of our observation. Furthermore, while the two groups of lizards had similar body condition early in the season, they differed later in the season. Lizards with dam access retained, whereas lizards without access lost body condition. Local heterogeneity in access to an artificial water resource resulted in spatially dependent behavioural variation among sleepy lizard individuals. This suggests that sleepy lizards have flexible responses to changing climatic conditions, depending on the availability of water. Furthermore, while reducing activity appears a suitable short term strategy, if harsh conditions persist, then access to dams could be of substantial benefit and could support sustained lizard activity and movement and allow maintenance of body condition. Hence, artificial watering points, such as the dams constructed by pastoralists, may provide local higher quality refugia for sleepy lizards and other species during drought conditions. PMID:26800274

  19. Artificial Water Point for Livestock Influences Spatial Ecology of a Native Lizard Species.

    PubMed

    Leu, Stephan T; Bull, C Michael

    2016-01-01

    Pastoralism is a major agricultural activity in drier environments, and can directly and indirectly impact native species in those areas. We investigated how the supply of an artificial watering point to support grazing livestock affected movement and activity patterns of the Australian sleepy lizard (Tiliqua rugosa) during a drought year. We observed 23 adult lizards; six had access to a dam, whereas 17 lizards did not. Lizards with access to the dam had larger home ranges, were substantially active on more days (days with >100 steps), and moved more steps per day compared to lizards that did not have access to the dam, both during the early and late period of our observation. Furthermore, while the two groups of lizards had similar body condition early in the season, they differed later in the season. Lizards with dam access retained, whereas lizards without access lost body condition. Local heterogeneity in access to an artificial water resource resulted in spatially dependent behavioural variation among sleepy lizard individuals. This suggests that sleepy lizards have flexible responses to changing climatic conditions, depending on the availability of water. Furthermore, while reducing activity appears a suitable short term strategy, if harsh conditions persist, then access to dams could be of substantial benefit and could support sustained lizard activity and movement and allow maintenance of body condition. Hence, artificial watering points, such as the dams constructed by pastoralists, may provide local higher quality refugia for sleepy lizards and other species during drought conditions. PMID:26800274

  20. Bone indicators of grasping hands in lizards

    PubMed Central

    2016-01-01

    Grasping is one of a few adaptive mechanisms that, in conjunction with clinging, hooking, arm swinging, adhering, and flying, allowed for incursion into the arboreal eco-space. Little research has been done that addresses grasping as an enhanced manual ability in non-mammalian tetrapods, with the exception of studies comparing the anatomy of muscle and tendon structure. Previous studies showed that grasping abilities allow exploitation for narrow branch habitats and that this adaptation has clear osteological consequences. The objective of this work is to ascertain the existence of morphometric descriptors in the hand skeleton of lizards related to grasping functionality. A morphological matrix was constructed using 51 morphometric variables in 278 specimens, from 24 genera and 13 families of Squamata. To reduce the dimensions of the dataset and to organize the original variables into a simpler system, three PCAs (Principal Component Analyses) were performed using the subsets of (1) carpal variables, (2) metacarpal variables, and (3) phalanges variables. The variables that demonstrated the most significant contributions to the construction of the PCA synthetic variables were then used in subsequent analyses. To explore which morphological variables better explain the variations in the functional setting, we ran Generalized Linear Models for the three different sets. This method allows us to model the morphology that enables a particular functional trait. Grasping was considered the only response variable, taking the value of 0 or 1, while the original variables retained by the PCAs were considered predictor variables. Our analyses yielded six variables associated with grasping abilities: two belong to the carpal bones, two belong to the metacarpals and two belong to the phalanges. Grasping in lizards can be performed with hands exhibiting at least two different independently originated combinations of bones. The first is a combination of a highly elongated centrale

  1. Tail loss and thermoregulation in the common lizard Zootoca vivipara

    NASA Astrophysics Data System (ADS)

    Herczeg, Gábor; Kovács, Tibor; Tóth, Tamás; Török, János; Korsós, Zoltán; Merilä, Juha

    2004-10-01

    Tail autotomy in lizards is an adaptive strategy that has evolved to reduce the risk of predation. Since tail loss reduces body mass and moving ability—which in turn are expected to influence thermal balance—there is potential for a trade-off between tail autotomy and thermoregulation. To test this hypothesis, we studied a common lizard (Zootoca vivipara) population at high latitude, inhabiting a high-cost thermal environment. Z. vivipara is a small, non-territorial lizard known as a very accurate thermoregulator. We made two predictions: (1) the reduced body weight due to tail loss results in faster heating rate (a benefit), and (2) the reduction in locomotor ability after tail loss induces a shift to the use of thermally poorer microhabitats (a cost), thus decreasing the field body temperatures of active lizards. We did not find any effect of tail loss on heating rate in laboratory experiments conducted under different thermal conditions. Likewise, no significant relationship between tail condition and field body temperatures, or between tail condition and thermal microhabitat use, were detected. Thus, our results suggest that tail autotomy does not influence the accuracy of thermoregulation in small-bodied lizards.

  2. Effects of feral cats on the evolution of anti-predator behaviours in island reptiles: insights from an ancient introduction.

    PubMed

    Li, Binbin; Belasen, Anat; Pafilis, Panayiotis; Bednekoff, Peter; Foufopoulos, Johannes

    2014-08-01

    Exotic predators have driven the extinction of many island species. We examined impacts of feral cats on the abundance and anti-predator behaviours of Aegean wall lizards in the Cyclades (Greece), where cats were introduced thousands of years ago. We compared populations with high and low cat density on Naxos Island and populations on surrounding islets with no cats. Cats reduced wall lizard populations by half. Lizards facing greater risk from cats stayed closer to refuges, were more likely to shed their tails in a standardized assay, and fled at greater distances when approached by either a person in the field or a mounted cat decoy in the laboratory. All populations showed phenotypic plasticity in flight initiation distance, suggesting that this feature is ancient and could have helped wall lizards survive the initial introduction of cats to the region. Lizards from islets sought shelter less frequently and often initially approached the cat decoy. These differences reflect changes since islet isolation and could render islet lizards strongly susceptible to cat predation. PMID:24943365

  3. Effects of feral cats on the evolution of anti-predator behaviours in island reptiles: insights from an ancient introduction

    PubMed Central

    Li, Binbin; Belasen, Anat; Pafilis, Panayiotis; Bednekoff, Peter; Foufopoulos, Johannes

    2014-01-01

    Exotic predators have driven the extinction of many island species. We examined impacts of feral cats on the abundance and anti-predator behaviours of Aegean wall lizards in the Cyclades (Greece), where cats were introduced thousands of years ago. We compared populations with high and low cat density on Naxos Island and populations on surrounding islets with no cats. Cats reduced wall lizard populations by half. Lizards facing greater risk from cats stayed closer to refuges, were more likely to shed their tails in a standardized assay, and fled at greater distances when approached by either a person in the field or a mounted cat decoy in the laboratory. All populations showed phenotypic plasticity in flight initiation distance, suggesting that this feature is ancient and could have helped wall lizards survive the initial introduction of cats to the region. Lizards from islets sought shelter less frequently and often initially approached the cat decoy. These differences reflect changes since islet isolation and could render islet lizards strongly susceptible to cat predation. PMID:24943365

  4. Dynamics of seasonal outbreaks of black band disease in an assemblage of Montipora species at Pelorus Island (Great Barrier Reef, Australia).

    PubMed

    Sato, Yui; Bourne, David G; Willis, Bette L

    2009-08-01

    Recurring summer outbreaks of black band disease (BBD) on an inshore reef in the central Great Barrier Reef (GBR) constitute the first recorded BBD epizootic in the region. In a 2.7 year study of 485 colonies of Montipora species, BBD affected up to 10 per cent of colonies in the assemblage. Mean maximum abundance of BBD reached 16+/-6 colonies per 100 m(2) (n=3 quadrats, each 100 m(2)) in summer, and decreased to 0-1 colony per 100 m(2) in winter. On average, BBD lesions caused 40 per cent tissue loss and 5 per cent of infections led to whole colony mortality. BBD reappearance on previously infected colonies and continuous tissue loss after the BBD signs had disappeared suggest that the disease impacts are of longer duration than indicated by the presence of characteristic signs. Rates of new infections and linear progression of lesions were both positively correlated with seasonal fluctuations in sea water temperatures and light, suggesting that seasonal increases in these environmental parameters promote virulence of the disease. Overall, the impacts of BBD are greater than previously reported on the GBR and likely to escalate with ocean warming. PMID:19419991

  5. Discovery of a Giant Chameleon-Like Lizard (Anolis) on Hispaniola and Its Significance to Understanding Replicated Adaptive Radiations.

    PubMed

    Mahler, D Luke; Lambert, Shea M; Geneva, Anthony J; Ng, Julienne; Hedges, S Blair; Losos, Jonathan B; Glor, Richard E

    2016-09-01

    We report a new chameleon-like Anolis species from Hispaniola that is ecomorphologically similar to congeners found only on Cuba. Lizards from both clades possess short limbs and a short tail and utilize relatively narrow perches, leading us to recognize a novel example of ecomorphological matching among islands in the well-known Greater Antillean anole radiation. This discovery supports the hypothesis that the assembly of island faunas can be substantially deterministic and highlights the continued potential for basic discovery to reveal new insights in well-studied groups. Restricted to a threatened band of midelevation transitional forest near the border of the Dominican Republic and Haiti, this new species appears to be highly endangered. PMID:27501092

  6. Seasonal reproductive endothermy in tegu lizards

    PubMed Central

    Tattersall, Glenn J.; Leite, Cleo A. C.; Sanders, Colin E.; Cadena, Viviana; Andrade, Denis V.; Abe, Augusto S.; Milsom, William K.

    2016-01-01

    With some notable exceptions, small ectothermic vertebrates are incapable of endogenously sustaining a body temperature substantially above ambient temperature. This view was challenged by our observations of nighttime body temperatures sustained well above ambient (up to 10°C) during the reproductive season in tegu lizards (~2 kg). This led us to hypothesize that tegus have an enhanced capacity to augment heat production and heat conservation. Increased metabolic rates and decreased thermal conductance are the same mechanisms involved in body temperature regulation in those vertebrates traditionally acknowledged as “true endotherms”: the birds and mammals. The appreciation that a modern ectotherm the size of the earliest mammals can sustain an elevated body temperature through metabolic rates approaching that of endotherms enlightens the debate over endothermy origins, providing support for the parental care model of endothermy, but not for the assimilation capacity model of endothermy. It also indicates that, contrary to prevailing notions, ectotherms can engage in facultative endothermy, providing a physiological analog in the evolutionary transition to true endothermy. PMID:26844295

  7. Interactions between a lizard and its thermal environment: implications for sprint performance and space utilization in the lizard Uta stansburiana

    SciTech Connect

    Waldschmidt, S.; Tracy, C.R.

    1983-06-01

    At the end of their breeding season, male side-blotched lizards, Uta stansburiana from western Colorado decreased their home range to a size not different from that of females. Both males and females showed a high degree of overlap in home ranges, not found in populations previously studied in Texas. Uta's sprint speed was dependent on body temperature, with maximum sprint speed occurring at body temperatures between 35/sup 0/C and 38/sup 0/C, with lower speeds at higher and lower temperatures. An energy budget model was used to predict the range of body temperatures (and thus sprint speeds) available to lizards in four microhabitats within each animal's home range. Predicted body temperatures were converted to a space-time index. The distribution of the space-time index in each microhabitat was used to predict the spatial and temporal distributions of lizards. Predicted distributions accurately reflected the measured distributions of lizards in the morning and late afternoon, but did not reflect the measured distributions during midday. These inconsistencies are thought to be the result of lizard responses to other temperature-dependent processes, such as evaporite water loss.

  8. Differences in demographic traits of four butterflyfish species between two reefs of the Great Barrier Reef separated by 1,200 km

    NASA Astrophysics Data System (ADS)

    Berumen, M. L.; Trip, E. D. L.; Pratchett, M. S.; Choat, J. H.

    2012-03-01

    Many species demonstrate variation in life history attributes in response to gradients in environmental conditions. For fishes, major drivers of life history variation are changes in temperature and food availability. This study examined large-scale variation in the demography of four species of butterflyfishes ( Chaetodon citrinellus, Chaetodon lunulatus, Chaetodon melannotus, and Chaetodon trifascialis) between two locations on Australia's Great Barrier Reef (Lizard Island and One Tree Island, separated by approximately 1,200 km). Variation in age-based demographic parameters was assessed using the re-parameterised von Bertalanffy growth function. All species displayed measurable differences in body size between locations, with individuals achieving a larger adult size at the higher latitude site (One Tree Island) for three of the four species examined. Resources and abundances of the study species were also measured, revealing some significant differences between locations. For example, for C. trifascialis, there was no difference in its preferred resource or in abundance between locations, yet it achieved a larger body size at the higher latitude location, suggesting a response to temperature. For some species, resources and abundances did vary between locations, limiting the ability to distinguish between a demographic response to temperature as opposed to a response to food or competition. Future studies of life histories and demographics at large spatial scales will need to consider the potentially confounding roles of temperature, resource usage and availability, and abundance/competition to disentangle the effects of these environmental variables.

  9. Embryonic development of the skull of the Andean lizard Ptychoglossus bicolor (Squamata, Gymnophthalmidae)

    PubMed Central

    Hernández-Jaimes, Carlos; Jerez, Adriana; Ramírez-Pinilla, Martha Patricia

    2012-01-01

    The study of cranial design and development in Gymnophthalmidae is important to understand the ontogenetic processes behind the morphological diversity of the group and to examine the possible effects of microhabitat use and other ecological parameters, as well as phylogenetic constraints, on skull anatomy. Complete morphological descriptions of embryonic skull development within Gymnophthalmidae are non-existent. Likewise, very little is known about the complete chondrocranium of the family. Herein, the development of the skull of the semi-fossorial lizard Ptychoglossus bicolor is described along with an examination of the chondrocranium of other gymnophthalmid taxa and the teiid Cnemidophorus lemniscatus. Cranial chondrification begins with early condensations in the ethmoid, orbitotemporal and occipital regions of the chondrocranium as well as the viscerocranium. Ossification of the skull starts with elements of the dermatocranium (pterygoid, prefrontal, maxilla and jugal). The orbitosphenoid is the last chondral bone to appear. At birth, the skull is almost completely ossified and exhibits a large frontoparietal fontanelle. In general terms, the chondrocranium of the gymnophthalmids studied is characteristic of lacertiform terrestrial lizards, in spite of their life habits, and resembles the chondrocranium of C. lemniscatus in many aspects. However, the gymnophthalmids show great variation in the orbitosphenoid and a complex nasal capsule. The latter exhibits greater development of some nasal cartilages, which make it more complex than in C. lemniscatus. These characteristics might be related to microhabitat use and the well-developed olfactory and vomeronasal systems observed within this clade. PMID:22881276

  10. Limited overwater dispersal and genetic differentiation of the snake-eyed skink (Cryptoblepharus nigropunctatus) in the Oceanic Ogasawara Islands, Japan.

    PubMed

    Hayashi, Fumio; Shima, Akina; Horikoshi, Kazuo; Kawakami, Kazuto; Segawa, Ryoko D; Aotsuka, Tadashi; Suzuki, Tadashi

    2009-08-01

    The genetic differentiation and speciation of lizards on oceanic islands may be affected by their rate of overwater dispersal. Cryptoblepharus is one of the most geographically widespread scincid lizards throughout the Indo-Pacific and Australian regions. Cryptoblepharus nigropunctatus is the northernmost species of the genus, dwelling on several small Pacific islands. To examine the colonization history of this lizard, mitochondrial 16S rDNA and D-loop sequences were compared among populations of the Ogasawara Islands consisting of four island groups (the Muko-jima, Chichi-jima, Haha-jima, and Kazan groups), and an isolated island, Minamitori-shima (Marcus Island). These four groups and Minamitori-shima have not been connected to each other because each is surrounded by deep sea (>100 m). DNA analyses showed that the lizard populations on individual islands had each representative haplotypes. The ancestors of C. nigropunctatus probably arrived on the islands from the southern Pacific Ocean via wave dispersal and differentiated to produce the present state. They appear to have dispersed from their origin along two independent pathways: one between Kitaiwo-to (Kazan group) and the Muko-jima and Chichi-jima groups, and the other among the Minamitori-shima, Minamiiwo-to (Kazan group), and Haha-jima groups. Limited long-distance overwater dispersal may be responsible for the genetic structure of the C. nigropunctatus populations on these oceanic islands. However, among the small islands within the same island group, D-loop haplotypes were shared and the local genetic diversity was usually high, suggesting frequent gene flow across the same group of islands. PMID:19719406

  11. Tail-assisted pitch control in lizards, robots and dinosaurs.

    PubMed

    Libby, Thomas; Moore, Talia Y; Chang-Siu, Evan; Li, Deborah; Cohen, Daniel J; Jusufi, Ardian; Full, Robert J

    2012-01-12

    In 1969, a palaeontologist proposed that theropod dinosaurs used their tails as dynamic stabilizers during rapid or irregular movements, contributing to their depiction as active and agile predators. Since then the inertia of swinging appendages has been implicated in stabilizing human walking, aiding acrobatic manoeuvres by primates and rodents, and enabling cats to balance on branches. Recent studies on geckos suggest that active tail stabilization occurs during climbing, righting and gliding. By contrast, studies on the effect of lizard tail loss show evidence of a decrease, an increase or no change in performance. Application of a control-theoretic framework could advance our general understanding of inertial appendage use in locomotion. Here we report that lizards control the swing of their tails in a measured manner to redirect angular momentum from their bodies to their tails, stabilizing body attitude in the sagittal plane. We video-recorded Red-Headed Agama lizards (Agama agama) leaping towards a vertical surface by first vaulting onto an obstacle with variable traction to induce a range of perturbations in body angular momentum. To examine a known controlled tail response, we built a lizard-sized robot with an active tail that used sensory feedback to stabilize pitch as it drove off a ramp. Our dynamics model revealed that a body swinging its tail experienced less rotation than a body with a rigid tail, a passively compliant tail or no tail. To compare a range of tails, we calculated tail effectiveness as the amount of tailless body rotation a tail could stabilize. A model Velociraptor mongoliensis supported the initial tail stabilization hypothesis, showing as it did a greater tail effectiveness than the Agama lizards. Leaping lizards show that inertial control of body attitude can advance our understanding of appendage evolution and provide biological inspiration for the next generation of manoeuvrable search-and-rescue robots. PMID:22217942

  12. Earliest Example of a Giant Monitor Lizard (Varanus, Varanidae, Squamata)

    PubMed Central

    Conrad, Jack L.; Balcarcel, Ana M.; Mehling, Carl M.

    2012-01-01

    Background Varanidae is a clade of tiny (<20 mm pre-caudal length [PCL]) to giant (>600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. Methodology/Principal Findings A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. Conclusions/Significance The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors. PMID:22900001

  13. The effects of prey species on food conversion efficiency and growth of an insectivorous lizard.

    PubMed

    Rich, C Nelson; Talent, Larry G

    2008-05-01

    Little is known about the effects of different prey species on lizard growth. We conducted a 6-week study to determine the relative effects of prey species on growth parameters of hatchling western fence lizards, Sceloporus occidentalis. Lizards were fed house cricket nymphs, Acheta domesticus, or mealworm larvae, Tenebrio molitor. The effects of prey species on growth were determined by measuring prey consumption, gross conversion efficiency of food [gain in mass (g)/food consumed (g)], gain in mass, and gain in snout-vent length. Lizards grew well on both the prey species. However, lizards that fed on crickets consumed a significantly higher percentage of their body mass per day than those fed mealworms. Nevertheless, lizards that consumed mealworms ingested significantly more metabolizable energy, had significantly higher food conversion efficiencies, significantly higher daily gains in mass, and significantly greater total growth in mass than lizards that fed on crickets. PMID:19360616

  14. Australia's Great Barrier Reef

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Great Barrier Reef extends for 2,000 kilometers along the northeastern coast of Australia. It is not a single reef, but a vast maze of reefs, passages, and coral cays (islands that are part of the reef). This nadir true-color image was acquired by the MISR instrument on August 26, 2000 (Terra orbit 3679), and shows part of the southern portion of the reef adjacent to the central Queensland coast. The width of the MISR swath is approximately 380 kilometers, with the reef clearly visible up to approximately 200 kilometers from the coast. It may be difficult to see the myriad details in the browse image, but if you retrieve the higher resolution version, a zoomed display reveals the spectacular structure of the many reefs.

    The more northerly coastal area in this image shows the vast extent of sugar cane cultivation, this being the largest sugar producing area in Australia, centered on the city of Mackay. Other industries in the area include coal, cattle, dairying, timber, grain, seafood, and fruit. The large island off the most northerly part of the coast visible in this image is Whitsunday Island, with smaller islands and reefs extending southeast, parallel to the coast. These include some of the better known resort islands such as Hayman, Lindeman, Hamilton, and Brampton Islands.

    Further south, just inland of the small semicircular bay near the right of the image, is Rockhampton, the largest city along the central Queensland coast, and the regional center for much of central Queensland. Rockhampton is just north of the Tropic of Capricorn. Its hinterland is a rich pastoral, agricultural, and mining region.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  15. Rapid change in the thermal tolerance of a tropical lizard.

    PubMed

    Leal, Manuel; Gunderson, Alex R

    2012-12-01

    The predominant view is that the thermal physiology of tropical ectotherms, including lizards, is not labile over ecological timescales. We used the recent introduction (∼35 years ago) of the Puerto Rican lizard Anolis cristatellus to Miami, Florida, to test this thermal rigidity hypothesis. We measured lower (critical thermal minimum [CT(min)]) and upper (critical thermal maximum [CT(max)]) thermal tolerances and found that the introduced population tolerates significantly colder temperatures (by ∼3°C) than does the Puerto Rican source population; however, CT(max) did not differ. These results mirror the thermal regimes experienced by each population: Miami reaches colder ambient temperatures than Puerto Rico, but maximum ambient temperatures are similar. The differences in CT(min) were observed even though lizards from both sites experienced nearly identical conditions for 49 days before CT(min) measurement. Our results demonstrate that changes in thermal tolerance occurred relatively rapidly (∼35 generations), which strongly suggests that the thermal physiology of tropical lizards is more labile than previously proposed. PMID:23149405

  16. Technique for Measuring Speed and Visual Motion Sensitivity in Lizards

    ERIC Educational Resources Information Center

    Woo, Kevin L.; Burke, Darren

    2008-01-01

    Testing sensory characteristics on herpetological species has been difficult due to a range of properties related to physiology, responsiveness, performance ability, and the type of reinforcer used. Using the Jacky lizard as a model, we outline a successfully established procedure in which to test the visual sensitivity to motion characteristics.…

  17. Structure and function of the hearts of lizards and snakes.

    PubMed

    Jensen, Bjarke; Moorman, Antoon F M; Wang, Tobias

    2014-05-01

    With approximately 7000 species, snakes and lizards, collectively known as squamates, are by far the most species-rich group of reptiles. It was from reptile-like ancestors that mammals and birds evolved and squamates can be viewed as phylogenetically positioned between them and fishes. Hence, their hearts have been studied for more than a century yielding insights into the group itself and into the independent evolution of the fully divided four-chambered hearts of mammals and birds. Structurally the heart is complex and debates persist on rudimentary issues such as identifying structures critical to understanding ventricle function. In seeking to resolve these controversies we have generated three-dimensional (3D) models in portable digital format (pdf) of the anaconda and anole lizard hearts ('typical' squamate hearts) and the uniquely specialized python heart with comprehensive annotations of structures and cavities. We review the anatomy and physiology of squamate hearts in general and emphasize the unique features of pythonid and varanid lizard hearts that endow them with mammal-like blood pressures. Excluding pythons and varanid lizards it is concluded that the squamate heart has a highly consistent design including a disproportionately large right side (systemic venous) probably due to prevailing pulmonary bypass (intraventricular shunting). Unfortunately, investigations on rudimentary features are sparse. We therefore point out gaps in our knowledge, such as the size and functional importance of the coronary vasculature and of the first cardiac chamber, the sinus venosus, and highlight areas with implications for vertebrate cardiac evolution. PMID:23998743

  18. Convergent evolution of kin-based sociality in a lizard

    PubMed Central

    Davis, Alison R.; Corl, Ammon; Surget-Groba, Yann; Sinervo, Barry

    2011-01-01

    Studies of social birds and mammals have produced extensive theory regarding the formation and dynamics of kin-based social groups in vertebrates. However, comparing kin dynamics in birds and mammals to social reptiles provides the opportunity to identify selective factors that promote independent origins of kin sociality across vertebrates. We combined a 5-year mark-recapture study with a DNA microsatellite analysis of relatedness in a social lizard (Xantusia vigilis) to examine the formation and stability of kin groups. We found that these lizards are highly sedentary and that groups often form through the delayed dispersal of offspring. Groups containing juveniles had higher relatedness than adult-only groups, as juveniles were commonly found in aggregations with at least one parent and/or sibling. Groups containing nuclear family members were more stable than groups of less-related lizards, as predicted by social theory. We conclude that X. vigilis aggregations conform to patterns of kin sociality observed in avian and mammalian systems and represent an example of convergent evolution in social systems. We suggest that kin-based sociality in this and other lizards may be a by-product of viviparity, which can promote delayed juvenile dispersal by allowing prolonged interaction between a neonate and its mother. PMID:20926442

  19. Leaping Lizards And Learning. In the Curriculum: Science

    ERIC Educational Resources Information Center

    Petersen, Diane; Nelson, Cathi

    2004-01-01

    In the broad fields that stretch toward the horizon in the Columbia Basin region of Washington state, the land is just right for at least two purposes: growing dryland wheat and providing habitat for shorthorned lizards, also known as horny toads. Our elementary school, enrolling 150 children from this rural farming community, has become a hub for…

  20. A preliminary report on the distribution of lizards in Qatar.

    PubMed

    Cogălniceanu, Dan; Castilla, Aurora M; Valdeón, Aitor; Gosá, Alberto; Al-Jaidah, Noora; Alkuwary, Ali; Saifelnasr, Essam O H; Mas-Peinado, Paloma; Richer, Renee; Al-Hemaidi, Ahmad Amer Mohd

    2014-01-01

    We have updated the list of the lizard species present in Qatar and produced the first distribution maps based on two field surveys in 2012 and 2013. We used the QND95/Qatar National Grid with a grid of 10 × 10 km squares for mapping. Our results show the occurrence of 21 lizard species in Qatar, from the 15 species indicated in the last biodiversity report conducted in 2004. The most abundant family found in Qatar is Gekkonidae with nine species (Bunopus tuberculatus, Cyrtopodion scabrum, Hemidactylus robustus, H. flaviviridis, H. persicus, Stenodactylus arabicus, S. slevini, S. doriae, Pseudoceramodactylus khobarensis), followed by Lacertidae with four species (Acanthodactylus schmidti, A. opheodurus, Mesalina brevirostris, M. adramitana), Agamidae with three species (Trapelus flavimaculatus, Uromastyx aegyptia, Phrynocephalus arabicus), Scincidae with two species (Scincus mitranus, Trachylepis septemtaeniata), and Varanidae (Varanus griseus), Sphaerodactylidae (Pristurus rupestris) and Trogonophiidae (Diplometopon zarudnyi) with one species each. The species richness fluctuated largely across Qatar between one and eleven species per grid square. We believe that the lizard fauna records in Qatar are still incomplete and that additional studies are required. However, our study here fills a gap concerning lizard biodiversity knowledge in the Gulf Region. PMID:24493961

  1. A preliminary report on the distribution of lizards in Qatar

    PubMed Central

    Cogălniceanu, Dan; Castilla, Aurora M; Valdeón, Aitor; Gosá, Alberto; Al-Jaidah, Noora; Alkuwary, Ali; Saifelnasr, Essam O. H.; Mas-Peinado, Paloma; Richer, Renee; Al-Hemaidi, Ahmad Amer Mohd

    2014-01-01

    Abstract We have updated the list of the lizard species present in Qatar and produced the first distribution maps based on two field surveys in 2012 and 2013. We used the QND95/Qatar National Grid with a grid of 10 × 10 km squares for mapping. Our results show the occurrence of 21 lizard species in Qatar, from the 15 species indicated in the last biodiversity report conducted in 2004. The most abundant family found in Qatar is Gekkonidae with nine species (Bunopus tuberculatus, Cyrtopodion scabrum, Hemidactylus robustus, H. flaviviridis, H. persicus, Stenodactylus arabicus, S. slevini, S. doriae, Pseudoceramodactylus khobarensis), followed by Lacertidae with four species (Acanthodactylus schmidti, A. opheodurus, Mesalina brevirostris, M. adramitana), Agamidae with three species (Trapelus flavimaculatus, Uromastyx aegyptia, Phrynocephalus arabicus), Scincidae with two species (Scincus mitranus, Trachylepis septemtaeniata), and Varanidae (Varanus griseus), Sphaerodactylidae (Pristurus rupestris) and Trogonophiidae (Diplometopon zarudnyi) with one species each. The species richness fluctuated largely across Qatar between one and eleven species per grid square. We believe that the lizard fauna records in Qatar are still incomplete and that additional studies are required. However, our study here fills a gap concerning lizard biodiversity knowledge in the Gulf Region. PMID:24493961

  2. Nocturnal activity by diurnal lizards (Sceloporus jarrovi, S. virgatus) eaten by small owls (Glaucidium gnoma, Otus trichopsis)

    USGS Publications Warehouse

    Duncan, W.W.; Gehlbach, F.R.; Middendorf, G. A., III

    2003-01-01

    Whiskered screech-owls (Otus trichopsis) and northern pygmy-owls (Glaucidium gnoma) delivered freshly caught Yarrow's spiny lizards (Sceloporus jarrovi) and striped plateau lizards (S. virgatus) to nestlings from dusk to dark in southeastern Arizona. This observation stimulated studies of the prey deliveries by the owls and lizard activity patterns, because the lizards are not known to be nocturnal. Lizards were more frequent prey of both owls than endothermic vertebrates but infrequent compared to arthropods, a pattern in the pygmy-owl that differs from its northern populations. Yarrow's spiny lizard, the most abundant and frequently captured lizard, was most active in the morning but also active in the evening. Striped plateau lizard, the second most abundant and depredated species, had morning and evening peaks of activity. Few lizards, including S. clarki and Urosaurus ornatus, but not Cnemidophorus exsanguis and C. sonorae, were active at or after dark, when relatively few were captured by the owls.

  3. Elevational covariation in environmental constraints and life histories of the desert lizard Sceloporus merriami

    SciTech Connect

    Grant, B.W. ); Dunham, A.E. )

    1990-10-01

    We examine environmental constraints on life history characters among three elevationally distinct populations of the desert lizard Sceloporus merriami in west Texas. We show how environmental gradients in temperature and food abundance interact to constrain body temperatures, daily activity times, growth rates, and age-specific body size. We suggest that these differences resulted in opposite responses from males and females with respect to their size and age at first reproduction. Results suggest an interaction between resource levels and biophysical constraints that may greatly influence differences among populations in important life history characteristics. Although these responses are hypothesized to be proximally induced by environmental constraints, the resulting life history differences in age-specific resource allocation to growth, storage, and reproduction may significantly affect fitness.

  4. Condition-dependent chemosignals in reproductive behavior of lizards.

    PubMed

    Martín, José; López, Pilar

    2015-02-01

    This article is part of a Special Issue "Chemosignals and Reproduction". Many lizards have diverse glands that produce chemosignals used in intraspecific communication and that can have reproductive consequences. For example, information in chemosignals of male lizards can be used in intrasexual competition to identify and assess the fighting potential or dominance status of rival males either indirectly through territorial scent-marks or during agonistic encounters. Moreover, females of several lizard species "prefer" to establish or spend more time on areas scent-marked by males with compounds signaling a better health or body condition or a higher genetic compatibility, which can have consequences for their mating success and inter-sexual selection processes. We review here recent studies that suggest that the information content of chemosignals of lizards may be reliable because several physiological and endocrine processes would regulate the proportions of chemical compounds available for gland secretions. Because chemosignals are produced by the organism or come from the diet, they should reflect physiological changes, such as different hormonal levels (e.g. testosterone or corticosterone) or different health states (e.g. parasitic infections, immune response), and reflect the quality of the diet of an individual. More importantly, some compounds that may function as chemosignals also have other important functions in the organism (e.g. as antioxidants or regulating the immune system), so there could be trade-offs between allocating these compounds to attending physiological needs or to produce costly sexual "chemical ornaments". All these factors may contribute to maintain chemosignals as condition-dependent sexual signals, which can inform conspecifics on the characteristics and state of the sender and allow making behavioral decisions with reproductive consequences. To understand the evolution of chemical secretions of lizards as sexual signals and their

  5. Stable social aggregations in an Australian lizard, Egernia stokesii

    NASA Astrophysics Data System (ADS)

    Duffield, Glen; Bull, Michael

    2002-08-01

    Social groups in many animal species contain family members, and are maintained by parental care, and then tolerance of related individuals in the group. Lizards rarely show prolonged parental care, and rarely form stable social aggregations, although cohesive groups have been reported in the Australian skink genus, Egernia. A population of Egernia stokesii was surveyed for six seasons on Camel Hill, South Australia. At this site individuals occupied rock crevices for refuges on an isolated rocky outcrop of about 1.5 ha. The population was divided into 17 stable social groups, each containing 2-17 individual lizards. Surveyed juveniles took more than 5 years to reach mature size, and most juveniles and subadults remained in the social group of their parents for that period and longer. There were 2-8 permanent adult members of each group. Group members shared common crevice refuges, basked close together (and sometimes on top of each other) and defecated in common scat piles. There was low mortality after the first 2 years of life, and low dispersal either into or out of the population. Some individuals were "floaters" that did not belong to a social group. Over the study a number of these became established in groups. The social structure of these lizards resembles the family groups reported in many species of birds and mammals where group members help to raise the offspring of relatives. The low level of parental care in lizards suggests that the evolution of this form of social organisation in lizards has resulted from different processes than in other vertebrate taxa.

  6. Functional and Structural Diversification of the Anguimorpha Lizard Venom System*

    PubMed Central

    Fry, Bryan G.; Winter, Kelly; Norman, Janette A.; Roelants, Kim; Nabuurs, Rob J. A.; van Osch, Matthias J. P.; Teeuwisse, Wouter M.; van der Weerd, Louise; Mcnaughtan, Judith E.; Kwok, Hang Fai; Scheib, Holger; Greisman, Laura; Kochva, Elazar; Miller, Laurence J.; Gao, Fan; Karas, John; Scanlon, Denis; Lin, Feng; Kuruppu, Sanjaya; Shaw, Chris; Wong, Lily; Hodgson, Wayne C.

    2010-01-01

    Venom has only been recently discovered to be a basal trait of the Anguimorpha lizards. Consequently, very little is known about the timings of toxin recruitment events, venom protein molecular evolution, or even the relative physical diversifications of the venom system itself. A multidisciplinary approach was used to examine the evolution across the full taxonomical range of this ∼130 million-year-old clade. Analysis of cDNA libraries revealed complex venom transcriptomes. Most notably, three new cardioactive peptide toxin types were discovered (celestoxin, cholecystokinin, and YY peptides). The latter two represent additional examples of convergent use of genes in toxic arsenals, both having previously been documented as components of frog skin defensive chemical secretions. Two other novel venom gland-overexpressed modified versions of other protein frameworks were also recovered from the libraries (epididymal secretory protein and ribonuclease). Lectin, hyaluronidase, and veficolin toxin types were sequenced for the first time from lizard venoms and shown to be homologous to the snake venom forms. In contrast, phylogenetic analyses demonstrated that the lizard natriuretic peptide toxins were recruited independently of the form in snake venoms. The de novo evolution of helokinestatin peptide toxin encoding domains within the lizard venom natriuretic gene was revealed to be exclusive to the helodermatid/anguid subclade. New isoforms were sequenced for cysteine-rich secretory protein, kallikrein, and phospholipase A2 toxins. Venom gland morphological analysis revealed extensive evolutionary tinkering. Anguid glands are characterized by thin capsules and mixed glands, serous at the bottom of the lobule and mucous toward the apex. Twice, independently this arrangement was segregated into specialized serous protein-secreting glands with thick capsules with the mucous lobules now distinct (Heloderma and the Lanthanotus/Varanus clade). The results obtained highlight

  7. Random Sampling of Squamate Reptiles in Spanish Natural Reserves Reveals the Presence of Novel Adenoviruses in Lacertids (Family Lacertidae) and Worm Lizards (Amphisbaenia)

    PubMed Central

    Szirovicza, Leonóra; López, Pilar; Kopena, Renáta; Benkő, Mária; Martín, José; Pénzes, Judit J.

    2016-01-01

    Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs) in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni), nine Iberian worm lizards (Blanus cinereus), and two Iberian green lizards (Lacerta schreiberi), respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses. PMID:27399970

  8. Long-Term Data Reveal a Population Decline of the Tropical Lizard Anolis apletophallus, and a Negative Affect of El Nino Years on Population Growth Rate

    PubMed Central

    Stapley, Jessica; Garcia, Milton; Andrews, Robin M.

    2015-01-01

    Climate change threatens biodiversity worldwide, however predicting how particular species will respond is difficult because climate varies spatially, complex factors regulate population abundance, and species vary in their susceptibility to climate change. Studies need to incorporate these factors with long-term data in order to link climate change to population abundance. We used 40 years of lizard abundance data and local climate data from Barro Colorado Island to ask how climate, total lizard abundance and cohort-specific abundance have changed over time, and how total and cohort-specific abundance relate to climate variables including those predicted to make the species vulnerable to climate change (i.e. temperatures exceeding preferred body temperature). We documented a decrease in lizard abundance over the last 40 years, and changes in the local climate. Population growth rate was related to the previous years’ southern oscillation index; increasing following cooler-wetter, la niña years, decreasing following warmer-drier, el nino years. Within-year recruitment was negatively related to rainfall and minimum temperature. This study simultaneously identified climatic factors driving long-term population fluctuations and climate variables influencing short-term annual recruitment, both of which may be contributing to the population decline and influence the population’s future persistence. PMID:25671423

  9. Random Sampling of Squamate Reptiles in Spanish Natural Reserves Reveals the Presence of Novel Adenoviruses in Lacertids (Family Lacertidae) and Worm Lizards (Amphisbaenia).

    PubMed

    Szirovicza, Leonóra; López, Pilar; Kopena, Renáta; Benkő, Mária; Martín, José; Pénzes, Judit J

    2016-01-01

    Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs) in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni), nine Iberian worm lizards (Blanus cinereus), and two Iberian green lizards (Lacerta schreiberi), respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses. PMID:27399970

  10. Long-term data reveal a population decline of the tropical lizard Anolis apletophallus, and a negative affect of el nino years on population growth rate.

    PubMed

    Stapley, Jessica; Garcia, Milton; Andrews, Robin M

    2015-01-01

    Climate change threatens biodiversity worldwide, however predicting how particular species will respond is difficult because climate varies spatially, complex factors regulate population abundance, and species vary in their susceptibility to climate change. Studies need to incorporate these factors with long-term data in order to link climate change to population abundance. We used 40 years of lizard abundance data and local climate data from Barro Colorado Island to ask how climate, total lizard abundance and cohort-specific abundance have changed over time, and how total and cohort-specific abundance relate to climate variables including those predicted to make the species vulnerable to climate change (i.e. temperatures exceeding preferred body temperature). We documented a decrease in lizard abundance over the last 40 years, and changes in the local climate. Population growth rate was related to the previous years' southern oscillation index; increasing following cooler-wetter, la niña years, decreasing following warmer-drier, el nino years. Within-year recruitment was negatively related to rainfall and minimum temperature. This study simultaneously identified climatic factors driving long-term population fluctuations and climate variables influencing short-term annual recruitment, both of which may be contributing to the population decline and influence the population's future persistence. PMID:25671423

  11. Great Apes

    USGS Publications Warehouse

    Sleeman, Jonathan M.; Cerveny, Shannon

    2014-01-01

    Anesthesia of great apes is often necessary to conduct diagnostic analysis, provide therapeutics, facilitate surgical procedures, and enable transport and translocation for conservation purposes. Due to the stress of remote delivery injection of anesthetic agents, recent studies have focused on oral delivery and/or transmucosal absorption of preanesthetic and anesthetic agents. Maintenance of the airway and provision of oxygen is an important aspect of anesthesia in great ape species. The provision of analgesia is an important aspect of the anesthesia protocol for any procedure involving painful stimuli. Opioids and nonsteroidal anti-inflammatory drugs (NSAIDs) are often administered alone, or in combination to provide multi-modal analgesia. There is increasing conservation management of in situ great ape populations, which has resulted in the development of field anesthesia techniques for free-living great apes for the purposes of translocation, reintroduction into the wild, and clinical interventions.

  12. Scale Morphology and Micro-Structure of Monitor Lizards (Squamata: Varanidae: Varanus spp.) and their Allies: Implications for Systematics, Ecology, and Conservation.

    PubMed

    Bucklitsch, Yannick; Böhme, Wolfgang; Koch, André

    2016-01-01

    We analysed scale morphology and micro-structure from five different body regions using scanning electron microscopy (SEM) across all nine recognized subgenera of the monitor lizard genus Varanus including 41 different species investigated. As far as we are aware, this qualitative visual technique was applied by us for the first time to most monitor lizard species and probably also to the primary outgroup and sister species Lanthanotus borneensis. A comprehensive list of 20 scalation characters each with up to seven corresponding character states was established and defined for the five body regions sampled. For the phylogenetic approach, parsimony analyses of the resulting morphological data matrix as well as Bremer and bootstrap support calculations were performed with the software TNT. Our results demonstrate that a variety of micro-ornamentations (i.e., ultra- or micro-dermatoglyphics) as seen in various squamate groups is hardly present in monitor lizards. In several species from six out of nine subgenera, however, we found a honeycomb-shaped micro-structure of foveate polygons. Two further samples of Euprepiosaurus Fitzinger, 1843 exhibit each another unique microscopic structure on the scale surface. Notably, the majority of species showing the honeycombed ultra-structure inhabit arid habitats in Australia, Africa and the Middle East. Therefore, it can be inferred that this microscopic scalation feature, which has also been identified in other desert dwelling lizard species, is taxonomically and ecologically correlated with a xeric habitat type in varanids, too. In addition, the systematic affiliation of V. spinulosus, an endemic monitor lizard species from the Solomon Islands with an extraordinary scale shape, is discussed in the light of current hypotheses about its phylogenetic position within the Varanidae. Due to its unique scalation characteristics, in combination with other morphological evidence, a new monotypic subgenus, Solomonsaurus subgen. nov

  13. Great Barrier Reef, Queensland, Australia

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Along the coast of Queensland, Australia (18.0S, 147.5E), timbered foothills of the Great Dividing Range separate the semi-arid interior of Queensland from the farmlands of the coastal plains. Prominent cleared areas in the forest indicate deforestation for farm and pasture lands. Offshore, islands and the Great Barrier Reef display sand banks along the southern sides of the structures indicating a dominant southerly wind and current direction.

  14. Advantages in exploring a new environment with the left eye in lizards.

    PubMed

    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-07-01

    Lizards (Podarcis muralis) preferentially use the left eye during spatial exploration in a binocular condition. Here we allowed 44 adult wild lizards to explore an unknown maze for 20 min under a temporary monocular condition whilst recording their movements, particularly the direction of turns made whilst walking within the maze. Lizards with a patch on their right eye, i.e. using their left eye to monitor the environment, moved faster than lizards with a patch on their left eye when turning both leftward and rightward in a T-cross. Hence, right eye-patched lizards were faster than left eye-patched lizards also in turning right, although their right eye was covered. Thus, lizards that could use the left eye/right hemisphere to attend spatial cues appeared to have more control and to be more prompt in exploring the maze. In addition, female lizards with their left eye covered stopped very frequently when they reached crosses, showing a high level of indecision. Results confirm that P. muralis lizards using their left eye only in exploring a new environment react faster and more efficiently than those using the right eye only in exploration. Hence lateralisation of spatial stimuli mediated by the left eye/right hemisphere could provide an advantage to this species. PMID:23590962

  15. Dragon's Paradise Lost: Palaeobiogeography, Evolution and Extinction of the Largest-Ever Terrestrial Lizards (Varanidae)

    PubMed Central

    Hocknull, Scott A.; Piper, Philip J.; van den Bergh, Gert D.; Due, Rokus Awe; Morwood, Michael J.; Kurniawan, Iwan

    2009-01-01

    Background The largest living lizard species, Varanus komodoensis Ouwens 1912, is vulnerable to extinction, being restricted to a few isolated islands in eastern Indonesia, between Java and Australia, where it is the dominant terrestrial carnivore. Understanding how large-bodied varanids responded to past environmental change underpins long-term management of V. komodoensis populations. Methodology/Principal Findings We reconstruct the palaeobiogeography of Neogene giant varanids and identify a new (unnamed) species from the island of Timor. Our data reject the long-held perception that V. komodoensis became a giant because of insular evolution or as a specialist hunter of pygmy Stegodon. Phyletic giantism, coupled with a westward dispersal from mainland Australia, provides the most parsimonious explanation for the palaeodistribution of V. komodoensis and the newly identified species of giant varanid from Timor. Pliocene giant varanid fossils from Australia are morphologically referable to V. komodoensis suggesting an ultimate origin for V. komodoensis on mainland Australia (>3.8 million years ago). Varanus komodoensis body size has remained stable over the last 900,000 years (ka) on Flores, a time marked by major faunal turnovers, extinction of the island's megafauna, the arrival of early hominids by 880 ka, co-existence with Homo floresiensis, and the arrival of modern humans by 10 ka. Within the last 2000 years their populations have contracted severely. Conclusions/Significance Giant varanids were once a ubiquitous part of Subcontinental Eurasian and Australasian faunas during the Neogene. Extinction played a pivotal role in the reduction of their ranges and diversity throughout the late Quaternary, leaving only V. komodoensis as an isolated long-term survivor. The events over the last two millennia now threaten its future survival. PMID:19789642

  16. The very-broad-band long-base tiltmeters of Grotta Gigante (Trieste, Italy): Secular term tilting and the great Sumatra-Andaman islands earthquake of December 26, 2004

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla; Romeo, Giovanni; Taccetti, Quintilio; Nagy, Ildikò

    2006-01-01

    The horizontal pendulums of the Grotta Gigante (Giant Cave) in the Trieste Karst, are long-base tiltmeters with Zöllner type suspension. The instruments have been continuously recording tilt and shear in the Grotta Gigante since the date of their installation by Prof. Antonio Marussi in 1966. Their setup has been completely overhauled several times since installation, restricting the interruptions of the measurements though to a minimum. The continuous recordings, apart from some interruptions, cover thus almost 40 years of measurements, producing a very noticeable long-term tiltmeter record of crustal deformation. The original recording system, still in function, was photographic with a mechanical timing and paper-advancing system, which has never given any problems at all, as it is very stable and not vulnerable by external factors as high humidity, problems in power supply, lightning or similar. In December 2003 a new recording system was installed, based on a solid-state acquisition system intercepting a laser light reflected from a mirror mounted on the horizontal pendulum beam. The sampling rate is 30 Hz, which turns the long-base instrument to a very-broad-band tiltmeter, apt to record the tilt signal on a broad-band of frequencies, ranging from secular deformation rate through the earth tides to seismic waves. Here we describe the acquisition system and present two endline members of the instrumental observation, the up to date long-term recording, and the observation of the great Sumatra-Andaman Islands earthquake of December 26, 2004, seismic moment magnitude Mw = 9.1-9.3 [Lay, T., Kanamori, H., Ammon, C.J., Nettles, M., Ward, S.N., Aster, R.C., Beck, S.L., Bilek, S.L., Brudzinski, M.L., Butler, R., DeShon, H.R., Ekström, G., Satake, K., Sipkin, S., 2005. The Great Sumatra-Andaman Earthquake of 26 December 2004. Science. 308, 1127-1133.]. The secular-term observations indicate an average tilting over the last four decades towards NW of 23.4 nrad

  17. Great Comets

    NASA Astrophysics Data System (ADS)

    Burnham, Robert

    2000-05-01

    Spectacular and mysterious objects that come and go in the night sky, comets have dwelt in our popular culture for untold ages. As remnants from the formation of the Solar system, they are objects of key scientific research and space missions. As one of nature's most potent and dramatic dangers, they pose a threat to our safety--and yet they were the origin of our oceans and perhaps even life itself. This beautifully illustrated book tells the story of the biggest and most awe-inspiring of all comets: those that have earned the title "Great." Robert Burnham focuses on the Great comets Hyakutake in 1996 and Hale-Bopp in 1997, which gripped attention worldwide because, for many, they were the first comets ever seen. He places these two recent comets in the context of their predecessors from past ages, among them the famous Comet Halley. Great Comets explains the exciting new discoveries that have come from these magnificent objects and profiles the spaceprobes to comets due for launch in the next few years. The book even takes a peek behind Hollywood's science-fiction fantasies to assess the real risks humanity faces from potential impacts of both comets and asteroids. For everyone interested in astronomy, this exciting book reveals the secrets of the Great Comets and provides essential tools for keeping up to date with comet discoveries in the future. Robert Burnham has been an amateur astronomer since the mid-1950s. He has been a senior editor of Astronomy magazine (1986-88) and is the author of many books and CD-ROMS, including Comet Hale-Bopp: Find and Enjoy the Great Comet and Comet Explorer.

  18. Colorful displays signal male quality in a tropical anole lizard

    NASA Astrophysics Data System (ADS)

    Cook, Ellee G.; Murphy, Troy G.; Johnson, Michele A.

    2013-10-01

    Parasites influence colorful ornaments and their behavioral display in many animal hosts. Because coloration and display behavior are often critical components of communication, variation in these traits may have important implications for individual fitness, yet it remains unclear whether such traits are signals of quality in many taxa. We investigated the association between ectoparasitic mite load and the color and behavioral use of the throat fan (dewlap) by male Anolis brevirostris lizards. We found that heavily parasitized lizards exhibited lower body condition, duller dewlaps, and less frequent dewlap displays than less parasitized individuals. Our results thus suggest that highly parasitized individuals invest less in both ornamental color and behavioral display of that color. Because the two components of the signal simultaneously provide information on male quality, this study provides novel support for the long-standing hypothesis that colorful traits may function as social or sexual signals in reptiles.

  19. Low Incubation Temperature Induces DNA Hypomethylation in Lizard Brains.

    PubMed

    Paredes, Ursula; Radersma, Reinder; Cannell, Naomi; While, Geoffrey M; Uller, Tobias

    2016-07-01

    Developmental stress can have organizational effects on suites of physiological, morphological, and behavioral characteristics. In lizards, incubation temperature is perhaps the most significant environmental variable affecting embryonic development. Wall lizards (Podarcis muralis) recently introduced by humans from Italy to England experience stressfully cool incubation conditions, which we here show reduce growth and increase the incidence of scale malformations. Using a methylation-sensitive AFLP protocol optimized for vertebrates, we demonstrate that this low incubation temperature also causes hypomethylation of DNA in brain tissue. A consistent pattern across methylation-susceptible AFLP loci suggests that hypomethylation is a general response and not limited to certain CpG sites. The functional consequences of hypomethylation are unknown, but it could contribute to genome stability and regulation of gene expression. Further studies of the effects of incubation temperature on DNA methylation in ectotherm vertebrates may reveal mechanisms that explain why the embryonic thermal environment often has physiological and behavioral consequences for offspring. PMID:27328739

  20. Frequency Clustering in Spontaneous Otoacoustic Emissions from a Lizard's Ear

    PubMed Central

    Vilfan, Andrej; Duke, Thomas

    2008-01-01

    Spontaneous otoacoustic emissions (SOAEs) are indicators of an active process in the inner ear that enhances the sensitivity and frequency selectivity of hearing. They are particularly regular and robust in certain lizards, so these animals are good model organisms for studying how SOAEs are generated. We show that the published properties of SOAEs in the bobtail lizard are wholly consistent with a mathematical model in which active oscillators, with exponentially varying characteristic frequencies, are coupled together in a chain by visco-elastic elements. Physically, each oscillator corresponds to a small group of hair cells, covered by a tectorial sallet, so our theoretical analysis directly links SOAEs to the micromechanics of active hair bundles. PMID:18689448

  1. Live birth among Iguanian lizards predates Pliocene–Pleistocene glaciations

    PubMed Central

    Schulte, James A.; Moreno-Roark, Franck

    2010-01-01

    Among tetrapods, viviparity is estimated to have evolved independently within Squamata (lizards and snakes) more than 100 times, most frequently in species occupying cold climate environments. Because of this relationship with cold climates, it is sometimes assumed that many origins of squamate viviparity occurred over the past 2.5–4 Myr during the Pliocene–Pleistocene glaciations; however, this hypothesis is untested. Divergence-dating analysis on a 733-species tree of Iguanian lizards recovers 20 independent lineages that have evolved viviparity, of which 13 multispecies groups derived live birth prior to glacial advances (8–66 Myr ago). These results place the transitions from egg-laying to live birth among squamates in a well-supported historical context to facilitate examination of the underlying phenotypic and genetic changes associated with this complex shift in reproduction. PMID:19812068

  2. Partial characterization of new adenoviruses found in lizards.

    PubMed

    Ball, Inna; Behncke, Helge; Schmidt, Volker; Geflügel, F T A; Papp, Tibor; Stöhr, Anke C; Marschang, Rachel E

    2014-06-01

    In the years 2011-2012, a consensus nested polymerase chain reaction was used for the detection of adenovirus (AdV) infection in reptiles. During this screening, three new AdVs were detected. One of these viruses was detected in three lizards from a group of green striped tree dragons (Japalura splendida). Another was detected in a green anole (Anolis carolinensis). A third virus was detected in a Jackson's chameleon (Chamaeleo jacksonii). Analysis of a portion of the DNA-dependent DNA polymerase genes of each of these viruses revealed that they all were different from one another and from all previously described reptilian AdVs. Phylogenetic analysis of the partial DNA polymerase gene sequence showed that all newly detected viruses clustered within the genus Atadenovirus. This is the first description of AdVs in these lizard species. PMID:25000689

  3. X-ray microtomography provides first data about the feeding behaviour of an endangered lizard, the Montserrat galliwasp (Diploglossus montisserrati).

    PubMed

    Bochaton, C; Boistel, R; Charles, L

    2015-12-01

    Reporting the diet of recently extinct or very rare taxa, only known by a few museum specimens, is challenging. This study uses X-ray microtomography, a non-destructive investigation method, to obtain the first data about feeding behaviours in the Montserrat galliwasp (Diploglossus montisserrati) by scanning one of the two specimens known to date. The scans revealed the occurrence of shell fragments of a freshwater snail (Omalonyx matheroni) in the digestive tract of the specimen. This data combined with morphological evidence shows the occurrence of a durophagous feeding habit and a possible tendency of association with freshwater environments. This information could be crucial to save this critically endangered lizard endemic on Montserrat island. PMID:27019732

  4. X-ray microtomography provides first data about the feeding behaviour of an endangered lizard, the Montserrat galliwasp (Diploglossus montisserrati)

    PubMed Central

    Bochaton, C.; Boistel, R.; Charles, L.

    2015-01-01

    Reporting the diet of recently extinct or very rare taxa, only known by a few museum specimens, is challenging. This study uses X-ray microtomography, a non-destructive investigation method, to obtain the first data about feeding behaviours in the Montserrat galliwasp (Diploglossus montisserrati) by scanning one of the two specimens known to date. The scans revealed the occurrence of shell fragments of a freshwater snail (Omalonyx matheroni) in the digestive tract of the specimen. This data combined with morphological evidence shows the occurrence of a durophagous feeding habit and a possible tendency of association with freshwater environments. This information could be crucial to save this critically endangered lizard endemic on Montserrat island. PMID:27019732

  5. Unidirectional pulmonary airflow patterns in the savannah monitor lizard.

    PubMed

    Schachner, Emma R; Cieri, Robert L; Butler, James P; Farmer, C G

    2014-02-20

    The unidirectional airflow patterns in the lungs of birds have long been considered a unique and specialized trait associated with the oxygen demands of flying, their endothermic metabolism and unusual pulmonary architecture. However, the discovery of similar flow patterns in the lungs of crocodilians indicates that this character is probably ancestral for all archosaurs--the group that includes extant birds and crocodilians as well as their extinct relatives, such as pterosaurs and dinosaurs. Unidirectional flow in birds results from aerodynamic valves, rather than from sphincters or other physical mechanisms, and similar aerodynamic valves seem to be present in crocodilians. The anatomical and developmental similarities in the primary and secondary bronchi of birds and crocodilians suggest that these structures and airflow patterns may be homologous. The origin of this pattern is at least as old as the split between crocodilians and birds, which occurred in the Triassic period. Alternatively, this pattern of flow may be even older; this hypothesis can be tested by investigating patterns of airflow in members of the outgroup to birds and crocodilians, the Lepidosauromorpha (tuatara, lizards and snakes). Here we demonstrate region-specific unidirectional airflow in the lungs of the savannah monitor lizard (Varanus exanthematicus). The presence of unidirectional flow in the lungs of V. exanthematicus thus gives rise to two possible evolutionary scenarios: either unidirectional airflow evolved independently in archosaurs and monitor lizards, or these flow patterns are homologous in archosaurs and V. exanthematicus, having evolved only once in ancestral diapsids (the clade encompassing snakes, lizards, crocodilians and birds). If unidirectional airflow is plesiomorphic for Diapsida, this respiratory character can be reconstructed for extinct diapsids, and evolved in a small ectothermic tetrapod during the Palaeozoic era at least a hundred million years before the

  6. Behavioural flexibility and problem-solving in a tropical lizard

    PubMed Central

    Leal, Manuel; Powell, Brian J.

    2012-01-01

    The role of behavioural flexibility in responding to new or changing environmental challenges is a central theme in cognitive ecology. Studies of behavioural flexibility have focused mostly on mammals and birds because theory predicts that behavioural flexibility is favoured in species or clades that exploit a diversity of habitats or food sources and/or have complex social structure, attributes not associated with ectothermic vertebrates. Here, we present the results of a series of experiments designed to test cognitive abilities across multiple cognitive modules in a tropical arboreal lizard: Anolis evermanni. This lizard shows behavioural flexibility across multiple cognitive tasks, including solving a novel motor task using multiple strategies and reversal learning, as well as rapid associative learning. This flexibility was unexpected because lizards are commonly believed to have limited cognitive abilities and highly stereotyped behaviour. Our findings indicate that the cognitive abilities of A. evermanni are comparable with those of some endothermic species that are recognized to be highly flexible, and strongly suggest a re-thinking of our understanding of the cognitive abilities of ectothermic tetrapods and of the factors favouring the evolution of behavioural flexibility. PMID:21752816

  7. Age-dependent social learning in a lizard

    PubMed Central

    Noble, Daniel W. A.; Byrne, Richard W.; Whiting, Martin J.

    2014-01-01

    Evidence of social learning, whereby the actions of an animal facilitate the acquisition of new information by another, is taxonomically biased towards mammals, especially primates, and birds. However, social learning need not be limited to group-living animals because species with less interaction can still benefit from learning about potential predators, food sources, rivals and mates. We trained male skinks (Eulamprus quoyii), a mostly solitary lizard from eastern Australia, in a two-step foraging task. Lizards belonging to ‘young’ and ‘old’ age classes were presented with a novel instrumental task (displacing a lid) and an association task (reward under blue lid). We did not find evidence for age-dependent learning of the instrumental task; however, young males in the presence of a demonstrator learnt the association task faster than young males without a demonstrator, whereas old males in both treatments had similar success rates. We present the first evidence of age-dependent social learning in a lizard and suggest that the use of social information for learning may be more widespread than previously believed. PMID:25009244

  8. Polyandry in dragon lizards: inbred paternal genotypes sire fewer offspring

    PubMed Central

    Frère, Celine H; Chandrasoma, Dani; Whiting, Martin J

    2015-01-01

    Multiple mating in female animals is something of a paradox because it can either be risky (e.g., higher probability of disease transmission, social costs) or provide substantial fitness benefits (e.g., genetic bet hedging whereby the likelihood of reproductive failure is lowered). The genetic relatedness of parental units, particularly in lizards, has rarely been studied in the wild. Here, we examined levels of multiple paternity in Australia's largest agamid lizard, the eastern water dragon (Intellagama lesueurii), and determined whether male reproductive success is best explained by its heterozygosity coefficient or the extent to which it is related to the mother. Female polyandry was the norm: 2/22 clutches (9.2%) were sired by three or more fathers, 17/22 (77.2%) were sired by two fathers, and only 3/22 (13.6%) clutches were sired by one father. Moreover, we reconstructed the paternal genotypes for 18 known mother–offspring clutches and found no evidence that females were favoring less related males or that less related males had higher fitness. However, males with greater heterozygosity sired more offspring. While the postcopulatory mechanisms underlying this pattern are not understood, female water dragons likely represent another example of reproduction through cryptic means (sperm selection/sperm competition) in a lizard, and through which they may ameliorate the effects of male-driven precopulatory sexual selection. PMID:25937911

  9. Speed and Endurance Do Not Trade Off in Phrynosomatid Lizards.

    PubMed

    de Albuquerque, Ralph Lacerda; Bonine, Kevin E; Garland, Theodore

    2015-01-01

    Trade-offs are a common focus of study in evolutionary biology and in studies of locomotor physiology and biomechanics. A previous comparative study of 12 species of European lacertid lizards found a statistically significant negative correlation between residual locomotor speed and stamina (controlling for variation in body size), consistent with ideas about trade-offs in performance based on variation in muscle fiber type composition and other subordinate traits. To begin examining the generality of this finding in other groups of squamates, we measured maximal sprint running speed on a high-speed treadmill and endurance at 1.0 km/h (0.28 m/s) in 14 species of North American phrynosomatid lizards, plus a sample of nine additional species to encompass some of the broadscale diversity of lizards. We used both conventional and phylogenetically informed regression analyses to control for some known causes of performance variation (body size, stockiness, body temperature) and then computed residual performance values. We found no evidence for a trade-off between speed and endurance among the 14 phrynosomatids or among the 23 species in the extended data set. Possible explanations for the apparent difference between lacertids and phrynosomatids are discussed. PMID:26658411

  10. Morphology of the feeding system in agamid lizards: ecological correlates.

    PubMed

    Herrel, A; Aerts, P; Fret, J; de Vree, F

    1999-04-01

    The interaction of organismal design with ecology, and its evolutionary development are the subject of many functional and ecomorphological studies. Many studies have shown that the morphology and mechanics of the masticatory apparatus in mammals are adapted to diet. To investigate the relations between diet and the morphological and physiological properties of the lizard jaw system, a detailed analysis of the structure of the jaw apparatus was undertaken in the insectivorous lizard Plocederma stellio and in closely related herbivorous lizards of the genus Uromastix. The morphological and physiological properties of the jaw system in P. stellio and U. aegyptius were studied by means of dissections, light microscopy, histochemical characterisations, and in vivo stimulation experiments. The skull of Uromastix seems to be built for forceful biting (high, short snout). Additionally, the pterygoid muscle is modified in P. stellio, resulting in an additional force component during static biting. Stimulation experiments indicate that jaw muscles in both species are fast, which is supported by histochemical stainings. However, the oxidative capacity of the jaw muscles is larger in Uromastix. Contraction characteristics and performance of the feeding system (force output) are clearly thermally dependent. We conclude that several characteristics of the jaw system (presence of extra portion of the pterygoid muscle, large oxidative capacity of jaw muscles) in Uromastix may be attributed to its herbivorous diet. Jaw muscles, however, are still faster than expected. This is presumably the result of trade-offs between the thermal characteristics of the jaw adductors and the herbivorous lifestyle of these animals. PMID:10203257

  11. Embryonic thermosensitivity and hatchling morphology differ between two coexisting lizards

    NASA Astrophysics Data System (ADS)

    Qu, Yan-Fu; Li, Hong; Gao, Jian-Fang; Ji, Xiang

    2011-07-01

    We incubated eggs of two coexisting lizards, Phrynocephalus frontalis and Phrynocephalus versicolor, at three constant temperatures (24, 28 and 32 °C) to examine whether they differ in embryonic thermosensitivity and hatchling morphology. Eggs incubated at the three temperatures produced morphologically different hatchlings in P. versicolor but not in P. frontalis. Snout-vent length (SVL), body mass and head width were greater in P. versicolor hatchlings from the 24 °C treatment than those from the 32 °C treatment when accounting for differences in initial egg mass, and tail length was smaller in P. versicolor hatchlings from the 24 °C treatment than those from the 32 °C treatment when accounting for differences in final egg mass. Body mass, head length, head width, tail length, fore-limb length and hind-limb length were greater in P. frontalis hatchlings than in P. versicolor hatchling when accounting for differences in initial or final egg mass. Moreover, P. frontalis females produce larger hatchlings than do P. versicolor females of the same SVL not only by laying larger eggs, but also by investing more dry materials (and thus, more energy) into the egg. Given a link between interspecific competition (and niche restriction) and morphology, it seems likely that morphological differences at hatching may facilitate the coexistence of the two lizards. The two lizards differed in embryonic thermosensitivity and water uptake by eggs during incubation, suggesting that they use different microhabitats in the area of sympatry.

  12. Polyandry in dragon lizards: inbred paternal genotypes sire fewer offspring.

    PubMed

    Frère, Celine H; Chandrasoma, Dani; Whiting, Martin J

    2015-04-01

    Multiple mating in female animals is something of a paradox because it can either be risky (e.g., higher probability of disease transmission, social costs) or provide substantial fitness benefits (e.g., genetic bet hedging whereby the likelihood of reproductive failure is lowered). The genetic relatedness of parental units, particularly in lizards, has rarely been studied in the wild. Here, we examined levels of multiple paternity in Australia's largest agamid lizard, the eastern water dragon (Intellagama lesueurii), and determined whether male reproductive success is best explained by its heterozygosity coefficient or the extent to which it is related to the mother. Female polyandry was the norm: 2/22 clutches (9.2%) were sired by three or more fathers, 17/22 (77.2%) were sired by two fathers, and only 3/22 (13.6%) clutches were sired by one father. Moreover, we reconstructed the paternal genotypes for 18 known mother-offspring clutches and found no evidence that females were favoring less related males or that less related males had higher fitness. However, males with greater heterozygosity sired more offspring. While the postcopulatory mechanisms underlying this pattern are not understood, female water dragons likely represent another example of reproduction through cryptic means (sperm selection/sperm competition) in a lizard, and through which they may ameliorate the effects of male-driven precopulatory sexual selection. PMID:25937911

  13. Evolution of extreme body size disparity in monitor lizards (Varanus).

    PubMed

    Collar, David C; Schulte, James A; Losos, Jonathan B

    2011-09-01

    Many features of species' biology, including life history, physiology, morphology, and ecology are tightly linked to body size. Investigation into the causes of size divergence is therefore critical to understanding the factors shaping phenotypic diversity within clades. In this study, we examined size evolution in monitor lizards (Varanus), a clade that includes the largest extant lizard species, the Komodo dragon (V. komodoensis), as well as diminutive species that are nearly four orders of magnitude smaller in adult body mass. We demonstrate that the remarkable body size disparity of this clade is a consequence of different selective demands imposed by three major habitat use patterns-arboreality, terrestriality, and rock-dwelling. We reconstructed phylogenetic relationships and ancestral habitat use and applied model selection to determine that the best-fitting evolutionary models for species' adult size are those that infer oppositely directed adaptive evolution associated with terrestriality and rock-dwelling, with terrestrial lineages evolving extremely large size and rock-dwellers becoming very small. We also show that habitat use affects the evolution of several ecologically important morphological traits independently of body size divergence. These results suggest that habitat use exerts a strong, multidimensional influence on the evolution of morphological size and shape disparity in monitor lizards. PMID:21884063

  14. The ultrastructure of the tracheal epithelium in European common lizard (Lacerta agilis L.) and in sand lizard (Lacerta vivipara Jacq.).

    PubMed

    Tĕsík, I

    1984-01-01

    This study describes the ultrastructure of the tracheal epithelium in the European Common lizard (Lacerta agilis L.) and in the Sand lizard (Lacerta vivipara Jacq .). The main attention is paid to the granular cells of secret-producing type, which form the substantial part of this epithelium and which were observed for the first time in the house gekko . Contrary to the findings in house gekko , in the representatives of the genus Lacerta 2 types of electrondense granules were observed. One type is homogeneous and lighter in colour, the other is darker with lamellar pattern. Among other elements, the ciliated cells as well as basal and plasmatic cells were found. In both species we also succeeded in proving the presence of isolated neurosecret -producing cells. PMID:6721200

  15. The phylogeny of varanoid lizards and the affinities of snakes

    PubMed Central

    Lee, M. S. Y.

    1997-01-01

    Evidence that platynotan squamates (living varanoid lizards, snakes and their fossil relatives) are monophyletic is presented. Evolutionary relationships within this group are then ascertained through a cladistic analysis of 144 osteological characters. Mosasauroids (aigialosaurs and mosasaurs), a group of large marine lizards, are identified as the nearest relatives of snakes, thus resolving the long-standing problem of snake affinities. The mosasauroid–snake clade (Pythonomorpha) is corroborated by 40 derived characters, including recumbent replacement teeth, thecodonty, four or fewer premaxillary teeth, supratemporal–prootic contact, free mandibular tips, crista circumfenestralis, straight vertical splenio-angular joint, loss of posterior ramus of the coronoid, reduced basipterygoid processes, reduced interpterygoid vacuity, zygosphene–zygantral articulations, and absence of epiphyses on the axial skeleton and skull. After mosasauroids, the next closest relatives of snakes are varanids (Varanus, Saniwa and Saniwides) and lanthanotids (Lanthanotus and Cherminotus). Derived features uniting varanids and lanthanotids include nine cervical vertebrae and three or fewer pairs of sternal ribs. The varanid–lanthanotid–pythonomorph clade, here termed Thecoglossa, is supported by features such as the anteriorly positioned basal tubera, and the loss of the second epibranchial. Successive outgroups to thecoglossans are Telmasaurus, an unresolved polytomy (Estesia, Gobidermatidae and Helodermatidae), Paravaranus and Proplatynota. The 'necrosaurs' are demonstrated to be an artificial (polyphyletic) assemblage of primitive platynotans that are not particularly closely related to each other. Snakes are presumed to have evolved from small, limbless, burrowing lizards and the inability of previous analyses to resolve the affinities of snakes has been attributed to extensive convergence among the numerous lineages of such lizards. The present study contradicts this claim

  16. 76 FR 19304 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-07

    ..., 2010 (75 FR 77801). We intend that any final action resulting from this proposed rule will be based on... the species. If you submitted comments or information on the proposed rule (75 FR 77801, December 14... a proposed rule (75 FR 77801) to list the dunes sagebrush lizard, a lizard known from...

  17. Stable isotope analysis of diet confirms niche separation of two sympatric species of Namib Desert lizard.

    PubMed

    Murray, Ian W; Lease, Hilary M; Hetem, Robyn S; Mitchell, Duncan; Fuller, Andrea; Woodborne, Stephan

    2016-01-01

    We used stable isotopes of carbon and nitrogen to study the trophic niche of two species of insectivorous lizards, the Husab sand lizard Pedioplanis husabensis and Bradfield's Namib day gecko living sympatrically in the Namib Desert. We measured the δ(13) C and δ(15) N ratios in lizard blood tissues with different turnover times (whole blood, red blood cells and plasma) to investigate lizard diet in different seasons. We also measured the δ(13) C and δ(15) N ratios in available arthropod prey and plant tissues on the site, to identify the avenues of nutrient movement between lizards and their prey. Through the use of stable isotope mixing models, we found that the two lizard species relied on a largely non-overlapping but seasonally variable array of arthropods: P. husabensis primarily fed on termites, beetles and wasps, while R. bradfieldi fed mainly on ants, wasps and hemipterans. Nutrients originating from C3 plants were proportionally higher for R. bradfieldi than for P. husabensis during autumn and late autumn/early winter, although not summer. Contrary to the few available data estimating the trophic transfer of nutrients in ectotherms in mixed C3 and C4 /crassulacean acid metabolism (CAM) plant landscapes, we found that our lizard species primarily acquired nutrients that originated from C4 /CAM plants. This work adds an important dimension to the general lack of studies using stable isotope analyses to estimate lizard niche partitioning and resource use. PMID:26817923

  18. Comparative analysis of the size and shape of the lizard eye.

    PubMed

    Hall, Margaret I

    2008-01-01

    Lizards occupy both scotopic (light-limited) and photopic (light-rich) environments, thereby making this clade ideal for analyses of eye morphology adaptations. This study examines how in lizards the morphology of the eye varies according to activity in these different light environments. Measurements were collected on corneal diameters and axial lengths of the eye for 239 specimens of 116 lizard species (including Sphenodon) that include both species with scotopic and photopic visual adaptations. I show that the light level available to a lizard for vision has a significant effect on eye shape and size. Scotopic lizards have eye shapes that are optimized for visual sensitivity, with larger corneal diameters relative to axial lengths. However, photopic lizards do not exhibit absolutely larger axial lengths than do scotopic lizards, and the groups have the same absolute axial lengths of the eye. Results also indicate that the light level the lizard functions under is a more significant influence on eye shape, as defined by the relationship between corneal diameter and axial length of the eye, than is phylogeny. PMID:18054216

  19. Physiological and microbial adjustments to diet quality permit facultative herbivory in an omnivorous lizard.

    PubMed

    Kohl, Kevin D; Brun, Antonio; Magallanes, Melisa; Brinkerhoff, Joshua; Laspiur, Alejandro; Acosta, Juan Carlos; Bordenstein, Seth R; Caviedes-Vidal, Enrique

    2016-06-15

    While herbivory is a common feeding strategy in a number of vertebrate classes, less than 4% of squamate reptiles feed primarily on plant material. It has been hypothesized that physiological or microbial limitations may constrain the evolution of herbivory in lizards. Herbivorous lizards exhibit adaptations in digestive morphology and function that allow them to better assimilate plant material. However, it is unknown whether these traits are fixed or perhaps phenotypically flexible as a result of diet. Here, we maintained a naturally omnivorous lizard, Liolaemus ruibali, on a mixed diet of 50% insects and 50% plant material, or a plant-rich diet of 90% plant material. We compared parameters of digestive performance, gut morphology and function, and gut microbial community structure between the two groups. We found that lizards fed the plant-rich diet maintained nitrogen balance and exhibited low minimum nitrogen requirements. Additionally, lizards fed the plant-rich diet exhibited significantly longer small intestines and larger hindguts, demonstrating that gut morphology is phenotypically flexible. Lizards fed the plant-rich diet harbored small intestinal communities that were more diverse and enriched in Melainabacteria and Oscillospira compared with mixed diet-fed lizards. Additionally, the relative abundance of sulfate-reducing bacteria in the small intestine significantly correlated with whole-animal fiber digestibility. Thus, we suggest that physiological and microbial limitations do not sensu stricto constrain the evolution of herbivory in lizards. Rather, ecological context and fitness consequences may be more important in driving the evolution of this feeding strategy. PMID:27307545

  20. Temporal and spatial variation in survival rates of the tropical lizard Anolis limifrons

    USGS Publications Warehouse

    Andrews, R.M.; Nichols, J.D.

    1990-01-01

    We evaluated survival of the lizard, Anolis limifrons at two sites, AVA and Lutz, from 1976-1979 and during two periods at Lutz site, 1971-1976 vs 1976-1979, at Barro Colorado Island, Panama. Survival of adult females and males did not differ nor did survival of juveniles and adults. In contrast, survival was significantly higher at Lutz site during 1971-1976 than during 1976-1979 and survival was significantly higher at AVA than at Lutz site during 1976-1979. On an annual basis, mean survival rates were 0.042,0.013,0.055 for Lutz 1971-1976, Lutz 1976-1979, and AVA 1976-1979, respectively. These rates are in accord with reports of annual population turnover for this and other small mainland Anolis. Temporal and spatial variation in survival was not associated with habitat, season, year of observation, or numbers and abundances of avian predators. Survival patterns of mainland Anolis are contrasted with those of West Indian species in terms of life history evolution.

  1. Amber fossils demonstrate deep-time stability of Caribbean lizard communities.

    PubMed

    Sherratt, Emma; del Rosario Castañeda, María; Garwood, Russell J; Mahler, D Luke; Sanger, Thomas J; Herrel, Anthony; de Queiroz, Kevin; Losos, Jonathan B

    2015-08-11

    Whether the structure of ecological communities can exhibit stability over macroevolutionary timescales has long been debated. The similarity of independently evolved Anolis lizard communities on environmentally similar Greater Antillean islands supports the notion that community evolution is deterministic. However, a dearth of Caribbean Anolis fossils--only three have been described to date--has precluded direct investigation of the stability of anole communities through time. Here we report on an additional 17 fossil anoles in Dominican amber dating to 15-20 My before the present. Using data collected primarily by X-ray microcomputed tomography (X-ray micro-CT), we demonstrate that the main elements of Hispaniolan anole ecomorphological diversity were in place in the Miocene. Phylogenetic analysis yields results consistent with the hypothesis that the ecomorphs that evolved in the Miocene are members of the same ecomorph clades extant today. The primary axes of ecomorphological diversity in the Hispaniolan anole fauna appear to have changed little between the Miocene and the present, providing evidence for the stability of ecological communities over macroevolutionary timescales. PMID:26216976

  2. Amber fossils demonstrate deep-time stability of Caribbean lizard communities

    PubMed Central

    Sherratt, Emma; del Rosario Castañeda, María; Garwood, Russell J.; Mahler, D. Luke; Sanger, Thomas J.; Herrel, Anthony; de Queiroz, Kevin; Losos, Jonathan B.

    2015-01-01

    Whether the structure of ecological communities can exhibit stability over macroevolutionary timescales has long been debated. The similarity of independently evolved Anolis lizard communities on environmentally similar Greater Antillean islands supports the notion that community evolution is deterministic. However, a dearth of Caribbean Anolis fossils—only three have been described to date—has precluded direct investigation of the stability of anole communities through time. Here we report on an additional 17 fossil anoles in Dominican amber dating to 15–20 My before the present. Using data collected primarily by X-ray microcomputed tomography (X-ray micro-CT), we demonstrate that the main elements of Hispaniolan anole ecomorphological diversity were in place in the Miocene. Phylogenetic analysis yields results consistent with the hypothesis that the ecomorphs that evolved in the Miocene are members of the same ecomorph clades extant today. The primary axes of ecomorphological diversity in the Hispaniolan anole fauna appear to have changed little between the Miocene and the present, providing evidence for the stability of ecological communities over macroevolutionary timescales. PMID:26216976

  3. Heavy metal contamination in a lizard, Agama stellio stellio, compared in urban, high altitude and agricultural, low altitude areas of north Greece

    SciTech Connect

    Loumbourdis, N.S.

    1997-06-01

    Contamination from heavy metals is a serious problem recognized In most countries of the world. Direct methods of metal detection are applied to soil and water; Indirect methods use plants and animals as bioindicators. Reptiles have not been used as bioindicators for various reasons: difficulty in sampling, ancient fears, little economic Importance, difficulty in the laboratory etc. Since Invertebrates are the prey of most lizards, the uptake of metals through invertebrates is an important pathway. Heavy metals accumulate through food ingestion and by incidental soil ingestion of soil. Reptiles have recently started to be used as bioindicators of pesticides entering the environment, with great success. The environment in Greece has a burden of heavy metals. The purpose of this paper is to ascertain whether reptiles, especially lizards, can be used as bioindicators of heavy metal pollution by compacting indirectly the level of pollution of two areas differing to some extent ecologically In the vicinity of a large city and in the vicinity of cultivated areas. The bioindicator species was the lizard Agama stellio stellio. 28 refs., 1 tab.

  4. Intraspecific competition and high food availability are associated with insular gigantism in a lizard

    NASA Astrophysics Data System (ADS)

    Pafilis, Panayiotis; Meiri, Shai; Foufopoulos, Johannes; Valakos, Efstratios

    2009-09-01

    Resource availability, competition, and predation commonly drive body size evolution. We assess the impact of high food availability and the consequent increased intraspecific competition, as expressed by tail injuries and cannibalism, on body size in Skyros wall lizards ( Podarcis gaigeae). Lizard populations on islets surrounding Skyros (Aegean Sea) all have fewer predators and competitors than on Skyros but differ in the numbers of nesting seabirds. We predicted the following: (1) the presence of breeding seabirds (providing nutrients) will increase lizard population densities; (2) dense lizard populations will experience stronger intraspecific competition; and (3) such aggression, will be associated with larger average body size. We found a positive correlation between seabird and lizard densities. Cannibalism and tail injuries were considerably higher in dense populations. Increases in cannibalism and tail loss were associated with large body sizes. Adult cannibalism on juveniles may select for rapid growth, fuelled by high food abundance, setting thus the stage for the evolution of gigantism.

  5. Effect of temperature on feeding period of larval blacklegged ticks (Acari: Ixodidae) on eastern fence lizards

    USGS Publications Warehouse

    Rulison, Eric L.; LeBrun, Roger A.; Ginsberg, Howard S.

    2014-01-01

    Ambient temperature can influence tick development time, and can potentially affect tick interactions with pathogens and with vertebrate hosts. We studied the effect of ambient temperature on duration of attachment of larval blacklegged ticks, Ixodes scapularis Say, to eastern fence lizards, Sceloporus undulatus (Bose & Daudin). Feeding periods of larvae that attached to lizards under preferred temperature conditions for the lizards (WARM treatment: temperatures averaged 36.6°C at the top of the cage and 25.8°C at the bottom, allowing behavioral thermoregulation) were shorter than for larvae on lizards held under cool conditions (COOL treatment temperatures averaged 28.4°C at top of cage and 24.9°C at the bottom). The lizards were infested with larvae four times at roughly monthly intervals. Larval numbers successfully engorging and dropping declined and feeding period was longer after the first infestation.

  6. Change your diet or die: predator-induced shifts in insectivorous lizard feeding ecology.

    PubMed

    Hawlena, Dror; Pérez-Mellado, Valentín

    2009-08-01

    Animal feeding ecology and diet are influenced by the fear of predation. While the mechanistic bases for such changes are well understood, technical difficulties often prevent testing how these mechanisms interact to affect a mesopredator's diet in natural environments. Here, we compared the insectivorous lizard Acanthodactylus beershebensis' feeding ecology and diet between high- and low-risk environments, using focal observations, intensive trapping effort and fecal pellet analysis. To create spatial variation in predation risk, we planted "artificial trees" in a scrubland habitat that lacks natural perches, allowing avian predators to hunt for lizards in patches that were previously unavailable to them. Lizards in elevated-risk environments became less mobile but did not change their microhabitat use or temporal activity. These lizards changed their diet, consuming smaller prey and less plant material. We suggest that diet shifts were mainly because lizards from risky environments consumed prey items that required shorter handling time. PMID:19466458

  7. Insects, birds and lizards as pollinators of the largest-flowered Scrophularia of Europe and Macaronesia

    PubMed Central

    Ortega-Olivencia, Ana; Rodríguez-Riaño, Tomás; Pérez-Bote, José L.; López, Josefa; Mayo, Carlos; Valtueña, Francisco J.; Navarro-Pérez, Marisa

    2012-01-01

    Background and Aims It has traditionally been considered that the flowers of Scrophularia are mainly pollinated by wasps. We studied the pollination system of four species which stand out for their large and showy flowers: S. sambucifolia and S. grandiflora (endemics of the western Mediterranean region), S. trifoliata (an endemic of the Tyrrhenian islands) and S. calliantha (an endemic of the Canary Islands). Our principal aim was to test whether these species were pollinated by birds or showed a mixed pollination system between insects and birds. Methods Censuses and captures of insects and birds were performed to obtain pollen load transported and deposited on the stigmas. Also, a qualitative and quantitative analysis of the flowers and inflorescences was carried out. Key Results Flowers were visited by Hymenoptera and by passerine birds. The Canarian species was the most visited by birds, especially by Phylloscopus canariensis, and its flowers were also accessed by juveniles of the lizard Gallotia stehlini. The most important birds in the other three species were Sylvia melanocephala and S. atricapilla. The most important insect-functional groups in the mixed pollination system were: honey-bees and wasps in S. sambucifolia; bumble-bees and wasps in S. grandiflora; wasps in S. trifoliata; and a small bee in S. calliantha. Conclusions The species studied show a mixed pollination system between insects and passerine birds. In S. calliantha there is, in addition, a third agent (juveniles of Gallotia stehlini). The participation of birds in this mixed pollination system presents varying degrees of importance because, while in S. calliantha they are the main pollinators, in the other species they interact to complement the insects which are the main pollinators. A review of different florae showed that the large showy floral morphotypes of Scrophularia are concentrated in the western and central Mediterranean region, Macaronesia and USA (New Mexico). PMID:22021816

  8. Ecological disturbance in a sandhills prairie: impact and importance to the lizard community on Arapaho Prairie in western Nebraska

    SciTech Connect

    Ballinger, R.E.; Jones, S.M.

    1985-01-01

    Lizard species occurring in the sandhills prairie of western Nebraska are typically restricted to microhabitats which have sparse vegetation. The fence lizard (Sceloporus undulatus) and the lesser earless lizard (Holbrookia maculata) are especially abundant in open blowouts. Only the six-lined racerunner (Cnemidophorus sexlineatus) occupies microhabitats with dense grass. Since cattle grazing was discontinued on Arapaho Prairie in 1977, associated vegetational changes have tended to reduce the microhabitats available for lizards. As a result of the decreased disturbance to the vegetation, lizards have become more restricted and less abundant on Arapaho Prairie. 19 references, 1 figure, 3 tables.

  9. Thermal dependence of sprint performance in the lizard Psammodromus algirus along a 2200-meter elevational gradient: Cold-habitat lizards do not perform better at low temperatures.

    PubMed

    Zamora-Camacho, Francisco Javier; Rubiño-Hispán, María Virtudes; Reguera, Senda; Moreno-Rueda, Gregorio

    2015-08-01

    Sprint speed has a capital relevance in most animals' fitness, mainly for fleeing from predators. Sprint performance is maximal within a certain range of body temperatures in ectotherms, whose thermal upkeep relies on exogenous thermal sources. Ectotherms can respond to diverse thermal environments either by shifting their thermal preferences or maintaining them through different adaptive mechanisms. Here, we tested whether maximum sprint speed of a lizard that shows conservative thermal ecology along a 2200-meter elevational gradient differs with body temperature in lizards from different elevations. Lizards ran faster at optimum than at suboptimum body temperature. Notably, high-elevation lizards were not faster than mid- and low-elevation lizards at suboptimum body temperature, despite their low-quality thermal environment. This result suggests that both preferred body temperature and thermal dependence of speed performance are co-adapted along the elevational gradient. High-elevation lizards display a number of thermoregulatory strategies that allow them to achieve high optimum body temperatures in a low thermal-quality habitat and thus maximize speed performance. As for reproductive condition, we did not find any effect of it on sprint speed, or any significant interaction with elevation or body temperature. However, strikingly, gravid females were significantly slower than males and non-gravid females at suboptimum temperature, but performed similarly well at optimal temperature. PMID:26267503

  10. MARINE BOTTOM COMMUNITIES OF BLOCK ISLAND WATERS

    EPA Science Inventory

    The sea has long been an integral part of Block Island's natural history, beginning when the rising sea surrounded the high spot on a Pleistocene terminal moraine that became Block Island. The southern New England continental shelf, which lies around Block Island, and the Great S...

  11. Thermoregulatory consequences of salt loading in the lizard Pogona vitticeps.

    PubMed

    Scarpellini, Carolina da Silveira; Bícego, Kênia C; Tattersall, Glenn J

    2015-04-15

    Previous research has demonstrated that dehydration increases the threshold temperature for panting and decreases the thermal preference of lizards. Conversely, it is unknown whether thermoregulatory responses such as shuttling and gaping are similarly influenced. Shuttling, as an active behavioural response, is considered one of the most effective thermoregulatory behaviours, whereas gaping has been proposed to be involved in preventing brain over-heating in lizards. In this study we examined the effect of salt loading, a proxy for increased plasma osmolality, on shuttling and gaping in Pogona vitticeps. Then, we determined the upper and lower escape ambient temperatures (UETa and LETa), the percentage of time spent gaping, the metabolic rate (V̇O2 ), the evaporative water loss (EWL) during gaping and non-gaping intervals and the evaporative effectiveness (EWL/V̇O2 ) of gaping. All experiments were performed under isotonic (154 mmol l(-1)) and hypertonic saline injections (625, 1250 or 2500 mmol l(-1)). Only the highest concentration of hypertonic saline altered the UETa and LETa, but this effect appeared to be the result of diminishing the animal's propensity to move, instead of any direct reduction in thermoregulatory set-points. Nevertheless, the percentage of time spent gaping was proportionally reduced according to the saline concentration; V̇O2 was also decreased after salt loading. Thermographic images revealed lower head than body surface temperatures during gaping; however this difference was inhibited after salt loading. Our data suggest that EWL/V̇O2 is raised during gaping, possibly contributing to an increase in heat transfer away from the lizard, and playing a role in head or brain cooling. PMID:25714566

  12. Field energetics and foraging mode of Kalahari lacertid lizards

    SciTech Connect

    Nagy, K.A.; Huey, R.B.; Bennett, A.F.

    1984-04-01

    The authors examined the energetic costs associated with foraging mode in the widely foraging lizard Eremias lugubris (mean mass 3.83 g) and the sit-and-wait lizard Eremias lineoocellata (3.27 g). These lizards are broadly sympatric in the Kalahari desert. The widely foraging species had significantly higher field metabolic rates (800 vs. 544 J/d, as measured with doubly labeled water), feeding rates (metabolizable energy of 1165 vs. 739 J/d), production rates (365 vs. 195 J/d) and water influx rates (0.285 vs. 0.156 mL/d). Measurements were made before the reproductive season began; there were no significant differences in these measures between sexes within either species. Resting metabolic rates (measured as O/sub 2/ consumed) were similar at 37/sup 0/C (0.240 vs. 0.252 mL g/sup -1/ H/sup -1/) and 26/sup 0/ (0.094 vs. 0.103 mL g/sup -1/ h/sup -1/), the field active and nocturnal burrow temperatures respectively, of both species. Field metabolic rates, on a 24-h basis, were 3.1 x resting in E. lugubris and 2.2 x resting in E. lineoocellata. Energy expenditures during the activity period were 12.0 x resting in the wide forager and 2.8 x resting in the sit-and-wait predator. Foraging efficiency (metabolizable energy gained while foraging/total energy spent while foraging) was higher in the wide forager (2.0 than in the sit-and-wait predator. The wide forager grew nearly twice as fast as did the sit-and-wait predator during this study. On an annual basis, variation in food availability or differences in predation rate may alter the relative fitness of these foraging modes.

  13. Food chemical discriminations by an herbivorous lizard, Corucia zebrata.

    PubMed

    Cooper, W E

    2000-03-01

    Adjustment of chemosensory response to diet should be apparent in evolutionary changes corresponding to dietary shifts. Because most lizards are generalist predators of small animals, relationships between chemosensory behavior and diet are difficult to detect. Nevertheless, the evolution of herbivory by a small number of lizards provides an opportunity to detect any corresponding change in response to plant chemicals. I studied tongue-flicking and biting by the large, herbivorous scincid lizard Corucia zebrata in response to chemical cues from crickets, romaine lettuce, and control stimuli presented on cotton swabs. The skinks exhibited significantly stronger response to plant and animal chemicals than to controls for several variables: greater number of individuals that bit swabs, shorter latency to bite, greater rate of tongue-flicks, and greater tongue-flick attack score. The clearest differences were observed for tongue-flick attack score, a composite variable that combines the effects of tongue-flicking and biting. An insectivorous member of the same subfamily, Scincella lateralis, shows strong tongue-flicking and biting response to chemical prey cues, but not to plant chemicals. This suggests that response to plant chemicals by C. zebrata may have evolved in tandem with the incorporation of plants into the diet and that response to cricket chemicals has been retained, perhaps due to similarities between plant and animal food. The findings support the hypothesis that dietary shifts induce corresponding changes in chemosensory response, but provide only a single independent contrast for a study of correlated evolution between plant diet and chemosensory response to plants. J. Exp. Zool. 286:372-378, 2000. PMID:10684560

  14. 33 CFR 117.720 - Great Channel.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Great Channel. 117.720 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.720 Great Channel. The draw of the County of Cape May bridge, mile 0.7, between Stone Harbor and Nummy Island, shall open on signal...

  15. 33 CFR 117.720 - Great Channel.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Great Channel. 117.720 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.720 Great Channel. The draw of the County of Cape May bridge, mile 0.7, between Stone Harbor and Nummy Island, shall open on signal...

  16. 33 CFR 117.720 - Great Channel.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Great Channel. 117.720 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.720 Great Channel. The draw of the County of Cape May bridge, mile 0.7, between Stone Harbor and Nummy Island, shall open on signal...

  17. 33 CFR 117.720 - Great Channel.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Great Channel. 117.720 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.720 Great Channel. The draw of the County of Cape May bridge, mile 0.7, between Stone Harbor and Nummy Island, shall open on signal...

  18. 33 CFR 117.720 - Great Channel.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Great Channel. 117.720 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.720 Great Channel. The draw of the County of Cape May bridge, mile 0.7, between Stone Harbor and Nummy Island, shall open on signal...

  19. Seabird Modulations of Isotopic Nitrogen on Islands

    PubMed Central

    Caut, Stéphane; Angulo, Elena; Pisanu, Benoit; Ruffino, Lise; Faulquier, Lucie; Lorvelec, Olivier; Chapuis, Jean-Louis; Pascal, Michel; Vidal, Eric; Courchamp, Franck

    2012-01-01

    The transport of nutrients by migratory animals across ecosystem boundaries can significantly enrich recipient food webs, thereby shaping the ecosystems’ structure and function. To illustrate the potential role of islands in enabling the transfer of matter across ecosystem boundaries to be gauged, we investigated the influence of seabirds on nitrogen input on islands. Basing our study on four widely differing islands in terms of their biogeography and ecological characteristics, sampled at different spatial and temporal intervals, we analyzed the nitrogen isotopic values of the main terrestrial ecosystem compartments (vascular plants, arthropods, lizards and rodents) and their relationship to seabird values. For each island, the isotopic values of the ecosystem were driven by those of seabirds, which ultimately corresponded to changes in their marine prey. First, terrestrial compartments sampled within seabird colonies were the most enriched in δ15N compared with those collected at various distances outside colonies. Second, isotopic values of the whole terrestrial ecosystems changed over time, reflecting the values of seabirds and their prey, showing a fast turnover throughout the ecosystems. Our results demonstrate that seabird-derived nutrients not only spread across the terrestrial ecosystems and trophic webs, but also modulate their isotopic values locally and temporally on these islands. The wealth of experimental possibilities in insular ecosystems justifies greater use of these model systems to further our understanding of the modalities of trans-boundary nutrient transfers. PMID:22723945

  20. Diagnostic sensitivity of ultrasound, radiography and computed tomography for gender determination in four species of lizards.

    PubMed

    Di Ianni, Francesco; Volta, Antonella; Pelizzone, Igor; Manfredi, Sabrina; Gnudi, Giacomo; Parmigiani, Enrico

    2015-01-01

    Gender determination is frequently requested by reptile breeders, especially for species with poor or absent sexual dimorphism. The aims of the current study were to describe techniques and diagnostic sensitivities of ultrasound, radiography, and computed tomography for gender determination (identification of hemipenes) in four species of lizards. Nineteen lizards of known sex, belonging to four different species (Pogona vitticeps, Uromastyx aegyptia, Tiliqua scincoides, Gerrhosaurus major) were prospectively enrolled. With informed owner consent, ultrasound, noncontrast CT, contrast radiography, and contrast CT (with contrast medium administered into the cloaca) were performed in conscious animals. Imaging studies were reviewed by three different operators, each unaware of the gender of the animals and of the results of the other techniques. The lizard was classified as a male when hemipenes were identified. Nineteen lizards were included in the study, 10 females and nine males. The hemipenes were seen on ultrasound in only two male lizards, and appeared as oval hypoechoic structures. Radiographically, hemipenes filled with contrast medium appeared as spindle-shaped opacities. Noncontrast CT identified hemipenes in only two lizards, and these appeared as spindle-shaped kinked structures with hyperattenuating content consistent with smegma. Hemipenes were correctly identified in all nine males using contrast CT (accuracy of 100%). Accuracy of contrast radiography was excellent (94.7%). Accuracy of ultrasound and of noncontrast CT was poor (64.3% and 63.1%, respectively). Findings from the current study supported the use of contrast CT or contrast radiography for gender determination in lizards. PMID:25065912

  1. The relative influence of road characteristics and habitat on adjacent lizard populations in arid shrublands

    USGS Publications Warehouse

    Hubbard, Kaylan A.; Chalfoun, Anna L.; Gerow, Kenneth G.

    2016-01-01

    As road networks continue to expand globally, indirect impacts to adjacent wildlife populations remain largely unknown. Simultaneously, reptile populations are declining worldwide and anthropogenic habitat loss and fragmentation are frequently cited causes. We evaluated the relative influence of three different road characteristics (surface treatment, width, and traffic volume) and habitat features on adjacent populations of Northern Sagebrush Lizards (Sceloporus graciosus graciosus), Plateau Fence Lizards (S. tristichus), and Greater Short-Horned Lizards (Phrynosoma hernandesi) in mixed arid shrubland habitats in southwest Wyoming. Neither odds of lizard presence nor relative abundance was significantly related to any of the assessed road characteristics, although there was a trend for higher Sceloporus spp. abundance adjacent to paved roads. Sceloporus spp. relative abundance did not vary systematically with distance to the nearest road. Rather, both Sceloporus spp. and Greater Short-Horned Lizards were associated strongly with particular habitat characteristics adjacent to roads. Sceloporus spp. presence and relative abundance increased with rock cover, relative abundance was associated positively with shrub cover, and presence was associated negatively with grass cover. Greater Short-Horned Lizard presence increased with bare ground and decreased marginally with shrub cover. Our results suggest that habitat attributes are stronger correlates of lizard presence and relative abundance than individual characteristics of adjacent roads, at least in our system. Therefore, an effective conservation approach for these species may be to consider the landscape through which new roads and their associated development would occur, and the impact that placement could have on fragment size and key habitat elements.

  2. Prey snapping and visual distance estimation in Texas horned lizards, Phrynosoma cornutum.

    PubMed

    Ott, Matthias; Ostheim, Joachim; Sherbrooke, Wade C

    2004-08-01

    Captive Texas horned lizards were high-speed videotaped while feeding on ants in order to study the role of vision in facilitating tongue-protrusion capture of prey. Analysis of tongue movements revealed that prey snapping in these lizards is not a typical fixed-action pattern. By contrast, it is variable in performance and duration. Lizards adjusted head and tongue direction during the strike, within a few milliseconds, in response to movements of the prey. The duration of a typical tongue strike was 100-150 ms. The strike duration was prolonged after ophthalmic lenses were placed in front of one or both eyes. These lenses were used to investigate whether horned lizards use accommodation to judge prey distance. Focal changes of negatively powered ophthalmic lenses (employed monocularly) induced a clear underestimation of prey distance by the lizards, confirming the hypothesized expectation that accommodation is used for depth perception. The effect of the lenses was different in the two animals tested with monocular restriction. This, together with the lack of difference in responses by the lizards when untreated and when both eyes were lens covered (binocular treatment of equal power, -9 D), illustrates that horned lizards also use other visual parameters for depth perception. PMID:15277561

  3. Prevalence of virus-like particles within a staghorn scleractinian coral ( Acropora muricata) from the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Patten, N. L.; Harrison, P. L.; Mitchell, J. G.

    2008-09-01

    Transmission electron microscopy (TEM) was used to determine whether Acropora muricata coral colonies from the Great Barrier Reef (GBR), Australia, harboured virus-like particles (VLPs). VLPs were present in all coral colonies sampled at Heron Island (southern GBR) and in tagged coral colonies sampled in at least two of the three sampling periods at Lizard Island (northern GBR). VLPs were observed within gastrodermal and epidermal tissues, and on rarer occasions, within the mesoglea. These VLPs had similar morphologies to known prokaryotic and eukaryotic viruses in other systems. Icosahedral VLPs were observed most frequently, however, filamentous VLPs (FVLPs) and phage were also noted. There were no clear differences in VLP size, morphology or location within the tissues with respect to sample date, coral health status or site. The most common VLP morphotype exhibited icosahedral symmetry, 120-150 nm in diameter, with an electron-dense core and an electronlucent membrane. Larger VLPs of similar morphology were also common. VLPs occurred as single entities, in groups, or in dense clusters, either as free particles within coral tissues, or within membrane-bound vacuoles. VLPs were commonly observed within the perinuclear region, with mitochondria, golgi apparatus and crescent-shaped particles frequently observed within close proximity. The host(s) of these observed VLPs was not clear; however, the different sizes and morphologies of VLPs observed within A. muricata tissues suggest that viruses are infecting either the coral animal, zooxanthellae, intracellular bacteria and/or other coral-associated microbiota, or that the one host is susceptible to infection from more than one type of virus. These results add to the limited but emerging body of evidence that viruses represent another potentially important component of the coral holobiont.

  4. Postautotomy tail activity in the Balearic lizard, Podarcis lilfordi

    NASA Astrophysics Data System (ADS)

    Pafilis, Panayiotis; Pérez-Mellado, Valentín; Valakos, Efstratios

    2008-03-01

    Caudal autotomy is an effective antipredator strategy widespread among lizards. The shed tail thrashes vigorously for long periods to distract the predator and facilitate the lizard’s escape. This movement is maintained by energy supplied by the anaerobic conversion of glycogen into lactate. It has been suggested that lactate accumulation serves as an index for the vigor of tail thrashing. We made three predictions: (1) tail loss frequency should be higher under heavier predation regime, (2) the duration of postautotomy tail movement should be extended in populations under heavy predation pressure as an adaptation to the higher risk and the increased need for defense, and (3) as result, lactate in these tail tissues should be concentrated at higher levels. To eliminate the impact of phylogeny and environmental factors on the interpretation of our result, we focused exclusively on one species, the Balearic lizard ( Podarcis lilfordi). We studied three populations under different predation pressure but sharing the same climatic conditions. We found no differences among the studied populations either in postautotomy duration of tail movement or in levels of final lactate accumulation while autotomy frequency was higher where predation pressure was more intense. Τail loss effectiveness is directly influenced by the level of predation, while secondary features of the trait appear to remain independent from the impact of environment.

  5. Age structured dynamical model for an endangered lizard Eulamprus leuraensis

    NASA Astrophysics Data System (ADS)

    Supriatna, A. K.; Rachmadani, Q.; Ilahi, F.; Anggriani, N.; Nuraini, N.

    2014-02-01

    The Blue Mountains Water Skink, Eulamprus leuraensis, is listed as an endangered species under the IUCN Red List. This lizard species has a typical characteristic of growth with a low fecundity. It is known that the offspring quality may decline with maternal age of the parents despite they can grow rapidly from neonatal size to adult size within two to three years. It is also believed that low adult survival rates and specialization on rare and fragmented type of habitat are the main cause leading to the endangered status of the lizard. A mathematical model with age structure for Eulamprus leuraensis, taking into account the variation of survival rate in each structure and the declining of offspring quality with respect to maternal age is considered here. Stable coexistence of non-trivial equilibriumis shown. It is also shown that an endangered status is due to combination oflow reproductive output and low rates of adult survival. Further, understanding the age structure within populations can facilitate efective management of the endangered species.

  6. Motion perception and visual signal design in Anolis lizards

    PubMed Central

    Fleishman, Leo J.; Pallus, Adam C.

    2010-01-01

    Anolis lizards communicate with displays consisting of motion of the head and body. Early portions of long-distance displays require movements that are effective at eliciting the attention of potential receivers. We studied signal-motion efficacy using a two-dimensional visual-motion detection (2DMD) model consisting of a grid of correlation-type elementary motion detectors. This 2DMD model has been shown to accurately predict Anolis lizard behavioural response. We tested different patterns of artificially generated motion and found that an abrupt 0.3° shift of position in less than 100 ms is optimal. We quantified motion in displays of 25 individuals from five species. Four species employ near-optimal movement patterns. We tested displays of these species using the 2DMD model on scenes with and without moderate wind. Display movements can easily be detected, even in the presence of windblown vegetation. The fifth species does not typically use the most effective display movements and display movements cannot be discerned by the 2DMD model in the presence of windblown vegetation. A number of Anolis species use abrupt up-and-down head movements approximately 10 mm in amplitude in displays, and these movements appear to be extremely effective for stimulating the receiver visual system. PMID:20591869

  7. Intercontinental community convergence of ecology and morphology in desert lizards

    PubMed Central

    Melville, Jane; Harmon, Luke J; Losos, Jonathan B

    2005-01-01

    Evolutionary ecologists have long debated the extent to which communities in similar environments but different geographic regions exhibit convergence. On the one hand, if species' adaptations and community structure are determined by environmental features, convergence would be expected. However, if historical contingencies have long-lasting effects convergence would be unlikely. Most studies to date have emphasized the differences between communities in similar environments and little quantitative evidence for convergence exists. The application of comparative phylogenetic methods to ecological studies provides an opportunity to further investigate hypotheses of convergence. We compared the evolutionary patterns of structural ecology and morphology of 42 species of iguanian lizards from deserts of Australia and North America. Using a comparative approach, we found that evolutionary convergence of ecology and morphology occurs both in overall, community-wide patterns and in terms of pairs of highly similar intercontinental pairs of species. This result indicates that in these desert lizards, deterministic adaptive evolution shapes community patterns and overrides the historical contingencies unique to particular lineages. PMID:16537126

  8. Retinal characteristics of the ornate dragon lizard, Ctenophorus ornatus.

    PubMed

    Barbour, Helen R; Archer, Michael A; Hart, Nathan S; Thomas, Nicole; Dunlop, Sarah A; Beazley, Lyn D; Shand, Julia

    2002-09-01

    The retina of a diurnal insectivorous lizard, Ctenophorus ornatus (Agamidae) was investigated using microspectrophotometry and light and electron microscopy. A prominent broad yellow band was observed that extended across the mid-retina. The yellow coloration was found to originate from both oil droplets and diffuse pigmentation within cone inner segments. Microspectrophotometric analysis revealed yellow oil droplets with variable absorption of wavelengths below 520 nm and transparent oil droplets with no detectable absorptance between 350 and 750 nm. Cones with transparent oil droplets lacked the diffuse yellow pigmentation. The mean wavelengths of maximum absorbance of visual pigments in the isolated cone outer segments were at 440, 493, and 571 nm. The retina was found to possess a deep convexiclivate fovea located within the yellow band, slightly dorsotemporal of the retinal midpoint. The topography of the retinal ganglion cells revealed that the fovea was contained within an area centralis. Photoreceptors were either single (80%) or unequal double (20%) cones. Within the region of the fovea, the cones were approximately 20% the diameter of those in the peripheral retina. Colored oil droplets and yellow pigment may increase visual acuity by absorbing short wavelength light scattered either by the atmosphere or the optical structures of the eye. The presence of a fovea containing slender cone photoreceptors and three visual pigments suggests that the lizard has high acuity and the potential for color vision. PMID:12209847

  9. Mother-offspring interactions affect natal dispersal in a lizard.

    PubMed Central

    Le Galliard, Jean-François; Ferrière, Régis; Clobert, Jean

    2003-01-01

    Interactions between relatives operate strong selective pressures on dispersal. Recently, a correlative study in the common lizard (Lacerta vivipara) suggested that natal dispersal might respond plastically to mother-offspring interactions. Here, we describe a factorial experiment supporting this observation. Two crossed treatments were applied to experimental patches of the common lizard: (i) presence versus absence of the mother, inducing a difference of kinship in offspring neighbourhoods; and (ii) high versus low patch density, resulting in two levels of conspecific abundance and modulating the effect of mother presence on the average kinship within a patch. Dispersal of the same cohort of offspring was observed at the juvenile and yearling stages. We found a sex-dependent response of offspring dispersal to the removal of the mother at the two stages. During the juvenile stage, higher dispersal was found in females in the presence of the mother, with males unaffected. During the yearling stage, the responses of both sexes to the presence of the mother opposed each other. In addition, we found a negative relationship between dispersal and patch density at the juvenile stage. No interaction between density and the presence of the mother was detected, which suggests that behavioural responses to kinship and density are disconnected and that kinship is assessed at a small social scale. We discuss the role of competition and inbreeding avoidance to explain the observed pattern. PMID:12816655

  10. Conserved sex chromosomes across adaptively radiated Anolis lizards.

    PubMed

    Rovatsos, Michail; Altmanová, Marie; Pokorná, Martina; Kratochvíl, Lukáš

    2014-07-01

    Vertebrates possess diverse sex-determining systems, which differ in evolutionary stability among particular groups. It has been suggested that poikilotherms possess more frequent turnovers of sex chromosomes than homoiotherms, whose effective thermoregulation can prevent the emergence of the sex reversals induced by environmental temperature. Squamate reptiles used to be regarded as a group with an extensive variability in sex determination; however, we document how the rather old radiation of lizards from the genus Anolis, known for exceptional ecomorphological variability, was connected with stability in sex chromosomes. We found that 18 tested species, representing most of the phylogenetic diversity of the genus, share the gene content of their X chromosomes. Furthermore, we discovered homologous sex chromosomes in species of two genera (Sceloporus and Petrosaurus) from the family Phrynosomatidae, serving here as an outgroup to Anolis. We can conclude that the origin of sex chromosomes within iguanas largely predates the Anolis radiation and that the sex chromosomes of iguanas remained conserved for a significant part of their evolutionary history. Next to therian mammals and birds, Anolis lizards therefore represent another adaptively radiated amniote clade with conserved sex chromosomes. We argue that the evolutionary stability of sex-determining systems may reflect an advanced stage of differentiation of sex chromosomes rather than thermoregulation strategy. PMID:24433436

  11. Phylogeography of Balkan wall lizard (Podarcis taurica) and its relatives inferred from mitochondrial DNA sequences.

    PubMed

    Poulakakis, N; Lymberakis, P; Valakos, E; Pafilis, P; Zouros, E; Mylonas, M

    2005-07-01

    Wall lizards of the genus Podarcis (Sauria, Lacertidae) comprise 17 currently recognized species in southern Europe, where they are the predominant reptile group. The taxonomy of Podarcis is complex and unstable. Based on DNA sequence data the species of Podarcis falls into four main groups that have substantial geographical conherence (western island group, southwestern group, Italian group and Balkan group). The Balkan species are divided in two subgroups: the subgroup of Podarcis taurica (P. taurica, P. milensis, P. gaigeae and perhaps P. melisellensis), and the subgroup of Podarcis erhardii (P. erhardii and P. peloponnesiaca). We addressed the question of phylogenetic relations among the species of the P. taurica subgroup encountered in Greece, as they can be inferred from partial mtDNA (cyt b and 16S) sequences. Our data support the monophyly of P. taurica subgroup and suggest that P. gaigeae, P. milensis and P. melisellensis form a clade, which thereinafter connects to P. taurica. Within the previous clade, P. gaigeae is more closely related to P. milensis than to P. melisellensis. However, the specimens of P. taurica were subdivided in two different groups. The first one includes the specimens from northeastern Greece, and the other group includes the specimens from the rest of continental Greece and Ionian islands. Because the molecular clock of the cyt b and 16 rRNA genes was not rejected in our model test, it is possible to estimate times of speciation events. Based on the splitting of the island of Crete from Peloponnisos [c. 5 million years ago (Ma)], the evolutionary rate for the cyt b is 1.55% per million years (Myr) and for the 16S rRNA is 0.46% per Myr. These results suggest that the evolutionary history of P. taurica in Greece is more complex than a single evolutionary invasion. The data analysed, stress the need for a reconsideration of the evolutionary history of Greek Podarcis species and help overcome difficulties that classical taxonomy has

  12. Sociality, stress, and the corpus striatum of the green anolis lizard.

    PubMed

    Greenberg, Neil

    2003-08-01

    The green anolis lizard, Anolis carolinensis, is a uniquely convenient species with great potential for providing insights about the causes and consequences of social behavior from an evolutionary perspective. In this species, social interactions are mediated by visual displays in which specific units of behavior are combined in various ways to communicate several more-or-less specific messages. Two related research programs that utilize this species converge in provocative ways to provide insight into this phenomenon. The first program is centered on the basal ganglia, now known to be crucial to the expression of aggressive territoriality in this species, and the second research program examines the way the physiological stress response is involved in aggression and its subsequent adaptive outcomes. Both the neural and the neuroendocrine systems affect the progress of social interactions as well as the subsequent social dominance relationships when combatants subsequently live together. Further, because body color depends almost exclusively on the stress response, skin color provides a unique in situ bioassay of otherwise inaccessible information about the animal's internal state. The fullest understanding of the physiological ethology of this model species will depend on an interdisciplinary approach that considers both proximate (physiological) and ultimate (evolutionary) causes of displays. Questions thus arising include how the nervous system controls and assembles the specific units of behavior-motor patterns and autonomic reflexes-into displays that are adaptive in specific contexts. PMID:12954437

  13. A performance-based cost to honest signalling in male green anole lizards (Anolis carolinensis).

    PubMed

    Lailvaux, Simon P; Gilbert, Rebecca L; Edwards, Jessica R

    2012-07-22

    Sexual signals are considered costly to produce and maintain under the handicap paradigm, and the reliability of signals is in turn thought to be maintained by these costs. Although previous studies have investigated the costly nature of signal production, few have considered whether honesty might be maintained not by the costliness of the signal itself, but by the costs involved in producing the signalled trait. If such a trait is itself costly to produce, then the burden of energetic investment may fall disproportionately on that trait, in addition to any costs of signal maintenance that may also be operating. Under limited resource conditions, these costs may therefore be great enough to disrupt an otherwise reliable signal-to-trait relationship. We present experimental evidence showing that dietary restriction decouples the otherwise honest relationship between a signal (dewlap size) and a whole-organism performance trait (bite force) in young adult male Anolis carolinensis lizards. Specifically, while investment in dewlap size is sustained under low-resource condition relative to the high-resource treatment, investment in bite force is substantially lower. Disruption of the otherwise honest dewlap size to bite force relationship is therefore driven by costs associated with the expression of performance rather than the costs of signal production in A. carolinensis. PMID:22418258

  14. A performance-based cost to honest signalling in male green anole lizards (Anolis carolinensis)

    PubMed Central

    Lailvaux, Simon P.; Gilbert, Rebecca L.; Edwards, Jessica R.

    2012-01-01

    Sexual signals are considered costly to produce and maintain under the handicap paradigm, and the reliability of signals is in turn thought to be maintained by these costs. Although previous studies have investigated the costly nature of signal production, few have considered whether honesty might be maintained not by the costliness of the signal itself, but by the costs involved in producing the signalled trait. If such a trait is itself costly to produce, then the burden of energetic investment may fall disproportionately on that trait, in addition to any costs of signal maintenance that may also be operating. Under limited resource conditions, these costs may therefore be great enough to disrupt an otherwise reliable signal-to-trait relationship. We present experimental evidence showing that dietary restriction decouples the otherwise honest relationship between a signal (dewlap size) and a whole-organism performance trait (bite force) in young adult male Anolis carolinensis lizards. Specifically, while investment in dewlap size is sustained under low-resource condition relative to the high-resource treatment, investment in bite force is substantially lower. Disruption of the otherwise honest dewlap size to bite force relationship is therefore driven by costs associated with the expression of performance rather than the costs of signal production in A. carolinensis. PMID:22418258

  15. Combined finite element and multibody dynamics analysis of biting in a Uromastyx hardwickii lizard skull

    PubMed Central

    Moazen, M; Curtis, N; Evans, S E; O'Higgins, P; Fagan, M J

    2008-01-01

    Lizard skulls vary greatly in shape and construction, and radical changes in skull form during evolution have made this an intriguing subject of research. The mechanics of feeding have surely been affected by this change in skull form, but whether this is the driving force behind the change is the underlying question that we are aiming to address in a programme of research. Here we have implemented a combined finite element analysis (FEA) and multibody dynamics analysis (MDA) to assess skull biomechanics during biting. A skull of Uromastyx hardwickii was assessed in the present study, where loading data (such as muscle force, bite force and joint reaction) for a biting cycle were obtained from an MDA and applied to load a finite element model. Fifty load steps corresponding to bilateral biting towards the front, middle and back of the dentition were implemented. Our results show the importance of performing MDA as a preliminary step to FEA, and provide an insight into the variation of stress during biting. Our findings show that higher stress occurs in regions where cranial sutures are located in functioning skulls, and as such support the hypothesis that sutures may play a pivotal role in relieving stress and producing a more uniform pattern of stress distribution across the skull. Additionally, we demonstrate how varying bite point affects stress distributions and relate stress distributions to the evolution of metakinesis in the amniote skull. PMID:19014357

  16. Long Island Solar Farm

    SciTech Connect

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  17. Monitor lizard bite-induced acute kidney injury--a case report.

    PubMed

    Vikrant, Sanjay; Verma, Balbir Singh

    2014-04-01

    Envenomations by venomous lizards are rare. Monitor lizard bite-induced acute kidney injury (AKI) is a previously unreported complication in humans. A 55-year-old female was bitten on her right leg during farming activity by a monitor lizard (Varanus bengalensis). The patient experienced severe local pain and bleeding from the wound, coagulopathy, hemolysis, rhabdomyolysis, sepsis, and AKI. Patient was treated with supportive care and peritoneal dialysis but succumbed to a sudden cardiac arrest. Post mortem kidney biopsy revealed pigment induced-acute tubular injury. AKI after monitor lizard envenomation is caused by acute tubular injury in the setting of intravascular hemolysis, rhabdomyolysis and sepsis. Coagulopathy and direct nephrotoxicity may be the other contributory factors in causing AKI. PMID:24341640

  18. Rates of pulmonary infection by pentastomids in lizards species from a restinga habitat in northeastern Brazil.

    PubMed

    Almeida, W O; Santana, G G; Vieira, W L S; Wanderley, I C; Ribeiro, S C

    2009-02-01

    Pulmonary parasitism by pentastomids was examined in two lizard species inhabiting an area of restinga vegetation (coastal sand dunes) situated in the municipality of Mataraca (6 degrees 29' S and 34 degrees 56' W), on the extreme northern coast of Paraíba State, Brazil. A total of 123 lizards were collected, being 75 specimens of Micrablepharus maximiliani (Gymnophtalmidae) and 48 specimens of Cnemidophorus ocellifer (Teiidae). Only a single species of Pentastomida (Raillietiella mottae) was found parasitizing three females M. maximiliani, with a prevalence of 4% and an average infection intensity of 2.3 +/- 1.3 (range 1-5). The infection rate by pentastomids encountered in the present study was similar to that seen with other species of restinga lizards. Raillietiella mottae is a generalist parasite species that is probably transmitted by common and widely distributed insects making up part of the diet of many insectivorous lizard species from northeastern Brazil. PMID:19347165

  19. Telling tails: selective pressures acting on investment in lizard tails.

    PubMed

    Fleming, Patricia A; Valentine, Leonie E; Bateman, Philip W

    2013-01-01

    Caudal autotomy is a common defense mechanism in lizards, where the animal may lose part or all of its tail to escape entrapment. Lizards show an immense variety in the degree of investment in a tail (i.e., length) across species, with tails of some species up to three or four times body length (snout-vent length [SVL]). Additionally, body size and form also vary dramatically, including variation in leg development and robustness and length of the body and tail. Autotomy is therefore likely to have fundamentally different effects on the overall body form and function in different species, which may be reflected directly in the incidence of lost/regenerating tails within populations or, over a longer period, in terms of relative tail length for different species. We recorded data (literature, museum specimens, field data) for relative tail length (n=350 species) and the incidence of lost/regenerating tails (n=246 species). We compared these (taking phylogeny into account) with intrinsic factors that have been proposed to influence selective pressures acting on caudal autotomy, including body form (robustness, body length, leg development, and tail specialization) and ecology (foraging behavior, physical and temporal niches), in an attempt to identify patterns that might reflect adaptive responses to these different factors. More gracile species have relatively longer tails (all 350 spp., P < 0.001; also significant for five of the six families tested separately), as do longer (all species, P < 0.001; Iguanidae, P < 0.05; Lacertidae, P < 0.001; Scindidae, P < 0.001), climbing (all species, P < 0.05), and diurnal (all species, P < 0.01; Pygopodidae, P < 0.01) species; geckos without specialized tails (P < 0.05); or active-foraging skinks (P < 0.05). We also found some relationships with the data for caudal autotomy, with more lost/regenerating tails for nocturnal lizards (all 246 spp., P < 0.01; Scindidae, P < 0.05), larger skinks (P < 0.05), climbing geckos (P < 0

  20. Influence of stress on gonadotrophin induced testicular recrudescence in the lizard Mabuya Carinata.

    PubMed

    Yajurvedi, H N; Menon, Sneha

    2005-07-01

    Administration (ip) of FSH (10 IU/0.1 ml distilled water (dw)/lizard/alternate days/30 days) to adult male lizards, Mabuya carinata, during the early recrudescence phase of the reproductive cycle caused activation of spermatogenic and steroidogenic activity of the testis, as shown by a significant increase in mean number of spermatogonia, primary spermatocytes and spermatids, and serum levels of testosterone, as compared to initial controls. In addition, there were abundant spermatozoa in the lumen of the seminiferous tubules. Interestingly, administration of a similar dosage of FSH to lizards exposed to stressors (handling, chasing, and noise randomly applied, five times a day for 30 days) resulted in a significant increase in mean number of spermatogonia and primary spermatocytes over initial control values, whereas the number of secondary spermatocytes and spermatids and serum levels of testosterone did not significantly differ from those of initial controls, and were significantly lower than FSH treated normal lizards. Further, spermatozoa were infrequently found in the seminiferous tubules of these lizards. Treatment controls (receiving 0.1 ml dw/lizard/alternate days for 30 days) did not show significant variation in mean number of spermatogonia, spermatocytes and spermatids, and serum levels of testosterone from initial controls. Another group of lizards was exposed to stressors and did not receive FSH. These lizards showed a significant decrease in mean number of secondary spermatocytes compared to treatment controls and all other parameters did not significantly differ from those of both control groups. The results reveal that gonadotrophin-induced spermatogonial proliferation occurs under stressful conditions, whereas progress of spermatogenesis beyond primary spermatocyte stage is impaired due to inhibition (under stress) of gonadotrophin induced steroidogenic activity in M. carinata. PMID:15945072

  1. The peak of thermoregulation effectiveness: Thermal biology of the Pyrenean rock lizard, Iberolacerta bonnali (Squamata, Lacertidae).

    PubMed

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2016-02-01

    We studied, at 2200m altitude, the thermal biology of the Pyrenean rock lizard, Iberolacerta bonnali, in the glacial cirque of Cotatuero (National Park of Ordesa, Huesca, Spain). The preferred thermal range (PTR) of I. bonnali indicates that it is a cold-adapted ectotherm with a narrow PTR (29.20-32.77°C). However, its PTR (3.57°C) is twice as wide as other Iberolacerta lizards, which may be explained by its broader historical distribution. The studied area is formed by a mosaic of microhabitats which offer different operative temperatures, so that lizards have, throughout their entire daily period of activity, the opportunity to choose the most thermally suitable substrates. I. bonnali achieves an effectiveness of thermoregulation of 0.95, which makes it the highest value found to date among the Lacertidae, and one of the highest among lizards. Their relatively wide distribution, their wider PTR, and their excellent ability of thermoregulation, would make I. bonnali lizards less vulnerable to climate change than other species of Iberolacerta. Thanks to its difficult access, the studied area is not visited by a large number of tourists, as are other areas of the National Park. Thus, it is a key area for the conservation of the Pyrenean rock lizard. By shuttling between suitable microhabitats, lizards achieve suitable body temperatures during all day. However, such thermally suitable microhabitats should vary in other traits than thermal quality, such as prey availability or predation risk. Hence, it seems that these not-thermal traits are not constraining habitat selection and thermoregulation in this population. Therefore, future research in this population may study the causes that would lead lizards to prioritize thermoregulation to such extent in this population. PMID:26857980

  2. Dicofol and DDT residues in lizard carcasses and bird eggs from Texas, Florida, and California

    USGS Publications Warehouse

    Clark, D.R.; Flickinger, Edward L.; White, D.H.; Hothem, R.L.; Belisle, A.A.

    1995-01-01

    Relatively high dicofol residues occured in some lizards in Texas citrus orchards in early summer when female lizards were producing eggs. The data from bird eggs were too few for conclusions, but to detect peak residue loads, future dicofol studies should concentrate on predaceous bird species likely to feed within the treated agricultural habitats, and collecting of eggs for analysis should begin within days after spray application.

  3. 75 FR 77801 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-14

    ...We, the U.S. Fish and Wildlife Service, propose to list the dunes sagebrush lizard (Sceloporus arenicolus), a lizard known from southeastern New Mexico and adjacent west Texas, as endangered under the Endangered Species Act of 1973, as amended. If we finalize the rule as proposed, it would extend the Act's protections to this species. We have determined that critical habitat for the dunes......

  4. The bioinvasion of Guam: inferring geographic origin, pace, pattern and process of an invasive lizard (Carlia) in the Pacific using multi-locus genomic data

    USGS Publications Warehouse

    Austin, C.C.; Rittmeyer, E.N.; Oliver, L.A.; Andermann, J.O.; Zug, G.R.; Rodda, G.H.; Jackson, N.D.

    2011-01-01

    Invasive species often have dramatic negative effects that lead to the deterioration and loss of biodiversity frequently coupled with the burden of expensive biocontrol programs and subversion of socioeconomic stability. The fauna and flora of oceanic islands are particularly susceptible to invasive species and the increase of global movements of humans and their products since WW II has caused numerous anthropogenic translocations and increased the ills of human-mediated invasions. We use a multi-locus genomic dataset to identify geographic origin, pace, pattern and historical process of an invasive scincid lizard (Carlia) that has been inadvertently introduced to Guam, the Northern Marianas, and Palau. This lizard is of major importance as its introduction is thought to have assisted in the establishment of the invasive brown treesnake (Boiga irregularis) on Guam by providing a food resource. Our findings demonstrate multiple waves of introductions that appear to be concordant with movements of Allied and Imperial Japanese forces in the Pacific during World War II.

  5. Galapagos Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  6. Vulnerability to climate change of Anolis allisoni in the mangrove habitats of Banco Chinchorro Islands, Mexico.

    PubMed

    Medina, Marlin; Fernández, Jimena B; Charruau, Pierre; de la Cruz, Fausto Méndez; Ibargüengoytía, Nora

    2016-05-01

    As niche specialist species, lizards from tropical environments are characterized by a low tolerance and high physiological sensitivity to temperature changes. The extent of vulnerability to thermal changes depends on the lizard's physiological plasticity to adjust the environmental changes. Herein we studied the thermal biology of Anolis allisoni, an endemic arboreal lizard from the tropical islands of the Banco Chinchorro Biosphere Reserve, Mexico, carried out during April and May 2012 and April 2014. We report field body (Tb) and preferred body temperatures in the laboratory (Tpref), operative temperatures (Te) and restriction of hours of activity. Anolis allisoni showed high and identical Tb and Tpref (33°C), not significantly different than the mean Te (32.15°C). The effectiveness of thermoregulation (E=-0.30) and the analysis of hours of restriction suggested that the high temperatures of Te (40-62.5°C) registered at midday (from 12:00 to 15:00) of A. allisoni habitat are hostile and force lizards to take refuge during a period of 3h of their daily time of activity. The scarcity of opportunities to find alternative refuges for thermoregulation in Banco Chinchorro point out the vulnerability of A. allisoni and the risk of local extinction when considering future predictions of increase in global environmental temperatures. PMID:27157328

  7. Great Barrier Reef

    Atmospheric Science Data Center

    2013-04-16

    ... reef, but a vast maze of reefs, passages, and coral cays (islands that are part of the reef). This nadir true-color image was acquired by ... visible in this image is Whitsunday Island, with smaller islands and reefs extending southeast, parallel to the coast. These include ...

  8. Male-biased predation of western green lizards by Eurasian kestrels

    NASA Astrophysics Data System (ADS)

    Costantini, David; Bruner, Emiliano; Fanfani, Alberto; Dell'Omo, Giacomo

    2007-12-01

    Selective predation can be an important force driving the evolution of organisms. In particular, sex-biased predation is expected to have implications for sexual selection, sex allocation and population dynamics. In this study, we analysed sex differences in the predation of the western green lizard ( Lacerta bilineata) by the Eurasian kestrel ( Falco tinnunculus) during the reproductive season. In addition, we investigated whether the rate of predation differed during the 8-year study period and among the three habitats studied. We collected lizard remains from nest boxes of kestrels. Freshly killed lizards were sexed by visual inspection, whilst the sex of head remains was assigned by analysing the cephalic scale morphology using geometric morphometrics. Our results show that the risk of being predated by a kestrel in our population was overall about 3.55 times higher for males than for females. To our knowledge this is the first study showing a male-biased predation in a lizard species. The selective predation of males was consistent between years over the 8-year study period (1999-2006) and also consistent between the three types of kestrel hunting habitat. Overall predation rates on lizards differed between habitats, depending on the year. We propose that the observed sex-biased predation is mainly due to sex differences in lizard behaviour.

  9. Coloration affects heating and cooling in three color morphs of the Australian bluetongue lizard, Tiliqua scincoides.

    PubMed

    Geen, Michael R S; Johnston, Gregory R

    2014-07-01

    The color-mediated thermoregulation hypothesis predicts that dark body color (low reflectance) allows organisms to gain heat more efficiently than does pale coloration (high reflectance). This prediction is intuitive and widely assumed to be true, but has poor empirical support. We used rare, captive-bred, mutant melanistic, albino and wild-type Australian bluetongue lizards, Tiliqua scincoides to measure the effects of skin reflectance on the heating and cooling rates. We measured heating under an artificial radiant heat source and cooling rates in an ice-cooled box using live lizards in a room with still air. The effect of skin reflectance on heat transfer was clear, despite the substantial influence of body size. Melanistic T. scincoides showed low reflectance and gained heat faster than highly reflective albinos. Melanistic lizards also lost heat faster than albinos. Wild-type lizards were intermediate in reflectance, gained heat at rates indistinguishable from melanistic lizards, and lost heat at rates indistinguishable from albino lizards. This study system allowed us to control for variables that were confounded in other studies and may explain the inconsistent support for the color-mediated thermoregulation hypothesis. Our results provide clear evidence that skin reflectance influences the rate of heating and cooling in ectotherms. PMID:24956958

  10. Uta stansburiana and Elgaria multicarinata on the California Channel Islands: Natural dispersal or artificial introduction?

    USGS Publications Warehouse

    Mahoney, M.J.; Parks, D.S.M.; Fellers, G.M.

    2003-01-01

    Uta stansburiana and Elgaria multicarinata occur on several California Channel Islands, and recent introduction of some populations has been suggested because of similarity in life-history traits and body size to mainland populations. We sequenced representatives of each species from mainland southern California and some of the islands on which they occur. For each species, cytochrome b sequence divergence is low across the narrow geographic area sampled. Analyses of 14 haplotypes of U. stansburiana suggest long-established residency on Santa Catalina and San Clemente Islands but more recent arrival on San Nicolas and Santa Cruz Islands. Analyses of eight haplotypes of E. multicarinata suggest these lizards may have been recently transported to San Nicolas Island.

  11. A new species of Pseudogekko (Squamata: Gekkonidae) from the Romblon Island Group, Central Philippines.

    PubMed

    Siler, Cameron D; Davis, Drew R; Diesmos, Arvin C; Guinto, Faith; Whitsett, Collin; Brown, Rafe M

    2016-01-01

    We describe a new species of lizard in the genus Pseudogekko from Sibuyan and Tablas islands in the Romblon Island Group of the central Philippines. The new species is diagnosed from other Philippine Pseudogekko by body size and shape, color pattern, and multiple differences in scale characteristics. Pseudogekko isapa sp. nov. has been collected only twice from leaves of shrubs in forested habitat on Sibuyan and Tablas islands. The distinctive new species of false gecko is undoubtedly endemic to this single, isolated island group. The fact that populations of such a distinctive new species of Pseudogekko has escaped notice of herpetologists on the reasonably well-studied and largely protected Sibuyan Island further emphasizes the secretive and forest-dependent habits of Philippine false geckos. These characteristics of their behavior and natural history render them difficult to study and challenge biologists' efforts to accurately assess their conservation status. PMID:27470802

  12. Akpatok Island

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243 m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on January 22, 2001. Image provided by the USGS EROS Data Center Satellite Systems Branch

  13. Heron Island, Australia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Heron Island is located at the sourthern end of Australia's 2,050 km-long Great Barrier Reef. Surrounded by coral reef and home to over 1000 species of fish, scuba divers and scientists alike are drawn to the island's resort and research station. The true-color image above was taken by Space Imaging's Ikonos satellite with a resolution of 4 meters per pixel-high enough to see individual boats tied up at the small marina. The narrow channel leading from the marina to the ocean was blasted and dredged decades ago, before the island became a national park. Since then the Australian government has implemented conservation measures, such as limiting the number of tourists and removing or recycling, instead of incinerating, all trash. One of the applications of remote sensing data from Ikonos is environmental monitoring, including studies of coral reef health. For more information about the island, read Heron Island. Image by Robert Simmon, based on data copyright Space Imaging

  14. Island Hopping

    ERIC Educational Resources Information Center

    Bennett, Gayle

    2009-01-01

    At some institutions, it may feel as though faculty live on one island and advancement staff on another. The islands form part of an archipelago, and they exchange ambassadors and send emissaries occasionally, but interactions are limited. It may even seem as though the two groups speak different languages, deal in different currencies, and abide…

  15. Direct and indirect effects of petroleum production activities on the western fence lizard (Sceloporus occidentalis) as a surrogate for the dunes sagebrush lizard (Sceloporus arenicolus).

    PubMed

    Weir, Scott M; Knox, Ami; Talent, Larry G; Anderson, Todd A; Salice, Christopher J

    2016-05-01

    The dunes sagebrush lizard (Sceloporus arenicolus) is a habitat specialist of conservation concern limited to shin oak sand dune systems of New Mexico and Texas (USA). Because much of the dunes sagebrush lizard's habitat occurs in areas of high oil and gas production, there may be direct and indirect effects of these activities. The congeneric Western fence lizard (Sceloporus occidentalis) was used as a surrogate species to determine direct effects of 2 contaminants associated with oil and gas drilling activities in the Permian Basin (NM and TX, USA): herbicide formulations (Krovar and Quest) and hydrogen sulfide gas (H2S). Lizards were exposed to 2 concentrations of H2 S (30 ppm or 90 ppm) and herbicide formulations (1× or 2× label application rate) representing high-end exposure scenarios. Sublethal behavioral endpoints were evaluated, including sprint speed and time to prey detection and capture. Neither H2S nor herbicide formulations caused significant behavioral effects compared to controls. To understand potential indirect effects of oil and gas drilling on the prey base, terrestrial invertebrate biomass and order diversity were quantified at impacted sites to compare with nonimpacted sites. A significant decrease in biomass was found at impacted sites, but no significant effects on diversity. The results suggest little risk from direct toxic effects, but the potential for indirect effects should be further explored. PMID:26456391

  16. Evolutionary basis of parallelism in North American scincid lizards.

    PubMed

    Richmond, Jonathan Q

    2006-01-01

    This study uses a phylogenetic framework to explore the causes of parallelism in two North American scincid lizard assemblages: the skiltonianus and fasciatus species groups of the genus Plestiodon. Each group consists of several closely related species with conserved neonate morphology; features that distinguish species become accentuated during ontogeny, and these differences often resemble different endpoints along a developmental continuum. This continuum is believed to be an expression of the ancestral ontogeny, and has led to the hypothesis that evolutionary change in development has generated much of the observed morphological diversity. However, progress on understanding these mechanisms is limited by a lack of well-supported phylogenetic data for the fasciatus group, and for Plestiodon in general. Recent phylogenetic studies on the skiltonianus group have revealed previously undetected cases of parallelism, and raise the possibility that similar cases have yet to be discovered in the fasciatus group. Here, I estimate a phylogeny to test the monophyly of the fasciatus group and infer its relationship with other North American Plestiodon using 2537 bp from six mtDNA genes. I use the phylogeny to reconstruct the mode (graduated vs. punctuated) and direction of body size evolution, to map the evolution of two predominant color morphs, and to test whether size and color pattern evolve concertedly. The results show that the morphotypes of the traditional fasciatus group constitute good species, but that the species group is rendered paraphyletic by several geographically overlapping species that deviate from the fasciatus-like ontogeny. Body size evolution has occurred gradually and bi-directionally, and shifts to large body size have been consistently associated with the loss of the striped color pattern during ontogeny. I show that parallelism, a lack of rigorous phylogenetic analysis, and a reliance on shared ontogenetic features for predicting phylogenetic

  17. Legitimate seed dispersal by lizards in an alpine habitat: The case of Berberis empetrifolia (Berberidaceae) dispersed by Liolaemus belii (Tropiduridae)

    NASA Astrophysics Data System (ADS)

    Celedón-Neghme, Constanza; San Martin, Leonardo A.; Victoriano, Pedro F.; Cavieres, Lohengrin A.

    2008-05-01

    In this study we determined the effect of seed passage through Liolaemus bellii lizard digestive tracts on germination of fleshy-fruited Andean shrub species Berberis empetrifolia (Berberidaceae), and evaluated the effect of this passage on seed coat characteristics. In addition, we assessed the spatial patterns of fecal deposition by lizards onto various microhabitats available in the Andean environments of central Chile. The germination rate and the final percentage of lizard-ingested B. empetrifolia seeds was greater than control seeds. Comparing photographs and seed coat histological cuts, we suggest that the cutine wax present on seed coats from lizard-ingested seeds was probably removed by abrasion inside the lizards' digestive tract. Sixty-two percent of the lizard's feces was deposited on bare soil near rocks commonly inhabited by lizards. However, this microhabitat represents only 29% of the available ground cover at the study site. By enhancing seed germination and depositing seeds onto potential safe sites for recruitment, the lizard Liolaemus bellii is acting, at least qualitatively, as an effective disperser of Berberis empetrifolia.

  18. 75 FR 9377 - Endangered and Threatened Wildlife and Plants; Listing the Flat-Tailed Horned Lizard as Threatened

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... distinct vertebrate population segments (61 FR 4722). (6) The potential effects global climate change may..., 1993 (58 FR 62624), to list the flat-tailed horned lizard as a threatened species, and reopens the... proposed rule to list the flat-tailed horned lizard as a threatened species under the Act (58 FR 62624)....

  19. What are carotenoids signaling? Immunostimulatory effects of dietary vitamin E, but not of carotenoids, in Iberian green lizards

    NASA Astrophysics Data System (ADS)

    Kopena, Renata; López, Pilar; Martín, José

    2014-12-01

    In spite that carotenoid-based sexual ornaments are one of the most popular research topics in sexual selection of animals, the antioxidant and immunostimulatory role of carotenoids, presumably signaled by these colorful ornaments, is still controversial. It has been suggested that the function of carotenoids might not be as an antioxidant per se, but that colorful carotenoids may indirectly reflect the levels of nonpigmentary antioxidants, such as melatonin or vitamin E. We experimentally fed male Iberian green lizards ( Lacerta schreiberi) additional carotenoids or vitamin E alone, or a combination of carotenoids and vitamin E dissolved in soybean oil, whereas a control group only received soybean oil. We examined the effects of the dietary supplementations on phytohaemagglutinin (PHA)-induced skin-swelling immune response and body condition. Lizards that were supplemented with vitamin E alone or a combination of vitamin E and carotenoids had greater immune responses than control lizards, but animals supplemented with carotenoids alone had lower immune responses than lizards supplemented with vitamin E and did not differ from control lizards. These results support the hypothesis that carotenoids in green lizards are not effective as immunostimulants, but that they may be visually signaling the immunostimulatory effects of non-pigmentary vitamin E. In contrast, lizards supplemented with carotenoids alone have higher body condition gains than lizards in the other experimental groups, suggesting that carotenoids may be still important to improve condition.

  20. Social context affects tail displays by Phrynocephalus vlangalii lizards from China

    PubMed Central

    Peters, Richard A.; Ramos, Jose A.; Hernandez, Juan; Wu, Yayong; Qi, Yin

    2016-01-01

    Competition between animals for limited resources often involves signaling to establish ownership or dominance. In some species, the defended resource relates to suitable thermal conditions and refuge from predators. This is particularly true of burrow-dwelling lizards such as the Qinghai toad-headed agama (Phrynocephalus vlangalii), which are found on the Tibetan plateau of western China. Male and female lizards occupy separate burrows, which are vital for anti-predator behaviour during warmer months when lizards are active and, crucially, provide shelter from harsh winter conditions. These lizards are readily observed signaling by means of tail displays on the sand dunes they inhabit. Given the selective pressure to hold such a resource, both males and females should exhibit territorial behaviour and we considered this study system to examine in detail how social context influences motion based territorial signaling. We confirmed that territorial signaling was used by both sexes, and by adopting a novel strategy that permitted 3D reconstruction of tail displays, we identified significant variation due to social context. However, signal structure was not related to lizard morphology. Clearly, the burrow is a highly valued resource and we suggest that additional variation in signaling behaviour might be mediated by resource quality. PMID:27526625

  1. Social context affects tail displays by Phrynocephalus vlangalii lizards from China.

    PubMed

    Peters, Richard A; Ramos, Jose A; Hernandez, Juan; Wu, Yayong; Qi, Yin

    2016-01-01

    Competition between animals for limited resources often involves signaling to establish ownership or dominance. In some species, the defended resource relates to suitable thermal conditions and refuge from predators. This is particularly true of burrow-dwelling lizards such as the Qinghai toad-headed agama (Phrynocephalus vlangalii), which are found on the Tibetan plateau of western China. Male and female lizards occupy separate burrows, which are vital for anti-predator behaviour during warmer months when lizards are active and, crucially, provide shelter from harsh winter conditions. These lizards are readily observed signaling by means of tail displays on the sand dunes they inhabit. Given the selective pressure to hold such a resource, both males and females should exhibit territorial behaviour and we considered this study system to examine in detail how social context influences motion based territorial signaling. We confirmed that territorial signaling was used by both sexes, and by adopting a novel strategy that permitted 3D reconstruction of tail displays, we identified significant variation due to social context. However, signal structure was not related to lizard morphology. Clearly, the burrow is a highly valued resource and we suggest that additional variation in signaling behaviour might be mediated by resource quality. PMID:27526625

  2. Carotenoid-Based Colours Reflect the Stress Response in the Common Lizard

    PubMed Central

    Fitze, Patrick S.; Cote, Julien; San-Jose, Luis Martin; Meylan, Sandrine; Isaksson, Caroline; Andersson, Staffan; Rossi, Jean-Marc; Clobert, Jean

    2009-01-01

    Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR. PMID:19352507

  3. Are mountain habitats becoming more suitable for generalist than cold-adapted lizards thermoregulation?

    PubMed Central

    Mencía, Abraham; Pérez-Mellado, Valentín

    2016-01-01

    Mountain lizards are highly vulnerable to climate change, and the continuous warming of their habitats could be seriously threatening their survival. We aim to compare the thermal ecology and microhabitat selection of a mountain lizard, Iberolacerta galani, and a widely distributed lizard, Podarcis bocagei, in a montane area. Both species are currently in close syntopy in the study area, at 1,400 m above the sea level. We determined the precision, accuracy and effectiveness of thermoregulation, and the thermal quality of habitat for both species. We also compared the selection of thermal microhabitats between both species. Results show that I. galani is a cold-adapted thermal specialist with a preferred temperature range of 27.9–29.7 °C, while P. bocagei would be a thermal generalist, with a broader and higher preferred temperature range (30.1–34.5 °C). In addition, I. galani selects rocky substrates while P. bocagei selects warmer soil and leaf litter substrates. The thermal quality of the habitat is higher for P. bocagei than for I. galani. Finally, P. bocagei achieves a significantly higher effectiveness of thermoregulation (0.87) than I. galani (0.80). Therefore, these mountain habitat conditions seem currently more suitable for performance of thermophilic generalist lizards than for cold-specialist lizards. PMID:27280076

  4. Understanding lizard's microhabitat use based on a mechanistic model of behavioral thermoregulation

    NASA Astrophysics Data System (ADS)

    Fei, Teng; Venus, Valentijn; Toxopeus, Bert; Skidmore, Andrew K.; Schlerf, Martin; Liu, Yaolin; van Overdijk, Sjef; Bian, Meng

    2008-12-01

    Lizards are an "excellent group of organisms" to examine the habitat and microhabitat use mainly because their ecology and physiology is well studied. Due to their behavioral body temperature regulation, the thermal environment is especially linked with their habitat use. In this study, for mapping and understanding lizard's distribution at microhabitat scale, an individual of Timon Lepidus was kept and monitored in a terrarium (245×120×115cm) in which sand, rocks, burrows, hatching chambers, UV-lamps, fog generators and heating devices were placed to simulate its natural habitat. Optical cameras, thermal cameras and other data loggers were fixed and recording the lizard's body temperature, ground surface temperature, air temperature, radiation and other important environmental parameters. By analysis the data collected, we propose a Cellular Automata (CA) model by which the movement of lizards is simulated and translated into their distribution. This paper explores the capabilities of applying GIS techniques to thermoregulatory activity studies in a microhabitat-scale. We conclude that microhabitat use of lizards can be explained in some degree by the rule based CA model.

  5. Learning outdoors: male lizards show flexible spatial learning under semi-natural conditions.

    PubMed

    Noble, Daniel W A; Carazo, Pau; Whiting, Martin J

    2012-12-23

    Spatial cognition is predicted to be a fundamental component of fitness in many lizard species, and yet some studies suggest that it is relatively slow and inflexible. However, such claims are based on work conducted using experimental designs or in artificial contexts that may underestimate their cognitive abilities. We used a biologically realistic experimental procedure (using simulated predatory attacks) to study spatial learning and its flexibility in the lizard Eulamprus quoyii in semi-natural outdoor enclosures under similar conditions to those experienced by lizards in the wild. To evaluate the flexibility of spatial learning, we conducted a reversal spatial-learning task in which positive and negative reinforcements of learnt spatial stimuli were switched. Nineteen (32%) male lizards learnt both tasks within 10 days (spatial task mean: 8.16 ± 0.69 (s.e.) and reversal spatial task mean: 10.74 ± 0.98 (s.e.) trials). We demonstrate that E. quoyii are capable of flexible spatial learning and suggest that future studies focus on a range of lizard species which differ in phylogeny and/or ecology, using biologically relevant cognitive tasks, in an effort to bridge the cognitive divide between ecto- and endotherms. PMID:23075525

  6. Can changes in the distribution of lizard species over the past 50 years be attributed to climate change?

    NASA Astrophysics Data System (ADS)

    Wu, Jianguo

    2015-07-01

    We analyzed changes in the distributions of nine lizard species in China over the past 50 years and identified whether these changes could be attributed to climate change. Long-term records of lizard distributions, grey relational analysis, fuzzy set classification techniques, and attribution methods were used. The distribution of nearly half of the lizard species primarily shifted northward, westward, or eastward since the 1970s, and most changes were related to the thermal index. In response to climate change over the past 50 years, the distribution boundary and center of some species have mainly shifted northward, westward, or eastward, with some irregular shifting during the process. The observed and predicted changes in distribution were highly consistent for some lizard species. The changes in the northern and eastern distribution limits of nearly half of the lizard species and the western limits and distribution centers of several species can be attributed to climate change.

  7. Can changes in the distribution of lizard species over the past 50 years be attributed to climate change?

    NASA Astrophysics Data System (ADS)

    Wu, Jianguo

    2016-08-01

    We analyzed changes in the distributions of nine lizard species in China over the past 50 years and identified whether these changes could be attributed to climate change. Long-term records of lizard distributions, grey relational analysis, fuzzy set classification techniques, and attribution methods were used. The distribution of nearly half of the lizard species primarily shifted northward, westward, or eastward since the 1970s, and most changes were related to the thermal index. In response to climate change over the past 50 years, the distribution boundary and center of some species have mainly shifted northward, westward, or eastward, with some irregular shifting during the process. The observed and predicted changes in distribution were highly consistent for some lizard species. The changes in the northern and eastern distribution limits of nearly half of the lizard species and the western limits and distribution centers of several species can be attributed to climate change.

  8. Biological science in the Great Basin

    USGS Publications Warehouse

    U.S. Geological Survey

    2005-01-01

    The Great Basin is an expanse of desert and high moun-tains situated between the Rocky Mountains and the Sierra Nevada of the western United States. The most explicit description of the Great Basin is that area in the West where surface waters drain inland. In other words, the Great Basin is comprised of many separate drainage areas - each with no outlet. What at first glance may appear as only a barren landscape, the Great Basin upon closer inspection reveals island mountains, sagebrush seas, and intermittent aquatic habitats, all teeming with an incredible number and variety of plants and animals. Biologists at the USGS are studying many different species and ecosystems in the Great Basin in order to provide information about this landscape for policy and land-management decision-making. The following stories represent a few of the many projects the USGS is conducting in the Great Basin.

  9. Siberian Islands

    Atmospheric Science Data Center

    2013-04-16

    ... Distinguishing Clouds from Ice over the East Siberian Sea, Russia     View Larger Image ... clouds from snow and ice. The central portion of Russia's East Siberian Sea, including one of the New Siberian Islands, Novaya ...

  10. Proximate determinants of bite force in Anolis lizards.

    PubMed

    Wittorski, Antoine; Losos, Jonathan B; Herrel, Anthony

    2016-01-01

    Performance measures associated with the vertebrate jaw system may provide important insights into vertebrate ecology and evolution because of their importance in many ecologically relevant tasks. Previous studies have shown that in many taxa, evolution toward higher bite force has gone hand in hand with the evolution of larger body size. However, independent of differences in overall body size, bite force may vary depending on head size and shape as well. Moreover, the underlying musculature may also drive variation in bite force. Here, we investigate the proximate determinants of bite force in lizards of the genus Anolis. We dissected the jaw muscles and quantified muscle mass, fibre length, and cross-sectional area. Data were analysed for both sexes independently given the sexual dimorphism detected in the dataset. Our results show that the traits that explain bite force are similar in both males and females with overall body size and muscle mass being the principal determinants. Among the different muscles examined, the adductor externus and the pseudotemporalis groups were the best determinants of bite force. However, models run for males predicted the variation in bite force better than models for females, suggesting that selection on morphology improving bite force may be stronger in males. PMID:26471984

  11. Corticosterone stimulates hatching of late-term tree lizard embryos.

    PubMed Central

    Weiss, Stacey L.; Johnston, Gwynne; Moore, Michael C.

    2007-01-01

    The regulation of hatching in oviparous animals is important for successful reproduction and survival, but is poorly understood. We unexpectedly found that RU-486, a progesterone and glucocorticoid antagonist, interferes with hatching of viable tree lizard (Urosaurus ornatus) embryos in a dose-dependent manner and hypothesized that embryonic glucocorticoids regulate hatching. To test this hypothesis, we treated eggs with corticosterone (CORT) or vehicle on Day 30 (85%) of incubation, left other eggs untreated, and observed relative hatch order and hatch time. In one study, the CORT egg hatched first in 9 of 11 clutches. In a second study, the CORT egg hatched first in 9 of 12 clutches, before vehicle-treated eggs in 10 of 12 clutches, and before untreated eggs in 7 of 9 clutches. On average, CORT eggs hatched 18.2h before vehicle-treated eggs and 11.6h before untreated eggs. Thus, CORT accelerates hatching of near-term embryos and RU-486 appears to block this effect. CORT may mobilize energy substrates that fuel hatching and/or accelerate lung development, and may provide a mechanism by which stressed embryos escape environmental stressors. PMID:17208477

  12. Sex ratio bias, male aggression, and population collapse in lizards.

    PubMed

    Le Galliard, Jean-François; Fitze, Patrick S; Ferrière, Régis; Clobert, Jean

    2005-12-13

    The adult sex ratio (ASR) is a key parameter of the demography of human and other animal populations, yet the causes of variation in ASR, how individuals respond to this variation, and how their response feeds back into population dynamics remain poorly understood. A prevalent hypothesis is that ASR is regulated by intrasexual competition, which would cause more mortality or emigration in the sex of increasing frequency. Our experimental manipulation of populations of the common lizard (Lacerta vivipara) shows the opposite effect. Male mortality and emigration are not higher under male-biased ASR. Rather, an excess of adult males begets aggression toward adult females, whose survival and fecundity drop, along with their emigration rate. The ensuing prediction that adult male skew should be amplified and total population size should decline is supported by long-term data. Numerical projections show that this amplifying effect causes a major risk of population extinction. In general, such an "evolutionary trap" toward extinction threatens populations in which there is a substantial mating cost for females, and environmental changes or management practices skew the ASR toward males. PMID:16322105

  13. Solubilization and purification of melatonin receptors from lizard brain

    SciTech Connect

    Rivkees, S.A.; Conron, R.W. Jr.; Reppert, S.M. )

    1990-09-01

    Melatonin receptors in lizard brain were identified and characterized using {sup 125}I-labeled melatonin (({sup 125}I)MEL) after solubilization with the detergent digitonin. Saturation studies of solubilized material revealed a high affinity binding site, with an apparent equilibrium dissociation constant of 181 +/- 45 pM. Binding was reversible and inhibited by melatonin and closely related analogs, but not by serotonin or norepinephrine. Treatment of solubilized material with the non-hydrolyzable GTP analog, guanosine 5'-(3-O-thiotriphosphate) (GTP-gamma-S), significantly reduced receptor affinity. Gel filtration chromatography of solubilized melatonin receptors revealed a high affinity, large (Mr 400,000) peak of specific binding. Pretreatment with GTP-gamma-S before solubilization resulted in elution of a lower affinity, smaller (Mr 150,000) peak of specific binding. To purify solubilized receptors, a novel affinity chromatography resin was developed by coupling 6-hydroxymelatonin with Epoxy-activated Sepharose 6B. Using this resin, melatonin receptors were purified approximately 10,000-fold. Purified material retained the pharmacologic specificity of melatonin receptors. These results show that melatonin receptors that bind ligand after detergent treatment can be solubilized and substantially purified by affinity chromatography.

  14. Ground resistance influences lizard burial in dry and wet sand

    NASA Astrophysics Data System (ADS)

    Sharpe, Sarah; Kuckuk, Robyn; Goldman, Daniel

    2012-11-01

    Many terrestrial animals move within soil in which water content can vary, and little is known about how water content affects locomotor performance. To investigate the effect of water content on burial, we created controlled dry and wet substrates. We used 0.3 mm glass particles and varied water content W, the mass of water to mass of dry loosely packed sand. Drag force on a submerged 1.6 cm diameter rod increased by a factor of 4 as W increased from 0 to 0.03, after which force increases were small. Drag force in wet media periodically fluctuated with time and corresponded with surface fracturing. We characterized how W affected burial performance and strategy of a generalist burrower, the ocellated skink lizard (Chalcides ocellatus). High speed x-ray imaging was used to measure head, body and limb kinematics in substrates with W= 0 and W= 0.03. In both states during burial the body was maintained in a curved posture and the animal moved using a start-stop motion. During movement, the head oscillated and the forelimb on the convex side of the body was used to push the animal forward. Both speed and angular excursion of the head oscillation decreased in the W= 0.03 state. The differences in locomotion were attributed to the changing resistance force within the media.

  15. Habitat use affects morphological diversification in dragon lizards

    PubMed Central

    COLLAR, D C; SCHULTE, J A; O’MEARA, B C; LOSOS, J B

    2010-01-01

    Habitat use may lead to variation in diversity among evolutionary lineages because habitats differ in the variety of ways they allow for species to make a living. Here, we show that structural habitats contribute to differential diversification of limb and body form in dragon lizards (Agamidae). Based on phylogenetic analysis and ancestral state reconstructions for 90 species, we find that multiple lineages have independently adopted each of four habitat use types: rock-dwelling, terrestriality, semi-arboreality and arboreality. Given these reconstructions, we fit models of evolution to species’ morphological trait values and find that rock-dwelling and arboreality limit diversification relative to terrestriality and semi-arboreality. Models preferred by Akaike information criterion infer slower rates of size and shape evolution in lineages inferred to occupy rocks and trees, and model-averaged rate estimates are slowest for these habitat types. These results suggest that ground-dwelling facilitates ecomorphological differentiation and that use of trees or rocks impedes diversification. PMID:20345808

  16. Lizards speed up visual displays in noisy motion habitats

    PubMed Central

    Ord, Terry J; Peters, Richard A; Clucas, Barbara; Stamps, Judy A

    2007-01-01

    Extensive research over the last few decades has revealed that many acoustically communicating animals compensate for the masking effect of background noise by changing the structure of their signals. Familiar examples include birds using acoustic properties that enhance the transmission of vocalizations in noisy habitats. Here, we show that the effects of background noise on communication signals are not limited to the acoustic modality, and that visual noise from windblown vegetation has an equally important influence on the production of dynamic visual displays. We found that two species of Puerto Rican lizard, Anolis cristatellus and A. gundlachi, increase the speed of body movements used in territorial signalling to apparently improve communication in visually ‘noisy’ environments of rapidly moving vegetation. This is the first evidence that animals change how they produce dynamic visual signals when communicating in noisy motion habitats. Taken together with previous work on acoustic communication, our results show that animals with very different sensory ecologies can face similar environmental constraints and adopt remarkably similar strategies to overcome these constraints. PMID:17264059

  17. Sleep and wakefulness in the green iguanid lizard (Iguana iguana).

    PubMed

    Ayala-Guerrero, F; Mexicano, G

    2008-11-01

    The reptile Iguana iguana exhibits four states of vigilance: active wakefulness (AW), quiet wakefulness (QW), quiet sleep (QS) and active sleep (AS). Cerebral activity decreases in amplitude and frequency when passing from wakefulness to QS. Both parameters show a slight increase during AS. Heart rate is at a maximum during AW (43.8+/-7.9 beats/min), decreases to a minimum in QS (25.3+/-3.2 beats/min) and increases in AS (36.1+/-5.7 beats/min). Tonical and phasical muscular activity is present in wakefulness, decreases or disappears in QS and reappears in AS. Single or conjugate ocular movements are observed during wakefulness, then disappear in QS and abruptly reappear in AS. Although these reptiles are polyphasic, their sleep shows a tendency to concentrate between 20:00 and 8:00 h. Quiet sleep occupies the greater percentage of the total sleep time. Active sleep episodes are of very short duration, showing an average of 21.5+/-4.9 (mean+/-SD). Compensatory increment of sleep following its total deprivation was significant only for QS. Reaction to stimuli decreased significantly when passing from wakefulness to sleep. It is suggested that the lizard I. iguana displays two sleep phases behaviorally and somatovegetatively similar to slow wave sleep and paradoxical sleep in birds and mammals. PMID:17462928

  18. Undulatory swimming of a sandfish lizard in granular media

    NASA Astrophysics Data System (ADS)

    Goldman, Daniel; Maladen, Ryan; Li, Chen; Ding, Yang

    2009-03-01

    We study the locomotion of the desert dwelling sandfish lizard (Scincus scincus) as it dives into and swims beneath the surface of sand (300 μm glass beads). Above the surface, the animal uses a diagonal gait to move rapidly across the sand. High speed x-ray imaging reveals that once subsurface the animal no longer uses limbs for propulsion but instead folds the limbs against the body and generates thrust using a large amplitude undulatory motion consisting of a traveling wave with frequency f that propagates down the body with one wave period. The forward swimming speed v (maximum 10 cm/sec) increases with increasing f. We measure v versus f as a function of packing fraction of the material φ. To predict v as a function of f and φ, we model the animal as a series of elements, each which produces thrust and experiences drag along its surface. We measure thrust and drag coefficients by performing drag measurements on a small stainless steel rod (grain-rod friction comparable to the animal's skin) as a function of rod angle, rod speed, and φ. Integrating the drag law over a sinusoidal wave form accurately predicts the v-f relationship of the animal in loose and close packed granular media.

  19. The Anolis Lizard Genome: An Amniote Genome without Isochores?

    PubMed Central

    Costantini, Maria; Greif, Gonzalo; Alvarez-Valin, Fernando; Bernardi, Giorgio

    2016-01-01

    Two articles published 5 years ago concluded that the genome of the lizard Anolis carolinensis is an amniote genome without isochores. This claim was apparently contradicting previous results on the general presence of an isochore organization in all vertebrate genomes tested (including Anolis). In this investigation, we demonstrate that the Anolis genome is indeed heterogeneous in base composition, since its macrochromosomes comprise isochores mainly from the L2 and H1 families (a moderately GC-poor and a moderately GC-rich family, respectively), and since the majority of the sequenced microchromosomes consists of H1 isochores. These families are associated with different features of genome structure, including gene density and compositional correlations (e.g., GC3 vs flanking sequence GC and intron GC), as in the case of mammalian and avian genomes. Moreover, the assembled Anolis chromosomes have an enormous number of gaps, which could be due to sequencing problems in GC-rich regions of the genome. In conclusion, the Anolis genome is no exception to the general rule of an isochore organization in the genomes of vertebrates (and other eukaryotes). PMID:26992416

  20. Island of Okinawa, Japan

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The island of Okinawa, (26.5N, 128.0E) largest of the Ryukyu Islands, Japan. The Ryukyu island group lies south of the main home islands of Japan in an arc towards the Chinese island Republic of Taiwan. As is typical throughout the Japanese home islands, intense urban development can be observed all over the island in this near vertical view.

  1. Mid-Cretaceous amber fossils illuminate the past diversity of tropical lizards.

    PubMed

    Daza, Juan D; Stanley, Edward L; Wagner, Philipp; Bauer, Aaron M; Grimaldi, David A

    2016-03-01

    Modern tropical forests harbor an enormous diversity of squamates, but fossilization in such environments is uncommon and little is known about tropical lizard assemblages of the Mesozoic. We report the oldest lizard assemblage preserved in amber, providing insight into the poorly preserved but potentially diverse mid-Cretaceous paleotropics. Twelve specimens from the Albian-Cenomanian boundary of Myanmar (99 Ma) preserve fine details of soft tissue and osteology, and high-resolution x-ray computed tomography permits detailed comparisons to extant and extinct lizards. The extraordinary preservation allows several specimens to be confidently assigned to groups including stem Gekkota and stem Chamaleonidae. Other taxa are assignable to crown clades on the basis of similar traits. The detailed preservation of osteological and soft tissue characters in these specimens may facilitate their precise phylogenetic placement, making them useful calibration points for molecular divergence time estimates and potential keys for resolving conflicts in higher-order squamate relationships. PMID:26973870

  2. Mass extinction of lizards and snakes at the Cretaceous-Paleogene boundary

    NASA Astrophysics Data System (ADS)

    Longrich, Nicholas R.; Bhullar, Bhart-Anjan S.; Gauthier, Jacques A.

    2012-12-01

    The Cretaceous-Paleogene (K-Pg) boundary is marked by a major mass extinction, yet this event is thought to have had little effect on the diversity of lizards and snakes (Squamata). A revision of fossil squamates from the Maastrichtian and Paleocene of North America shows that lizards and snakes suffered a devastating mass extinction coinciding with the Chicxulub asteroid impact. Species-level extinction was 83%, and the K-Pg event resulted in the elimination of many lizard groups and a dramatic decrease in morphological disparity. Survival was associated with small body size and perhaps large geographic range. The recovery was prolonged; diversity did not approach Cretaceous levels until 10 My after the extinction, and resulted in a dramatic change in faunal composition. The squamate fossil record shows that the end-Cretaceous mass extinction was far more severe than previously believed, and underscores the role played by mass extinctions in driving diversification.

  3. Booming during a bust: Asynchronous population responses of arid zone lizards to climatic variables

    NASA Astrophysics Data System (ADS)

    Read, John L.; Kovac, Kelli-Jo; Brook, Barry W.; Fordham, Damien A.

    2012-04-01

    The productivity of arid environments and the reproductive success of vertebrates in these systems, are typically thought to be primarily influenced by rainfall patterns. Data from our 15 year study at an Australian arid zone site reveals asynchronous demographic responses to rainfall and other climatic variables among different lizard species. We show that, in addition to precipitation, key demographic rates (fecundity, recruitment and survival) are correlated strongly with temporal variability in temperature, during and prior to the breeding season, and also to the density of sympatric lizard species. There were nine-fold fluctuations through time in the relative abundance of two similar-sized Ctenotus species, and asynchronous recruitment success and survival among other species, despite the absence of direct anthropogenic affects Understanding the drivers and magnitude of the substantial natural variability in arid-zone lizard assemblages is integral to predicting and interpreting their responses to future land use or climate-change scenarios.

  4. Granulomatous pneumonia and hepatitis associated with Providencia rettgeri infection in a crocodile monitor lizard (Varanus salvadorii).

    PubMed

    Kycko, Anna; Kozaczyński, Wojciech; Jasik, Agnieszka; Kędrak-Jabłońska, Agnieszka; Borkowska-Opacka, Bogna; Reichert, Michał

    2013-03-01

    The present report describes a case of granulomatous pneumonia and hepatitis in a male crocodile monitor lizard (Varanus salvadorii). During the necropsy of the monitor lizard, multifocal to coalescing pale yellow lesions were observed in both lung lobes, as well as similar, though milder, changes in the liver, and an ulcerative lesion on the food pad of the right hindlimb. Histopathologically, the presence of multiple necrotising, chronic granulomas containing bacterial clumps were observed in the parenchyma of the lung and the liver. By microbiological examination of the pathologically altered lung tissues, Providencia rettgeri was identified. Altogether, our findings indicate that the bacterial infection resulting in extensive chronic necrotising granulomatous inflammation was the primary cause of the reptile's death. To our knowledge, this is the first report of Providencia rettgeri-associated granulomatous pneumonia and hepatitis in the monitor lizard. PMID:23439291

  5. Mid-Cretaceous amber fossils illuminate the past diversity of tropical lizards

    PubMed Central

    Daza, Juan D.; Stanley, Edward L.; Wagner, Philipp; Bauer, Aaron M.; Grimaldi, David A.

    2016-01-01

    Modern tropical forests harbor an enormous diversity of squamates, but fossilization in such environments is uncommon and little is known about tropical lizard assemblages of the Mesozoic. We report the oldest lizard assemblage preserved in amber, providing insight into the poorly preserved but potentially diverse mid-Cretaceous paleotropics. Twelve specimens from the Albian-Cenomanian boundary of Myanmar (99 Ma) preserve fine details of soft tissue and osteology, and high-resolution x-ray computed tomography permits detailed comparisons to extant and extinct lizards. The extraordinary preservation allows several specimens to be confidently assigned to groups including stem Gekkota and stem Chamaleonidae. Other taxa are assignable to crown clades on the basis of similar traits. The detailed preservation of osteological and soft tissue characters in these specimens may facilitate their precise phylogenetic placement, making them useful calibration points for molecular divergence time estimates and potential keys for resolving conflicts in higher-order squamate relationships. PMID:26973870

  6. Mass extinction of lizards and snakes at the Cretaceous–Paleogene boundary

    PubMed Central

    Longrich, Nicholas R.; Bhullar, Bhart-Anjan S.; Gauthier, Jacques A.

    2012-01-01

    The Cretaceous–Paleogene (K-Pg) boundary is marked by a major mass extinction, yet this event is thought to have had little effect on the diversity of lizards and snakes (Squamata). A revision of fossil squamates from the Maastrichtian and Paleocene of North America shows that lizards and snakes suffered a devastating mass extinction coinciding with the Chicxulub asteroid impact. Species-level extinction was 83%, and the K-Pg event resulted in the elimination of many lizard groups and a dramatic decrease in morphological disparity. Survival was associated with small body size and perhaps large geographic range. The recovery was prolonged; diversity did not approach Cretaceous levels until 10 My after the extinction, and resulted in a dramatic change in faunal composition. The squamate fossil record shows that the end-Cretaceous mass extinction was far more severe than previously believed, and underscores the role played by mass extinctions in driving diversification. PMID:23236177

  7. The importance of remnant native vegetation of Amazonian submontane forest for the conservation of lizards.

    PubMed

    Silva, D J; Santos-Filho, M; Canale, G R

    2014-08-01

    Forest fragmentation affects animal population dynamics mainly by loss of habitat and disruption of animal movement. Lizard assemblages are affected by environmental changes, but, depending on their ecological needs, some species might be more vulnerable than others. The southern Amazon suffers accelerated anthropic actions replacing natural environments by farmland (crops and pasture). This region is considerably drier than most of the northern Amazon, with stational semi-deciduous forests fragmented and isolated by pasture, and crops to a lesser extent. Here we report data on lizard assemblages using semi-deciduous forests, forest edge and the surrounding pasture in the southern Amazon in Mato Grosso, Brazil. Lizards were collected in 21 forest fragments (41 to 7,035 ha) surrounded by pasture; using pitfall traps placed on a degradation gradient - from pasture inwards forest fragment (up to 200 m). We collected 242 individuals (14 species, seven families) in 6,300 trap-days. The pattern of species occurrence was largely nested and this nesting was associated with three habitat guilds (generalist, edge-tolerant, and forest species). Although there was no obvious fragmentation effect on lizards diversity community-wise, Hoplocercus spinosus, Bachia dorbignyi, Micrablepharus maximiliani and Kentropyx calcarta were more vulnerable to such effects than all other ten species collected. We verified that assemblages inhabiting pasture and forest edge are a nested subset of assemblages from the forest core. The remnant native vegetation is not distributed homogeneously and lizards species can persist in different parts of the landscape, therefore we recommend the protection of forest remnants as an important conservation action for lizards of the southern Amazon. PMID:25296198

  8. Adherence to Bergmann's rule by lizards may depend on thermoregulatory mode: support from a nocturnal gecko.

    PubMed

    Penniket, Sophie; Cree, Alison

    2015-06-01

    Bergmann's rule predicts an increase in body size with decreasing environmental temperature; however, the converse pattern has been found in the majority of lizards studied to date. For these ectotherms, small body size may provide thermal benefits (rapid heat uptake when basking), which would be highly advantageous in cold environments. Yet such an advantage may not exist in nocturnal lizards (which do not avidly bask), in which Bergmann's rule has not been closely studied. We have examined whether the body size of a primarily nocturnal gecko, Woodworthia "Otago/Southland" changed with elevation and operative temperature (determined using physical copper models). In a laboratory study, we investigated whether thermoregulatory mode (heliothermy or thigmothermy) alters the effect of body size on heating and cooling rates. This gecko followed Bergmann's rule, thereby showing the opposite of the dominant pattern in diurnal lizards. Size at maturity, maximum size of adults and size at birth were larger at higher elevations and at lower operative temperatures. Using physical models, we found that large body size can confer thermal benefits for nocturnal lizards that remain within diurnal retreats. Bergmann's rule should not be dismissed for all lizards. Our results clearly support Bergmann's rule for at least one thigmothermic species, for which large body size may provide thermal benefits. Future studies on Bergmann's rule in lizards should consider thermoregulatory mode. We advocate that this ecogeographic rule be examined in relation to operative temperature measured at field sites. Finally, we predict that climate warming may weaken the relationship between body size and elevation in this gecko. PMID:25663371

  9. Temporal overlap of humans and giant lizards (Varanidae; Squamata) in Pleistocene Australia

    NASA Astrophysics Data System (ADS)

    Price, Gilbert J.; Louys, Julien; Cramb, Jonathan; Feng, Yue-xing; Zhao, Jian-xin; Hocknull, Scott A.; Webb, Gregory E.; Nguyen, Ai Duc; Joannes-Boyau, Renaud

    2015-10-01

    An obvious but key prerequisite to testing hypotheses concerning the role of humans in the extinction of late Quaternary 'megafauna' is demonstrating that humans and the extinct taxa overlapped, both temporally and spatially. In many regions, a paucity of reliably dated fossil occurrences of megafauna makes it challenging, if not impossible, to test many of the leading extinction hypotheses. The giant monitor lizards of Australia are a case in point. Despite commonly being argued to have suffered extinction at the hands of the first human colonisers (who arrived by 50 ka), it has never been reliably demonstrated that giant monitors and humans temporally overlapped in Australia. Here we present the results of an integrated U-Th and 14C dating study of a late Pleistocene fossil deposit that has yielded the youngest dated remains of giant monitor lizards in Australia. The site, Colosseum Chamber, is a cave deposit in the Mt Etna region, central eastern Australia. Sixteen new dates were generated and demonstrate that the bulk of the material in the deposit accumulated since ca. 50 ka. The new monitor fossil is, minimally, 30 ky younger than the previous youngest reliably dated record for giant lizards in Australia and for the first time, demonstrates that on a continental scale, humans and giant lizards overlapped in time. The new record brings the existing geochronological dataset for Australian giant monitor lizards to seven dated occurrences. With such sparse data, we are hesitant to argue that our new date represents the time of their extinction from the continent. Rather, we suspect that future fossil collecting will yield new samples both older and younger than 50 ka. Nevertheless, we unequivocally demonstrate that humans and giant monitor lizards overlapped temporally in Australia, and thus, humans can only now be considered potential drivers for their extinction.

  10. Testing amniote models of prey transport kinematics: a quantitative analysis of mouth opening patterns in lizards.

    PubMed

    McBrayer, Lance D; Reilly, Stephen M

    2002-01-01

    Two models have been proposed to describe the prey transport kinematics of terrestrial vertebrates (Bramble and Wake, 1985; Reilly and Lauder, 1990). The critical difference between the models is the presence or absence of a slow open-II phase (SO-II) in the gape profile during mouth opening. Each of these models has been applied to lizards, however to date, lizard feeding kinematics have not been adequately quantified to assess the utility of these models for this clade. Neither model has been sufficiently tested due to the lack of a methodology to assess the specific differences between the models. We describe a method that uses explicit mathematical criteria to define the kinematic phases in tetrapod feeding. This "slope analysis& is used to precisely quantify and compare the transport kinematics of seven lizard species. Lizard transport kinematics were highly variable both within and across taxa. However, several common gape cycle patterns were identified. The predominant patterns were slow-fast opening (37.3%), fast opening only (22.9%) and slow opening only (21.2%). The most common pattern explicitly fits the prediction of the Reilly and Lauder model while the other two are similar to patterns observed in salamanders. Thus, lizards possess both the slow opening-fast opening pattern predicted for amniotes and the more primitive, simple opening pattern characteristic of more basal tetrapods. Plateau phases were found in only 12.8% of the profiles and only a fourth of these (3.4% of the total) explicitly fit the Bramble and Wake model (slow opening, plateau, fast opening) and two species never exhibited plateaus in their gape cycles. Thus, it is clear that the Bramble and Wake model is not supported as a generalized model for lizards or generalized tetrapods. PMID:16351858

  11. Male Texas Horned Lizards increase daily movements and area covered in spring: A mate searching strategy?

    USGS Publications Warehouse

    Stark, Richard C.; Fox, S. F.; David, M.L., Jr.

    2005-01-01

    Texas Horned Lizards, Phrynosoma cornutum, were tracked using fluorescent powder to determine exact daily movements. Daily linear movements and daily space use were compared between adult males and females. Lizards that traveled the greatest linear distances also covered the largest areas. In Oklahoma, adults emerge from hibernation in late April and early May and mate soon afterward. Males traveled significantly greater distances (and covered significantly larger areas in a day) than females in May but not after May. We propose that males move more and cover more area than females early in the mating season to intercept receptive females. Copyright 2005 Society for the Study of Amphibians and Reptiles.

  12. The Galapagos Islands: Darwin and Modern Conservation Stories

    ERIC Educational Resources Information Center

    Burr, Susan

    2010-01-01

    The author visited the Galapagos Islands in 2009 and here looks at their biodiversity through pictures taken then. The diverse habitats of the Islands are reflected in the great diversity of flora and fauna found on them, with many species endemic to the Islands. The stories of the land iguanas, control of introduced species and the giant…

  13. Review of "Great Teachers and Great Leaders"

    ERIC Educational Resources Information Center

    Shaker, Paul

    2010-01-01

    "Great Teachers and Great Leaders" (GTGL) is one of six research summaries issued by the U.S. Department of Education in support of its Blueprint for Reform. This review examines the presentation of research about improving teacher and administrator quality in GTGL. The review concludes that there are serious flaws in the research summary. The…

  14. Abundance of ticks (Acari: Ixodidae) infesting the western fence lizard, Sceloporus occidentalis, in relation to environmental factors.

    PubMed

    Tälleklint-Eisen, L; Eisen, R J

    1999-09-01

    We examined the impact of environmental characteristics, such as habitat type, topographic exposure and presence of leaf litter, on the abundance of Ixodes pacificus ticks infesting the western fence lizard (Sceloporus occidentalis) at the University of California Hopland Research and Extension Center (HREC), Mendocino County, California. A total of 383 adult lizards were slip-noosed and examined for tick infestation in April and May 1998. At least 94% of the lizards were infested by ticks and at least 20% of the females and 33% of the males carried > 15 ticks. This intensive utilization of western fence lizards (which do not serve as natural reservoirs for Lyme disease spirochetes) by subadult ticks, is probably the primary reason for the low prevalence of infection with Borrelia burgdorferi in I. pacificus nymphs and adults previously recorded at the HREC. Tick loads were higher on male than female lizards. Also, male lizards were generally more heavily infested in late April than in late May. The prevalence of tick infestation exceeded 88% in all habitat types but males collected in woodland and grass/woodland edges had higher tick loads than those collected in open grassland. Male lizards captured in open, exposed grassland tended to carry heavier tick loads in northern/eastern, as compared to southern/western, exposures, and when leaf litter was present. PMID:10581712

  15. Variation in stress and innate immunity in the tree lizard (Urosaurus ornatus) across an urban-rural gradient

    PubMed Central

    French, Susannah S.; Fokidis, H. Bobby; Moore, Michael C.

    2009-01-01

    The urban environment presents new and different challenges to wildlife, but also potential opportunities depending on the species. As urban encroachment onto native habitats continues, understanding the impact of this expansion on native species is vital to conservation. A key physiological indicator of environmental disturbance is the vertebrate stress response, involving increases in circulating glucocorticoids (i.e., corticosterone), which exert influence on numerous physiological parameters including energy storage, reproduction, and immunity. We examined how urbanization in Phoenix, Arizona influences corticosterone levels, blood parasitism, and innate immunity in populations of tree lizards (Urosaurus ornatus) to determine whether urbanization may be detrimental or beneficial to this species. Both baseline and stress-induced corticosterone concentrations were significantly lower in urban lizards relative to the rural ones, however, the magnitude of the increase in corticosterone with stress did not differ across populations. Urban lizards also had a lower ratio of heterophils to lymphocytes, but elevated overall leukocyte count, as compared to lizards from the natural site. Urban and rural lizards did not differ in their prevalence of the blood parasite, Plasmodium mexicanum. Taken together, these results suggest that urban tree lizards may have suppressed overall corticosterone concentrations possibly from down-regulation as a result of frequent exposure to stressors, or increased access to urban resources. Also, urban lizards may have bolstered immunocompetence possibly from increased immune challenges, such as wounding, in the urban environment, or from greater energetic reserves being available as a result of access to urban resources. PMID:18594834

  16. Mammalian X homolog acts as sex chromosome in lacertid lizards.

    PubMed

    Rovatsos, M; Vukić, J; Kratochvíl, L

    2016-07-01

    Among amniotes, squamate reptiles are especially variable in their mechanisms of sex determination; however, based largely on cytogenetic data, some lineages possess highly evolutionary stable sex chromosomes. The still very limited knowledge of the genetic content of squamate sex chromosomes precludes a reliable reconstruction of the evolutionary history of sex determination in this group and consequently in all amniotes. Female heterogamety with a degenerated W chromosome typifies the lizards of the family Lacertidae, the widely distributed Old World clade including several hundreds of species. From the liver transcriptome of the lacertid Takydromus sexlineatus female, we selected candidates for Z-specific genes as the loci lacking single-nucleotide polymorphisms. We validated the candidate genes through the comparison of the copy numbers in the female and male genomes of T. sexlineatus and another lacertid species, Lacerta agilis, by quantitative PCR that also proved to be a reliable technique for the molecular sexing of the studied species. We suggest that this novel approach is effective for the detection of Z-specific and X-specific genes in lineages with degenerated W, respectively Y chromosomes. The analyzed gene content of the Z chromosome revealed that lacertid sex chromosomes are not homologous with those of other reptiles including birds, but instead the genes have orthologs in the X-conserved region shared by viviparous mammals. It is possible that this part of the vertebrate genome was independently co-opted for the function of sex chromosomes in viviparous mammals and lacertids because of its content of genes involved in gonad differentiation. PMID:26980341

  17. Polymorphic ROS scavenging revealed by CCCP in a lizard

    NASA Astrophysics Data System (ADS)

    Olsson, Mats; Wilson, Mark; Isaksson, Caroline; Uller, Tobias

    2009-07-01

    Ingestion of antioxidants has been argued to scavenge circulating reactive molecules (e.g., free radicals), play a part in mate choice (by mediating access to this important resource), and perhaps increase life span. However, recent work has come to question these relationships. We have shown elsewhere in the polychromatic lizard, Ctenophorus pictus, that diet supplementation of carotenoids as antioxidants does not depress circulating natural reactive oxygen species (ROS) levels and leads to no corresponding improvement of color traits. However, a much stronger test would be to experimentally manipulate the ROS levels themselves and assess carotenoid-induced ROS depression. Here, we achieve this by using carbonyl cyanide 3-chlorophenylhydrazone, which elevates superoxide (SO) formation approximately threefold at 10 μM in this model system. We then look for depressing effects on ROS of the carotenoids in order to assess whether ‘super-production’ of SO makes carotenoid effects on elevated ROS levels detectable. The rationale for this treatment was that if not even such elevated levels of SO are reduced by carotenoid supplementation, the putative link carotenoids, ROS depression, and mate quality (in terms of antioxidant capacity) is highly questionable. We conclude that there is no significant effect of carotenoids on mean SO levels even at the induced ROS levels. However, our results showed a significant interaction effect between carotenoid treatment and male color, with red males having higher ROS levels than yellow males. We suggest that this may be because different pigments are differently involved in the generation of the integumental colors in the two morphs with concomitant effects on ROS depletion depending on carotenoid uptake or allocation to coloration and antioxidation.

  18. Musculoskeletal anatomical changes that accompany limb reduction in lizards.

    PubMed

    Abdala, Virginia; Grizante, Mariana B; Diogo, Rui; Molnar, Julia; Kohlsdorf, Tiana

    2015-11-01

    Muscles, bones, and tendons in the adult tetrapod limb are intimately integrated, both spatially and functionally. However, muscle and bone evolution do not always occur hand in hand. We asked, how does the loss of limb bones affect limb muscle anatomy, and do these effects vary among different lineages? To answer these questions, we compared limb muscular and skeletal anatomy among gymnophthalmid lizards, which exhibit a remarkable variation in limb morphology and different grades of digit and limb reduction. We mapped the characters onto a phylogeny of the group to assess the likelihood that they were acquired independently. Our results reveal patterns of reduction of muscle and bone elements that did not always coincide and examples of both, convergent and lineage-specific non-pentadactyl musculoskeletal morphologies. Among lineages in which non-pentadactyly evolved independently, the degree of convergence seems to depend on the number of digits still present. Most tetradactyl and tridactyl limbs exhibited profound differences in pattern and degree of muscle loss/reduction, and recognizable morphological convergence occurred only in extremely reduced morphologies (e.g., spike-like appendix). We also found examples of muscles that persisted although the bones to which they plesiomorphically attach had been lost, and examples of muscles that had been lost although their normal bony attachments persisted. Our results demonstrate that muscle anatomy in reduced limbs cannot be predicted from bone anatomy alone, meaning that filling the gap between osteological and myological data is an important step toward understanding this recurrent phenomenon in the evolution of tetrapods. PMID:26251347

  19. Lizard movement tracks: variation in path re-use behaviour is consistent with a scent-marking function

    PubMed Central

    Jackson, Grant; Roddick, John F.; Bull, C. Michael

    2016-01-01

    Individual movement influences the spatial and social structuring of a population. Animals regularly use the same paths to move efficiently to familiar places, or to patrol and mark home ranges. We found that Australian sleepy lizards (Tiliqua rugosa), a monogamous species with stable pair-bonds, repeatedly used the same paths within their home ranges and investigated whether path re-use functions as a scent-marking behaviour, or whether it is influenced by site familiarity. Lizards can leave scent trails on the substrate when moving through the environment and have a well-developed vomeronasal system to detect and respond to those scents. Path re-use would allow sleepy lizards to concentrate scent marks along these well-used trails, advertising their presence. Hypotheses of mate attraction and mating competition predict that sleepy lizard males, which experience greater intra-sexual competition, mark more strongly. Consistent with those hypotheses, males re-used their paths more than females, and lizards that showed pairing behaviour with individuals of the opposite sex re-used paths more than unpaired lizards, particularly among females. Hinterland marking is most economic when home ranges are large and mobility is low, as is the case in the sleepy lizard. Consistent with this strategy, re-used paths were predominantly located in the inner 50% home range areas. Together, our detailed movement analyses suggest that path re-use is a scent marking behaviour in the sleepy lizard. We also investigated but found less support for alternative explanations of path re-use behaviour, such as site familiarity and spatial knowledge. Lizards established the same number of paths, and used them as often, whether they had occupied their home ranges for one or for more years. We discuss our findings in relation to maintenance of the monogamous mating system of this species, and the spatial and social structuring of the population. PMID:27019790

  20. Lizard movement tracks: variation in path re-use behaviour is consistent with a scent-marking function.

    PubMed

    Leu, Stephan T; Jackson, Grant; Roddick, John F; Bull, C Michael

    2016-01-01

    Individual movement influences the spatial and social structuring of a population. Animals regularly use the same paths to move efficiently to familiar places, or to patrol and mark home ranges. We found that Australian sleepy lizards (Tiliqua rugosa), a monogamous species with stable pair-bonds, repeatedly used the same paths within their home ranges and investigated whether path re-use functions as a scent-marking behaviour, or whether it is influenced by site familiarity. Lizards can leave scent trails on the substrate when moving through the environment and have a well-developed vomeronasal system to detect and respond to those scents. Path re-use would allow sleepy lizards to concentrate scent marks along these well-used trails, advertising their presence. Hypotheses of mate attraction and mating competition predict that sleepy lizard males, which experience greater intra-sexual competition, mark more strongly. Consistent with those hypotheses, males re-used their paths more than females, and lizards that showed pairing behaviour with individuals of the opposite sex re-used paths more than unpaired lizards, particularly among females. Hinterland marking is most economic when home ranges are large and mobility is low, as is the case in the sleepy lizard. Consistent with this strategy, re-used paths were predominantly located in the inner 50% home range areas. Together, our detailed movement analyses suggest that path re-use is a scent marking behaviour in the sleepy lizard. We also investigated but found less support for alternative explanations of path re-use behaviour, such as site familiarity and spatial knowledge. Lizards established the same number of paths, and used them as often, whether they had occupied their home ranges for one or for more years. We discuss our findings in relation to maintenance of the monogamous mating system of this species, and the spatial and social structuring of the population. PMID:27019790

  1. Dance of Adatom Islands: Brownian Motion, Scaling and Reshaping

    NASA Astrophysics Data System (ADS)

    Metiu, Horia; Weakliem, Paul; Bogicevic, Alex; Liu, Shudun

    1998-03-01

    Dynamics of adatom islands of sizes 17 to 2000 is studied by means of kinetic Monte Carlo simulation. Structures of the islands, especially their relation to the sizes of the islands, are examined in great detail. These information provides us a better understanding of how the diffusion constants of these islands scale with the sizes of the islands. Our earlier prediction that the scaling exponents depend on both the temperature and the systems have recently been confirmed by STM measurements. A simple picture for the Brownian motion of large islands will be presented.

  2. Immunolocalization of FGF1 and FGF2 in the regenerating tail of the lizard Lampropholis guichenoti: implications for FGFs as trophic factors in lizard tail regeneration.

    PubMed

    Alibardi, Lorenzo; Lovicu, Frank J

    2010-09-01

    A role for fibroblast growth factors in stimulating limb and tail regeneration in amphibians has been shown; however, it is unknown whether these growth factors are also involved in the regeneration of the tail of lizard, an amniote model for studies on tissue regeneration. The presence of fibroblast growth factor-1 (FGF1) and -2 (FGF2) in the regenerating tail of the lizard Lampropholis guichenoti has been studied using immunofluorescence labeling. The study reveals that FGF2 is mainly localized in the wound and scaling epidermis, in differentiating muscles, in spinal ganglia, regenerating nerves and spinal cord. FGF1 is also present in the wound and differentiating epidermis, but is detectable at lower levels in the regenerating muscles and spinal cord. FGF1 is present in blastema cells, while FGF2 labeling is relatively low in these cells. Fibroblasts of the forming dermis are rich in FGF1 but not in FGF2. Developing blood vessels label for both FGF1 and FGF2 while the cartilaginous, bone and fat tissues are poorly labeled or unlabeled for FGFs. The present study suggests that most FGFs in the regenerating tail are located in the nervous system, in the epidermis and muscles, and these tissues most likely require these growth factors for their differentiation and growth. The present study suggests that FGFs produced in the regenerating epidermis, spinal cord and nerves can stimulate tail regeneration in lizards. PMID:19589562

  3. Thermal ecology and activity patterns of the short-horned lizard (Phrynosoma douglassi) and the sage brush lizard (Sceloporus graciosus) in southeastern Idaho

    SciTech Connect

    Guyer, C.; Linder, A.D.

    1985-10-31

    A mark-recapture study of the short-horned lizard (Phyrnosoma douglassi) and the sagebrush lizard (Sceloporus graciosus) was performed from 1976 to 1977 in southeastern Idaho. Both species had mean cloacal temperatures of approximately 33 C. However, P. douglassi had more variable cloacal temperatures, particularly during morning and evening periods. This was caused by differences in sleeping sites chosen by the two species. Adults of both species were active from mid-April through late August, with peak activity in June. Juvenile P. douglassi displayed a seasonal activity pattern similar to that of adults. Juvenile S. graciosus were most active later in the year (August), when adults were disappearing. In both species, young-of-the-year appeared in early to mid-August. Adult and juvenile P. douglassi were active during all daylight hours and displayed no activity peaks, whereas young-of-the-year displayed a bimodal activity pattern. Adult and juvenile S. graciosus were active over all daylight hours but had peak activity between 1200 and 1500 h. Ants (Pogonomyrmex) were the lizard's principle prey. However, only young-of-the-year P. douglassi had activity patterns that paralleled that of ants on their mounds. 22 references, 4 figures.

  4. Habitat-related variation in infestation of lizards and rodents with Ixodes ticks in dense woodlands in Mendocino County, California.

    PubMed

    Eisen, Rebecca J; Eisen, Lars; Lane, Robert S

    2004-01-01

    During the spring and early summer of 2002, we examined the relative importance of Borrelia-refractory lizards (Sceloporus occidentalis, Elgaria spp.) versus potential Borrelia burgdorferi sensu lato (s.l.)-reservoirs (rodents) as hosts for Ixodes pacificus immatures in 14 woodland areas (six oak, five mixed oak/Douglas fir, and three redwood/tanoak areas) distributed throughout Mendocino County, California. Lizards were estimated to serve as hosts for 93-98% of all larvae and > or =99.6% of all nymphs infesting lizards or rodents in oak woodlands and oak/Douglas fir sites in the southern part of the county. In redwood/tanoak woodlands and oak/Douglas fir sites in northern Mendocino County, the contribution of rodents to larval feedings reached 36-69% but lizards still accounted for 94-100% of nymphal bloodmeals. From late April to mid-June, I. pacificus larvae were recovered from 95 to 96% of lizards and dusky-footed woodrats (Neotoma fuscipes) and from 59% of Peromyscus spp. mice. In contrast, 99% of lizards but few woodrats (15%) and none of the mice were infested by nymphs. Comparisons of tick loads for 19 lizard-Peromyscus spp. mouse pairings, where the lizard and mouse were captured within 10m of each other, revealed that the lizards harbored 36 times more larvae and >190 times more nymphs than the mice. In oak woodlands, loads of I. pacificus larvae decreased from late April/early May to late June for S. occidentalis lizards but increased for Peromyscus spp. mice. We conclude that the relative utilization of Borrelia-refractory lizards, as compared to rodents, by I. pacificus larvae was far higher in dry oak woodlands than in moister habitats such as redwood/tanoak and oak/Douglas fir woodlands in northern Mendocino County. Non-lizard-infesting potential enzootic vectors of B. burgdorferi s.l. (I. angustus and I. spinipalpis) were recorded from rodents in three of six oak woodland areas, two of five oak/Douglas fir woodland areas, and two of three redwood

  5. The influence of competitor density on space use in juvenile striped plateau lizards ( Sceloporus virgatus)

    NASA Astrophysics Data System (ADS)

    Manteuffel, V. Mark; Eiblmaier, Martin

    2008-05-01

    To investigate the role of competitor density in influencing space use patterns of juvenile striped plateau lizards ( Sceloporus virgatus), a density manipulation experiment was conducted within large (800 m 2) field enclosures treated with low (20) and high (60) densities of hatchlings. Enclosures were monitored for 10 months, after which the experiment was replicated. Home range and core area sizes after release of lizards and initial establishment in the fall were significantly reduced in the high-density treatments; fall home range shape, measured as the perimeter-to-area ratio, was significantly reduced in low-density treatments; no significant differences were detected between treatments in core area shape or overlap. During the spring/early summer activity season after the lizard's first winter, no significant differences between density treatments were detected for any of these variables, as enclosure densities had converged between treatments. Individuals in high-density enclosures had increased their space use as competitor density had declined. These results illustrate that competitor density has significant influence on space use by juvenile lizards.

  6. Sound Localization in Lizards: Functioning of a Pressure-Gradient Receiver

    NASA Astrophysics Data System (ADS)

    van Hemmen, J. Leo

    2009-03-01

    Because of their small interaural distance, lizards as well as some other animals have developed a special hearing mechanism, the ``pressure-gradient receiver''. The lizard peripheral auditory system differs from the mammalian one by a coupling of the two eardrums through the internal mouth cavity. We present a three-dimensional analytical model of the pressure-gradient receiver. The central aspect of the coupling of the membranes through the mouth cavity is realized by means of the boundary conditions. Moreover, the lizard's middle ear, a simple lever construction called columella, is asymmetrically attached to the tympanic membrane. This has motivated us to solve the problem of how the middle ear influences the spatial-amplitude profile and the frequency distribution of the tympanic membrane vibration. Finally, we show results from numerical simulations of the eigenfunctions and eigenfrequencies in a lizard's internal mouth cavity bounded by the eardrums. To this end, we have constructed the complex geometry from a cast imprint of the cavity with the help of three-dimensional scans. Our results led to an interesting speculation regarding the neurobiological use of the pressure-gradient system.

  7. Vitamin D supplementation increases the attractiveness of males' scent for female Iberian rock lizards

    PubMed Central

    Martín, José; López, Pilar

    2006-01-01

    Evolutionary theory proposes that signals used in sexual selection can only be stable if they are honest and condition dependent. However, despite the fact that chemical signals are used by many animals, empirical research has mainly focused on visual and acoustic signals. Vitamin D is an essential nutrient for lizards, but in some lizards its precursor (cholesta-5,7-dien-3-ol=provitamin D) is found in femoral gland secretions, which males use for scent marking and intraspecific communication. By allocating provitamin D to secretions, males might need to divert vitamin D from metabolism. This might be costly and condition dependent. We tested whether diet quality affected chemical signals of male Iberian rock lizards (Lacerta monticola) and its consequences for sexual selection. After experimental supplementation of dietary vitamin D, males increased the proportion of provitamin D in femoral secretions. Further experiments showed that females detected these changes in males' signals by chemosensory cues, and discriminated provitamin D, and changes in its concentration, from similar steroids (i.e. cholesterol) found in secretions. Moreover, females preferred areas scent marked by males with more provitamin D in their secretions. This mechanism would confer honesty to chemical signals of male lizards, and, thus, females may rely on it to select high-quality males. We suggest that the allocation of vitamins and other essential nutrients to either visual (e.g. carotenoids) or chemical ornaments might be the common basis of honest sexual displays in many animals. PMID:17002947

  8. Immune responses of eastern fence lizards (Sceloporus undulatus) to repeated acute elevation of corticosterone.

    PubMed

    McCormick, Gail L; Langkilde, Tracy

    2014-08-01

    Prolonged elevations of glucocorticoids due to long-duration (chronic) stress can suppress immune function. It is unclear, however, how natural stressors that result in repeated short-duration (acute) stress, such as frequent agonistic social encounters or predator attacks, fit into our current understanding of the immune consequences of stress. Since these types of stressors may activate the immune system due to increased risk of injury, immune suppression may be reduced at sites where individuals are repeatedly exposed to potentially damaging stressors. We tested whether repeated acute elevation of corticosterone (CORT, a glucocorticoid) suppresses immune function in eastern fence lizards (Sceloporus undulatus), and whether this effect varies between lizards from high-stress (high baseline CORT, invaded by predatory fire ants) and low-stress (low baseline CORT, uninvaded) sites. Lizards treated daily with exogenous CORT showed higher hemagglutination of novel proteins by their plasma (a test of constitutive humoral immunity) than control lizards, a pattern that was consistent across sites. There was no significant effect of CORT treatment on bacterial killing ability of plasma. These results suggest that repeated elevations of CORT, which are common in nature, produce immune effects more typical of those expected at the acute end of the acute-chronic spectrum and provide no evidence of modulated consequences of elevated CORT in animals from high-stress sites. PMID:24852352

  9. Fifty years of chasing lizards: new insights advance optimal escape theory.

    PubMed

    Samia, Diogo S M; Blumstein, Daniel T; Stankowich, Theodore; Cooper, William E

    2016-05-01

    Systematic reviews and meta-analyses often examine data from diverse taxa to identify general patterns of effect sizes. Meta-analyses that focus on identifying generalisations in a single taxon are also valuable because species in a taxon are more likely to share similar unique constraints. We conducted a comprehensive phylogenetic meta-analysis of flight initiation distance in lizards. Flight initiation distance (FID) is a common metric used to quantify risk-taking and has previously been shown to reflect adaptive decision-making. The past decade has seen an explosion of studies focused on quantifying FID in lizards, and, because lizards occur in a wide range of habitats, are ecologically diverse, and are typically smaller and differ physiologically from the better studied mammals and birds, they are worthy of detailed examination. We found that variables that reflect the costs or benefits of flight (being engaged in social interactions, having food available) as well as certain predator effects (predator size and approach speed) had large effects on FID in the directions predicted by optimal escape theory. Variables that were associated with morphology (with the exception of crypsis) and physiology had relatively small effects, whereas habitat selection factors typically had moderate to large effect sizes. Lizards, like other taxa, are very sensitive to the costs of flight. PMID:25620002

  10. Estrogenic contamination by manure fertilizer in organic farming: a case study with the lizard Podarcis sicula.

    PubMed

    Verderame, Mariailaria; Limatola, Ermelinda; Scudiero, Rosaria

    2016-01-01

    In the last years, worldwide organic farming has grown exponentially; as a consequence, the use of animal manure as a soil fertility source has become the principal agricultural choice. However, the use of manure as fertilizer can increase the amount of steroid hormone metabolites in the soil. In southern Italy, lacertidae lizards are the most abundant vertebrate group in agroecosystems and have been identified as potential model species for ecotoxicological studies. The aim of this study was to understand if the manure applied in organic farming has estrogen-like effects in the lizard Podarcis sicula. Adult male lizards were captured in two organic agricultural fields (manure-treated sites) and in an uncultivated field (control site). Lizards from the two organic farms displayed hepatic biosynthetic alterations typical of an estrogenic contamination; hepatocytes contained both vitellogenin and estrogen receptor alpha transcripts and proteins, detected by in situ hybridization and immunocytochemistry. The same cells did not show cadmium, lead and metallothionein accumulation, indicative of the lack of inorganic contamination. These findings suggest that exogenous estrogens, arising from the use of manure, could affect the welfare of wild animals and animal breeding, leading to bioaccumulation of estrogens in food chain, with possible risk for human consumers. For this reason, organic farming should implement the use of sustainable practices such as crop rotation to preserve the soil biological activity, rather than organic manure as fertilizer. PMID:26475047

  11. Thermal and energetic constraints on ectotherm abundance: A global test using lizards

    USGS Publications Warehouse

    Buckley, L.B.; Rodda, G.H.; Jetz, W.

    2008-01-01

    Population densities of birds and mammals have been shown to decrease with body mass at approximately the same rate as metabolic rates increase, indicating that energetic needs constrain endotherm population densities. In ectotherms, the exponential increase of metabolic rate with body temperature suggests that environmental temperature may additionally constrain population densities. Here we test simple bioenergetic models for an ecologically important group of ectothermic vertebrates by examining 483 lizard populations. We find that lizard population densities decrease as a power law of body mass with a slope approximately inverse to the slope of the relationship between metabolic rates and body mass. Energy availability should limit population densities. As predicted, environmental productivity has a positive effect on lizard density, strengthening the relationship between lizard density and body mass. In contrast, the effect of environmental temperature is at most weak due to behavioral thermoregulation, thermal evolution, or the temperature dependence of ectotherm performance. Our results provide initial insights into how energy needs and availability differentially constrain ectotherm and endotherm density across broad spatial scales. ?? 2008 by the Ecological Society of America.

  12. Photoresponsive control of color, albedo, and structure in lizard skin: a smart functional system

    NASA Astrophysics Data System (ADS)

    Vaughan, Gerald L.

    1996-02-01

    Skin from the lizard, Anolis carolinensis, carries a molecular photosensor and will, in response to visible light, change from bright green to dark brown within minutes. The color/albedo change, involving control of three types of pigment cell, exhibits the sensor, effector, and function aspects of a smart functional system.

  13. Functional characterization and expression analysis of myoglobin in high-altitude lizard Phrynocephalus erythrurus.

    PubMed

    Xin, Ying; Tang, Xiaolong; Wang, Huihui; Lu, Songsong; Wang, Yan; Zhang, Yang; Chen, Qiang

    2015-10-01

    Myoglobin (Mb) is a monomeric hemoprotein which plays an important role in oxygen storage and transport in cardiac and skeletal muscle under hypoxia. The red tail toad-headed lizard Phrynocephalus erythrurus (Lacertilia: Agamidae), which inhabits at an elevation of 4500-5300 m on the Qinghai-Tibetan plateau, is known to be the highest living lizard in the world. To investigate the characters of myoglobin of this unique species, another low altitude lizard Phrynocephalus przewalskii (Lacertilia: Agamidae) was selected as a reference. The open reading frame (ORF) of myoglobin in two lizards was 465 bp which encodes a polypeptide of 154 amino acids with different theoretical molecular weight and isoelectric point. The amino acid substitutions of myoglobin between two species were found at Thr13Ile, Lys87Thr and His118Asn. Homology modeling results indicated that P. erythrurus myoglobin has a greater heme pocket, which may be more favorable to oxygen binding and unloading. On the other hand, the mRNA levels of myoglobin in both cardiac and skeletal muscle in P. erythrurus were significantly larger than those in low altitude P. przewalskii. At protein level, myoglobin concentration in skeletal muscle in P. erythrurus was notably increased, but no significant difference was observed in cardiac muscle. PMID:26116966

  14. How do food passage rate and assimilation differ between herbivorous lizards and nonruminant mammals?

    PubMed

    Karasov, W H; Petrossian, E; Rosenberg, L; Diamond, J M

    1986-01-01

    What digestive adaptations permit herbivorous nonruminant mammals to sustain much higher metabolic rates than herbivorous lizards, despite gross similarity in digestive anatomy and physiology? We approached this question by comparing four herbivorous species eating the same diet of alfalfa pellets: two lizards (chuckwalla and desert iugana) and two mammals (desert woodrat and laboratory mouse). The mammals had longer small and large intestines, greater intestinal surface area, much higher (by an order of magnitude) food intake normalized to metabolic live mass, and much faster food passage times (a few hours instead of a few days). Among both reptiles and mammals, passage times increase with body size and are longer for herbivores than for carnivores. The herbivorous lizards, despite these much slower passage times, had slightly lower apparent digestive efficiencies than the mammals. At least for chuckwallas, this difference from mammals was not due to differences in body temperature regime. Comparisons of chuckwallas and woodrats in their assimilation of various dietary components showed that the woodrat's main advantage lay in greater assimilation of the dietary fiber fraction. Woodrats achieved greater fiber digestion despite shorter residence time, but possibly because of a larger fermentation chamber, coprophagy, and/or different conditions for microbial fermentation. We conclude with a comparative overview of digestive function in herbivorous lizards and mammals, and with a list of four major unsolved questions. PMID:3734193

  15. Impact and intrusion of the foot of a lizard running rapidly on sand

    NASA Astrophysics Data System (ADS)

    Li, Chen; Hsieh, Tonia; Umbanhowar, Paul; Goldman, Daniel

    2012-11-01

    The desert-dwelling zebra-tailed lizard (Callisaurus draconoides, 10 cm, 10 g) runs rapidly (~10 BL/s) on granular media (GM) like sand and gravel. On loosely packed GM, its large hind feet penetrate into the substrate during each step. Based on above-ground observation, a previous study (Li et al., JEB 2012) hypothesized that the hind foot rotated in the vertical plane subsurface to generate lift. To explain the observed center-of-mass dynamics, the model assumed that ground reaction force was dominated by speed-independent frictional drag. Here we use x-ray high speed video to obtain subsurface foot kinematics of the lizard running on GM, which confirms the hypothesized subsurface foot rotation following rapid foot impact at touchdown. However, using impact force measurements, a resistive force model, and the observed foot kinematics, we find that impact force during initial foot touchdown and speed-independent frictional drag during rotation only account for part of the required lift to support locomotion. This suggests that the rapid foot rotation further allows the lizard to utilize inertial forces from the local acceleration of the substrate (particles), similar to small robots running on GM (Qian et al., RSS 2012) and the basilisk (Jesus) lizard running on water.

  16. 76 FR 62087 - Draft Conservation Plan and Draft Environmental Assessment; Dunes Sagebrush Lizard, Texas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-06

    ... application includes the draft Texas Conservation Plan for the Dunes Sagebrush Lizard (TCP). The draft TCP... future, the draft TCP will also serve as a Habitat Conservation Plan (HCP) in support of future applications for Incidental Take Permits under the Act. The draft TCP and the draft Environmental...

  17. Thermoregulatory Behavior in Diurnal Lizards as a Vehicle for Teaching Scientific Process

    ERIC Educational Resources Information Center

    Platz, James E.

    2009-01-01

    Field experiments offer the opportunity for hands on experience with the scientific process. While this is true of a wide variety of activities, many have pitfalls both experimental and logistical that reduce the overall rate of success, in turn, influencing student learning outcomes. Relying on small, territorial, diurnal lizards and an array of…

  18. Quantification of correlational selection on thermal physiology, thermoregulatory behavior, and energy metabolism in lizards

    PubMed Central

    Artacho, Paulina; Saravia, Julia; Ferrandière, Beatriz Decencière; Perret, Samuel; Le Galliard, Jean-François

    2015-01-01

    Phenotypic selection is widely accepted as the primary cause of adaptive evolution in natural populations, but selection on complex functional properties linking physiology, behavior, and morphology has been rarely quantified. In ectotherms, correlational selection on thermal physiology, thermoregulatory behavior, and energy metabolism is of special interest because of their potential coadaptation. We quantified phenotypic selection on thermal sensitivity of locomotor performance (sprint speed), thermal preferences, and resting metabolic rate in captive populations of an ectothermic vertebrate, the common lizard, Zootoca vivipara. No correlational selection between thermal sensitivity of performance, thermoregulatory behavior, and energy metabolism was found. A combination of high body mass and resting metabolic rate was positively correlated with survival and negatively correlated with fecundity. Thus, different mechanisms underlie selection on metabolism in lizards with small body mass than in lizards with high body mass. In addition, lizards that selected the near average preferred body temperature grew faster that their congeners. This is one of the few studies that quantifies significant correlational selection on a proxy of energy expenditure and stabilizing selection on thermoregulatory behavior. PMID:26380689

  19. Phylogenetic Analyses of Novel Squamate Adenovirus Sequences in Wild-Caught Anolis Lizards

    PubMed Central

    Ascher, Jill M.; Geneva, Anthony J.; Ng, Julienne; Wyatt, Jeffrey D.; Glor, Richard E.

    2013-01-01

    Adenovirus infection has emerged as a serious threat to the health of captive snakes and lizards (i.e., squamates), but we know relatively little about this virus' range of possible hosts, pathogenicity, modes of transmission, and sources from nature. We report the first case of adenovirus infection in the Iguanidae, a diverse family of lizards that is widely-studied and popular in captivity. We report adenovirus infections from two closely-related species of Anolis lizards (anoles) that were recently imported from wild populations in the Dominican Republic to a laboratory colony in the United States. We investigate the evolution of adenoviruses in anoles and other squamates using phylogenetic analyses of adenovirus polymerase gene sequences sampled from Anolis and a range of other vertebrate taxa. These phylogenetic analyses reveal that (1) the sequences detected from each species of Anolis are novel, and (2) adenoviruses are not necessarily host-specific and do not always follow a co-speciation model under which host and virus phylogenies are perfectly concordant. Together with the fact that the Anolis adenovirus sequences reported in our study were detected in animals that became ill and subsequently died shortly after importation while exhibiting clinical signs consistent with acute adenovirus infection, our discoveries suggest the need for renewed attention to biosecurity measures intended to prevent the spread of adenovirus both within and among species of snakes and lizards housed in captivity. PMID:23593364

  20. Correlates of average daily metabolism of field-active zebra-tailed lizards (Callisaurus draconoides).

    PubMed

    Karasov, W H; Anderson, R A

    1998-01-01

    The extent of variation in reptile field metabolism, and its causal bases, are poorly understood. We studied the energetics of the insectivorous lizard Callisaurus draconoides at a site in the California Desert (Desert Center) and at a site at the southern tip of the Baja Peninsula (Cabo San Lucas; hereafter, Cabo). Reproducing Callisaurus were smaller at Cabo than at Desert Center. The allometry of metabolism with body mass can account for most differences in whole-animal metabolism. There was no significant effect of sex or source population on mass-adjusted metabolic rate in the laboratory (resting metabolism, measured by closed-system respirometry) or in the field (field metabolism, measured with doubly labeled water). The mass-adjusted resting metabolism and field metabolism of gravid females and the field metabolism of juvenile lizards were not significantly different from those of nonreproductive adults. Temperature had a significant effect on resting metabolism (Q10 = 2.7); fed lizards had resting metabolism that was 22% higher than that of fasted lizards; field metabolism was positively correlated with growth rate in juveniles; and field metabolism of adults increased from spring to late summer at Desert Center by 25%, probably because of longer activity period length and slightly higher activity period body temperature. We calculated from water influx and field metabolism that juveniles allocated 18% of their metabolizable energy intake to growth and that most energy deposited into eggs was transferred from energy stores rather than ingested in the weeks prior to laying. PMID:9472817

  1. Genome Sequence of Devriesea agamarum, Isolated from Agamid Lizards with Dermatitis

    PubMed Central

    Van Nieuwerburgh, Filip; Haesebrouck, Freddy; Deforce, Dieter; Pasmans, Frank; Martel, An

    2015-01-01

    We report the genome sequence of Devriesea agamarum strain IMP2, isolated from the liver of a female Agama impalearis. This actinobacterium is associated with septicemia and dermatitis in agamid lizards. Availability of this genome sequence will contribute to the understanding of this pathogen’s virulence. PMID:26294637

  2. The dragon lizard Pogona vitticeps has ZZ/ZW micro-sex chromosomes.

    PubMed

    Ezaz, Tariq; Quinn, Alexander E; Miura, Ikuo; Sarre, Stephen D; Georges, Arthur; Marshall Graves, Jennifer A

    2005-01-01

    The bearded dragon, Pogona vitticeps (Agamidae: Reptilia) is an agamid lizard endemic to Australia. Like crocodilians and many turtles, temperature-dependent sex determination (TSD) is common in agamid lizards, although many species have genotypic sex determination (GSD). P. vitticeps is reported to have GSD, but no detectable sex chromosomes. Here we used molecular cytogenetic and differential banding techniques to reveal sex chromosomes in this species. Comparative genomic hybridization (CGH), GTG- and C-banding identified a highly heterochromatic microchromosome specific to females, demonstrating female heterogamety (ZZ/ZW) in this species. We isolated the P. vitticeps W chromosome by microdissection, re-amplified the DNA and used it to paint the W. No unpaired bivalents were detected in male synaptonemal complexes at meiotic pachytene, confirming male homogamety. We conclude that P. vitticeps has differentiated previously unidentifable W and Z micro-sex chromosomes, the first to be demonstrated in an agamid lizard. Our finding implies that heterochromatinization of the heterogametic chromosome occurred during sex chromosome differentiation in this species, as is the case in some lizards and many snakes, as well as in birds and mammals. Many GSD reptiles with cryptic sex chromosomes may also prove to have micro-sex chromosomes. Reptile microchromosomes, long dismissed as non-functional minutiae and often omitted from karyotypes, therefore deserve closer scrutiny with new and more sensitive techniques. PMID:16331408

  3. Vitamin D supplementation increases the attractiveness of males' scent for female Iberian rock lizards.

    PubMed

    Martín, José; López, Pilar

    2006-10-22

    Evolutionary theory proposes that signals used in sexual selection can only be stable if they are honest and condition dependent. However, despite the fact that chemical signals are used by many animals, empirical research has mainly focused on visual and acoustic signals. Vitamin D is an essential nutrient for lizards, but in some lizards its precursor (cholesta-5,7-dien-3-ol=provitamin D) is found in femoral gland secretions, which males use for scent marking and intraspecific communication. By allocating provitamin D to secretions, males might need to divert vitamin D from metabolism. This might be costly and condition dependent. We tested whether diet quality affected chemical signals of male Iberian rock lizards (Lacerta monticola) and its consequences for sexual selection. After experimental supplementation of dietary vitamin D, males increased the proportion of provitamin D in femoral secretions. Further experiments showed that females detected these changes in males' signals by chemosensory cues, and discriminated provitamin D, and changes in its concentration, from similar steroids (i.e. cholesterol) found in secretions. Moreover, females preferred areas scent marked by males with more provitamin D in their secretions. This mechanism would confer honesty to chemical signals of male lizards, and, thus, females may rely on it to select high-quality males. We suggest that the allocation of vitamins and other essential nutrients to either visual (e.g. carotenoids) or chemical ornaments might be the common basis of honest sexual displays in many animals. PMID:17002947

  4. Immune responses of a wall lizard to whole-body exposure to radiofrequency electromagnetic radiation.

    PubMed

    Mina, Despoina; Sagonas, Kostas; Fragopoulou, Adamantia F; Pafilis, Panayiotis; Skouroliakou, Aikaterini; Margaritis, Lukas H; Tsitsilonis, Ourania E; Valakos, Efstratios D

    2016-03-01

    Purpose During the last three decades, the number of devices that emit non-ionizing electromagnetic radiation (EMR) at the wireless communication spectrum has rapidly increased and possible effects on living organisms have become a major concern. The purpose of this study was to investigate the effects of radiofrequency EMR emitted by a widely used wireless communication device, namely the Digital Enhanced Communication Telephony (DECT) base, on the immune responses of the Aegean wall lizard (Podarcis erhardii). Materials and methods Adult male lizards were exposed 24 h/day for 8 weeks to 1880-1900 MHz DECT base radiation at average electric field intensity of 3.2 V/m. Immune reactivity was assessed using the phytohemagglutinin (PHA) skin swelling and mixed lymphocyte reaction (MLR) tests. Results Our results revealed a noticeable suppression (approximately 45%) of inflammatory responses in EMR-exposed lizards compared to sham-exposed animals. T cell-mediated responses were marginally affected. Conclusion Daily radiofrequency EMR exposure seems to affect, at least partially, the immunocompetence of the Aegean wall lizard. PMID:26853383

  5. Early Holocene turnover, followed by stability, in a Caribbean lizard assemblage

    NASA Astrophysics Data System (ADS)

    Kemp, Melissa E.; Hadly, Elizabeth A.

    2016-03-01

    Understanding how communities are impacted by environmental perturbations is integral for addressing the ongoing biodiversity crisis that impacts ecosystems worldwide. The fossil record serves as a window into ancient interactions and the responses of communities to past perturbations. Here, we re-examine paleontological data from Katouche Bay, Anguilla, a Holocene site in the Lesser Antilles. We reveal that the site was more diverse than previously indicated, with long-term, continuous records of three genera of extant lizards (Anolis, Ameiva, and Thecadactylus), and the early Holocene presence of Leiocephalus, a large ground-dwelling lizard that has since been completely extirpated from the Lesser Antilles. The disappearance of Leiocephalus from Katouche Bay resulted in high turnover, decreased evenness, and decreased species richness-a trend that continues to the present day. Our body size reconstructions for the most abundant genus, Anolis, are consistent with the presence of only one species, Anolis cf. gingivinus, at Katouche Bay throughout the Holocene, contrary to previously published studies. Additionally, we find no evidence of dwarfism in A. cf. gingivinus, which contrasts with a global study of contemporary insular lizards. Our data reveal that the impacts of diversity loss on lizard communities are long lasting and irreversible over millennia.

  6. The regeneration blastema of lizards: an amniote model for the study of appendage replacement

    PubMed Central

    Gilbert, E. A. B.; Delorme, S. L.

    2015-01-01

    Abstract Although amniotes (reptiles, including birds, and mammals) are capable of replacing certain tissues, complete appendage regeneration is rare. Perhaps the most striking example is the lizard tail. Tail loss initiates a spontaneous epimorphic (blastema‐mediated) regenerative program, resulting in a fully functional but structurally non‐identical replacement. Here we review lizard tail regeneration with a particular focus on the blastema. In many lizards, the original tail has evolved a series of fracture planes, anatomical modifications that permit the tail to be self‐detached or autotomized. Following tail loss, the wound site is covered by a specialized wound epithelium under which the blastema develops. An outgrowth of the spinal cord, the ependymal tube, plays a key role in governing growth (and likely patterning) of the regenerate tail. In some species (e.g., geckos), the blastema forms as an apical aggregation of proliferating cells, similar to that of urodeles and teleosts. For other species (e.g., anoles) the identification of a proliferative blastema is less obvious, suggesting an unexpected diversity in regenerative mechanisms among tail‐regenerating lizards. PMID:27499867

  7. Making Olympic lizards: the effects of specialised exercise training on performance.

    PubMed

    Husak, Jerry F; Keith, Allison R; Wittry, Beth N

    2015-03-01

    Exercise training is well known to affect a suite of physiological and performance traits in mammals, but effects of training in other vertebrate tetrapod groups have been inconsistent. We examined performance and physiological differences among green anole lizards (Anolis carolinensis) that were trained for sprinting or endurance, using an increasingly rigorous training regimen over 8 weeks. Lizards trained for endurance had significantly higher post-training endurance capacity compared with the other treatment groups, but groups did not show post-training differences in sprint speed. Although acclimation to the laboratory environment and training explain some of our results, mechanistic explanations for these results correspond with the observed performance differences. After training, endurance-trained lizards had higher haematocrit and larger fast glycolytic muscle fibres. Despite no detectable change in maximal performance of sprint-trained lizards, we detected that they had significantly larger slow oxidative muscle fibre areas compared with the other treatments. Treatment groups did not differ in the proportion of number of fibre types, nor in the mass of most limb muscles or the heart. Our results offer some caveats for investigators conducting training research on non-model organisms and they reveal that muscle plasticity in response to training may be widespread phylogenetically. PMID:25617462

  8. Devon Island

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mars Researchers Rendezvous on Remote Arctic Island   ... equipment and technology that may be deployed during a human mission to Mars. One of the many objectives of the project scientists is to ... Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's ...

  9. Hawaiian Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Multiangle Imaging Spectro-Radiometer (MISR) image of five Hawaiian Islands was acquired by the instrument's vertical- viewing (nadir) camera on June 3, 2000. The image shows the islands of Oahu, Molokai, Lanai, Maui, and Kahoolawe. The prevailing Pacific trade winds bring higher levels of rainfall to the eastern slopes of the islands, leading to a greater abundance of vegetation on the windward coasts. The small change in observation angle across the nadir camera's field-of- view causes the right-hand portion of the image to be more affected by Sun glint, making the ocean surface appear brighter. Oahu is the westernmost of the islands seen in this image. Waikiki Beach and the city of Honolulu are located on the southern shore, to the west of Diamond Head caldera. MISR is one of several Earth-observing instruments on the Terra satellite, launched in December 1999. The Terra spacecraft, the flagship of a fleet of satellites dedicated to understanding our global environment, is part of NASA's Earth Sciences Enterprise, a long-term research program dedicated to understanding how human-induced and natural changes affect our world. Image courtesy NASA/GSFC/JPL, MISR Team

  10. Anatahan Island

    Atmospheric Science Data Center

    2013-04-19

    ... Snorkelers around this island are likely to encounter the fish Achilles Tang and the Moorish Idol (Acanthurus achilles and Zanclus ... Terra circles the Earth in the same orbit as Landsat 7, flying at an altitude of about 700 kilometers above the Earth's surface. ...

  11. Does the conceptus of the viviparous lizard Barisia imbricata imbricata participates in the regulation of progesterone production and the control of luteolysis?

    PubMed

    Martínez-Torres, Martín; Salcedo-Álvarez, Martha; Alvarez-Rodríguez, Carmen; Cárdenas-León, Mario; Luis, Juana; Moreno-Fierros, Leticia

    2014-08-01

    It is generally accepted that progesterone is necessary to maintain gestation; however, the mechanisms that control the production of this steroid remain unknown. The corpus luteum has been assigned a central role in the maintenance of gestation based on its capacity to produce progesterone. A pseudopregnancy model was performed in a viviparous lizard, Barisia imbricata imbricata, to determine whether the absence of embryos would affect the pattern of progesterone production or the corpus luteum histology. Blood samples were obtained prior to ovulation and at 8, 16, and 24 weeks after ovulation (pseudopregnant and pregnant lizards), as well as one day after parturition (pregnant lizards) or 32 weeks after ovulation (pseudopregnant lizards). The corpus luteum was surgically removed one day after blood samples were obtained. Blood aliquots from nongravid females were obtained at similar timepoints. We found a significant reduction in plasma progesterone concentrations at 24 and 32 weeks post-ovulation in pseudopregnant lizards compared with those observed at similar times in intact pregnant lizards, whereas the progesterone levels in non-gestant lizards remained significantly lower than in either pseudopregnant or pregnant lizards. Moreover, we observed that the histological appearance of the corpus luteum from pseudogestational females (obtained 24 and 32 weeks post-ovulation) differed from the corpora lutea from lizards in late gestation and intact parturient lizards. These observations suggest that the conceptus participates in the regulation of progesterone production in late gestation and also in luteolysis control. PMID:24975848

  12. Adaptive Decision Modeling in Wisconsin River Islands

    NASA Astrophysics Data System (ADS)

    Gyawali, R.; Greb, S. R.; Watkins, D. W., Jr.; Block, P.

    2014-12-01

    River islands in Wisconsin are of high ecological significance. Understanding of climate change impacts and appropriate management alternatives in these islands are of great interest to all stakeholders, including the State of Wisconsin and Bureau of Land Management (BLM) who have jurisdiction of these islands in WI. We use historical areal imagery to describe island dynamics and river morphometry, such as changes in island shape and size. Relationships of related changes are explored with concurrent changes in river flow regimes. In an effort to integrate climate change uncertainties into decision making, we demonstrate an application of a multistage adaptive decision making framework to Wisconsin River islands, with a particular emphasis on flood management and planning. The framework is comprised of hydro-climatic ensemble projections generated from CMIP5 climate model outputs and multiple hydrologic models, including statistical and physically based approaches.

  13. Microsatellite Analysis of the Population Genetic Structure of Anolis carolinensis Introduced to the Ogasawara Islands.

    PubMed

    Sugawara, Hirotaka; Takahashi, Hiroo; Hayashi, Fumio

    2015-01-01

    DNA analysis can reveal the origins and dispersal patterns of invasive species. The green anole Anolis carolinensis is one such alien animal, which has been dispersed widely by humans from its native North America to many Pacific Ocean islands. In the Ogasawara (Bonin) Islands, this anole was recorded from Chichi-jima at the end of the 1960s, and then from Haha-jima in the early 1980s. These two islands are inhabited. In 2013, it was also found on the uninhabited Ani-jima, close to Chichi-jima. Humans are thought to have introduced the anole to Haha-jima, while the mode of introduction to Ani-jima is unknown. To clarify its dispersal patterns within and among these three islands, we assessed the fine-scale population genetic structure using five microsatellite loci. The results show a homogeneous genetic structure within islands, but different genetic structures among islands, suggesting that limited gene flow occurs between islands. The recently established Ani-jima population may have originated from several individuals simultaneously, or by repeated immigration from Chichi-jima. We must consider frequent incursions among these islands to control these invasive lizard populations and prevent their negative impact on native biodiversity. PMID:25660696

  14. Does ecophysiology mediate reptile responses to fire regimes? Evidence from Iberian lizards

    PubMed Central

    Ferreira, Catarina C.; Santos, Xavier

    2016-01-01

    Background. Reptiles are sensitive to habitat disturbance induced by wildfires but species frequently show opposing responses. Functional causes of such variability have been scarcely explored. In the northernmost limit of the Mediterranean bioregion, lizard species of Mediterranean affinity (Psammodromus algirus and Podarcis guadarramae) increase in abundance in burnt areas whereas Atlantic species (Lacerta schreiberi and Podarcis bocagei) decrease. Timon lepidus, the largest Mediterranean lizard in the region, shows mixed responses depending on the locality and fire history. We tested whether such interspecific differences are of a functional nature, namely, if ecophysiological traits may determine lizard response to fire. Based on the variation in habitat structure between burnt and unburnt sites, we hypothesise that Mediterranean species, which increase density in open habitats promoted by frequent fire regimes, should be more thermophile and suffer lower water losses than Atlantic species. Methods. We submitted 6–10 adult males of the five species to standard experiments for assessing preferred body temperatures (Tp) and evaporativewater loss rates (EWL), and examined the variation among species and along time by means of repeated-measures AN(C)OVAs. Results. Results only partially supported our initial expectations, since the medium-sized P. algirus clearly attained higher Tp and lower EWL. The two small wall lizards (P. bocagei and P. guadarramae) displayed low Tp and high EWL while the two large green lizards (T. lepidus and L. schreiberi) displayed intermediate values for both parameters. Discussion. The predicted differences according to the biogeographic affinities within each pair were not fully confirmed. We conclude that ecophysiology may help to understand functional reptile responses to fire but other biological traits are also to be considered. PMID:27330864

  15. Does ecophysiology mediate reptile responses to fire regimes? Evidence from Iberian lizards.

    PubMed

    Ferreira, Catarina C; Santos, Xavier; Carretero, Miguel A

    2016-01-01

    Background. Reptiles are sensitive to habitat disturbance induced by wildfires but species frequently show opposing responses. Functional causes of such variability have been scarcely explored. In the northernmost limit of the Mediterranean bioregion, lizard species of Mediterranean affinity (Psammodromus algirus and Podarcis guadarramae) increase in abundance in burnt areas whereas Atlantic species (Lacerta schreiberi and Podarcis bocagei) decrease. Timon lepidus, the largest Mediterranean lizard in the region, shows mixed responses depending on the locality and fire history. We tested whether such interspecific differences are of a functional nature, namely, if ecophysiological traits may determine lizard response to fire. Based on the variation in habitat structure between burnt and unburnt sites, we hypothesise that Mediterranean species, which increase density in open habitats promoted by frequent fire regimes, should be more thermophile and suffer lower water losses than Atlantic species. Methods. We submitted 6-10 adult males of the five species to standard experiments for assessing preferred body temperatures (T p ) and evaporativewater loss rates (EWL), and examined the variation among species and along time by means of repeated-measures AN(C)OVAs. Results. Results only partially supported our initial expectations, since the medium-sized P. algirus clearly attained higher Tp and lower EWL. The two small wall lizards (P. bocagei and P. guadarramae) displayed low Tp and high EWL while the two large green lizards (T. lepidus and L. schreiberi) displayed intermediate values for both parameters. Discussion. The predicted differences according to the biogeographic affinities within each pair were not fully confirmed. We conclude that ecophysiology may help to understand functional reptile responses to fire but other biological traits are also to be considered. PMID:27330864

  16. Regeneration of Articular Cartilage in Lizard Knee from Resident Stem/Progenitor Cells

    PubMed Central

    Alibardi, Lorenzo

    2015-01-01

    The epiphysis of femur and tibia in the lizard Podarcis muralis can extensively regenerate after injury. The process involves the articular cartilage and metaphyseal (growth) plate after damage. The secondary ossification center present between the articular cartilage and the growth plate is replaced by cartilaginous epiphyses after about one month of regeneration at high temperature. The present study analyzes the origin of the chondrogenic cells from putative stem cells located in the growing centers of the epiphyses. The study is carried out using immunocytochemistry for the detection of 5BrdU-labeled long retaining cells and for the localization of telomerase, an enzyme that indicates stemness. The observations show that putative stem cells retaining 5BrdU and positive for telomerase are present in the superficial articular cartilage and metaphyseal growth plate located in the epiphyses. This observation suggests that these areas represent stem cell niches lasting for most of the lifetime of lizards. In healthy long bones of adult lizards, the addition of new chondrocytes from the stem cells population in the articular cartilage and the metaphyseal growth plate likely allows for slow, continuous longitudinal growth. When the knee is injured in the adult lizard, new populations of chondrocytes actively producing chondroitin sulfate proteoglycan are derived from these stem cells to allow for the formation of completely new cartilaginous epiphyses, possibly anticipating the re-formation of secondary centers in later stages. The study suggests that in this lizard species, the regenerative ability of the epiphyses is a pre-adaptation to the regeneration of the articular cartilage. PMID:26340619

  17. Behavioral buffering of global warming in a cold-adapted lizard.

    PubMed

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2016-07-01

    Alpine lizards living in restricted areas might be particularly sensitive to climate change. We studied thermal biology of Iberolacerta cyreni in high mountains of central Spain. Our results suggest that I. cyreni is a cold-adapted thermal specialist and an effective thermoregulator. Among ectotherms, thermal specialists are more threatened by global warming than generalists. Alpine lizards have no chance to disperse to new suitable habitats. In addition, physiological plasticity is unlikely to keep pace with the expected rates of environmental warming. Thus, lizards might rely on their behavior in order to deal with ongoing climate warming. Plasticity of thermoregulatory behavior has been proposed to buffer the rise of environmental temperatures. Therefore, we studied the change in body and environmental temperatures, as well as their relationships, for I. cyreni between the 1980s and 2012. Air temperatures have increased more than 3.5°C and substrate temperatures have increased by 6°C in the habitat of I. cyreni over the last 25 years. However, body temperatures of lizards have increased less than 2°C in the same period, and the linear relationship between body and environmental temperatures remains similar. These results show that alpine lizards are buffering the potential impact of the increase in their environmental temperatures, most probably by means of their behavior. Body temperatures of I. cyreni are still cold enough to avoid any drop in fitness. Nonetheless, if warming continues, behavioral buffering might eventually become useless, as it would imply spending too much time in shelter, losing feeding, and mating opportunities. Eventually, if body temperature exceeds the thermal optimum in the near future, fitness would decrease abruptly. PMID:27386098

  18. Great Lakes: Chemical Monitoring

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1976-01-01

    The Tenth Great Lakes Regional Meeting of the American Chemical Society met to assess current Chemical Research activity in the Great Lakes Basin, and addressed to the various aspects of the theme, Chemistry of the Great Lakes. Research areas reviewed included watershed studies, atmospheric and aquatic studies, and sediment studies. (BT)

  19. Relationship between lizard home range and body size: A reanalysis of the data. [Uta stansburiana, Conolophus pallidus

    SciTech Connect

    Christian, K.A.; Waldschmidt, S.

    1984-01-01

    The authors reanalyzed the relationship between range and lizard body size. Their analysis includes home ranges estimated with the convex polygon technique and a recently proposed method for eliminating sample size bias. When analyzed separately, neither insectivorous, carnivorous nor female herbivorous lizards had a significant regression of home range size against body mass; male herbivores had a marginally significant regression. Combining data for the different foraging types resulted in significant regressions for both males and females; the regression for the pooled data set (males plus females) was also significant. These regression equations differ significantly from previously published equations derived from home range estimates adjusted for sample size bias. Except for the intercepts of the female regressions, the equations do not differ significantly from earlier equations derived from unadjusted home range estimates. The analysis showed that home range size for the side-blotched lizard, Uta stansburiana, could be accurately determined, without sample size bias, with an average of 13 resightings per lizard.

  20. Ecological immunization: in situ training of free-ranging predatory lizards reduces their vulnerability to invasive toxic prey.

    PubMed

    Ward-Fear, G; Pearson, D J; Brown, G P; Rangers, Balanggarra; Shine, R

    2016-01-01

    In Australia, large native predators are fatally poisoned when they ingest invasive cane toads (Rhinella marina). As a result, the spread of cane toads has caused catastrophic population declines in these predators. Immediately prior to the arrival of toads at a floodplain in the Kimberley region, we induced conditioned taste aversion in free-ranging varanid lizards (Varanus panoptes), by offering them small cane toads. By the end of the 18-month study, only one of 31 untrained lizards had survived longer than 110 days, compared to more than half (nine of 16) of trained lizards; the maximum known survival of a trained lizard in the presence of toads was 482 days. In situ aversion training (releasing small toads in advance of the main invasion front) offers a logistically simple and feasible way to buffer the impact of invasive toads on apex predators. PMID:26740565

  1. Streamlined Island

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-514, 15 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows a streamlined island in Marte Vallis, a large outflow channel system that crosses the 180oW meridian between the Elysium and Amazonis regions of Mars. The flow patterns on the floor of Marte Vallis might be the remains of lava flows or mud flows. Marte is the Spanish word for Mars. Most of the largest valleys on the red planet are named for 'Mars' in various languages. This island is located near 21.8oN, 175.3oW. The picture covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  2. Atlas of Great Comets

    NASA Astrophysics Data System (ADS)

    Stoyan, Ronald; Dunlop, Storm

    2015-01-01

    Foreword; Using this book; Part I. Introduction: Cometary beliefs and fears; Comets in art; Comets in literature and poetry; Comets in science; Cometary science today; Great comets in antiquity; Great comets of the Middle Ages; Part II. The 30 Greatest Comets of Modern Times: The Great Comet of 1471; Comet Halley 1531; The Great Comet of 1556; The Great Comet of 1577; Comet Halley, 1607; The Great Comet of 1618; The Great Comet of 1664; Comet Kirch, 1680; Comet Halley, 1682; The Great Comet of 1744; Comet Halley, 1759; Comet Messier, 1769; Comet Flaugergues, 1811; Comet Halley, 1835; The Great March Comet of 1843; Comet Donati, 1858; Comet Tebbutt, 1861; The Great September Comet of 1882; The Great January Comet of 1910; Comet Halley, 1910; Comet Arend-Roland, 1956; Comet Ikeya-Seki, 1965; Comet Bennett, 1970; Comet Kohoutek, 1973-4; Comet West, 1976; Comet Halley, 1986; Comet Shoemaker-Levy 9, 1994; Comet Hyakutake, 1996; Comet Hale-Bopp, 1997; Comet McNaught, 2007; Part III. Appendices; Table of comet data; Glossary; References; Photo credits; Index.

  3. Classifying Pacific islands

    NASA Astrophysics Data System (ADS)

    Nunn, Patrick D.; Kumar, Lalit; Eliot, Ian; McLean, Roger F.

    2016-12-01

    An earth-science-based classification of islands within the Pacific Basin resulted from the preparation of a database describing the location, area, and type of 1779 islands, where island type is determined as a function of the prevailing lithology and maximum elevation of each island, with an island defined as a discrete landmass composed of a contiguous land area ≥1 ha (0.01 km2) above mean high-water level. Reefs lacking islands and short-lived (<20 years) transient islands are not included. The principal aim of the classification is to assess the spatial diversity of the geologic and geomorphic attributes of Pacific islands. It is intended to be valid at a regional scale and based on two attributes: five types of lithology (volcanic, limestone, composite, continental, surficial) and a distinction between high and low islands. These attributes yielded eight island types: volcanic high and low islands; limestone high and low islands; composite high and low islands; reef (including all unconsolidated) islands; and continental islands. Most common are reef islands (36 %) and volcanic high islands (31 %), whereas the least common are composite low islands (1 %). Continental islands, 18 of the 1779 islands examined, are not included in maps showing the distribution of island attributes and types. Rationale for the spatial distributions of the various island attributes is drawn from the available literature and canvassed in the text. With exception of the few continental islands, the distribution of island types is broadly interpretable from the proximity of island-forming processes. It is anticipated the classification will become the basis for more focused investigation of spatial variability of the climate and ocean setting as well as the biological attributes of Pacific islands. It may also be used in spatial assessments of second-order phenomena associated with the islands, such as their vulnerability to various disasters, coastal erosion, or ocean pollution as

  4. Potential Mortality Effects of Off-Highway Vehicles on the Flat-Tailed Horned Lizard ( Phrynosoma mcallii): A Manipulative Experiment

    NASA Astrophysics Data System (ADS)

    Grant, Tyler J.; Doherty, Paul F.

    2009-03-01

    Southern California desert public lands receive especially high levels of off-highway recreation due to large population centers nearby and popular riding environments such as sand dunes. Controversy has developed over the flat-tailed horned lizard ( Phrynosoma mcallii), previously a candidate for listing under the Endangered Species Act. Some evidence suggests lower lizard abundance in areas of higher recreational use than in areas with low or no use. We designed a manipulative experiment to ensure maximum inference in evaluating the direct impact of recreational riding of off-highway vehicles on lizards. Thirty-six lizards, in situ, were treated with an off-highway vehicle treatment during hibernation season in three treatment groups: high impact, low impact, and control. Treatments consisted of timed riding by off-highway vehicles. In all treatment groups survival was 100%, despite hibernation of lizards at very shallow depths. Consequently, indirect effects of off-highway vehicles deserve increased attention. The relative importance of direct versus indirect (i.e., degradation of lizard habitat) impacts caused by off-highway vehicles remains unknown. These indirect effects may include the altering of vegetation, substrate, and prey. We recommend that a manipulative approach be adopted to investigate these possibilities.

  5. The Functional Significance of Aposematic Signals: Geographic Variation in the Responses of Widespread Lizard Predators to Colourful Invertebrate Prey

    PubMed Central

    Tseng, Hui-Yun; Lin, Chung-Ping; Hsu, Jung-Ya; Pike, David A.; Huang, Wen-San

    2014-01-01

    Conspicuous colouration can evolve as a primary defence mechanism that advertises unprofitability and discourages predatory attacks. Geographic overlap is a primary determinant of whether individual predators encounter, and thus learn to avoid, such aposematic prey. We experimentally tested whether the conspicuous colouration displayed by Old World pachyrhynchid weevils (Pachyrhynchus tobafolius and Kashotonus multipunctatus) deters predation by visual predators (Swinhoe’s tree lizard; Agamidae, Japalura swinhonis). During staged encounters, sympatric lizards attacked weevils without conspicuous patterns at higher rates than weevils with intact conspicuous patterns, whereas allopatric lizards attacked weevils with intact patterns at higher rates than sympatric lizards. Sympatric lizards also attacked masked weevils at lower rates, suggesting that other attributes of the weevils (size/shape/smell) also facilitate recognition. Allopatric lizards rapidly learned to avoid weevils after only a single encounter, and maintained aversive behaviours for more than three weeks. The imperfect ability of visual predators to recognize potential prey as unpalatable, both in the presence and absence of the aposematic signal, may help explain how diverse forms of mimicry exploit the predator’s visual system to deter predation. PMID:24614681

  6. Anatomy of the crus and pes of neotropical iguanian lizards in relation to habitat use and digitally based grasping capabilities.

    PubMed

    Abdala, Virginia; Tulli, María José; Russell, Anthony P; Powell, George L; Cruz, Félix B

    2014-03-01

    Ecomorphological studies of lizards have explored the role of various morphological traits and how these may be associated with, among other things, habitat use. We present an analysis of selected traits of internal morphology of the hind limbs of Neotropical iguanian lizards and their relationship to habitat use. Considering that one of the most widely-held hypotheses relating to the origin of grasping is associated with the exploitation of the narrow-branch arboreal habitat, we include subdivisions of this designation as two of our ecologically defined categories of habitat exploitation for analysis, and compare lizards assigned to these categories to the features displayed by terrestrial lizards. The influence of phylogeny in shaping the morphology of lizards was assessed by using the comparative method. K values were significant for several osteological traits. Most of the K values for the variables based upon muscle and tendon morphometric characters (13 out 21), by contrast, had values <1, suggesting that their variation cannot be explained by phylogeny alone. Results of our phylogenetic and conventional ANCOVA analyses reveal that the characters highlighted through the application of the comparative method are not absolutely related to habitat in terms of the categories considered here. It appears that the bauplan of the lizard pes incorporates a morphological configuration that is sufficiently versatile to enable exploitation of almost all of the available habitats. As unexpected as conservation of internal gross morphology appears, it represents a means of accommodating to environmental challenges by apparently permitting adequacy for all situations examined. PMID:24482428

  7. Seafloor character and sedimentary processes in eastern Long Island Sound and western Block Island Sound

    NASA Astrophysics Data System (ADS)

    Poppe, L. J.; Digiacomo-Cohen, M. L.; Smith, S. M.; Stewart, H. F.; Forfinski, N. A.

    2006-06-01

    Multibeam bathymetric data and seismic-reflection profiles collected in eastern Long Island Sound and western Block Island Sound reveal previously unrecognized glacial features and modern bedforms. Glacial features include an ice-sculptured bedrock surface, a newly identified recessional moraine, exposed glaciolacustrine sediments, and remnants of stagnant-ice-contact deposits. Modern bedforms include fields of transverse sand waves, barchanoid waves, giant scour depressions, and pockmarks. Bedform asymmetry and scour around obstructions indicate that net sediment transport is westward across the northern part of the study area near Fishers Island, and eastward across the southern part near Great Gull Island.

  8. Great Facts for September.

    ERIC Educational Resources Information Center

    Hansen, Karen L.

    1992-01-01

    Offers answers to questions on this issue's September calendar of events for elementary students. Items addressed include the Viking 2 spacecraft, children's poetry, Ellis Island, the space shuttle Discovery, space satellites and space junk, ice cream cones, Dr. Seuss, and the praying mantis. (SM)

  9. Deep divergence and structure in the Tropical Oceanic Pacific: a multilocus phylogeography of a widespread gekkonid lizard (Squamata: Gekkonidae: Gehyra oceanica)

    USGS Publications Warehouse

    Tonione, Maria A.; Fisher, Robert N.; Zhu, Catherine; Moritz, Craig

    2016-01-01

    Aim The islands of the Tropical Oceanic Pacific (TOP) host both local radiations and widespread, colonizing species. The few phylogeographical analyses of widespread species often point to recent human-aided expansions through the Pacific, suggesting that the communities are recently assembled. Here we apply multilocus data to infer biogeographical history of the gekkonid lizard, Gehyra oceanica, which is widespread, but for which prior analyses suggested a pre-human history and in situ diversification. Location Tropical Oceanic Pacific. Methods We generated a data set including mtDNA and diagnostic SNPs for 173 individuals of G. oceanica spanning Micronesia, Melanesia, and Polynesia. For a subset of these individuals, we also sequenced nuclear loci. From these data, we performed maximum likelihood and Bayesian inference to reveal major clades. We also performed Bayesian clustering analyses and coalescence–based species delimitation tests to infer the number of species in this area. Results We found evidence for six independent evolutionary lineages (candidate species) within G. oceanica that diverged between the Pliocene and the early Pleistocene, with high diversity through northern Melanesia, and pairing of northern Melanesian endemic taxa with widespread lineages across Micronesia and Polynesia. Main conclusions The islands of northern Melanesia not only have unrecognized diversity, but also were the source of independent expansions of lineages through the more remote northern and eastern Pacific. These results highlight the very different evolutionary histories of island faunas on remote archipelagos versus those across Melanesia and point to the need for more intensive studies of fauna within Melanesia if we are to understand the evolution of diversity across the tropical Pacific.

  10. The Great Unescape: Three Mile Island, Fukushima, and Beyond

    ERIC Educational Resources Information Center

    Spector, Hannah

    2015-01-01

    During the Second World War, the Luftwaffe ran a maximum security prisoner of war (POW) camp called "Stalag Luft III," which imprisoned captured Allied air force servicemen. The story of the 1944 escape from Stalag Luft III is one of the most famous stories of the Second World War as described in the firsthand written account and…

  11. Clonal diversity of a lizard malaria parasite, Plasmodium mexicanum, in its vertebrate host, the western fence lizard: role of variation in transmission intensity over time and space.

    PubMed

    Vardo, A M; Schall, J J

    2007-07-01

    Within the vertebrate host, infections of a malaria parasite (Plasmodium) could include a single genotype of cells (single-clone infections) or two to several genotypes (multiclone infections). Clonal diversity of infection plays an important role in the biology of the parasite, including its life history, virulence, and transmission. We determined the clonal diversity of Plasmodium mexicanum, a lizard malaria parasite at a study region in northern California, using variable microsatellite markers, the first such study for any malaria parasite of lizards or birds (the most common hosts for Plasmodium species). Multiclonal infections are common (50-88% of infections among samples), and measures of genetic diversity for the metapopulation (expected heterozygosity, number of alleles per locus, allele length variation, and effective population size) all indicated a substantial overall genetic diversity. Comparing years with high prevalence (1996-1998 = 25-32% lizards infected), and years with low prevalence (2001-2005 = 6-12%) found fewer alleles in samples taken from the low-prevalence years, but no reduction in overall diversity (H = 0.64-0.90 among loci). In most cases, rare alleles appeared to be lost as prevalence declined. For sites chronically experiencing low transmission intensity (prevalence approximately 1%), overall diversity was also high (H = 0.79-0.91), but there were fewer multiclonal infections. Theory predicts an apparent excess in expected heterozygosity follows a genetic bottleneck. Evidence for such a distortion in genetic diversity was observed after the drop in parasite prevalence under the infinite alleles mutation model but not for the stepwise mutation model. The results are similar to those reported for the human malaria parasite, Plasmodium falciparum, worldwide, and support the conclusion that malaria parasites maintain high genetic diversity in host populations despite the potential for loss in alleles during the transmission cycle or

  12. Solomon Islands.

    PubMed

    1988-06-01

    The Solomon Islands, which form an archipelago in the Southwest Pacific about 1900 km northeast of Australia, are described. Included are brief descriptions about such points as geography, people, history, type of government, political conditions, economy, and foreign relations. In 1987 the population was 301,180 (49% under age 14); the annual growth rate was 3.67%. The infant mortality rate is 46/1000; the life expectancy, 54 years. Health conditions in the Solomons generally are adequate, and the country does not suffer from serious endemic diseases other than malaria, in both the vivax and falsiparum strains. Hospitals and pharmacies are limited to population centers and missions. PMID:12177986

  13. Female Iberian wall lizards prefer male scents that signal a better cell-mediated immune response.

    PubMed

    López, Pilar; Martín, José

    2005-12-22

    In spite of the importance of chemoreception in sexual selection of lizards, only a few studies have examined the composition of chemical signals, and it is unknown whether and how chemicals provide honest information. Chemical signals might be honest if there were a trade-off between sexual advertisement and the immune system. Here, we show that proportions of cholesta-5,7-dien-3-ol in femoral secretions of male Iberian wall lizards (Podarcis hispanica) were related to their T-cell-mediated immune response. Thus, only males with a good immune system may allocate higher amounts of this chemical to signalling. Furthermore, females selected scents of males with higher proportions of cholesta-5,7-dien-3-ol and lower proportions of cholesterol. Thus, females might base their mate choice on the males' quality as indicated by the composition of their chemical signals. PMID:17148218

  14. Life history and demographic variation in the lizard Sceloporus graciosus: A long-term study

    SciTech Connect

    Tinkle, D.W. ); Dunham, A.E. ); Congdon, J.D. )

    1993-12-01

    An 11-yr study of life history and demographic variation in the sagebrush lizard Sceloporus graciosus was carried out on two study areas (Rattlesnake Ridge and Ponderosa Flat) in the Kolob Mesa Section of Zion National Park, Utah. Two primary objectives of this mark-recapture study were to: (1) quantify variation in age structure, age, and size at maturity, age-specific survivorship and fecundity, and individual growth rates, and (2) conduct a series of density reduction experiments designed to elucidate the effects of density on growth rates and survival of posthatchling lizards. In addition, the authors examined the relationships of variation in population density and deviation from long-term average precipitation and temperature to variation in individual growth, reproduction, and demography. 43 refs., 5 figs., 11 tabs.

  15. Lack of supercooling evolution related to winter severity in a lizard.

    PubMed

    Michels-Boyce, Madeline; Zani, Peter A

    2015-10-01

    As organisms move into higher latitudes, they may evolve physiological mechanisms to survive in harsher climates. One such mechanism is supercooling, the capacity to survive at subzero temperatures without freezing. While interspecific comparisons reveal greater thermal tolerances at higher latitudes in insects and vertebrates, evidence for intraspecific evolution in supercooling related to latitude is only evident in insects. We measured the supercooling points of lizards from 12 populations reared from hatch in common laboratory conditions to test for evolved differences in supercooling related to winter. Results indicate that winter harshness (depth or length) cannot explain supercooling points regardless of how data are analyzed, which suggests that populations have not evolved greater supercooling capacity. While our results are consistent with the idea that thermal physiology is evolutionarily conserved in vertebrates, we cannot reject several alternatives including the possibility that lizards are able to behaviorally avoid the extreme temperatures that would select for thermal evolution. PMID:26590458

  16. Cloning and Expression of Leishmania infantum LPG3 Gene by the Lizard Leishmania Expression System

    PubMed Central

    Pirdel, Leila; Hosseini, Ahmad Zavaran; Kazemi, Bahram; Rasouli, Manoochehr; Bandehpour, Mojgan; Soudi, Sara

    2012-01-01

    Background Various prokaryotic and eukaryotic expression systems have been developed for the production of recombinant proteins. In the present study, we used a new protein expression system based on the Iranian Lizard Leishmania, a trypanosomatid protozoan as a host, for the expression of LPG3 gene from Leishmania infantum (L.infantum). Methods The LPG3 gene was cloned in the expression cassette for integration into the small subunit of the ribosomal RNA locus of Lizard Leishmania genome by electroporation. Expression of the recombinant LPG3 protein was confirmed by western blotting and immunofluorescence staining. Results Western blotting confirmed the expression and production of rLPG3 protein. Immunofluoresence analysis also revealed the staining throughout the cytoplasm of transfected parasites, indicating that the protein has been expressed. Conclusion These results demonstrate that Leishmania cells can be suggested an expression system for the production of recombinant LPG3 (rLPG3) to further research in vaccine designing against leishmaniasis. PMID:23407850

  17. Erosion of lizard diversity by climate change and altered thermal niches.

    PubMed

    Sinervo, Barry; Méndez-de-la-Cruz, Fausto; Miles, Donald B; Heulin, Benoit; Bastiaans, Elizabeth; Villagrán-Santa Cruz, Maricela; Lara-Resendiz, Rafael; Martínez-Méndez, Norberto; Calderón-Espinosa, Martha Lucía; Meza-Lázaro, Rubi Nelsi; Gadsden, Héctor; Avila, Luciano Javier; Morando, Mariana; De la Riva, Ignacio J; Victoriano Sepulveda, Pedro; Rocha, Carlos Frederico Duarte; Ibargüengoytía, Nora; Aguilar Puntriano, César; Massot, Manuel; Lepetz, Virginie; Oksanen, Tuula A; Chapple, David G; Bauer, Aaron M; Branch, William R; Clobert, Jean; Sites, Jack W

    2010-05-14

    It is predicted that climate change will cause species extinctions and distributional shifts in coming decades, but data to validate these predictions are relatively scarce. Here, we compare recent and historical surveys for 48 Mexican lizard species at 200 sites. Since 1975, 12% of local populations have gone extinct. We verified physiological models of extinction risk with observed local extinctions and extended projections worldwide. Since 1975, we estimate that 4% of local populations have gone extinct worldwide, but by 2080 local extinctions are projected to reach 39% worldwide, and species extinctions may reach 20%. Global extinction projections were validated with local extinctions observed from 1975 to 2009 for regional biotas on four other continents, suggesting that lizards have already crossed a threshold for extinctions caused by climate change. PMID:20466932

  18. Prevalence and molecular identification of Cryptosporidium isolates from pet lizards and snakes in Italy.

    PubMed

    Rinaldi, L; Capasso, M; Mihalca, A D; Cirillo, R; Cringoli, G; Cacciò, S

    2012-11-01

    In order to acquire prevalence and genetic data on Cryptosporidium infections in captive lizards and snakes kept as pets, a survey was conducted on 150 individual reptiles from southern Italy. Fecal samples were preserved in 5% formalin and analyzed using a commercial immunofluorescence assay (IFA) for the detection of Cryptosporidium oocysts and Giardia cysts. IFA revealed the presence of Cryptosporidium oocysts in nine of the 150 samples examined (6.0%), precisely in 6/125 snakes (4.8%) and in 3/25 lizards (12.0%); all fecal samples tested negative for the presence of Giardia cysts. Molecular characterization based on nested PCR amplification and sequencing of the SSU-rRNA gene, revealed the presence of Cryptosporidium serpentis in three samples from snakes (Boa constrictor constrictor, Elapheguttata guttata guttata and Python molurus). PMID:23193530

  19. Prevalence and molecular identification of Cryptosporidium isolates from pet lizards and snakes in Italy

    PubMed Central

    Rinaldi, L.; Capasso, M.; Mihalca, A.D.; Cirillo, R.; Cringoli, G.; Cacciò, S.

    2012-01-01

    In order to acquire prevalence and genetic data on Cryptosporidium infections in captive lizards and snakes kept as pets, a survey was conducted on 150 individual reptiles from southern Italy. Fecal samples were preserved in 5% formalin and analyzed using a commercial immunofluorescence assay (IFA) for the detection of Cryptosporidium oocysts and Giardia cysts. IFA revealed the presence of Cryptosporidium oocysts in nine of the 150 samples examined (6.0%), precisely in 6/125 snakes (4.8%) and in 3/25 lizards (12.0%); all fecal samples tested negative for the presence of Giardia cysts. Molecular characterization based on nested PCR amplification and sequencing of the SSU-rRNA gene, revealed the presence of Cryptosporidium serpentis in three samples from snakes (Boa constrictor constrictor, Elapheguttata guttata guttata and Python molurus). PMID:23193530

  20. Immune activation affects chemical sexual ornaments of male Iberian wall lizards

    NASA Astrophysics Data System (ADS)

    López, Pilar; Gabirot, Marianne; Martín, José

    2009-01-01

    Many animals use chemical signals in sexual selection, but it is not clear how these sexual traits might have evolved to signal honestly male condition. It is possible that there is a trade-off between maintaining the immune system and the elaboration of ornaments. We experimentally challenged the immune system of male Iberian wall lizards, Podarcis hispanica, with a bacterial antigen (lipopolysaccharide), without pathogenic effects, to explore whether the immune activation affected chemical ornaments. Immune activation resulted in decreased proportions of a major chemical in femoral secretions (cholesta-5,7-dien-3-ol = provitamin D3) known to be selected in scent of males by females and which active form (vitamin D) has a variety of important effects on immune system function. This result suggests the existence of a potential trade-off between physiological regulation of the immune system and the allocation of essential nutrients (vitamins) to sexual chemical ornaments in male lizards.

  1. Galanin immunoreactivity in the brain of the desert lizard Uromastyx acanthinura during activity season.

    PubMed

    Hammouche, Sadjia Benmansour; Bennis, Mohammed

    2013-01-01

    The distribution of galanin immunoreactive perikarya and nerve fibers in the brain of the desert lizard U. acanthinura was studied by means of immunofluorescence using an antiserum against rabbit galanin. The animals were captured during the activity season in March (wet season) just before reproduction period and in June (arid season) after ovulation period. Immunoreactive neurons were mostly detected in the mediobasal and the infundibular recess nuclei, the nucleus of the paraventricular organ, the paraventricular organ, the periventricular nucleus and in the anterior hypothalamus at the level of the periventricular nucleus, the paraventricular nucleus and the supraoptic nucleus. The differences in brain galanin expression between animals collected under both sets of environmental conditions indicated changes which occur during the annual and reproductive cycles. The wide hypothalamic and extrahypothalamic distribution of galanin immunoreactive fibers suggests that this peptide may have hypophysiotropic, neuromodulator and neurotransmitter roles in the lizard U. acanthinura. PMID:23690217

  2. The Next Great Generation?

    ERIC Educational Resources Information Center

    Brownstein, Andrew

    2000-01-01

    Discusses ideas from a new book, "Millennials Rising: The Next Great Generation," (by Neil Howe and William Strauss) suggesting that youth culture is on the cusp of a radical shift with the generation beginning with this year's college freshmen who are typically team oriented, optimistic, and poised for greatness on a global scale. Includes a…

  3. GREAT LAKES LIMNOLOGY MONITORING

    EPA Science Inventory

    The Great Lakes National Program Office (GLNPO) of the United States Environmental Protection Agency (USEPA) has primary responsibility within the U.S. for conducting surveillance monitoring of the offshore waters of the Great Lakes. This monitoring is intended to fulfill provis...

  4. Great Lakes Teacher's Guide.

    ERIC Educational Resources Information Center

    Reid, Ron

    The Great Lakes are one of the world's greatest reservoirs of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. They are also a magnificent resource for the teachers of Ontario. Study of the Great Lakes can bring to life the factors that shape the ecology…

  5. Great Lakes Literacy Principles

    NASA Astrophysics Data System (ADS)

    Fortner, Rosanne W.; Manzo, Lyndsey

    2011-03-01

    Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

  6. The Effect of Ear Canal Pressure on Spontaneous Otoacoustic Emissions:. Comparison Between Human and Lizard Ears

    NASA Astrophysics Data System (ADS)

    van Dijk, P.; Manley, G. A.

    2009-02-01

    The center frequency, height and width of peaks in SOAE spectra depend on ear canal pressure. The width is interpreted as a measure of the inner ear source-signal-to-(e.g. thermal)-noise ratio. In humans, width increases with decreasing height. Apparently, ear canal pressure modifies the amplitude of the inner ear emission source signal. In lizards, the relation between peak width and height is not consistent. Here, middle ear transmission changes may account for many the observed amplitude effects.

  7. Elevational variation in body-temperature response to immune challenge in a lizard.

    PubMed

    Zamora-Camacho, Francisco Javier; Reguera, Senda; Moreno-Rueda, Gregorio

    2016-01-01

    Immunocompetence benefits animal fitness by combating pathogens, but also entails some costs. One of its main components is fever, which in ectotherms involves two main types of costs: energy expenditure and predation risk. Whenever those costs of fever outweigh its benefits, ectotherms are expected not to develop fever, or even to show hypothermia, reducing costs of thermoregulation and diverting the energy saved to other components of the immune system. Environmental thermal quality, and therefore the thermoregulation cost/benefit balance, varies geographically. Hence, we hypothesize that, in alpine habitats, immune-challenged ectotherms should show no thermal response, given that (1) hypothermia would be very costly, as the temporal window for reproduction is extremely small, and (2) fever would have a prohibitive cost, as heat acquisition is limited in such habitat. However, in temperate habitats, immune-challenged ectotherms might show a febrile response, due to lower cost/benefit balance as a consequence of a more suitable thermal environment. We tested this hypothesis in Psammodromus algirus lizards from Sierra Nevada (SE Spain), by testing body temperature preferred by alpine and non-alpine lizards, before and after activating their immune system with a typical innocuous pyrogen. Surprisingly, non-alpine lizards responded to immune challenge by decreasing preferential body-temperature, presumably allowing them to save energy and reduce exposure to predators. On the contrary, as predicted, immune-challenged alpine lizards maintained their body-temperature preferences. These results match with increased costs of no thermoregulation with elevation, due to the reduced window of time for reproduction in alpine environment. PMID:27168981

  8. Hysteresis of heart rate and heat exchange of fasting and postprandial savannah monitor lizards (Varanus exanthematicus).

    PubMed

    Zaar, Morten; Larsen, Einer; Wang, Tobias

    2004-04-01

    Reptiles are ectothermic, but regulate body temperatures (T(b)) by behavioural and physiological means. Body temperature has profound effects on virtually all physiological functions. It is well known that heating occurs faster than cooling, which seems to correlate with changes in cutaneous perfusion. Increased cutaneous perfusion, and hence elevated cardiac output, during heating is reflected in an increased heart rate (f(H)), and f(H), at a given T(b), is normally higher during heating compared to cooling ('hysteresis of heart rate'). Digestion is associated with an increased metabolic rate. This is associated with an elevated f(H) and many species of reptiles also exhibited a behavioural selection of higher T(b) during digestion. Here, we examine whether digestion affects the rate of heating and cooling as well as the hysteresis of heart rate in savannah monitor lizards (Varanus exanthematicus). Fasting lizards were studied after 5 days of food deprivation while digesting lizards were studied approximately 24 h after ingesting dead mice that equalled 10% of their body mass. Heart rate was measured while T(b) increased from 28 to 38 degrees C under a heat lamp and while T(b) decreased during a subsequent cooling phase. The lizards exhibited hysteresis of heart rate, and heating occurred faster than cooling. Feeding led to an increased f(H) (approximately 20 min(-1) irrespective of T(b)), but did not affect the rate of temperature change during heating or cooling. Therefore, it is likely that the increased blood flows during digestion are distributed exclusively to visceral organs and that the thermal conductance remains unaffected by the elevated metabolic rate during digestion. PMID:15123175

  9. A new Andean lizard of the genus Potamites (Sauria, Gymnophthalmidae) from Manu National Park, southeastern Peru.

    PubMed

    Chávez, Germán; Catenazzi, Alessandro

    2014-01-01

    We describe a new lizard of the genus Potamites from elevations of 1000-2100 m in the montane forests of the Cordillera de Paucartambo and the upper Kosñipata valley, Region of Cusco, Peru. The new species differs from other species of Potamites by having scattered keeled scales on dorsum, an undivided frontonasal and absence of femoral pores in females. PMID:24871404

  10. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards.

    PubMed

    Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang; Baumgartner, Werner

    2011-01-01

    Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales) has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus), the Arabian toadhead agama (Phrynocephalus arabicus) and the Texas horned lizard (Phrynosoma cornutum). All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive - and for Phrynosoma directed - transport of water. PMID:21977432

  11. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

    PubMed Central

    Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang

    2011-01-01

    Summary Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales) has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus), the Arabian toadhead agama (Phrynocephalus arabicus) and the Texas horned lizard (Phrynosoma cornutum). All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive – and for Phrynosoma directed – transport of water. PMID:21977432

  12. Elevational variation in body-temperature response to immune challenge in a lizard

    PubMed Central

    Reguera, Senda; Moreno-Rueda, Gregorio

    2016-01-01

    Immunocompetence benefits animal fitness by combating pathogens, but also entails some costs. One of its main components is fever, which in ectotherms involves two main types of costs: energy expenditure and predation risk. Whenever those costs of fever outweigh its benefits, ectotherms are expected not to develop fever, or even to show hypothermia, reducing costs of thermoregulation and diverting the energy saved to other components of the immune system. Environmental thermal quality, and therefore the thermoregulation cost/benefit balance, varies geographically. Hence, we hypothesize that, in alpine habitats, immune-challenged ectotherms should show no thermal response, given that (1) hypothermia would be very costly, as the temporal window for reproduction is extremely small, and (2) fever would have a prohibitive cost, as heat acquisition is limited in such habitat. However, in temperate habitats, immune-challenged ectotherms might show a febrile response, due to lower cost/benefit balance as a consequence of a more suitable thermal environment. We tested this hypothesis in Psammodromus algirus lizards from Sierra Nevada (SE Spain), by testing body temperature preferred by alpine and non-alpine lizards, before and after activating their immune system with a typical innocuous pyrogen. Surprisingly, non-alpine lizards responded to immune challenge by decreasing preferential body-temperature, presumably allowing them to save energy and reduce exposure to predators. On the contrary, as predicted, immune-challenged alpine lizards maintained their body-temperature preferences. These results match with increased costs of no thermoregulation with elevation, due to the reduced window of time for reproduction in alpine environment. PMID:27168981

  13. A new scincomorph lizard from the Palaeocene of Belgium and the origin of Scincoidea in Europe

    NASA Astrophysics Data System (ADS)

    Folie, A.; Sigé, B.; Smith, T.

    2005-11-01

    Well-preserved jaw fragments and skull bones of a new scincomorphan lizard are described from the continental Hainin Formation (Middle Palaeocene) of the Mons Basin in southwestern Belgium. This taxon, Scincoideus haininensis gen. et sp. nov., is characterised by vermiculate dermal rugosities and represents the earliest formally recognised scincoid in Europe. It differs from cordylids (girdled lizards) by lacking the parietal downgrowth and differs from scincids (skinks) by having robustly built bones and a well-developed lingual cusp on tooth crowns. By its mosaic characters, S. haininensis is considered here as being a basal scincoid lizard close to the origin of cordylids and scincids. Palaeobiogeographic analysis suggests that scincoids were present in Europe from the Palaeocene or maybe even before the Cretaceous/Palaeogene boundary and that they were replaced by modern scincoids such as true scincids and cordylids during the Eocene. The origin of the latter two families in Europe was very likely related with the immigration of the first modern mammals.

  14. Controlled preparation of wet granular media reveals limits to lizard burial ability.

    PubMed

    Sharpe, Sarah S; Kuckuk, Robyn; Goldman, Daniel I

    2015-07-01

    Many animals move within ground composed of granular media (GM); the resistive properties of such substrates can depend on water content and compaction, but little is known about how such parameters affect locomotion or the physics of drag and penetration. Using apparatus to control compaction of GM, our recent studies of movement in dry GM have revealed locomotion strategies of specialized dry-sand-swimming reptiles. However, these animals represent a small fraction of the diversity and presumed burial strategies of fossorial reptilian fauna. Here we develop a system to create states of wet GM of varying moisture content and compaction in quantities sufficient to study the burial and subsurface locomotion of the Ocellated skink (C. ocellatus), a generalist lizard. X-ray imaging revealed that in wet and dry GM the lizard slowly buried (≈30 s) propagating a wave from head to tail, while moving in a start-stop motion. During forward movement, the head oscillated, and the forelimb on the convex side of the body propelled the animal. Although body kinematics and 'slip' were similar in both substrates, the burial depth was smaller in wet GM. Penetration and drag force experiments on smooth cylinders revealed that wet GM was ≈4× more resistive than dry GM. In total, our measurements indicate that while the rheology of the dry and wet GM differ substantially, the lizard's burial motor pattern is conserved across substrates, while its burial depth is largely constrained by environmental resistance. PMID:26109565

  15. Sex and boldness explain individual differences in spatial learning in a lizard

    PubMed Central

    Carazo, Pau; Noble, Daniel W. A.; Chandrasoma, Dani; Whiting, Martin J.

    2014-01-01

    Understanding individual differences in cognitive performance is a major challenge to animal behaviour and cognition studies. We used the Eastern water skink (Eulamprus quoyii) to examine associations between exploration, boldness and individual variability in spatial learning, a dimension of lizard cognition with important bearing on fitness. We show that males perform better than females in a biologically relevant spatial learning task. This is the first evidence for sex differences in learning in a reptile, and we argue that it is probably owing to sex-specific selective pressures that may be widespread in lizards. Across the sexes, we found a clear association between boldness after a simulated predatory attack and the probability of learning the spatial task. In contrast to previous studies, we found a nonlinear association between boldness and learning: both ‘bold’ and ‘shy’ behavioural types were more successful learners than intermediate males. Our results do not fit with recent predictions suggesting that individual differences in learning may be linked with behavioural types via high–low-risk/reward trade-offs. We suggest the possibility that differences in spatial cognitive performance may arise in lizards as a consequence of the distinct environmental variability and complexity experienced by individuals as a result of their sex and social tactics. PMID:24619443

  16. Giant lizards occupied herbivorous mammalian ecospace during the Paleogene greenhouse in Southeast Asia

    PubMed Central

    Head, Jason J.; Gunnell, Gregg F.; Holroyd, Patricia A.; Hutchison, J. Howard; Ciochon, Russell L.

    2013-01-01

    Mammals dominate modern terrestrial herbivore ecosystems, whereas extant herbivorous reptiles are limited in diversity and body size. The evolution of reptile herbivory and its relationship to mammalian diversification is poorly understood with respect to climate and the roles of predation pressure and competition for food resources. Here, we describe a giant fossil acrodontan lizard recovered with a diverse mammal assemblage from the late middle Eocene Pondaung Formation of Myanmar, which provides a historical test of factors controlling body size in herbivorous squamates. We infer a predominately herbivorous feeding ecology for the new acrodontan based on dental anatomy, phylogenetic relationships and body size. Ranking body masses for Pondaung Formation vertebrates indicates that the lizard occupied a size niche among the larger herbivores and was larger than most carnivorous mammals. Paleotemperature estimates of Pondaung Formation environments based on the body size of the new lizard are approximately 2–5°C higher than modern. These results indicate that competitive exclusion and predation by mammals did not restrict body size evolution in these herbivorous squamates, and elevated temperatures relative to modern climates during the Paleogene greenhouse may have resulted in the evolution of gigantism through elevated poikilothermic metabolic rates and in response to increases in floral productivity. PMID:23740779

  17. Widespread primary, but geographically restricted secondary, human introductions of wall lizards, Podarcis muralis.

    PubMed

    Michaelides, Sozos N; While, Geoffrey M; Zajac, Natalia; Uller, Tobias

    2015-06-01

    Establishing the introduction pathways of alien species is a fundamental task in invasion biology. The common wall lizard, Podarcis muralis, has been widely introduced outside of its native range in both Europe and North America, primarily through escaped pets or deliberate release of animals from captive or wild populations. Here, we use Bayesian clustering, approximate Bayesian computation (ABC) methods and network analyses to reconstruct the origin and colonization history of 23 non-native populations of wall lizards in England. Our analyses show that established populations in southern England originate from at least nine separate sources of animals from native populations in France and Italy. Secondary introductions from previously established non-native populations were supported for eleven (47%) populations. In contrast to the primary introductions, secondary introductions were highly restricted geographically and appear to have occurred within a limited time frame rather than being increasingly common. Together, these data suggest that extant wall lizard populations in England are the result of isolated accidental and deliberate releases of imported animals since the 1970s, with only local translocation of animals from established non-native populations. Given that populations introduced as recently as 25 years ago show evidence of having adapted to cool climate, discouraging further translocations may be important to prevent more extensive establishment on the south coast of England. PMID:25891955

  18. Allelic expression of mammalian imprinted genes in a matrotrophic lizard, Pseudemoia entrecasteauxii.

    PubMed

    Griffith, Oliver W; Brandley, Matthew C; Belov, Katherine; Thompson, Michael B

    2016-03-01

    Genomic imprinting is a process that results in the differential expression of genes depending on their parent of origin. It occurs in both plants and live-bearing mammals, with imprinted genes typically regulating the ability of an embryo to manipulate the maternal provision of nutrients. Genomic imprinting increases the potential for selection to act separately on paternally and maternally expressed genes, which increases the number of opportunities that selection can facilitate embryonic control over maternal nutrient provision. By looking for imprinting in an independent matrotrophic lineage, the viviparous lizard Pseudemoia entrecasteauxii (Scincidae), we test the hypothesis that genomic imprinting facilitates the evolution of substantial placental nutrient transport to embryos (matrotrophy). We sequenced transcriptomes from the embryonic component of lizard placentae to determine whether there are parent-of-origin differences in expression of genes that are imprinted in mammals. Of these genes, 19 had sufficiently high expression in the lizard to identify polymorphisms in transcribed sequences. We identified bi-allelic expression in 17 genes (including insulin-like growth factor 2), indicating that neither allele was imprinted. These data suggest that either genomic imprinting has not evolved in this matrotrophic skink or, if it has, it has evolved in different genes to mammals. We outline how these hypotheses can be tested. This study highlights important differences between mammalian and reptile pregnancy and the absence of any shared imprinting genes reflects fundamental differences in the way that pregnancy has evolved in these two lineages. PMID:26943808

  19. When Field Experiments Yield Unexpected Results: Lessons Learned from Measuring Selection in White Sands Lizards

    PubMed Central

    Hardwick, Kayla M.; Harmon, Luke J.; Hardwick, Scott D.; Rosenblum, Erica Bree

    2015-01-01

    Determining the adaptive significance of phenotypic traits is key for understanding evolution and diversification in natural populations. However, evolutionary biologists have an incomplete understanding of how specific traits affect fitness in most populations. The White Sands system provides an opportunity to study the adaptive significance of traits in an experimental context. Blanched color evolved recently in three species of lizards inhabiting the gypsum dunes of White Sands and is likely an adaptation to avoid predation. To determine whether there is a relationship between color and susceptibility to predation in White Sands lizards, we conducted enclosure experiments, quantifying survivorship of Holbrookia maculate exhibiting substrate-matched and substrate-mismatched phenotypes. Lizards in our study experienced strong predation. Color did not have a significant effect on survival, but we found several unexpected relationships including variation in predation over small spatial and temporal scales. In addition, we detected a marginally significant interaction between sex and color, suggesting selection for substrate matching may be stronger for males than females. We use our results as a case study to examine six major challenges frequently encountered in field-based studies of natural selection, and suggest that insight into the complexities of selection often results when experiments turn out differently than expected. PMID:25714838

  20. Low rate of interchromosomal rearrangements during old radiation of gekkotan lizards (Squamata: Gekkota).

    PubMed

    Johnson Pokorná, Martina; Trifonov, Vladimir A; Rens, Willem; Ferguson-Smith, Malcolm A; Kratochvíl, Lukáš

    2015-06-01

    Gekkotan lizards are a highly specious (∼1600 described species) clade of squamate lizards with nearly cosmopolitan distribution in warmer areas. The clade is primarily nocturnal and forms an ecologically dominant part of the world nocturnal herpetofauna. However, molecular cytogenetic methods to study the evolution of karyotypes have not been widely applied in geckos. Our aim here was to uncover the extent of chromosomal rearrangements across the whole group Gekkota and to search for putative synapomorphies supporting the newly proposed phylogenetic relationships within this clade. We applied cross-species chromosome painting with the recently derived whole-chromosomal probes from the gekkonid species Gekko japonicus to members of the major gekkotan lineages. We included members of the families Diplodactylidae, Carphodactylidae, Pygopodidae, Eublepharidae, Phyllodactylidae and Gekkonidae. Our study demonstrates relatively high chromosome conservatism across the ancient group of gekkotan lizards. We documented that many changes in chromosomal shape across geckos can be attributed to intrachromosomal rearrangements. The documented rearrangements are not totally in agreement with the recently newly erected family Phyllodactylidae. The results also pointed to homoplasy, particularly in the reuse of chromosome breakpoints, in the evolution of gecko karyotypes. PMID:25665924

  1. Directional, passive liquid transport: the Texas horned lizard as a model for a biomimetic 'liquid diode'.

    PubMed

    Comanns, Philipp; Buchberger, Gerda; Buchsbaum, Andreas; Baumgartner, Richard; Kogler, Alexander; Bauer, Siegfried; Baumgartner, Werner

    2015-08-01

    Moisture-harvesting lizards such as the Texas horned lizard (Iguanidae: Phrynosoma cornutum) live in arid regions. Special skin adaptations enable them to access water sources such as moist sand and dew: their skin is capable of collecting and transporting water directionally by means of a capillary system between the scales. This fluid transport is passive, i.e. requires no external energy, and directs water preferentially towards the lizard's snout. We show that this phenomenon is based on geometric principles, namely on a periodic pattern of interconnected half-open capillary channels that narrow and widen. Following a biomimetic approach, we used these principles to develop a technical prototype design. Building upon the Young-Laplace equation, we derived a theoretical model for the local behaviour of the liquid in such capillaries. We present a global model for the penetration velocity validated by experimental data. Artificial surfaces designed in accordance with this model prevent liquid flow in one direction while sustaining it in the other. Such passive directional liquid transport could lead to process improvements and reduction of resources in many technical applications. PMID:26202685

  2. Location of fruit using only airborne odor cues by a lizard.

    PubMed

    Cooper, W E; Pérez-Mellado, V

    2001-10-01

    Although squamate reptiles are known to locate conspecifics by scent-trailing and to locate and identify prey by tongue-flicking substrates, an ability to locate food using only airborne cues has previously only been suspected based on observations that dead animals can be used as bait for Komodo dragons and that some nocturnal geckos aggregate on flowers. We conducted a simple field test of the ability of the omnivorous lizard Podarcis lilfordi to find fruit hidden under opaque cups. When a board having two identical cups spaced 1 m apart, one empty and the other hiding a freshly cut piece of apricot, was placed in the habitat, lizards first contacted the cup hiding fruit at well above chance frequency. Upon contact with a cup, lizards were significantly more likely to stay next to the cup, tongue-flick at high rates, climb the cup, and attempt to bite the cup if it hid a piece of apricot. The ability to follow a concentration gradient of airborne volatile chemicals to its source is very likely mediated by olfaction, but participation by or primacy of vomerolfaction cannot be excluded. PMID:11714497

  3. Spatiotemporal changes in metallothionein gene expression during embryogenesis in the wall lizard Podarcis sicula.

    PubMed

    Simoniello, Palma; Motta, Chiara Maria; Scudiero, Rosaria; Trinchella, Francesca; Filosa, Silvana

    2010-08-01

    Lizard embryos are nutritionally independent from their environment. During the early phases of oogenesis, the egg prepares for development by storing reserve organelles, proteins, and RNAs sufficient to allow the zygote to transform into a juvenile. This preparation also includes the storage of metallothionein (MT) transcripts. This study investigated the localization of these transcripts by in situ hybridization throughout Podarcis sicula developmental stages. Our data show that MT expression undergoes shifts in both regional and cellular localization. MT transcripts were detected early in the central nervous system, later in tissues implicated in metabolic processes. Results are discussed highlighting differences in lizard embryonic spatial and temporal MT expression compared with piscine, amphibian, and mammalian embryos. We hypothesize that, under natural conditions, the nutritionally closed system represented by the lizard egg protects the developing embryo from an unwanted excess of metals. This mechanism would make MT expression and accumulation in detoxifying organs in developing animals unnecessary until hatching and food intake begins. Conversely, the presence of MT transcripts during brain development may ensure the correct final architecture of this organ. PMID:20623798

  4. Controlled preparation of wet granular media reveals limits to lizard burial ability

    NASA Astrophysics Data System (ADS)

    Sharpe, Sarah S.; Kuckuk, Robyn; Goldman, Daniel I.

    2015-07-01

    Many animals move within ground composed of granular media (GM); the resistive properties of such substrates can depend on water content and compaction, but little is known about how such parameters affect locomotion or the physics of drag and penetration. Using apparatus to control compaction of GM, our recent studies of movement in dry GM have revealed locomotion strategies of specialized dry-sand-swimming reptiles. However, these animals represent a small fraction of the diversity and presumed burial strategies of fossorial reptilian fauna. Here we develop a system to create states of wet GM of varying moisture content and compaction in quantities sufficient to study the burial and subsurface locomotion of the Ocellated skink (C. ocellatus), a generalist lizard. X-ray imaging revealed that in wet and dry GM the lizard slowly buried (≈ 30 s) propagating a wave from head to tail, while moving in a start-stop motion. During forward movement, the head oscillated, and the forelimb on the convex side of the body propelled the animal. Although body kinematics and ‘slip’ were similar in both substrates, the burial depth was smaller in wet GM. Penetration and drag force experiments on smooth cylinders revealed that wet GM was ≈ 4× more resistive than dry GM. In total, our measurements indicate that while the rheology of the dry and wet GM differ substantially, the lizard's burial motor pattern is conserved across substrates, while its burial depth is largely constrained by environmental resistance.

  5. Pre- and Postcopulatory Traits of Salvator Male Lizards in Allopatry and Sympatry.

    PubMed

    Naretto, Sergio; Blengini, Cecilia S; Cardozo, Gabriela; Chiaraviglio, Margarita

    2016-01-01

    The reproductive traits of males are under influence of sexual pressures before and after copulation. The strength of sexual selection varies across populations because they undergo varying competition for mating opportunities. Besides intraspecific pressures, individuals seem to be subjected to pressures driven by interspecific interactions in sympatry. Lizards may vary their reproductive strategies through varying sexual characters, body size, gonadal investment, and sperm traits. We evaluated the reproductive traits, involved in pre- and postcopulatory competition, in allopatric and sympatric populations of Salvator lizards. We observed a spatial gradient of male competition among populations, with the following order: allopatric zone of S. rufescens; sympatric zone; and allopatric zone of S. merianae. Accordingly, variation in secondary sexual character, the relative testis mass, and the length of sperm component was observed between allopatry and sympatry in each species, suggesting differences in the investment of reproductive traits. However, we found that these two Salvator species did not differ in secondary sexual characters in sympatry. Interestingly, the trade-off between testes and muscle varied differently from allopatry to sympatry between these Salvator species, suggesting that the influence of social context on reproductive traits investment would affect lizard species differently. PMID:27110428

  6. Evidence for a carotid body homolog in the lizard Tupinambis merianae.

    PubMed

    Reichert, Michelle N; Brink, Deidre L; Milsom, William K

    2015-01-15

    The homolog to the mammalian carotid body has not yet been identified in lizards. Observational studies and evolutionary history provide indirect evidence for the existence of a chemoreceptor population at the first major bifurcation of the common carotid artery in lizards, but a chemoreceptive role for this area has not yet been definitively demonstrated. We explored this possibility by measuring changes in cardiorespiratory variables in response to focal arterial injections of the hypoxia mimic sodium cyanide (NaCN) into the carotid artery of 12 unanesthetized specimens of Tupinambis merianae. These injections elicited increases in heart rate (f(H); 101±35% increase) and respiratory rate (f(R); 620±119% increase), but not mean arterial blood pressure (MAP). These responses were eliminated by vagal denervation. Similar responses were elicited by injections of the neurotransmitters acetylcholine (ACh) and serotonin (5-HT) but not norepinephrine. Heart rate and respiratory rate increases in response to NaCN could be blocked or reduced by antagonists to ACh (atropine) and/or 5-HT (methysergide). Finally, using immunohistochemistry, we demonstrate the presence of putative chemoreceptive cells immunopositive for the cholinergic cell marker vesicular ACh transporter (VAChT) and 5-HT on internal lattice-like structures at the carotid bifurcation. These results provide evidence in lizards for the existence of dispersed chemoreceptor cells at the first carotid bifurcation in the central cardiovascular area that have similar properties to known carotid body homologs, adding to the picture of chemoreceptor evolution in vertebrates. PMID:25524981

  7. Giant lizards occupied herbivorous mammalian ecospace during the Paleogene greenhouse in Southeast Asia.

    PubMed

    Head, Jason J; Gunnell, Gregg F; Holroyd, Patricia A; Hutchison, J Howard; Ciochon, Russell L

    2013-07-22

    Mammals dominate modern terrestrial herbivore ecosystems, whereas extant herbivorous reptiles are limited in diversity and body size. The evolution of reptile herbivory and its relationship to mammalian diversification is poorly understood with respect to climate and the roles of predation pressure and competition for food resources. Here, we describe a giant fossil acrodontan lizard recovered with a diverse mammal assemblage from the late middle Eocene Pondaung Formation of Myanmar, which provides a historical test of factors controlling body size in herbivorous squamates. We infer a predominately herbivorous feeding ecology for the new acrodontan based on dental anatomy, phylogenetic relationships and body size. Ranking body masses for Pondaung Formation vertebrates indicates that the lizard occupied a size niche among the larger herbivores and was larger than most carnivorous mammals. Paleotemperature estimates of Pondaung Formation environments based on the body size of the new lizard are approximately 2-5°C higher than modern. These results indicate that competitive exclusion and predation by mammals did not restrict body size evolution in these herbivorous squamates, and elevated temperatures relative to modern climates during the Paleogene greenhouse may have resulted in the evolution of gigantism through elevated poikilothermic metabolic rates and in response to increases in floral productivity. PMID:23740779

  8. A gravid lizard from the Cretaceous of China and the early history of squamate viviparity

    NASA Astrophysics Data System (ADS)

    Wang, Yuan; Evans, Susan E.

    2011-09-01

    Although viviparity is most often associated with mammals, roughly one fifth of extant squamate reptiles give birth to live young. Phylogenetic analyses indicate that the trait evolved more than 100 times within Squamata, a frequency greater than that of all other vertebrate clades combined. However, there is debate as to the antiquity of the trait and, until now, the only direct fossil evidence of squamate viviparity was in Late Cretaceous mosasauroids, specialised marine lizards without modern equivalents. Here, we document viviparity in a specimen of a more generalised lizard, Yabeinosaurus, from the Early Cretaceous of China. The gravid female contains more than 15 young at a level of skeletal development corresponding to that of late embryos of living viviparous lizards. This specimen documents the first occurrence of viviparity in a fossil reptile that was largely terrestrial in life, and extends the temporal distribution of the trait in squamates by at least 30 Ma. As Yabeinosaurus occupies a relatively basal position within crown-group squamates, it suggests that the anatomical and physiological preconditions for viviparity arose early within Squamata.

  9. Phylogenetic evidence for multiple losses of a sexually selected character in phrynosomatid lizards

    PubMed Central

    Wiens, J. J.

    1999-01-01

    The evolution of conspicuous male display ornaments is a common trend in diverse groups of organisms and a continuing challenge to studies of sexual selection. A phylogenetic approach was used to examine macro-evolutionary patterns of change in sexually dichromatic display coloration (distinctively coloured belly patches) among 130 taxa of phrynosomatid lizards. The results showed repeated losses of sexual dimorphism, which occur through losses of conspicuous male coloration or gains of conspicuous female coloration. The frequent loss of male traits is surprising, given that sexual selection presumably drives their evolutionary origin and maintenance, but is consistent with a recently proposed hypothesis suggesting that females may lose responsiveness to male traits over macro-evolutionary time-scales. The observation of repeated losses of male traits in phrynosomatid lizards (and other groups) may have implications for testing among competing models for the evolution of female preferences. A concentrated changes test showed that changes in male display coloration are significantly associated with the use of ground-dwelling habitat, as opposed to rock- or tree-dwelling habitats. This result suggests a role for natural selection in the loss of male display traits in phrynosomatid lizards, but habitat type alone may be insufficient to explain these losses.

  10. Lizard tail skeletal regeneration combines aspects of fracture healing and blastema-based regeneration.

    PubMed

    Lozito, Thomas P; Tuan, Rocky S

    2016-08-15

    Lizards are amniotes with the remarkable ability to regenerate amputated tails. The early regenerated lizard tail forms a blastema, and the regenerated skeleton consists of a cartilage tube (CT) surrounding the regenerated spinal cord. The proximal, but not distal, CT undergoes hypertrophy and ossifies. We hypothesized that differences in cell sources and signaling account for divergent cartilage development between proximal and distal CT regions. Exogenous spinal cord implants induced ectopic CT formation in lizard (Anolis carolinensis) blastemas. Regenerated spinal cords expressed Shh, and cyclopamine inhibited CT induction. Blastemas containing vertebrae with intact spinal cords formed CTs with proximal hypertrophic regions and distal non-hypertrophic regions, whereas removal of spinal cords resulted in formation of proximal CT areas only. In fate-mapping studies, FITC-labeled vertebra periosteal cells were detected in proximal, but not distal, CT areas. Conversely, FITC-labeled blastema cells were restricted to distal CT regions. Proximal cartilage formation was inhibited by removal of periosteum and could be recapitulated in vitro by periosteal cells treated with Ihh and BMP-2. These findings suggest that proximal CTs are directly derived from vertebra periosteal cells in response to BMP and Ihh signaling, whereas distal CTs form from blastema cells in response to Shh signals from regenerated spinal cords. PMID:27387871

  11. Ontogenetic Variation in the Thermal Biology of Yarrow's Spiny Lizard, Sceloporus jarrovii

    PubMed Central

    Gilbert, Anthony L.; Lattanzio, Matthew S.

    2016-01-01

    Climate change is rapidly altering the way current species interact with their environment to satisfy life-history demands. In areas anticipated to experience extreme warming, rising temperatures are expected to diminish population growth, due either to environmental degradation, or the inability to tolerate novel temperature regimes. Determining how at risk ectotherms, and lizards in particular, are to changes in climate traditionally emphasizes the thermal ecology and thermal sensitivity of physiology of adult members of a population. In this study, we reveal ontogenetic differences in thermal physiological and ecological traits that have been used to anticipate how ectotherms will respond to climate change. We show that the thermal biological traits of juvenile Yarrow’s Spiny Lizards (Sceloporus jarrovii) differ from the published estimates of the same traits for adult lizards. Juvenile S. jarrovii differ in their optimal performance temperature, field field-active body temperature, and critical thermal temperatures compared to adult S. jarrovii. Within juvenile S. jarrovii, males and females exhibit differences in field-active body temperature and desiccation tolerance. Given the observed age- and sex-related variation in thermal physiology, we argue that not including physiological differences in thermal biology throughout ontogeny may lead to misinterpretation of patterns of ecological or evolutionary change due to climate warming. Further characterizing the potential for ontogenetic changes in thermal biology would be useful for a more precise and accurate estimation of the role of thermal physiology in mediating population persistence in warmer environments. PMID:26840620

  12. Pre- and Postcopulatory Traits of Salvator Male Lizards in Allopatry and Sympatry

    PubMed Central

    Naretto, Sergio; Blengini, Cecilia S.; Cardozo, Gabriela; Chiaraviglio, Margarita

    2016-01-01

    The reproductive traits of males are under influence of sexual pressures before and after copulation. The strength of sexual selection varies across populations because they undergo varying competition for mating opportunities. Besides intraspecific pressures, individuals seem to be subjected to pressures driven by interspecific interactions in sympatry. Lizards may vary their reproductive strategies through varying sexual characters, body size, gonadal investment, and sperm traits. We evaluated the reproductive traits, involved in pre- and postcopulatory competition, in allopatric and sympatric populations of Salvator lizards. We observed a spatial gradient of male competition among populations, with the following order: allopatric zone of S. rufescens; sympatric zone; and allopatric zone of S. merianae. Accordingly, variation in secondary sexual character, the relative testis mass, and the length of sperm component was observed between allopatry and sympatry in each species, suggesting differences in the investment of reproductive traits. However, we found that these two Salvator species did not differ in secondary sexual characters in sympatry. Interestingly, the trade-off between testes and muscle varied differently from allopatry to sympatry between these Salvator species, suggesting that the influence of social context on reproductive traits investment would affect lizard species differently. PMID:27110428

  13. Foraging behaviors of two sympatric ant species in response to lizard eggs.

    PubMed

    Huang, Wen-San

    2010-03-01

    The trade-off between behavioral dominance and resource discovery ability represents a mechanism which could facilitate the coexistence of species, but evidence of the existence of this trade-off is limited and is often derived from experiments using artificial bait. In this study, I performed a field experiment to investigate the outcome of potential food competition between an encounter species (Paratrechina longicornis) and an exploitative one (Pheidole taivanensis) and to examine the factors that may explain the behavior of P. taivanensis when obtaining food (lizard eggs) without being attacked by P. longicornis. When P. longicornis was experimentally introduced to eggs occupied by P. taivanensis for 1 day, it displaced P. taivanensis. However, P. longicornis ignored lizard eggs which had been occupied by P. taivanensis for 2 or more days, and did not displace P. taivanensis, because by that time the eggshells had been damaged by P. taivanensis so they could no longer be used by P. longicornis. Eggshells were damaged more quickly by P. taivanensis at Santimen, southwestern Taiwan, than at four other study sites where there were lower intensities of food competition between P. taivanensis and P. longicornis. The displacement percentage was higher at Santimen which had higher ant population densities. The present study shows that lizard eggs may constitute a natural, ephemeral resource for which ants compete in space and time. Comparisons between study sites with and without ants suggest the existence of a trade-off between resource discovery and territorial defense. PMID:20199855

  14. Parasites and health affect multiple sexual signals in male common wall lizards, Podarcis muralis

    NASA Astrophysics Data System (ADS)

    Martín, José; Amo, Luisa; López, Pilar

    2008-04-01

    Multiple advertising sexual traits may either advertise different characteristics of male condition or be redundant to reinforce reliability of signals. Research has focused on multiple visual traits. However, in animals that use different multiple additional sensory systems, such as chemoreception, different types of traits might have evolved to signal similar characteristics of a male quality using different sensory channels. We examined whether ventral coloration and chemicals in femoral gland secretions of male common wall lizards, Podarcis muralis, are affected by their health state (blood-parasite load and cell-mediated immune response). Our results indicated that less parasitized lizards had brighter and more yellowish ventral colorations and also femoral secretions with higher proportions of two esters of octadecenoic acid. In addition, lizards with a greater immune response had more saturated coloration and secretions with higher proportions of octadecenoic acid methyl ester. We suggest that these signals would be reliable because only healthier males seemed able to allocate more carotenoids to coloration and presumably costly chemicals to secretions. The use of multiple sensory channels may provide more opportunities to signal a male quality under different circumstances, but also may reinforce the reliability of the signal when both types of traits may be perceived simultaneously.

  15. Correlation between ovarian steroidogenesis and beta-endorphin in the Lizard Uromastyx acanthinura: Immunohistochemical approach.

    PubMed

    Hammouche, Sadjia; Gernigon, Thérese; Exbrayat, Jean Marie

    2009-01-01

    In Mammals, opioid peptides are involved in various physiological processes including the reproductive function. The knowledge of the distribution of beta-endorphin, one of opioid peptides in Reptiles ovaries is very limited. Therefore, the present study used the lizard ovarian follicles to further elucidate the role of this peptide in steroidogenesis. In Uromastyx acanthinura, the localization of both this peptide and sex steroid hormone was investigated by the immunohistochemical approach. This technique was used to evaluate the distribution of these substances and their relationship. The beta-endorphin is strongly distributed in the granulosa cells and oocyte cytoplasm of the previtellogenic follicles in sexually quiescent lizards (winter) when steroidogenesis was interrupted. In spring, the signal became weak, or even absent, in the vitellogenic and previtellogenic follicles. The granulosa cells of the previtellogenic follicles showed an important synthesis of 17beta-estradiol. Females that did not undergo in vitellogenesis in spring showed the same profile than quiescent females of winter. These findings represent the first evidence of the presence of beta-endorphin in the ovary of this lizard. The seasonal variations observed in the reproductive cycle suggest that this opioid peptide is involved in the modulation of seasonal steroidogenesis. PMID:20067902

  16. Responses to chemical cues from animal and plant foods by actively foraging insectivorous and omnivorous scincine lizards.

    PubMed

    Cooper, W E; Al-Johany, A M; Vitt, L J; Habegger, J J

    2000-10-01

    If tongue-flicking is important to lizards to sample chemical cues permitting identification of foods, tongue-flicking and subsequent feeding responses should be adjusted to match diet. This hypothesis can be examined for plant foods because most lizards are insectivores, but herbivory/omnivory has evolved independently in many lizard taxa. Here we present experimental data on chemosensory responses to chemical cues from animal prey and palatable plants by three species of the scincine lizards. When tested with chemical stimuli presented on cotton swabs, the insectivorous Eumeces fasciatus responded strongly to prey chemicals but not to chemicals from plants palatable to omnivorous lizards or to pungent or odorless control stimuli. Two omnivorous species, E. schneideri and Scincus mitranus, responded more strongly to chemical cues from both prey and food plants than to the control chemicals. All available data for actively foraging lizards, including these skinks, show that they are capable of prey chemical discrimination, and insectivores do not exhibit elevated tongue-flicking or biting responses to chemical cues from palatable plants. In all of the several species of herbivores/omnivores tested, the lizards show elevated responses to both animal and plant chemicals. We suggest two independent origins of both omnivory and plant chemical discrimination that may account for the evolution of diet and food chemical discriminations in the eight species of skinks studied, five of which are omnivores. All data are consistent with the hypothesis that acquisition of omnivory is accompanied by acquisition of plant chemical discrimination, but data on a broad diversity of taxa are needed for a definitive comparative test of the evolutionary hypothesis. J. Exp. Zool. 287:327-339, 2000. PMID:10980491

  17. Testing the robustness of transmission network models to predict ectoparasite loads. One lizard, two ticks and four years☆

    PubMed Central

    Wohlfiel, Caroline K.; Leu, Stephan T.; Godfrey, Stephanie S.; Bull, C. Michael

    2013-01-01

    We investigated transmission pathways for two tick species, Bothriocroton hydrosauri and Amblyomma limbatum, among their sleepy lizard (Tiliqua rugosa) hosts in a natural population in South Australia. Our aim was to determine whether a transmission network model continued to predict parasite load patterns effectively under varying ecological conditions. Using GPS loggers we identified the refuge sites used by each lizard on each day. We estimated infectious time windows for ticks that detached from a lizard in a refuge. Time windows were from the time when a detached tick molted and become infective, until the time it died from desiccation while waiting for a new host. Previous research has shown that A. limbatum molts earlier and survives longer than B. hydrosauri. We developed two transmission network models based on these differences in infective time windows for the two tick species. Directed edges were generated in the network if one lizard used a refuge that had previously been used by another lizard within the infectious time window. We used those models to generate values of network node in-strength for each lizard, a measure of how strongly connected an individual is to other lizards in the transmission network, and a prediction of infection risk for each host. The consistent correlations over time between B. hydrosauri infection intensity and network derived infection risk suggest that network models can be robust to environmental variation among years. However, the contrasting lack of consistent correlation in A. limbatum suggests that the utility of the same network models may depend on the specific biology of a parasite species. PMID:24533346

  18. Island Formation: Constructing a Coral Island

    ERIC Educational Resources Information Center

    Austin, Heather; Edd, Amelia

    2009-01-01

    The process of coral island formation is often difficult for middle school students to comprehend. Coral island formation is a dynamic process, and students should have the opportunity to experience this process in a synergistic context. The authors provide instructional guidelines for constructing a coral island. Students play an interactive role…

  19. Aspidoscelis deppii (Black-bellied Racerunner). Predation by Great Egrets

    USGS Publications Warehouse

    Reynolds, Robert P.; Whatton, James F.; Gebhard, Christina A.

    2014-01-01

    Aspidoscelis deppii) is widely distributed from Veracruz and Michoacan, Mexico to Costa Rica (Köhler et al. 2006. The Amphibians and Reptiles of El Salvador. Krieger Publishing Co., Malabar, Florida. 238 pp.). Neotropical lizards are abundant and common prey to all classes of terrestrial vertebrates, and bird predation of lizards is well known.

  20. Recovery of frog and lizard communities following primary habitat alteration in Mizoram, Northeast India

    PubMed Central

    Pawar, Samraat S; Rawat, Gopal S; Choudhury, Binod C

    2004-01-01

    Background Community recovery following primary habitat alteration can provide tests for various hypotheses in ecology and conservation biology. Prominent among these are questions related to the manner and rate of community assembly after habitat perturbation. Here we use space-for-time substitution to analyse frog and lizard community assembly along two gradients of habitat recovery following slash and burn agriculture (jhum) in Mizoram, Northeast India. One recovery gradient undergoes natural succession to mature tropical rainforest, while the other involves plantation of jhum fallows with teak Tectona grandis monoculture. Results Frog and lizard communities accumulated species steadily during natural succession, attaining characteristics similar to those from mature forest after 30 years of regeneration. Lizards showed higher turnover and lower augmentation of species relative to frogs. Niche based classification identified a number of guilds, some of which contained both frogs and lizards. Successional change in species richness was due to increase in the number of guilds as well as the number of species per guild. Phylogenetic structure increased with succession for some guilds. Communities along the teak plantation gradient on the other hand, did not show any sign of change with chronosere age. Factor analysis revealed sets of habitat variables that independently determined changes in community and guild composition during habitat recovery. Conclusions The timescale of frog and lizard community recovery was comparable with that reported by previous studies on different faunal groups in other tropical regions. Both communities converged on primary habitat attributes during natural vegetation succession, the recovery being driven by deterministic, nonlinear changes in habitat characteristics. On the other hand, very little faunal recovery was seen even in relatively old teak plantation. In general, tree monocultures are unlikely to support recovery of natural

  1. [Morphologic variation of the parthenogenetic lizard Aspidoscelis rodecki (Squamata: Teiidae): evolutionary and conservation implications].

    PubMed

    Elizalde-Rocha, Sandra P; Méndez-de la Cruz, Fausto R; Méndez-Sánchez, J Fernando; Granados-González, Gisela; Hernândez-Gallegos, Oswaldo

    2008-12-01

    Post-formational divergence has been used for the recognition of new parthenogenetic species. Currently, the parthenogenetic lizard Aspidoscelis rodecki McCoy and Maslin 1962 is recognized as a single taxon that was derived from a single, parthenogenetically capable, hybrid. This lizard had been derived via hybridization between individuals of two gonochoristic species, Aspidoscelis ungusticeps Cope 1878 and Aspidoscelis deppii Wiegmann 1834. The distribution of A. rodecki includes Isla Contoy and Isla Mujeres and the adjacent mainland of Quintana Roo, México. Previous studies have found post-formational divergence in genetic, chromatic and life-history characteristics among a continental population (Puerto Juárez) and an insular population (Isla Contoy). A meristic analysis was carried out to evaluate the morphological divergence among both populations of A. rodecki. We used 38 individuals from Puerto Juárez and 23 individuals from Isla Contoy. Nine meristic characters with discrimination value among species of the genus Aspidoscelis were used in both univariate (t-Student) and multivariate analyses (principal components and canonical variate analysis). According to both analyses, Puerto Juárez is meristically distinguishable from Isla Contoy. Both populations differ in five meristic characters and were a high correct classification in the canonical variate analysis: 97% of Puerto Juárez and 100% of Isla Contoy. A small sample from Isla Mujeres and a single specimen from Punta Sam (mainland) may represent different morphological groups. Due to the patterns of phenotypic variation, A. rodecki is considered as a single variable parthenogenetic species with high priority to conservation. The populations of A. rodecki have been extremely affected by the tourism developers. If the habitat of the parthenogenetic lizard (beach grasses) is allowed to stay, the expansion by the developers will not affect the survivorship of these populations. Nevertheless, the first

  2. Intersexual differences in energy expenditure of Anolis carolinensis lizards during breeding and postbreeding seasons.

    PubMed

    Orrell, K S; Congdon, J D; Jenssen, T A; Michener, R H; Kunz, T H

    2004-01-01

    Although the amount of energy that males and females invest in reproduction is an integral component of theories explaining the evolution of particular mating strategies, few studies have actually determined the amount of energy that each sex allocates to reproduction. We compared how energy is expended by male and female Anolis carolinensis lizards during both the breeding and postbreeding seasons. We used laboratory respirometry to determine resting metabolic rates (RMRs) of inactive, freshly captured lizards and the doubly labeled water technique to determine field metabolic rates (FMRs) of free-ranging lizards. Both RMRs and FMRs were influenced by body mass but not by sex. Season did not influence FMRs; however, RMRs of both sexes increased approximately 40% from the breeding to the postbreeding season. The seasonal increase in RMRs was attributed to a postreproductive increase in feeding rate and specific dynamic action. We used RMRs, FMRs, and thermal profiles of lizards to calculate energy budgets for breeding and postbreeding seasons. Energy budgets partitioned daily field energy (DFE; calculated from FMRs) into daily activity energy (DAE) and daily resting energy (DRE; calculated from RMRs). Energy expended for reproduction was estimated as DAE during the breeding season plus egg production (for females). Despite males having 40% greater body mass, females expended 46% more energy for reproduction than did males (906 and 619 J/d, respectively). Total metabolizable energy (TME=DFE+egg production for females) expended during the breeding season was similar for males and females (1,280 and 1,365 J/d, respectively). Although TME of females decreased 44% from the breeding to the postbreeding season (1,365 vs. 766 J/d), TME of males was similar during both seasons (1,280 vs. 1,245 J/d). There were both seasonal and sexual differences in DRE and DAE. Compared with most lizards from semiarid/desert habitats, A. carolinensis in a temperate habitat expends more

  3. Morphology and fibre-type distribution in the tongue of the Pogona vitticeps lizard (Iguania, Agamidae).

    PubMed

    Zghikh, Leïla-Nastasia; Vangysel, Emilie; Nonclercq, Denis; Legrand, Alexandre; Blairon, Bernard; Berri, Cécile; Bordeau, Thierry; Rémy, Christophe; Burtéa, Carmen; Montuelle, Stéphane J; Bels, Vincent

    2014-10-01

    Agamid lizards use tongue prehension for capturing all types of prey. The purpose of this study was to investigate the functional relationship between tongue structure, both surface and musculature, and function during prey capture in Pogona vitticeps. The lack of a detailed description of the distribution of fibre-types in the tongue muscles in some iguanian lizards has hindered the understanding of the functional morphology of the lizard tongue. Three methodological approaches were used to fill this gap. First, morphological analyses were performed (i) on the tongue surface through scanning electron microscopy, and (ii) on the lingual muscle by histological coloration and histochemistry to identify fibre-typing. Secondly, kinematics of prey capture was quantified by using high-speed video recordings to determine the movement capabilities of the tongue. Finally, electromyography (EMG) was used to identify the motor pattern tongue muscles during prey capture. Morphological and functional data were combined to discuss the functional morphology of the tongue in agamid lizards, in relation to their diet. During tongue protraction, M. genioglossus contracts 420 ± 96 ms before tongue-prey contact. Subsequently, Mm. verticalis and hyoglossus contract throughout tongue protraction and retraction. Significant differences are found between the timing of activity of the protractor muscles between omnivorous agamids (Pogona sp., this study) and insectivorous species (Agama sp.), despite similar tongue and jaw kinematics. The data confirm that specialisation toward a diet which includes more vegetal materials is associated with significant changes in tongue morphology and function. Histoenzymology demonstrates that protractor and retractor muscles differ in fibre composition. The proportion of fast glycolytic fibres is significantly higher in the M. hyoglossus (retractor muscle) than in the M. genioglossus (protractor muscle), and this difference is proposed to be associated

  4. Phylogeny and biogeography of the most diverse clade of South American gymnophthalmid lizards (Squamata, Gymnophthalmidae, Cercosaurinae).

    PubMed

    Torres-Carvajal, Omar; Lobos, Simón E; Venegas, Pablo J; Chávez, Germán; Aguirre-Peñafiel, Vanessa; Zurita, Daniel; Echevarría, Lourdes Y

    2016-06-01

    Nearly 50% of the diversity of the speciose Neotropical lizard clade Gymnophthalmidae is nested within the subclade Cercosaurinae. The taxonomy of Cercosaurinae lizards has been historically confusing because many diagnostic characters of those clades traditionally ranked as genera do not represent true diagnostic apomorphies. Even though molecular phylogenies of several 'genera' have been presented in the last few years, some of them remain poorly sampled (e.g., Anadia, Echinosaura, Potamites, Riama). In this paper we present a more comprehensive phylogeny of Cercosaurinae lizards with emphasis on Andean taxa from Ecuador and Peru, as well as a time-calibrated phylogeny with reconstruction of ancestral areas. Our analysis includes 52% of all recognized species of Cercosaurinae (67 species) and 1914 characters including three mitochondrial and one nuclear gene. We find that Anadia, Echinosaura, Euspondylus, Potamites, Proctoporus, and Riama are not monophyletic: the Tepuian Anadia mcdiarmidi is not sister to Andean species of Anadia; Echinosaura sulcarostrum is not included in the same clade formed by other species of Echinosaura and their more recent common ancestor; Teuchocercus is nested within Echinosaura; species of Euspondylus included in this study are nested within Proctoporus; Riama laudahnae is included in Proctoporus; and Potamites is paraphyletic and split in two separate clades, one of which we name Gelanesaurus, also a new genus-group name. Within Potamites, P. ecpleopus is paraphyletic, and P. strangulatus strangulatus and P. strangulatus trachodus are recognized as two distinct species. We also identify three unnamed clades (i.e., not nested within any of the recognized 'genera') from Andean populations in Ecuador and Peru. The estimated age of the clade Cercosaurinae (∼60Ma) corresponds to the early stages of the northern Andes. Even though the distribution of the most recent common ancestor of Cercosaurinae remains equivocal, our analysis shows

  5. Jupiter's Great Red Spot

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This view of Jupiter's Great Red Spot is a mosaic of two images taken by the Galileo spacecraft. The image was created using two filters, violet and near-infrared, at each of two camera positions. The Great Red Spot is a storm in Jupiter's atmosphere and is at least 300 years-old. Winds blow counterclockwise around the Great Red Spot at about 400 kilometers per hour (250 miles per hour). The size of the storm is more than one Earth diameter (13,000 kilometers or 8,000 miles) in the north-south direction and more than two Earth diameters in the east-west direction. In this oblique view, where the Great Red Spot is shown on the planet's limb, it appears longer in the north-south direction. The image was taken on June 26, 1996.

    The Galileo mission is managed by NASA's Jet Propulsion Laboratory.

  6. THE GREAT RIVERS NEWSLETTER

    EPA Science Inventory

    The Great Rivers Newsletter is a periodic publication of the EPA's Mid-Continent Ecology Division. It is designed to disseminate timely information about the EMAP-GRE project among EPA investigators; state, federal, and tribal collaborators; and other stakeholders.

  7. The impacts of invaders: basal and acute stress glucocorticoid profiles and immune function in native lizards threatened by invasive ants.

    PubMed

    Graham, Sean P; Freidenfelds, Nicole A; McCormick, Gail L; Langkilde, Tracy

    2012-05-01

    As anthropogenic stressors increase exponentially in the coming decades, native vertebrates will likely face increasing threats from these novel challenges. The success or failure of the primary physiological mediator of these stressors--the HPA axis--will likely involve numerous and chaotic outcomes. Among the most challenging of these new threats are invasive species. These have the capacity to simultaneously challenge the HPA axis and the immune system as they are often associated with, or the cause of, emerging infectious diseases, and energetic tradeoffs with the HPA response can have immunosuppressive effects. To determine the effects of invasive species on the vertebrate GC response to a novel stressor, and on immunity, we examined the effects of invasive fire ants on native lizards, comparing lizards from sites with long histories with fire ants to those outside the invasion zone. We demonstrated higher baseline and acute stress (captive restraint) CORT levels in lizards from within fire ant invaded areas; females are more strongly affected than males, suggesting context-specific effects of invasion. We found no effect of fire ant invasion on the immune parameters we measured (complement bacterial lysis and antibody hemagglutination) with the exception of ectoparasite infestation. Mites were far less prevalent on lizards within fire ant invaded sites, suggesting fire ants may actually benefit lizards in this regard. This study suggests that invasive species may impose physiological stress on native vertebrates, but that the consequences of this stress may be complicated and unpredictable. PMID:22226759

  8. When the going gets tough: behavioural type-dependent space use in the sleepy lizard changes as the season dries.

    PubMed

    Spiegel, Orr; Leu, Stephan T; Sih, Andrew; Godfrey, Stephanie S; Bull, C Michael

    2015-11-22

    Understanding space use remains a major challenge for animal ecology, with implications for species interactions, disease spread, and conservation. Behavioural type (BT) may shape the space use of individuals within animal populations. Bolder or more aggressive individuals tend to be more exploratory and disperse further. Yet, to date we have limited knowledge on how space use other than dispersal depends on BT. To address this question we studied BT-dependent space-use patterns of sleepy lizards (Tiliqua rugosa) in southern Australia. We combined high-resolution global positioning system (GPS) tracking of 72 free-ranging lizards with repeated behavioural assays, and with a survey of the spatial distributions of their food and refuge resources. Bayesian generalized linear mixed models (GLMM) showed that lizards responded to the spatial distribution of resources at the neighbourhood scale and to the intensity of space use by other conspecifics (showing apparent conspecific avoidance). BT (especially aggressiveness) affected space use by lizards and their response to ecological and social factors, in a seasonally dependent manner. Many of these effects and interactions were stronger later in the season when food became scarce and environmental conditions got tougher. For example, refuge and food availability became more important later in the season and unaggressive lizards were more responsive to these predictors. These findings highlight a commonly overlooked source of heterogeneity in animal space use and improve our mechanistic understanding of processes leading to behaviourally driven disease dynamics and social structure. PMID:26609082

  9. Field test of a paradigm: hysteresis of heart rate in thermoregulation by a free-ranging lizard (Pogona barbata).

    PubMed

    Grigg, G C; Seebacher, F

    1999-06-22

    The discovery that changes in heart rate and blood flow allow some reptiles to heat faster than they cool has become a central paradigm in our understanding of reptilian thermoregulation. However, this hysteresis in heart rate has been demonstrated only in simplistic laboratory heating and cooling trials, leaving its functional significance in free-ranging animals unproven. To test the validity of this paradigm, we measured heart rate and body temperature (Tb) in undisturbed, free-ranging bearded dragons (Pogona barbata), the species in which this phenomenon was first described. Our field data confirmed the paradigm and we found that heart rate during heating usually exceeded heart rate during cooling at any Tb. Importantly, however, we discovered that heart rate was proportionally faster in cool lizards whose Tb was still well below the 'preferred Tb range' compared to lizards whose Tb was already close to it. Similarly, heart rate during cooling was proportionally slower the warmer the lizard and the greater its cooling potential compared to lizards whose Tb was already near minimum operative temperature. Further, we predicted that, if heart rate hysteresis has functional significance, a 'reverse hysteresis' pattern should be observable when lizards risked overheating. This was indeed the case and, during heating on those occasions when Tb reached very high levels (> 40 degrees C), heart rate was significantly lower than heart rate during the immediately following cooling phase. These results demonstrate that physiological control of thermoregulation in reptiles is more complex than has been previously recognized. PMID:10418165

  10. Field test of a paradigm: hysteresis of heart rate in thermoregulation by a free-ranging lizard (Pogona barbata).

    PubMed Central

    Grigg, G C; Seebacher, F

    1999-01-01

    The discovery that changes in heart rate and blood flow allow some reptiles to heat faster than they cool has become a central paradigm in our understanding of reptilian thermoregulation. However, this hysteresis in heart rate has been demonstrated only in simplistic laboratory heating and cooling trials, leaving its functional significance in free-ranging animals unproven. To test the validity of this paradigm, we measured heart rate and body temperature (Tb) in undisturbed, free-ranging bearded dragons (Pogona barbata), the species in which this phenomenon was first described. Our field data confirmed the paradigm and we found that heart rate during heating usually exceeded heart rate during cooling at any Tb. Importantly, however, we discovered that heart rate was proportionally faster in cool lizards whose Tb was still well below the 'preferred Tb range' compared to lizards whose Tb was already close to it. Similarly, heart rate during cooling was proportionally slower the warmer the lizard and the greater its cooling potential compared to lizards whose Tb was already near minimum operative temperature. Further, we predicted that, if heart rate hysteresis has functional significance, a 'reverse hysteresis' pattern should be observable when lizards risked overheating. This was indeed the case and, during heating on those occasions when Tb reached very high levels (> 40 degrees C), heart rate was significantly lower than heart rate during the immediately following cooling phase. These results demonstrate that physiological control of thermoregulation in reptiles is more complex than has been previously recognized. PMID:10418165

  11. Effects of protective fencing on birds, lizards, and black-tailed hares in the Western Mojave Desert

    USGS Publications Warehouse

    Brooks, M.

    1999-01-01

    Effects of protective fencing on birds, lizards, black-tailed hares (Lepus californicus), perennial plant cover, and structural diversity of perennial plants were evaluated from spring 1994 through winter 1995 at the Desert Tortoise Research Natural Area (DTNA), in the Mojave Desert, California. Abundance and species richness of birds were higher inside than outside the DTNA, and effects were larger during breeding than wintering seasons and during a high than a low rainfall year. Ash-throated flycatchers (Myiarchus cinerascens), cactus wrens (Campylorhynchus brunneicapillus), LeConte's thrashers (Toxostoma lecontei), loggerhead shrikes (Lanius ludovicianus), sage sparrows (Amphispiza belli), and verdins (Auriparus flaviceps) were more abundant inside than outside the DTNA. Nesting activity was also more frequent inside. Total abundance and species richness of lizards and individual abundances of western whiptail lizards (Cnemidophorous tigris) and desert spiny lizards (Sceloporus magister) were higher inside than outside. In contrast, abundance of black-tailed hares was lower inside. Structural diversity of the perennial plant community did not differ due to protection, but cover was 50% higher in protected areas. Black-tailed hares generally prefer areas of low perennial plant cover, which may explain why they were more abundant outside than inside the DTNA. Habitat structure may not affect bird and lizard communities as much as availability of food at this desert site, and the greater abundance and species richness of vertebrates inside than outside the DTNA may correlate with abundances of seeds and invertebrate prey.

  12. Hybridization between multiple fence lizard lineages in an ecotone: locally discordant variation in mitochondrial DNA, chromosomes, and morphology.

    PubMed

    Leaché, Adam D; Cole, Charles J

    2007-03-01

    We investigated a hybrid zone between two major lineages of fence lizards (Sceloporus cowlesi and Sceloporus tristichus) in the Sceloporus undulatus species complex in eastern Arizona. This zone occurs in an ecotone between Great Basin Grassland and Conifer Woodland habitats. We analysed spatial variation in mtDNA (N=401; 969 bp), chromosomes (N=217), and morphology (N=312; 11 characters) to characterize the hybrid zone and assess species limits. A fine-scale population level phylogenetic analysis refined the boundaries between these species and indicated that four nonsister mtDNA clades (three belonging to S. tristichus and one to S. cowlesi) are sympatric at the centre of the zone. Estimates of cytonuclear disequilibria in the population closest to the centre of the hybrid zone suggest that the S. tristichus clades are randomly mating, but that the S. cowlesi haplotype has a significant nonrandom association with nuclear alleles. Maximum-likelihood cline-fitting analyses suggest that the karyotype, morphology, and dorsal colour pattern clines are all coincident, but the mtDNA cline is skewed significantly to the south. A temporal comparison of cline centres utilizing karyotype data collected in the early 1970s and in 2002 suggests that the cline may have shifted by approximately 1.5 km to the north over a 30-year period. The recent northward expansion of juniper trees into the Little Colorado River Basin resulting from intense cattle overgrazing provides a plausible mechanism for a shifting hybrid zone and the introgression of the mtDNA haplotypes, which appear to be selectively neutral. It is clear that complex interactions are operating simultaneously in this contact zone, including the formation of hybrids between populations within S. tristichus having diagnostic mtDNA, morphology, karyotypes, and dorsal colour patterns, and secondary contact between these and a distantly related yet morphologically cryptic mtDNA lineage (S. cowlesi). PMID:17305859

  13. Evidence for a Great Aleutian Paleotsunami on Kaua`i

    NASA Astrophysics Data System (ADS)

    Butler, R.; Bai, Y.; Burney, D. A.; Cheung, K.; Yamazaki, Y.

    2013-12-01

    The Hawaiian Islands location amid the Pacific Ocean is threatened by tsunamis from great earthquakes in nearly all directions. Historical great earthquakes Mw>8.5 in the last 100 years have produced large inundations and loss of life in the Islands, but have not accounted for a substantial (>100 m^3) paleotsunami deposit in the Makauwahi sinkhole at Maha`ulepu on the Island of Kaua`i. High-resolution, digital elevation models of bathymetry and topography have been used in conjunction with a non-linear, hydrostatic tsunami model to simulate inundations from giant earthquakes in the Aleutian Islands and elsewhere to estimate the extent of tsunami threats to the State of Hawaii. We model the inundation of the sinkhole by an earthquake with a minimum moment-magnitude of Mw 9.2 located within the eastern Aleutians, where the tsunami energy is focused toward Hawaii. An alternative hypothesis wherein the deposit entered through a small cave entrance is not consistent with fine speleothems, intact in the cave, that pre-date the deposit. The results indicate that a giant earthquake in the eastern Aleutian Islands circa 1425-1665 AD, located between the source regions of the 1946 and 1957 great tsunamigenic earthquakes, generated a tsunami in Hawaii much larger than the historical record. A tsunami deposit in the Aleutians dated circa ~1550 AD is consistent with this eastern Aleutian source region.

  14. Hawaiian Island Archipelago

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The entire Hawaiian Island Archipelago (21.5N, 158.0W) is seen in this single view. The islands are a favorite international resort and tourist attraction drawing visitors from all over the world to enjoy the tropical climate, year round beaches and lush island flora. Being volcanic in origin, the islands' offer a rugged landscape and on the big island of Hawaii, there is still an occasional volcanic eruption of lava flows and steam vents.

  15. Diet composition of the invasive cane toad (Chaunus marinus) on Rota, Northern Mariana Islands

    USGS Publications Warehouse

    Reed, R.N.; Bakkegard, K.A.; Desy, G.E.; Plentovich, S.M.

    2007-01-01

    The cane or marine toad (Chaunus marinus, formerly Bufo marinus) was introduced to the Northern Mariana Islands starting in the 1930s. The effects of this exotic predator on native vertebrates (especially lizards) are largely unknown. We analysed the stomach contents of 336 cane toads collected from the island of Rota, with the goal of estimating the level of toad predation on native vertebrates. Beetles, ants, millipedes, and grasshoppers/crickets comprised the majority of prey classes consumed by toads. The introduced Brahminy blindsnake (Ramphotyphlops braminus; N = 6) and conspecific cane toads (N = 4) were the vertebrates most commonly found in toad stomachs. Skinks (Emoia; N = 2) were the only native vertebrates represented in our sample. The small numbers of nocturnal terrestrial vertebrates native to Rota likely translates to relatively low rates of predation by cane toads on native vertebrates.

  16. The Great Ice Age

    USGS Publications Warehouse

    Ray, Louis L.

    1992-01-01

    The Great Ice Age, a recent chapter in the Earth's history, was a period of recurring widespread glaciations. During the Pleistocene Epoch of the geologic time scale, which began about a million or more years ago, mountain glaciers formed on all continents, the icecaps of Antarctica and Greenland were more extensive and thicker than today, and vast glaciers, in places as much as several thousand feet thick, spread across northern North America and Eurasia. So extensive were these glaciers that almost a third of the present land surface of the Earth was intermittently covered by ice. Even today remnants of the great glaciers cover almost a tenth of the land, indicating that conditions somewhat similar to those which produced the Great Ice Age are still operating in polar and subpolar climates.

  17. An investigation into the Swan Island Honduras collecting event of Tiaporus fuliginosus Cope (Reptilia: Teiidae) and its systematic status

    USGS Publications Warehouse

    McCranie, James R.; Gotte, Steve W.

    2015-01-01

    Confusion exists in the literature concerning the collecting event of the teiid lizard Tiaporus fuliginosus. We investigated the literature and documents stored at the Smithsonian Institution Archives involving the collector of those specimens in an effort to resolve that confusion. We conclude that the type series was collected on the Swan Islands of Honduras by Charles H. Townsend during 1887. We also provide a redescription of that nominal form and show that it is a valid species that should be called Ameiva fuliginosa. We also examined the type series of A. panchlora from Old Providence, Colombia and confirm that its 1950 placement as a junior synonym of A. fuliginosa is correct.

  18. Survey of the reptilian fauna of the Kingdom of Saudi Arabia. V. The lizard fauna of Turaif region.

    PubMed

    Al-Sadoon, Mohammed K; Paray, Bilal Ahmad; Al-Otaibi, Hamad S

    2016-09-01

    Turaif area located in the Northern border region of Saudi Arabia is one of the most important regions of the Kingdom. This work was proposed to throw light on the diversity of lizard fauna investigated through the collection and subsequent identification of specimens from different localities of Turaif region of Kingdom of Saudi Arabia. Sixteen species of lizards belonging to 5 families (Agamidae, Gekkonidae, Lacertidae, Scincidae and Varanidae) were recorded. Lacertidae was the most common family. Three species of lizards namely Acanthodactylus orientalis, Acanthodactylus scutellatus and Acanthodactylus grandis were reported for the first time in the Turaif region of Saudi Arabia. The geographical distribution of the collected species within this province was mapped. PMID:27579015

  19. The Ecological Associations of Surface-Dwelling Lizards in Qom Province in the Northwest of Central Plateau of Iran

    PubMed Central

    Ebrahimi, Mehregan; Ahmadzadeh, Faraham; Mostafavi, Hossein; Mehrabian, Aahmad Reza; Abdoli, Asghar; Mahini, Abdolrasoul Salman

    2013-01-01

    We used pitfall trapping to investigate the effects of elevation, plant density and soil structure on species diversity and the impact of these habitat factors on lizard habitat selectivity in the Qom Province in the Central Plateau of Iran. From a total of 12 1-ha plots, we captured 363 individuals of 15 species of lizards (six species of Lacertidae, five species of Agamidae, two species of Gekkonidae, one species of Varanidae and one species of Scincidae). A generalized linear model (GLM) determined that elevation was the most important factor impacting species diversity. The highest species diversity was at the intermediate elevation (1289 m). Abundance of 6 out of 15 species showed strong relationships with some habitat factors. These relationships were demonstrated by habitat selectivity index (Ivlev's index). Our result supports other surveys that showed that elevation plays an important role in determining lizard species diversity. PMID:24349557

  20. Kidney function and the role of arginine vasotocin in three agamid lizards from habitats of differing aridity in Western Australia.

    PubMed

    Ford, S S; Bradshaw, S D

    2006-05-15

    Western Australian agamid lizards are diverse and inhabit mesic to very arid areas of the state. Although reptilian kidneys are unable to elaborate hyperosmotic urine, we hypothesised that the renal system of lizards inhabiting arid areas would display an enhanced ability to conserve water under the control of the antidiuretic peptide hormone, arginine vasotocin (AVT). To examine this, the renal physiological and endocrine responses to osmotic challenge in three closely-related Australian agamid lizards inhabiting arid, semi-arid, and mesic environments were studied. The species studied were Pogona minor (mesic), Ctenophorus salinarum (semi-arid), and Ctenophorus nuchalis (arid). Circulating AVT was assayed and renal variables such as glomerular filtration rate (GFR), urine flow rate (V), and fractional reabsorption of filtrate FRH2O were measured in response to hypernatraemia, water load, and dehydration. Hypernatraemia and dehydration induced antidiuresis in all three species through similar mechanisms involving both glomerular and tubular responses. However, in salt-loaded P. minor the response was largely glomerular in nature, as FRH2O did not increase relative to the hydrated condition. The magnitude of the antidiuretic response was also greater in P. minor, indicating a greater sensitivity to osmotic challenge. Plasma concentrations of AVT were significantly correlated with FRH2O in P. minor (r2=0.38, P=0.025), but with GFR in C. nuchalis (r2=0.16, P=0.041). We found that the control and mechanisms of renal function among these lizards were largely similar, and there was little support for the hypothesis that arid lizards possess physiological adaptations not present in closely-related mesic lizards. Yet, differences remain in their response to hypernatraemia which may reflect the aridity of their different environments, or their varying habits. PMID:16423351

  1. Experimental support for the cost-benefit model of lizard thermoregulation: the effects of predation risk and food supply.

    PubMed

    Herczeg, Gábor; Herrero, Annika; Saarikivi, Jarmo; Gonda, Abigél; Jäntti, Maria; Merilä, Juha

    2008-02-01

    Huey and Slatkin's (Q Rev Biol 51:363-384, 1976) cost-benefit model of lizard thermoregulation predicts variation in thermoregulatory strategies (from active thermoregulation to thermoconformity) with respect to the costs and benefits of the thermoregulatory behaviour and the thermal quality of the environment. Although this framework has been widely employed in correlative field studies, experimental tests aiming to evaluate the model are scarce. We conducted laboratory experiments to see whether the common lizard Zootoca vivipara, an active and effective thermoregulator in the field, can alter its thermoregulatory behaviour in response to differences in perceived predation risk and food supply in a constant thermal environment. Predation risk and food supply were represented by chemical cues of a sympatric snake predator and the lizards' food in the laboratory, respectively. We also compared males and postpartum females, which have different preferred or "target" body temperatures. Both sexes thermoregulated actively in all treatments. We detected sex-specific differences in the way lizards adjusted their accuracy of thermoregulation to the treatments: males were less accurate in the predation treatment, while no such effects were detected in females. Neither sex reacted to the food treatment. With regard to the two main types of thermoregulatory behaviour (activity and microhabitat selection), the treatments had no significant effects. However, postpartum females were more active than males in all treatments. Our results further stress that increasing physiological performance by active thermoregulation has high priority in lizard behaviour, but also shows that lizards can indeed shift their accuracy of thermoregulation in response to costs with possible immediate negative fitness effects (i.e. predation-caused mortality). PMID:17985159

  2. Snakes on the Balearic islands: an invasion tale with implications for native biodiversity conservation.

    PubMed

    Silva-Rocha, Iolanda; Salvi, Daniele; Sillero, Neftalí; Mateo, Jose A; Carretero, Miguel A

    2015-01-01

    Biological invasions are a major conservation threat for biodiversity worldwide. Islands are particularly vulnerable to invasive species, especially Mediterranean islands which have suffered human pressure since ancient times. In the Balearic archipelago, reptiles represent an outstanding case with more alien than native species. Moreover, in the last decade a new wave of alien snakes landed in the main islands of the archipelago, some of which were originally snake-free. The identification of the origin and colonization pathways of alien species, as well as the prediction of their expansion, is crucial to develop effective conservation strategies. In this study, we used molecular markers to assess the allochthonous status and the putative origin of the four introduced snake species (Hemorrhois hippocrepis, Malpolon monspessulanus, Macroprotodon mauritanicus and Rhinechis scalaris) as well as ecological niche models to infer their patterns of invasion and expansion based on current and future habitat suitability. For most species, DNA sequence data suggested the Iberian Peninsula as the potential origin of the allochthonous populations, although the shallow phylogeographic structure of these species prevented the identification of a restricted source-area. For all of them, the ecological niche models showed a current low habitat suitability in the Balearic, which is however predicted to increase significantly in the next few decades under climate change scenarios. Evidence from direct observations and spatial distribution of the first-occurrence records of alien snakes (but also lizards and worm lizards) suggest the nursery trade, and in particular olive tree importation from Iberian Peninsula, as the main pathway of introduction of alien reptiles in the Balearic islands. This trend has been reported also for recent invasions in NE Spain, thus showing that olive trees transplantation may be an effective vector for bioinvasion across the Mediterranean. The

  3. Snakes on the Balearic Islands: An Invasion Tale with Implications for Native Biodiversity Conservation

    PubMed Central

    Sillero, Neftalí; Mateo, Jose A.; Carretero, Miguel A.

    2015-01-01

    Biological invasions are a major conservation threat for biodiversity worldwide. Islands are particularly vulnerable to invasive species, especially Mediterranean islands which have suffered human pressure since ancient times. In the Balearic archipelago, reptiles represent an outstanding case with more alien than native species. Moreover, in the last decade a new wave of alien snakes landed in the main islands of the archipelago, some of which were originally snake-free. The identification of the origin and colonization pathways of alien species, as well as the prediction of their expansion, is crucial to develop effective conservation strategies. In this study, we used molecular markers to assess the allochthonous status and the putative origin of the four introduced snake species (Hemorrhois hippocrepis, Malpolon monspessulanus, Macroprotodon mauritanicus and Rhinechis scalaris) as well as ecological niche models to infer their patterns of invasion and expansion based on current and future habitat suitability. For most species, DNA sequence data suggested the Iberian Peninsula as the potential origin of the allochthonous populations, although the shallow phylogeographic structure of these species prevented the identification of a restricted source-area. For all of them, the ecological niche models showed a current low habitat suitability in the Balearic, which is however predicted to increase significantly in the next few decades under climate change scenarios. Evidence from direct observations and spatial distribution of the first-occurrence records of alien snakes (but also lizards and worm lizards) suggest the nursery trade, and in particular olive tree importation from Iberian Peninsula, as the main pathway of introduction of alien reptiles in the Balearic islands. This trend has been reported also for recent invasions in NE Spain, thus showing that olive trees transplantation may be an effective vector for bioinvasion across the Mediterranean. The

  4. Great Barrier Reef

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A better than average view of the Great Barrier Reef was captured by SeaWiFS on a recent overpass. There is sunglint northeast of the reef and there appears to be some sort of filamentous bloom in the Capricorn Channel.

  5. Great Expectations. [Lesson Plan].

    ERIC Educational Resources Information Center

    Devine, Kelley

    Based on Charles Dickens' novel "Great Expectations," this lesson plan presents activities designed to help students understand the differences between totalitarianism and democracy; and a that a writer of a story considers theme, plot, characters, setting, and point of view. The main activity of the lesson involves students working in groups to…

  6. The Great Poetry Race

    ERIC Educational Resources Information Center

    Pitcher, Sharon M.

    2009-01-01

    Research suggests that parent involvement improves academic achievement, but in the busy world in which we live it is often difficult to promote. Many researchers suggest that successful programs value parents' limited time constraints, diversity of literacy skills, and availability of materials. The Great Poetry Race provides an easy vehicle to…

  7. The Great Lakes.

    ERIC Educational Resources Information Center

    Seasons, 1987

    1987-01-01

    The Great Lakes are one of the world's greatest reserviors of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. These lakes and their relationship with people of Canada and the United States can be useful as a subject for teaching the impact of human…

  8. 1 Great Question

    ERIC Educational Resources Information Center

    Nethery, Carrie

    2011-01-01

    In this article, the author presents an ideal question that can take an art teacher and his or her students through all the levels of thought in Bloom's taxonomy--perfect for modeling the think-aloud process: "How many people is the artist inviting into this picture?" This great question always helps the students look beyond the obvious and dig…

  9. The Great Mathematician Project

    ERIC Educational Resources Information Center

    Goldberg, Sabrina R.

    2013-01-01

    The Great Mathematician Project (GMP) introduces both mathematically sophisticated and struggling students to the history of mathematics. The rationale for the GMP is twofold: first, mathematics is a uniquely people-centered discipline that is used to make sense of the world; and second, students often express curiosity about the history of…

  10. The ultrastructure of the spermatozoon of the lizard Iguana iguana (Reptilia, Squamata, Iguanidae) and the variability of sperm morphology among iguanian lizards

    PubMed Central

    Vieira, Gustavo H C; Colli, Guarino R; Báo, Sônia N

    2004-01-01

    The spermatozoon of Iguana iguana is filiform and resembles that of other iguanian lizards, being most similar to Tropidurus. All sperm synapomorphies of Tetrapoda, Amniota and Squamata are present in the sperm of Iguana iguana. By reconstructing the evolution of 30 sperm characters we identified a novel synapomorphy of Iguania: the presence of a well-developed acrosomal ridge at the level of the epinuclear lucent zone. Because of the poor topological resolution among iguanian clades we could not discount the possibility of convergence or neutral selection as determinant of the variability in characteristics of the sperm cell. In agreement with previous studies, we identified heterogeneous rates of evolution among the three main regions of the sperm cell, namely the head, midpiece and tail. PMID:15198687

  11. Evaluating trans-tethys migration: an example using acrodont lizard phylogenetics.

    PubMed

    Macey, J R; Schulte, J A; Larson, A; Ananjeva, N B; Wang, Y; Pethiyagoda, R; Rastegar-Pouyani, N; Papenfuss, T J

    2000-06-01

    A phylogenetic tree for acrodont lizards (Chamaeleonidae and Agamidae) is established based on 1434 bases (1041 informative) of aligned DNA positions from a 1685-1778 base pair region of the mitochondrial genome. Sequences from three protein-coding genes (ND1, ND2, and COI) are combined with sequences from eight intervening tRNA genes for samples of 70 acrodont taxa and two outgroups. Parsimony analysis of nucleotide sequences identifies eight major clades in the Acrodonta. Most agamid lizards are placed into three distinct clades. One clade is composed of all taxa occurring in Australia and New Guinea; Physignathus cocincinus from Southeast Asia is the sister taxon to the Australia-New Guinea clade. A second clade is composed of taxa occurring from Tibet and the Indian Subcontinent east through South and East Asia. A third clade is composed of taxa occurring from Africa east through Arabia and West Asia to Tibet and the Indian Subcontinent. These three clades contain all agamid lizards except Uromastyx, Leiolepis, and Hydrosaurus, which represent three additional clades of the Agamidae. The Chamaeleonidae forms another clade weakly supported as the sister taxon to the Agamidae. All eight clades of the Acrodonta contain members occurring on land masses derived from Gondwanaland. A hypothesis of agamid lizards rafting with Gondwanan plates is examined statistically. This hypothesis suggests that the African/West Asian clade is of African or Indian origin, and the South Asian clade is either of Indian or Southeast Asian origin. The shortest tree suggests a possible African origin for the former and an Indian origin for the latter, but this result is not statistically robust. The Australia-New Guinea clade rafted with the Australia-New Guinea plate and forms the sister group to a Southeast Asian taxon that occurs on plates that broke from northern Australia-New Guinea. Other acrodont taxa are inferred to be associated with the plates of Afro-Arabia and Madagascar

  12. What great managers do.

    PubMed

    Buckingham, Marcus

    2005-03-01

    Much has been written about the qualities that make a great manager, but most of the literature overlooks a fundamental question: What does a great manager actually do? While there are countless management styles, one thing underpins the behavior of all great managers. Above all, an exceptional manager comes to know and value the particular quirks and abilities of her employees. She figures out how to capitalize on her staffers' strengths and tweaks her environment to meet her larger goals. Such a specialized approach may seem like a lot of work. But in fact, capitalizing on each person's uniqueness can save time. Rather than encourage employees to conform to strict job descriptions that may include tasks they don't enjoy and aren't good at, a manager who develops positions for his staff members based on their unique abilities will be rewarded with behaviors that are far more efficient and effective than they would be otherwise. This focus on individuals also makes employees more accountable. Because staffers are evaluated on their particular strengths and weaknesses, they are challenged to take responsibility for their abilities and to hone them. Capitalizing on a person's uniqueness also builds a stronger sense of team. By taking the time to understand what makes each employee tick, a great manager shows that he sees his people for who they are. This personal investment not only motivates individuals but also galvanizes the entire team. Finally, this approach shakes up existing hierarchies, which leads to more creative thinking. To take great managing from theory to practice, the author says, you must know three things about a person: her strengths, the triggers that activate those strengths, and how she learns. By asking the right questions, squeezing the right triggers, and becoming aware of your employees' learning styles, you will discover what motivates each person to excel. PMID:15768677

  13. Prevalence of antibodies against Leptospira sp. in snakes, lizards and turtles in Slovenia

    PubMed Central

    2013-01-01

    Background Leptospiral infections in poikilothermic (cold blooded) animals have received very little attention and the literature concerning natural infections of these animals is limited. The aim of this study was to determine the prevalence of leptospiral antibodies in reptiles, imported into Slovenia and intended to be pets in close contact with humans. A total of 297 reptiles (22 snakes, 210 lizards and 65 turtles) were tested for specific antibodies against serovars of Leptospira interrogans sensu stricto using the microscopic agglutination test (MAT). Live cultures of different serovars were used as antigens. MAT was performed according to standard procedures and the degree of reaction was interpreted by estimating the percentage of agglutinated leptospires. Samples showing titres of ≥ 50 against one or more serovars were considered as positive. Results Antibodies against seven pathogenic serovars of L. interrogans sensu stricto were detected in 46 of 297 reptiles. Among 22 snakes, specific antibodies against pathogenic serovars of three Leptospira species (L. interrogans, L. kirschneri and L. borgpetersenii) at titre levels from 1:50 to 1:400 were detected in 6 snakes. In 31 of 210 lizards, specific antibodies were found in titres from 1:50 to 1:1000 and, finally, among 65 turtles (terrapins and tortoises), 9 had specific antibodies at titre levels between 1:50 and 1:1600. Animals imported from non-EU countries showed significantly higher prevalence (25.0%; 95 confidence interval: 16.7–33.3%) than animals from EU member states (10.4%; confidence interval: 6.1–14.7%). Conclusions Reptiles may be considered as potential reservoirs of L. interrogans sensu stricto. Origin of the animals is a risk factor for presence of leptospiral antibodies, especially in lizards. Special attention should be focused on animals from non-EU member states. PMID:24020619

  14. Developmental regulation of hemoglobin synthesis in the green anole lizard Anolis carolinensis

    PubMed Central

    Storz, Jay F.; Hoffmann, Federico G.; Opazo, Juan C.; Sanger, Thomas J.; Moriyama, Hideaki

    2011-01-01

    Tetrapod vertebrates possess multiple α- and β-like globin genes that are ontogenetically regulated, such that functionally distinct hemoglobin (Hb) isoforms are synthesized during different stages of development. The α- and β-like globin genes of amphibians, birds and mammals are differentially expressed during embryonic development and postnatal life, but little is known about the developmental regulation of globin gene expression in non-avian reptiles. Here we report an investigation into the developmental regulation of Hb synthesis in the green anole lizard Anolis carolinensis. We tested two hypotheses derived from comparative genomic studies of the globin gene clusters in tetrapod vertebrates. First, we tested whether the product of the Anolis αD-globin gene is incorporated into embryonic Hb, thereby performing the role that would normally be performed by the embyronic αE-globin gene (which has been deleted from the green anole genome). Second, we tested whether two ‘lizard-specific’ β-globin paralogs have independently evolved a division of labor between an early-expressed embryonic gene and a later-expressed adult gene. Results of a proteomic analysis revealed that α- and β-like globin genes of the anole are differentially expressed during embryonic development. However, the same repertoire of α- and β-chain Hb isoforms was expressed during all stages of development and postnatal life, and the ontogenetic shifts in isoform composition were relatively subtle. In contrast to the pattern that has been documented in other tetrapod vertebrates, it appears that the developmental regulation of Hb synthesis in the green anole lizard does not involve discrete, stage-specific switches in gene activation and gene silencing. PMID:21270305

  15. Neither male gonadal androgens nor female reproductive costs drive development of sexual size dimorphism in lizards.

    PubMed

    Starostová, Zuzana; Kubička, Lukáš; Golinski, Alison; Kratochvíl, Lukáš

    2013-05-15

    Sexual size dimorphism (SSD) is an extensively studied phenomenon in animals, including reptiles, but the proximate mechanism of its development is poorly understood. The most pervasive candidates are: (1) androgen-mediated control of growth, i.e. a positive effect of gonadal androgens (testosterone) on male growth in male-larger species, and a negative effect in female-larger species; and (2) sex-specific differences in energy allocation to growth, e.g. sex with larger reproductive costs should result in smaller body size. We tested these hypotheses in adults of the male-larger lizard Paroedura picta by conducting castrations with and without testosterone implants in males and manipulating reproductive status in females. Castration or testosterone replacement had no significant effect on final body length in males. High investment to reproduction had no significant effect on final body length in intact females. Interestingly, ovariectomized females and females with testosterone implants grew to larger body size than intact females. We did not find support for either of the above hypotheses and suggest that previously reported effects of gonadal androgens on growth in male lizards could be a consequence of altered behaviour or social status in manipulated individuals. Exogenous testosterone in females led to decreased size of ovaries; its effect on body size may be caused by interference with normal ovarian function. We suggest that ovarian factors, perhaps estrogens, not reproductive costs, can modify growth in female lizards and may thus contribute to the development of SSD. This hypothesis is largely supported by published results on the effect of testosterone treatment or ovariectomy on body size in female squamates. PMID:23393279

  16. Thermoregulation in the lizard Psammodromus algirus along a 2200-m elevational gradient in Sierra Nevada (Spain).

    PubMed

    Zamora-Camacho, Francisco Javier; Reguera, Senda; Moreno-Rueda, Gregorio

    2016-05-01

    Achieving optimal body temperature maximizes animal fitness. Since ambient temperature may limit ectotherm thermal performance, it can be constrained in too cold or hot environments. In this sense, elevational gradients encompass contrasting thermal environments. In thermally pauperized elevations, ectotherms may either show adaptations or suboptimal body temperatures. Also, reproductive condition may affect thermal needs. Herein, we examined different thermal ecology and physiology capabilities of the lizard Psammodromus algirus along a 2200-m elevational gradient. We measured field (T(b)) and laboratory-preferred (T(pref)) body temperatures of lizards with different reproductive conditions, as well as ambient (T(a)) and copper-model operative temperature (T(e)), which we used to determine the