Science.gov

Sample records for adult desert tortoises

  1. Three-year movement patterns of adult desert tortoises at Yucca Mountain

    SciTech Connect

    Holt, E.A.; Rautenstrauch, K.R.

    1995-12-31

    We studied the home-range size and site fidelity of adult desert tortoises (Gopherus agassizii) at Yucca Mountain, Nevada, during 1992-1994. Of 67 adult tortoises monitored at Yucca Mountain during this period, we evaluated the movements of 22 female and 16 male radiomarked tortoises that were located >50 times during each of the 1992, 1993, and 1994 activity seasons. We measured annual and three-year home range sizes by either 100% minimum convex polygon (MCP) or by 95% cluster.

  2. Oxalosis in wild desert tortoises, Gopherus agassizii

    USGS Publications Warehouse

    Jacobson, Elliott R.; Berry, Kristin H.; Stacy, Brian; Huzella, Louis M.; Kalasinsky, Victor F.; Fleetwood, Michelle L.; Mense, Mark G.

    2009-01-01

    We necropsied a moribund, wild adult male desert tortoise (Gopherus agassizii) with clinical signs of respiratory disease and elevated plasma biochemical analytes indicative of renal disease (blood urea nitrogen [415 mg/dl], uric acid [11.8 mg/dl], sodium >180 mmol/l] and chloride [139 mmol/l]). Moderate numbers of birefringent oxalate crystals, based on infrared and electron microscopy, were present within renal tubules; small numbers were seen in colloid within thyroid follicles. A retrospective analysis of 66 additional cases of wild desert tortoises was conducted to determine whether similar crystals were present in thyroid and kidney. The tortoises, from the Mojave and Sonoran deserts, were necropsied between 1992 and 2003 and included juveniles and adults. Tortoises were classified as healthy (those that died due to trauma and where no disease was identified after necropsy and evaluation by standard laboratory tests used for other tortoises) or not healthy (having one or more diseases or lesions). For all 67 necropsied tortoises, small numbers of crystals of similar appearance were present in thyroid glands from 44 of 54 cases (81%) and in kidneys from three of 65 cases (5%). Presence of oxalates did not differ significantly between healthy and unhealthy tortoises, between age classes, or between desert region, and their presence was considered an incidental finding. Small numbers of oxalate crystals seen within the kidney of two additional tortoises also were considered an incidental finding. Although the source of the calcium oxalate could not be determined, desert tortoises are herbivores, and a plant origin seems most likely. Studies are needed to evaluate the oxalate content of plants consumed by desert tortoises, and particularly those in the area where the tortoise in renal failure was found.

  3. Serologic and molecular evidence for Testudinid herpesvirus 2 infection in wild Agassiz's desert tortoises, Gopherus agassizii.

    PubMed

    Jacobson, Elliott R; Berry, Kristin H; Wellehan, James F X; Origgi, Francesco; Childress, April L; Braun, Josephine; Schrenzel, Mark; Yee, Julie; Rideout, Bruce

    2012-07-01

    Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.

  4. The Desert Tortoise: A Delicate Balance

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This award winning program looks at the efforts to preserve the desert tortoise in and around the Edwards Air Force Base, CA area. It also explains what people should do if they come in contact with a tortoise. This video was produced in cooperation with Edwards Air Force Base.

  5. Habitat selection by juvenile Mojave Desert tortoises

    USGS Publications Warehouse

    Todd, Brian D; Halstead, Brian J.; Chiquoine, Lindsay P.; Peaden, J. Mark; Buhlmann, Kurt A.; Tuberville, Tracey D.; Nafus, Melia G.

    2016-01-01

    Growing pressure to develop public lands for renewable energy production places several protected species at increased risk of habitat loss. One example is the Mojave desert tortoise (Gopherus agassizii), a species often at the center of conflicts over public land development. For this species and others on public lands, a better understanding of their habitat needs can help minimize negative impacts and facilitate protection or restoration of habitat. We used radio-telemetry to track 46 neonate and juvenile tortoises in the Eastern Mojave Desert, California, USA, to quantify habitat at tortoise locations and paired random points to assess habitat selection. Tortoise locations near burrows were more likely to be under canopy cover and had greater coverage of perennial plants (especially creosote [Larrea tridentata]), more coverage by washes, a greater number of small-mammal burrows, and fewer white bursage (Ambrosia dumosa) than random points. Active tortoise locations away from burrows were closer to washes and perennial plants than were random points. Our results can help planners locate juvenile tortoises and avoid impacts to habitat critical for this life stage. Additionally, our results provide targets for habitat protection and restoration and suggest that diverse and abundant small-mammal populations and the availability of creosote bush are vital for juvenile desert tortoises in the Eastern Mojave Desert.

  6. Desert tortoise use of burned habitat in the Eastern Mojave desert

    USGS Publications Warehouse

    Drake, Karla K.; Esque, Todd C.; Nussear, Kenneth E.; DeFalco, Lesley; Scoles, Sara; Modlin, Andrew T.; Medica, Philip A.

    2015-01-01

    Wildfires burned 24,254 ha of critical habitat designated for the recovery of the threatened Mojave desert tortoise (Gopherus agassizii) in southern Nevada during 2005. The proliferation of non-native annual grasses has increased wildfire frequency and extent in recent decades and continues to accelerate the conversion of tortoise habitat across the Mojave Desert. Immediate changes to vegetation are expected to reduce quality of critical habitat, yet whether tortoises will use burned and recovering habitat differently from intact unburned habitat is unknown. We compared movement patterns, home-range size, behavior, microhabitat use, reproduction, and survival for adult desert tortoises located in, and adjacent to, burned habitat to understand how tortoises respond to recovering burned habitat. Approximately 45% of home ranges in the post-fire environment contained burned habitat, and numerous observations (n = 12,223) corroborated tortoise use of both habitat types (52% unburned, 48% burned). Tortoises moved progressively deeper into burned habitat during the first 5 years following the fire, frequently foraging in burned habitats that had abundant annual plants, and returning to adjacent unburned habitat for cover provided by intact perennial vegetation. However, by years 6 and 7, the live cover of the short-lived herbaceous perennial desert globemallow (Sphaeralcea ambigua) that typically re-colonizes burned areas declined, resulting in a contraction of tortoise movements from the burned areas. Health and egg production were similar between burned and unburned areas indicating that tortoises were able to acquire necessary resources using both areas. This study documents that adult Mojave desert tortoises continue to use habitat burned once by wildfire. Thus, continued management of this burned habitat may contribute toward the recovery of the species in the face of many sources of habitat loss.

  7. The heat is on: desert tortoises and survival

    USGS Publications Warehouse

    Wessells, Stephen M.; Schwarzbach, Steven E.

    2010-01-01

    To highlight USGS scientists' research and build support for the work being done to help with desert tortoise recovery. To educate people about desert tortoises, their habitat needs, and what people might do to help. Length: 30 minutes

  8. Elevation Derivatives for Mojave Desert Tortoise Habitat

    USGS Publications Warehouse

    Wallace, Cynthia S.A.; Gass, Leila

    2008-01-01

    This report describes the methods used to derive various elevation-derivative grids that were inputted to the Mojave Desert Tortoise Habitat model (L. Gass and others, unpub. data). These grids, which capture information on surface roughness and topographic characteristics, are a subset of the environmental datasets evaluated for the tortoise habitat model. This habitat model is of major importance to the U.S. Fish and Wildlife Service, which is charged with management of this threatened population, including relocating displaced tortoises to areas identified as suitable habitat.

  9. Attributes of desert tortoise populations at the National Training Center, Central Mojave Desert, California, USA

    USGS Publications Warehouse

    Berry, K.H.; Bailey, T.Y.; Anderson, K.M.

    2006-01-01

    We sampled 21 study plots for desert tortoises (Gopherus agassizii) at the National Training Center, Fort Irwin, California. Each plot was sampled once between 1997 and 2003 to obtain a snapshot of population attributes, status, and relationships between tortoise densities and human activities. Densities ranged from <1 to 28 tortoises km-2; overall, tortoises were uncommon to rare at 16 of the 21 plots. Tortoise densities were negatively correlated with death rates, infectious disease (mycoplasmosis), surface disturbance and trash. Health status of tortoises was correlated with some anthropogenic uses. The presence of infectious disease in tortoises was negatively correlated with distances from offices, the Ft. Irwin cantonment, and paved roads. Also, significantly more tortoises with shell disease were found on plots with current and recent military use than on plots with no history of military use. Factors contributing to or causing deaths of tortoises included vehicles, vandalism, predation, mycoplasmosis and shell diseases. Annual death rates for subadult and adult tortoises ranged from 1.9% to 95.2% for the 4 years preceding surveys. Deaths from anthropogenic sources were significantly correlated with surface disturbances, trash, military ordnance, and proximity to offices and paved roads-typical characteristics of military training areas.

  10. Serologic and molecular evidence for testudinid herpesvirus 2 infection in wild Agassiz’s desert tortoise, Gopherus agassizii

    USGS Publications Warehouse

    Jacobson, Elliott R.; Berry, Kristin H.; Wellehan, James F. X.; Origgi, Francesco; Childress, April L.; Braun, Josephine; Schrenzel, Mark; Yee, Julie; Rideout, Bruce

    2012-01-01

    Following field observations of wild Agassiz’s desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.

  11. Gopherus agassizii (desert tortoise) and Crotalus ruber (red diamond rattlesnake). Burrow co-occupancy

    USGS Publications Warehouse

    Lovich, Jeffrey E.

    2011-01-01

    I observed an adult Desert Tortoise and an adult Red Diamond Rattlesnake (sexes unknown) in a shallow tortoise burrow on 6 January 1997 at a wind energy generation facility near Palm Springs, Riverside Co., California, USA (33.9599°N, 116.6613°W).

  12. Gopherus agassizii (desert tortoise). Burrow collapse

    USGS Publications Warehouse

    Loughran, Caleb L.; Ennen, Joshua; Lovich, Jeffrey E.

    2011-01-01

    In the deserts of the southwestern U.S., burrows are utilized by the Desert Tortoise to escape environmental extremes (reviewed by Ernst and Lovich 2009. Turtles of the United States and Canada. 2nd ed. Johns Hopkins Univ. Press, Baltimore, Maryland. 827 pp.). However, the potential for mortality through burrow collapse and entrapment is poorly documented. Nicholson and Humphreys (1981. Proceedings of the Desert Tortoise Council, pp. 163−194) suggested that collapse due to livestock trampling may cause mortality. In addition, Lovich et al. (2011. Chelon. Cons. Biol. 10[1]:124–129) documented a Desert Tortoise that used a steel culvert as a burrow surrogate. The culvert filled completely with sediment following a significant rain event, entombing the animal and ultimately resulting in its death. We note that this mortality was associated with an anthropogenic structure; because tortoises are prodigious diggers, one might hypothesize that they have the ability to dig out of collapsed natural burrows in most situations. Circumstances described here presented us with an opportunity to test this hypothesis.

  13. Modeling Agassiz's Desert Tortoise Population Response to Anthropogenic Stressors

    EPA Science Inventory

    Mojave Desert tortoise (Gopherus agassizii) populations are exposed to a variety of anthropogenic threats, which vary in nature, severity, and frequency. Tortoise management in conservation areas can be compromised when the relative importance of these threats is not well underst...

  14. Desert tortoise hibernation: Temperatures, timing, and environment

    USGS Publications Warehouse

    Nussear, K.E.; Esque, T.C.; Haines, D.F.; Tracy, C.R.

    2007-01-01

    This research examined the onset, duration, and termination of hibernation in Desert Tortoises (Gopherus agassizii) over several years at multiple sites in the northeastern part of their geographic range, and recorded the temperatures experienced by tortoises during winter hibernation. The timing of hibernation by Desert Tortoises differed among sites and years. Environmental cues acting over the short-term did not appear to influence the timing of the hibernation period. Different individual tortoises entered hibernation over as many as 44 days in the fall and emerged from hibernation over as many as 49 days in the spring. This range of variation in the timing of hibernation indicates a weak influence at best of exogenous cues hypothesized to trigger and terminate hibernation. There do appear to be regional trends in hibernation behavior as hibernation tended to begin earlier and continue longer at sites that were higher in elevation and generally cooler. The emergence date was generally more similar among study sites than the date of onset. While the climate and the subsequent timing of hibernation differed among sites, the average temperatures experienced by tortoises while hibernating differed by only about five degrees from the coldest site to the warmest site. ?? 2007 by the American Society of Ichthyologists and Herpetologists.

  15. Multiple factors affect a population of Agassiz's desert tortoise (Gopherus agassizii) in the Northwestern Mojave Desert

    USGS Publications Warehouse

    Berry, Kristin H.; Yee, Julie L.; Coble, Ashley A.; Perry, William M.; Shields, Timothy A.

    2013-01-01

    Numerous factors have contributed to declines in populations of the federally threatened Agassiz's Desert Tortoise (Gopherus agassizii) and continue to limit recovery. In 2010, we surveyed a low-density population on a military test facility in the northwestern Mojave Desert of California, USA, to evaluate population status and identify potential factors contributing to distribution and low densities. Estimated densities of live tortoises ranged spatially from 1.2/km2 to 15.1/km2. Although only one death of a breeding-age tortoise was recorded for the 4-yr period prior to the survey, remains of 16 juvenile and immature tortoises were found, and most showed signs of predation by Common Ravens (Corvus corax) and mammals. Predation may have limited recruitment of young tortoises into the adult size classes. To evaluate the relative importance of different types of impacts to tortoises, we developed predictive models for spatially explicit densities of tortoise sign and live tortoises using topography (i.e., slope), predators (Common Raven, signs of mammalian predators), and anthropogenic impacts (distances from paved road and denuded areas, density of ordnance fragments) as covariates. Models suggest that densities of tortoise sign increased with slope and signs of mammalian predators and decreased with Common Ravens, while also varying based on interaction effects involving these predictors as well as distances from paved roads, denuded areas, and ordnance. Similarly, densities of live tortoises varied by interaction effects among distances to denuded areas and paved roads, density of ordnance fragments, and slope. Thus multiple factors predict the densities and distribution of this population.

  16. Nelson's big horn sheep (Ovis canadensis nelsoni) trample Agassiz's desert tortoise (Gopherus agassizii) burrow at a California wind energy facility

    USGS Publications Warehouse

    Agha, Mickey; Delaney, David F.; Lovich, Jeffrey E.; Briggs, Jessica; Austin, Meaghan; Price, Steven J.

    2015-01-01

    Research on interactions between Agassiz's desert tortoises (Gopherus agassizii) and ungulates has focused exclusively on the effects of livestock grazing on tortoises and their habitat (Oldemeyer, 1994). For example, during a 1980 study in San Bernardino County, California, 164 desert tortoise burrows were assessed for vulnerability to trampling by domestic sheep (Ovis aries). Herds of grazing sheep damaged 10% and destroyed 4% of the burrows (Nicholson and Humphreys 1981). In addition, a juvenile desert tortoise was trapped and an adult male was blocked from entering a burrow due to trampling by domestic sheep. Another study found that domestic cattle (Bos taurus) trampled active desert tortoise burrows and vegetation surrounding burrows (Avery and Neibergs 1997). Trampling also has negative impacts on diversity of vegetation and intershrub soil crusts in the desert southwest (Webb and Stielstra 1979). Trampling of important food plants and overgrazing has the potential to create competition between desert tortoises and domestic livestock (Berry 1978; Coombs 1979; Webb and Stielstra 1979).

  17. Are wildlife detector dogs or people better at finding Desert Tortoises (Gopherus agassizii)?

    USGS Publications Warehouse

    Nussear, K.E.; Esque, T.C.; Heaton, J.S.; Cablk, Mary E.; Drake, K.K.; Valentin, C.; Yee, J.L.; Medica, P.A.

    2008-01-01

    Our ability to study threatened and endangered species depends on locating them readily in the field. Recent studies highlight the effectiveness of trained detector dogs to locate wildlife during field surveys, including Desert Tortoises in a semi-natural setting. Desert Tortoises (Gopherus agassizii) are cryptic and difficult to detect during surveys, especially the smaller size classes. We conducted comparative surveys to determine whether human or detector dog teams were more effective at locating Desert Tortoises in the wild. We compared detectability of Desert Tortoises and the costs to deploy human and dog search teams. Detectability of tortoises was not statistically different for either team, and was estimated to be approximately 70% (SE = 5%). Dogs found a greater proportion of tortoises located in vegetation than did humans. The dog teams finished surveys 2.5 hours faster than the humans on average each day. The human team cost was approximately $3,000 less per square kilometer sampled. Dog teams provided a quick and effective method for surveying for adult Desert Tortoises; however, we were unable to determine-their effectiveness at locating smaller size classes. Detection of smaller size classes during surveys would improve management of the species and should be addressed by future research using Desert Tortoise detector dogs.

  18. Integrating Gene Transcription-Based Biomarkers to Understand Desert Tortoise and Ecosystem Health.

    PubMed

    Bowen, Lizabeth; Miles, A Keith; Drake, K Kristina; Waters, Shannon C; Esque, Todd C; Nussear, Kenneth E

    2015-09-01

    Tortoises are susceptible to a wide variety of environmental stressors, and the influence of human disturbances on health and survival of tortoises is difficult to detect. As an addition to current diagnostic methods for desert tortoises, we have developed the first leukocyte gene transcription biomarker panel for the desert tortoise (Gopherus agassizii), enhancing the ability to identify specific environmental conditions potentially linked to declining animal health. Blood leukocyte transcript profiles have the potential to identify physiologically stressed animals in lieu of clinical signs. For desert tortoises, the gene transcript profile included a combination of immune or detoxification response genes with the potential to be modified by biological or physical injury and consequently provide information on the type and magnitude of stressors present in the animal's habitat. Blood from 64 wild adult tortoises at three sites in Clark County, NV, and San Bernardino, CA, and from 19 captive tortoises in Clark County, NV, was collected and evaluated for genes indicative of physiological status. Statistical analysis using a priori groupings indicated significant differences among groups for several genes, while multidimensional scaling and cluster analyses of transcription C T values indicated strong differentiation of a large cluster and multiple outlying individual tortoises or small clusters in multidimensional space. These analyses highlight the effectiveness of the gene panel at detecting environmental perturbations as well as providing guidance in determining the health of the desert tortoise.

  19. Integrating gene transcription-based biomarkers to understand desert tortoise and ecosystem health

    USGS Publications Warehouse

    Bowen, Lizabeth; Miles, A. Keith; Drake, Karla K.; Waters, Shannon C.; Esque, Todd C.; Nussear, Kenneth E.

    2015-01-01

    Tortoises are susceptible to a wide variety of environmental stressors, and the influence of human disturbances on health and survival of tortoises is difficult to detect. As an addition to current diagnostic methods for desert tortoises, we have developed the first leukocyte gene transcription biomarker panel for the desert tortoise (Gopherus agassizii), enhancing the ability to identify specific environmental conditions potentially linked to declining animal health. Blood leukocyte transcript profiles have the potential to identify physiologically stressed animals in lieu of clinical signs. For desert tortoises, the gene transcript profile included a combination of immune or detoxification response genes with the potential to be modified by biological or physical injury and consequently provide information on the type and magnitude of stressors present in the animal’s habitat. Blood from 64 wild adult tortoises at three sites in Clark County, NV, and San Bernardino, CA, and from 19 captive tortoises in Clark County, NV, was collected and evaluated for genes indicative of physiological status. Statistical analysis using a priori groupings indicated significant differences among groups for several genes, while multidimensional scaling and cluster analyses of transcriptionC T values indicated strong differentiation of a large cluster and multiple outlying individual tortoises or small clusters in multidimensional space. These analyses highlight the effectiveness of the gene panel at detecting environmental perturbations as well as providing guidance in determining the health of the desert tortoise.

  20. Desert tortoise annotated bibliography, 1991-2015

    USGS Publications Warehouse

    Berry, Kristin H.; Lyren, Lisa M.; Mack, Jeremy S.; Brand, L. Arriana; Wood, Dustin A.

    2016-03-01

    Agassiz’s Desert Tortoise (hereinafter called desert tortoise) is a state- and federally-listed threatened species (U.S. Fish and Wildlife Service, 1990; California Department of Fish and Game, 2015). The first population federally listed as threatened occurred on the Beaver Dam Slope, Utah (U.S. Fish and Wildlife Service, 1980). In 1990, the entire geographic range north and west of the Colorado River was federally listed as threatened (U.S. Fish and Wildlife Service, 1990), with the exception being a small population in northwestern Arizona. The purpose of this annotated bibliography is to support recovery efforts for the species, because populations have continued to decline in spite of designation of critical habitat and publication of a recovery plan (U.S. Fish and Wildlife Service, 1994). For example, between 2005 and 2014, populations in critical habitats declined about 50% (U.S. Fish and Wildlife Service, 2015).

  1. Mycoplasma testudineum in free-ranging desert tortoises, Gopherus agassizii

    USGS Publications Warehouse

    Jacobson, Elliott R.; Berry, Kristin H.

    2012-01-01

    We performed clinico-pathological evaluations of 11 wild Agassiz's desert tortoises (Gopherus agassizii) from a translocation project in the central Mojave Desert, California, USA. Group 1 consisted of nine tortoises that were selected primarily due to serologic status, indicating exposure to Mycoplasma testudineum (seven) or both M. agassizii and M. testudineum (two), and secondarily due to clinical signs of upper respiratory tract disease (URTD). Group 2 consisted of two tortoises that were antibody-negative for Mycoplasma and had no clinical signs of URTD, but did have other signs of illness. Of the Group 1 tortoises, M. testudineum, but not M. agassizii, was amplified by polymerase chain reaction and DNA fingerprinted from two tortoises. Using light microscopy, mild to severe pathologic changes were observed in one or more histologic sections of either one or both nasal cavities of each tortoise in Group 1. Our findings support a causal relationship between M. testudineum and URTD in desert tortoises.

  2. Mycoplasma agassizii in Morafka's desert tortoise (Gopherus morafkai) in Mexico.

    PubMed

    Berry, Kristin H; Brown, Mary B; Vaughn, Mercy; Gowan, Timothy A; Hasskamp, Mary Ann; Torres, Ma Cristina Meléndez

    2015-01-01

    We conducted health evaluations of 69 wild and 22 captive Morafka's desert tortoises (Gopherus morafkai) in Mexico between 2005 and 2008. The wild tortoises were from 11 sites in the states of Sonora and Sinaloa, and the captive tortoises were from the state-managed Centro Ecológico de Sonora Zoo in Hermosillo and a private residence in the town of Alamos. We tested 88 tortoises for mycoplasmal upper respiratory tract disease (URTD) using enzyme-linked immunosorbent assays for specific antibody and by culture and PCR for detection of Mycoplasma agassizii and Mycoplasma testudineum. Fifteen of 22 captive tortoises had one or more positive diagnostic test results for M. agassizii whereas no wild tortoises had positive tests. Tortoises with positive tests also had significantly more moderate and severe clinical signs of mycoplasmosis on beaks and nares compared to tortoises with negative tests. Captive tortoises also exhibited significantly more clinical signs of illness than did wild tortoises, including lethargy and moderate to severe ocular signs. The severity of trauma and diseases of the shell and integument did not differ significantly among tortoises by site; however, clinical signs of moderate to severe trauma and disease were more prevalent in older tortoises. Similar to research findings for other species in the genus Gopherus in the US, we found that URTD is an important disease in captive tortoises. If they escape or are released by intention or accident to the wild, captive tortoises are likely to pose risks to healthy, naïve wild populations.

  3. Range and habitats of the desert tortoise

    USGS Publications Warehouse

    Germano, D.J.; Bury, R.B.; Esque, T.C.; Fritts, T.H.; Bury, R.B.; Germano, D.J.

    1994-01-01

    We determined the current range of the desert tortoise (Gopherus agassizii) based on the available latest data from government agencies, the literature, and our experience. We developed the first detailed range map of this species and summarized information about habitat preferences. New records of occurrences were incorporated, and some peripheral localities of questionable authenticity were deleted. The distribution oCG. agassizii covers the broadest range of latitude, climatic regimes, habitats, and biotic regions of any North American tortoise. The northern portion ofits range is in the Mojave Desert of sDuth"eastern California, southern Nevada, southwestern Utah, and northwestern Arizona. The central portion of the range consists of several subdivisions of the Sonaran Desert in southeastern California, western and southern Arizona, and western Sonora, Mexico. The southern edge of its range is in the semitropical Sinaloan thornscrub and Sinaloan deciduous forest of eastern Sonora and northern Sinaloa, Mexico. This species has marked geogi-aphic differences but seems to construct burrows throughout its range.

  4. Clinical disease and laboratory abnormalities in free-ranging desert tortoises in California (1990-1995)

    USGS Publications Warehouse

    Christopher, Mary M.; Berry, Kristin H.; Henen, Brian T.; Nagy, Kenneth A.

    2003-01-01

    Desert tortoise (Gopherus agassizii) populations have experienced precipitous declines resulting from the cumulative impact of habitat loss and human and disease-related mortality. Diagnosis of disease in live, free-ranging tortoises is facilitated by evaluation of clinical signs and laboratory test results but may be complicated by seasonal and environmental effects. The goals of this study were: 1) to describe and monitor clinical and laboratory signs of disease in adult, free-ranging desert tortoises at three sites in the Mojave Desert of California (USA) between October 1990 and October 1995; 2) to evaluate associations between clinical signs and hematologic, biochemical, serologic, and microbiologic test results; 3) to characterize disease patterns by site, season, and sex; and 4) to assess the utility of diagnostic tests in predicting morbidity and mortality. Venous blood samples were obtained four times per year from tortoises of both sexes at the Desert Tortoise Research Natural Area (DTNA), Goffs/Fenner Valley, and Ivanpah Valley. Tortoises were given a physical examination, and clinical abnormalities were graded by type and severity. Of 108 tortoises, 68.5% had clinical signs of upper respiratory tract disease consistent with mycoplasmosis at least once during the study period. In addition, 48.1% developed moderate to severe shell lesions consistent with cutaneous dyskeratosis. Ulcerated or plaque-like oral lesions were noted on single occasions in 23% of tortoises at Goffs and 6% of tortoises at Ivanpah. Tortoises with oral lesions were significantly more likely than tortoises without lesions to have positive nasal cultures for Mycoplasma agassizii(P=0.001) and to be dehydrated (P=0.0007). Nine tortoises had marked azotemia (blood urea nitrogen [BUN] >100 mg/dl) or persistent azotemia (BUN 63–76 mg/dl); four of these died, three of which had necropsy confirmation of urinary tract disease. Laboratory tests had low sensitivity but high specificity in

  5. Does translocation influence physiological stress in the desert tortoise?

    USGS Publications Warehouse

    Drake, K.K.; Nussear, K.E.; Esque, T.C.; Barber, A.M.; Vittum, K.M.; Medica, P.A.; Tracy, C.R.; Hunter, K.W.

    2012-01-01

    Wildlife translocation is increasingly used to mitigate disturbances to animals or habitat due to human activities, yet little is known about the extent to which translocating animals causes stress. To understand the relationship between physiological stress and translocation, we conducted a multiyear study (2007–2009) using a population of desert tortoises (Gopherus agassizii) near Fort Irwin, California. Blood samples were collected from adult tortoises in three treatment groups (resident, translocated and control) for 1 year prior to and 2 years after translocation. Samples were analyzed by radioimmunoassay for plasma total corticosterone (CORT), a glucocorticoid hormone commonly associated with stress responses in reptiles. CORT values were analyzed in relation to potential covariates (animal sex, date, behavior, treatment, handling time, air temperature, home-range size, precipitation and annual plant production) among seasons and years. CORT values in males were higher than in females, and values for both varied monthly throughout the activity season and among years. Year and sex were strong predictors of CORT, and translocation explained little in terms of CORT. Based on these results, we conclude that translocation does not elicit a physiological stress response in desert tortoises.

  6. Mycoplasma agassizii in Morafka's desert tortoise (Gopherus morafkai) in Mexico

    USGS Publications Warehouse

    Berry, Kristin H.; Brown, Mary B.; Vaughn, Mercy; Gowan, Timothy A.; Hasskamp, Mary Ann; Torres, Ma. Cristina Melendez

    2015-01-01

    We conducted health evaluations of 69 wild and 22 captive Morafka's desert tortoises (Gopherus morafkai) in Mexico between 2005 and 2008. The wild tortoises were from 11 sites in the states of Sonora and Sinaloa, and the captive tortoises were from the state-managed Centro Ecológico de Sonora Zoo in Hermosillo and a private residence in the town of Alamos. We tested 88 tortoises for mycoplasmal upper respiratory tract disease (URTD) using enzyme-linked immunosorbent assays for specific antibody and by culture and PCR for detection of Mycoplasma agassizii and Mycoplasma testudineum. Fifteen of 22 captive tortoises had one or more positive diagnostic test results for M. agassizii whereas no wild tortoises had positive tests. Tortoises with positive tests also had significantly more moderate and severe clinical signs of mycoplasmosis on beaks and nares compared to tortoises with negative tests. Captive tortoises also exhibited significantly more clinical signs of illness than did wild tortoises, including lethargy and moderate to severe ocular signs. The severity of trauma and diseases of the shell and integument did not differ significantly among tortoises by site; however, clinical signs of moderate to severe trauma and disease were more prevalent in older tortoises. Similar to research findings for other species in the genus Gopherusin the US, we found that URTD is an important disease in captive tortoises. If they escape or are released by intention or accident to the wild, captive tortoises are likely to pose risks to healthy, naïve wild populations.

  7. Field trials of line transect methods applied to estimation of desert tortoise abundance

    USGS Publications Warehouse

    Anderson, David R.; Burnham, Kenneth P.; Lubow, Bruce C.; Thomas, L. E. N.; Corn, Paul Stephen; Medica, Philip A.; Marlow, R.W.

    2001-01-01

    We examine the degree to which field observers can meet the assumptions underlying line transect sampling to monitor populations of desert tortoises (Gopherus agassizii). We present the results of 2 field trials using artificial tortoise models in 3 size classes. The trials were conducted on 2 occasions on an area south of Las Vegas, Nevada, where the density of the test population was known. In the first trials, conducted largely by experienced biologists who had been involved in tortoise surveys for many years, the density of adult tortoise models was well estimated (-3.9% bias), while the bias was higher (-20%) for subadult tortoise models. The bias for combined data was -12.0%. The bias was largely attributed to the failure to detect all tortoise models on or near the transect centerline. The second trials were conducted with a group of largely inexperienced student volunteers and used somewhat different searching methods, and the results were similar to the first trials. Estimated combined density of subadult and adult tortoise models had a negative bias (-7.3%), again attributable to failure to detect some models on or near the centerline. Experience in desert tortoise biology, either comparing the first and second trials or in the second trial with 2 experienced biologists versus 16 novices, did not have an apparent effect on the quality of the data or the accuracy of the estimates. Observer training, specific to line transect sampling, and field testing are important components of a reliable survey. Line transect sampling represents a viable method for large-scale monitoring of populations of desert tortoise; however, field protocol must be improved to assure the key assumptions are met.

  8. Enhancing and restoring habitat for the desert tortoise

    USGS Publications Warehouse

    Abella, Scott R.; Berry, Kristin H.

    2016-01-01

    Habitat has changed unfavorably during the past 150 y for the desert tortoise Gopherus agassizii, a federally threatened species with declining populations in the Mojave Desert and western Sonoran Desert. To support recovery efforts, we synthesized published information on relationships of desert tortoises with three habitat features (cover sites, forage, and soil) and candidate management practices for improving these features for tortoises. In addition to their role in soil health and facilitating recruitment of annual forage plants, shrubs are used by desert tortoises for cover and as sites for burrows. Outplanting greenhouse-grown seedlings, protected from herbivory, has successfully restored (>50% survival) a variety of shrubs on disturbed desert soils. Additionally, salvaging and reapplying topsoil using effective techniques is among the more ecologically beneficial ways to initiate plant recovery after severe disturbance. Through differences in biochemical composition and digestibility, some plant species provide better-quality forage than others. Desert tortoises selectively forage on particular annual and herbaceous perennial species (e.g., legumes), and forage selection shifts during the year as different plants grow or mature. Nonnative grasses provide low-quality forage and contribute fuel to spreading wildfires, which damage or kill shrubs that tortoises use for cover. Maintaining a diverse “menu” of native annual forbs and decreasing nonnative grasses are priorities for restoring most desert tortoise habitats. Reducing herbivory by nonnative animals, carefully timing herbicide applications, and strategically augmenting annual forage plants via seeding show promise for improving tortoise forage quality. Roads, another disturbance, negatively affect habitat in numerous ways (e.g., compacting soil, altering hydrology). Techniques such as recontouring road berms to reestablish drainage patterns, vertical mulching (“planting” dead plant material

  9. Climatic variation and tortoise survival: has a desert species met its match?

    USGS Publications Warehouse

    Lovich, Jeffrey E.; Yackulic, Charles B.; Freilich, Jerry; Agha, Mickey; Austin, Meaghan; Meyer, Katherine P.; Arundel, Terence R.; Hansen, Jered; Vamstad, Michael S.; Root, Stephanie A.

    2014-01-01

    While demographic changes in short-lived species may be observed relatively quickly in response to climate changes, measuring population responses of long-lived species requires long-term studies that are not always available. We analyzed data from a population of threatened Agassiz’s desert tortoises (Gopherus agassizii) at a 2.59 km2 study plot in the Sonoran Desert ecosystem of Joshua Tree National Park, California, USA from 1978 to 2012 to examine variation in apparent survival and demography in this long-lived species. Transect-based, mark-recapture surveys were conducted in 10 of those years to locate living and dead tortoises. Previous modeling suggested that this area would become unsuitable as tortoise habitat under a warming and drying climate scenario. Estimated adult population size declined greatly from 1996 to 2012. The population appeared to have high apparent survival from 1978 to 1996 but apparent survival decreased from 1997 to 2002, concurrent with persistent drought. The best model relating apparent survivorship of tortoises ≥18 cm over time was based on a three year moving average of estimated winter precipitation. The postures and positions of a majority of dead tortoises found in 2012 were consistent with death by dehydration and starvation. Some live and many dead tortoises found in 2012 showed signs of predation or scavenging by mammalian carnivores. Coyote (Canis latrans) scats and other evidence from the site confirmed their role as tortoise predators and scavengers. Predation rates may be exacerbated by drought if carnivores switch from preferred mammalian prey to tortoises during dry years. Climate modeling suggests that the region will be subjected to even longer duration droughts in the future and that the plot may become unsuitable for continued tortoise survival. Our results showing wide fluctuations in apparent survival and decreasing tortoise density over time may be early signals of that possible outcome.

  10. Desert Tortoises (Gopherus agassizii) Are Selective Herbivores that Track the Flowering Phenology of Their Preferred Food Plants

    PubMed Central

    Jennings, W. Bryan; Berry, Kristin H.

    2015-01-01

    Previous studies of desert tortoise foraging ecology in the western Mojave Desert suggest that these animals are selective herbivores, which alter their diet according to the temporal availability of preferred food plants. These studies, however, did not estimate availability of potential food plants by taking into account the spatial and temporal variability in ephemeral plant abundance that occurs within the spring season. In this study, we observed 18 free-ranging adult tortoises take 35,388 bites during the spring foraging season. We also estimated the relative abundance of potential food plants by stratifying our sampling across different phenological periods of the 3-month long spring season and by different habitats and microhabitats. This methodology allowed us to conduct statistical tests comparing tortoise diet against plant abundance. Our results show that tortoises choose food plants non-randomly throughout the foraging season, a finding that corroborates the hypothesis that desert tortoises rely on key plants during different phenological periods of spring. Moreover, tortoises only consumed plants in a succulent state until the last few weeks of spring, at which time most annuals and herbaceous perennials had dried and most tortoises had ceased foraging. Many species of food plants—including several frequently eaten species—were not detected in our plant surveys, yet tortoises located these rare plants in their home ranges. Over 50% of bites consumed were in the group of undetected species. Interestingly, tortoises focused heavily on several leguminous species, which could be nutritious foods owing to their presumably high nitrogen contents. We suggest that herbaceous perennials, which were rare on our study area but represented ~30% of tortoise diet, may be important in sustaining tortoise populations during droughts when native annuals are absent. These findings highlight the vulnerability of desert tortoises to climate change if such changes

  11. Desert tortoises (Gopherus agassizii) are selective herbivores that track the flowering phenology of their preferred food plants

    USGS Publications Warehouse

    Jennings, Bryan W.; Berry, Kristin H.

    2015-01-01

    Previous studies of desert tortoise foraging ecology in the western Mojave Desert suggest that these animals are selective herbivores, which alter their diet according to the temporal availability of preferred food plants. These studies, however, did not estimate availability of potential food plants by taking into account the spatial and temporal variability in ephemeral plant abundance that occurs within the spring season. In this study, we observed 18 free-ranging adult tortoises take 35,388 bites during the spring foraging season. We also estimated the relative abundance of potential food plants by stratifying our sampling across different phenological periods of the 3-month long spring season and by different habitats and microhabitats. This methodology allowed us to conduct statistical tests comparing tortoise diet against plant abundance. Our results show that tortoises choose food plants non-randomly throughout the foraging season, a finding that corroborates the hypothesis that desert tortoises rely on key plants during different phenological periods of spring. Moreover, tortoises only consumed plants in a succulent state until the last few weeks of spring, at which time most annuals and herbaceous perennials had dried and most tortoises had ceased foraging. Many species of food plants—including several frequently eaten species—were not detected in our plant surveys, yet tortoises located these rare plants in their home ranges. Over 50% of bites consumed were in the group of undetected species. Interestingly, tortoises focused heavily on several leguminous species, which could be nutritious foods owing to their presumably high nitrogen contents. We suggest that herbaceous perennials, which were rare on our study area but represented ~30% of tortoise diet, may be important in sustaining tortoise populations during droughts when native annuals are absent. These findings highlight the vulnerability of desert tortoises to climate change if such changes

  12. Desert tortoises (Gopherus agassizii) are selective herbivores that track the flowering phenology of their preferred food plants.

    PubMed

    Jennings, W Bryan; Berry, Kristin H

    2015-01-01

    Previous studies of desert tortoise foraging ecology in the western Mojave Desert suggest that these animals are selective herbivores, which alter their diet according to the temporal availability of preferred food plants. These studies, however, did not estimate availability of potential food plants by taking into account the spatial and temporal variability in ephemeral plant abundance that occurs within the spring season. In this study, we observed 18 free-ranging adult tortoises take 35,388 bites during the spring foraging season. We also estimated the relative abundance of potential food plants by stratifying our sampling across different phenological periods of the 3-month long spring season and by different habitats and microhabitats. This methodology allowed us to conduct statistical tests comparing tortoise diet against plant abundance. Our results show that tortoises choose food plants non-randomly throughout the foraging season, a finding that corroborates the hypothesis that desert tortoises rely on key plants during different phenological periods of spring. Moreover, tortoises only consumed plants in a succulent state until the last few weeks of spring, at which time most annuals and herbaceous perennials had dried and most tortoises had ceased foraging. Many species of food plants--including several frequently eaten species--were not detected in our plant surveys, yet tortoises located these rare plants in their home ranges. Over 50% of bites consumed were in the group of undetected species. Interestingly, tortoises focused heavily on several leguminous species, which could be nutritious foods owing to their presumably high nitrogen contents. We suggest that herbaceous perennials, which were rare on our study area but represented ~30% of tortoise diet, may be important in sustaining tortoise populations during droughts when native annuals are absent. These findings highlight the vulnerability of desert tortoises to climate change if such changes alter

  13. Severe mortality of a population of threatened Agassiz’s desert tortoises: the American badger as a potential predator

    USGS Publications Warehouse

    Emblidge, Patrick G.; Nussear, Ken E.; Esque, Todd C.; Aiello, Christina M.; Walde, Andrew D.

    2015-01-01

    In the Mojave Desert of the southwestern United States, adult Agassiz’s desert tortoises Gopherus agassizii typically experience high survival, but population declines associated with anthropogenic impacts led to their listing as a threatened Species under the US Endangered Species Act in 1990. Predation of adult tortoises is not often considered a significant threat as they are adapted to deter most predation attempts. Despite these adaptations, some populations have experienced elevated mortality attributed to predators, suggesting that predation pressure may occasionally increase. During the tortoise activity seasons of 2012 and 2013, we observed unsustainably high mortality in 1 of 4 populations of adult desert tortoises (22 and 84%, respectively) in the western Mojave Desert in the vicinity of Barstow, CA. Photographic evidence from trail cameras and examination of carcass condition suggest that American badgers Taxidea taxus— a sometimes cited but unconfirmed predator of adult tortoises — may have been responsible for some of the mortality observed. We discuss the American badger as a plausible predator of a local tortoise population, but recommend further investigation into these events and the impacts such mortality can have on tortoise persistence.

  14. Distribution, habitat and habits of the desert tortoise (Gopherus agassizii) in the eastern Mojave Desert

    SciTech Connect

    Esque, T.C.; Bury, R.B. ); Medica, P.A. )

    1990-01-01

    The desert tortoise is widely distributed across most of southern Nevada below 1500 meters elevation and then ranges northeast into the Arizona Strip and southwestern Utah. There are several large populations, but also many isolated groups of desert tortoises due to the rugged topography and, possibly, unsuitable soils. We suggest that the greatest threats to tortoises in the eastern Mojave Desert are with peripheral populations. Tortoises in the eastern Mojave Desert occupy a wide variety of habitats from flats and bajadas in lower elevation to rocky slopes bordering on blackbrush and juniper woodland. In winter they use shallow burrows near Las Vegas but frequent deep caves in the northeast edge of their range. Tortoises in all areas may occur in steep, rocky habitats. Climatic extremes are frequent in this region and rainfall can be spotty due to several major mountain ranges that cause rain shadows. Forage is highly variable and this species can be an opportunistic herbivore. 11 refs., 13 figs.

  15. Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates

    USGS Publications Warehouse

    Esque, T.C.; Schwalbe, C.R.; DeFalco, L.A.; Duncan, R.B.; Hughes, T.J.

    2003-01-01

    We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation cover. A range of 0 to 7 tortoises was encountered during surveys, and live tortoises were found on all transects. In addition to desert tortoises, only small (<1 kg) mammals and reptiles (11 taxa) were found dead on the study areas. We hypothesize that indirect effects of fire on desert habitats might result in changes in the composition of diets and loss of vegetation cover, resulting in an increase in predation and loss of protection from temperature extremes. These changes in habitat also might cause changes in vertebrate communities in burned areas.

  16. Relative abundance of desert tortoises on the Nevada Test Site

    SciTech Connect

    Rautenstrauch, K.R.; O`Farrell, T.P.

    1993-12-31

    Seven hundred fifty-nine transects having a total length of 1,191 km were walked during 1981--1986 to determine the distribution and relative abundance of desert tortoises (Gopherus agassizii) on the Nevada Test Site (NTS). The abundance of tortoises on NTS was low to very low relative to other populations in the Mojave Desert. Sign of tortoises was found from 880 to 1,570 m elevation and was more abundant above 1,200 m than has been reported previously for Nevada. Tortoises were more abundant on NTS on the upper alluvial fans and slopes of mountains than in valley bottoms. They also were more common on or near limestone and dolomite mountains than on mountains of volcanic origin.

  17. Can modeling improve estimation of desert tortoise population densities?

    USGS Publications Warehouse

    Nussear, K.E.; Tracy, C.R.

    2007-01-01

    The federally listed desert tortoise (Gopherus agassizii) is currently monitored using distance sampling to estimate population densities. Distance sampling, as with many other techniques for estimating population density, assumes that it is possible to quantify the proportion of animals available to be counted in any census. Because desert tortoises spend much of their life in burrows, and the proportion of tortoises in burrows at any time can be extremely variable, this assumption is difficult to meet. This proportion of animals available to be counted is used as a correction factor (g0) in distance sampling and has been estimated from daily censuses of small populations of tortoises (6-12 individuals). These censuses are costly and produce imprecise estimates of g0 due to small sample sizes. We used data on tortoise activity from a large (N = 150) experimental population to model activity as a function of the biophysical attributes of the environment, but these models did not improve the precision of estimates from the focal populations. Thus, to evaluate how much of the variance in tortoise activity is apparently not predictable, we assessed whether activity on any particular day can predict activity on subsequent days with essentially identical environmental conditions. Tortoise activity was only weakly correlated on consecutive days, indicating that behavior was not repeatable or consistent among days with similar physical environments. ?? 2007 by the Ecological Society of America.

  18. Can modeling improve estimation of desert tortoise population densities?

    PubMed

    Nussear, Kenneth E; Tracy, C Richard

    2007-03-01

    The federally listed desert tortoise (Gopherus agassizii) is currently monitored using distance sampling to estimate population densities. Distance sampling, as with many other techniques for estimating population density, assumes that it is possible to quantify the proportion of animals available to be counted in any census. Because desert tortoises spend much of their life in burrows, and the proportion of tortoises in burrows at any time can be extremely variable, this assumption is difficult to meet. This proportion of animals available to be counted is used as a correction factor (g0) in distance sampling and has been estimated from daily censuses of small populations of tortoises (6-12 individuals). These censuses are costly and produce imprecise estimates of go due to small sample sizes. We used data on tortoise activity from a large (N = 150) experimental population to model activity as a function of the biophysical attributes of the environment, but these models did not improve the precision of estimates from the focal populations. Thus, to evaluate how much of the variance in tortoise activity is apparently not predictable, we assessed whether activity on any particular day can predict activity on subsequent days with essentially identical environmental conditions. Tortoise activity was only weakly correlated on consecutive days, indicating that behavior was not repeatable or consistent among days with similar physical environments.

  19. Reference intervals and physiologic alterations in hematologic and biochemical values of free-ranging desert tortoises in the Mojave Desert

    USGS Publications Warehouse

    Christopher, Mary M.; Berry, Kristin H.; Wallis, I.R.; Nagy, K.A.; Henen, B.T.; Peterson, C.C.

    1999-01-01

    Desert tortoise (Gopherus agassizii) populations have experienced precipitous declines resulting from the cumulative impact of habitat loss, and human and disease-related mortality. Evaluation of hematologic and biochemical responses of desert tortoises to physiologic and environmental factors can facilitate the assessment of stress and disease in tortoises and contribute to management decisions and population recovery. The goal of this study was to obtain and analyze clinical laboratory data from free-ranging desert tortoises at three sites in the Mojave Desert (California, USA) between October 1990 and October 1995, to establish reference intervals, and to develop guidelines for the interpretation of laboratory data under a variety of environmental and physiologic conditions. Body weight, carapace length, and venous blood samples for a complete blood count and clinical chemistry profile were obtained from 98 clinically healthy adult desert tortoises of both sexes at the Desert Tortoise Research Natural area (western Mojave), Goffs (eastern Mojave) and Ivanpah Valley (northeastern Mojave). Samples were obtained four times per year, in winter (February/March), spring (May/June), summer (July/August), and fall (October). Years of near-, above- and below-average rainfall were represented in the 5 yr period. Minimum, maximum and median values, and central 95 percentiles were used as reference intervals and measures of central tendency for tortoises at each site and/or season. Data were analyzed using repeated measures analysis of variance for significant (P < 0.01) variation on the basis of sex, site, season, and interactions between these variables. Significant sex differences were observed for packed cell volume, hemoglobin concentration, aspartate transaminase activity, and cholesterol, triglyceride, calcium, and phosphorus concentrations. Marked seasonal variation was observed in most parameters in conjunction with reproductive cycle, hibernation, or seasonal

  20. Gopherus agassizii (Desert Tortoise). Non-native seed dispersal

    USGS Publications Warehouse

    Ennen, J.R.; Loughran, Caleb L.; Lovich, Jeffrey E.

    2011-01-01

    Sahara Mustard (Brassica tournefortii) is a non-native, highly invasive weed species of southwestern U.S. deserts. Sahara Mustard is a hardy species, which flourishes under many conditions including drought and in both disturbed and undisturbed habitats (West and Nabhan 2002. In B. Tellman [ed.], Invasive Plants: Their Occurrence and Possible Impact on the Central Gulf Coast of Sonora and the Midriff Islands in the Sea of Cortes, pp. 91–111. University of Arizona Press, Tucson). Because of this species’ ability to thrive in these habitats, B. tournefortii has been able to propagate throughout the southwestern United States establishing itself in the Mojave and Sonoran Deserts in Arizona, California, Nevada, and Utah. Unfortunately, naturally disturbed areas created by native species, such as the Desert Tortoise (Gopherus agassizii), within these deserts could have facilitated the propagation of B. tournefortii. (Lovich 1998. In R. G. Westbrooks [ed.], Invasive Plants, Changing the Landscape of America: Fact Book, p. 77. Federal Interagency Committee for the Management of Noxious and Exotic Weeds [FICMNEW], Washington, DC). However, Desert Tortoises have never been directly observed dispersing Sahara Mustard seeds. Here we present observations of two Desert Tortoises dispersing Sahara Mustard seeds at the interface between the Mojave and Sonoran deserts in California.

  1. Gopherus Agassizii (Desert Tortoise). Predation/Mountain Lions (Pre-Print)

    SciTech Connect

    Paul D. Greger and Philip A. Medica

    2009-01-01

    During a long-term study on tortoise growth within 3 fenced 9-ha enclosures in Rock Valley, Nevada Test Site (NTS), Nye County, Nevada, USA, tortoises have been captured annually since 1964 (Medica et al. 1975. Copeia 1975:630-643; Turner et al. 1987. Copeia 1987:974-979). Between early August and mid October 2003 we observed a significant mortality event. The Rock Valley enclosures were constructed of 6 x 6 mm mesh 1.2 m wide hardware cloth, buried 0.3 m in the soil with deflective flashing on both sides on the top to restrict the movement of small mammals and lizards from entering or leaving the enclosures (Rundel and Gibson 1996, Ecological communities and process in a Mojave Desert ecosystem: Rock Valley, Nevada, Cambridge University Press, Great Britain. 369 pp.). On August 6, 2003, the carcass of an adult female Desert Tortoise No.1411 (carapace length 234 mm when alive) was collected while adult male tortoise No.4414 (carapace length 269 mm) was observed alive and in good health on the same day. Subsequently the carcass of No.4414 was found on October 16, 2003. Between October 16-17, 2003, the remains of 6 (5 adult and 1 juvenile) Desert Tortoises were found, some within each of the 3 enclosures in Rock Valley. A seventh adult tortoise was found on September 26, 2006, its death also attributed to the 2003 mortality event based upon the forensic evidence. Each of the 7 adult Desert Tortoises had the central portion of their carapace broken open approximately to the dorsal portion of the marginal scutes while the plastron was still intact (Figure 1A). Adjacent to 7 of the 8 remains we located numerous bone fragments including parts of the carapace and limbs as well as dried intestines in a nearby Range Rhatany (Krameria parvifolia) shrub. The significance of the frequent use of this shrub is puzzling. Three of the Desert Tortoise shell remains possessed distinctive intercanine punctures measuring 55-60 mm center to center indicating that this was an adult

  2. Desert tortoise (Gopherus agassizii) survival at two eastern Mojave Desert sites: Death by short-term drought?

    USGS Publications Warehouse

    Longshore, Kathleen; Jaeger, Jef R.; Sappington, J. Mark

    2003-01-01

    Survival of adult Desert Tortoises (Gopherus agassizii) appears related to site-specific variation in precipitation and productivity of annual plants. We studied adult tortoise survival rates at two closely situated, but physiographically different, sites in the eastern Mojave Desert over a nine-year period (spring 1992 to spring 2001). Survival rates were initially derived from population surveys conducted over a three-year period and by radio-telemetry monitoring over a seven-year period beginning in 1994. After a period of initial stability, survival rates on the two sites diverged over the study period, and seven-year survival rates estimated from radio-telemetry monitoring were 0.900 and 0.269, respectively. A die-off in 1996 on the latter site appears to have been triggered by a period of drought, which began in the summer of 1995, coupled with a failure of annual vegetation production in 1996. Depressed survival rates on this site were associated with drought conditions during three of four years. Although the decline had the appearance of an epizootic, there were no clinical signs of disease. Relatively short-term drought, combined with little or no annual biomass, appears to have caused severe reductions in tortoise survival. If periods of drought-induced low survival are common over relatively small areas, then source-sink population dynamics may be an important factor determining tortoise population densities.

  3. Spatial organization of desert tortoises and their burrows at a landscape scale

    USGS Publications Warehouse

    Duda, Jeffrey J.; Krzysik, Anthony J.; Meloche, Joel M.

    2001-01-01

    We thoroughly surveyed two 9 km 2 study plots using 624 km of transect lines in the south- central Mojave Desert, California, mapping with a precision global positioning system the location of desert tortoises (Gopherus agassizii) and their burrows. We found 98 desert tortoises and 1463 tortoise burrows. Three separate geospatial methods (quadrat-variance, nearest neighbor, and 3 geospatial functions) confirmed that active and total desert tortoise burrows were aggregated on the landscape at multiple spatial scales. Desert tortoises also displayed an aggregated pattern, although results were not consistent between the two plots. We also found a significant positive association between desert tortoises and their burrows using Type II linear regression and Ripley's K 12(t) function. A strong positive association between active burrows/km 2 and tortoises/km2 (r2 = 0.88) and between total burrows/km2 and tortoises/km2 (r2 = 0.80) and the supporting results of Ripley's K 12(t) geospatial function suggest that, within a given year and locality, desert tortoise burrows can be used to determine relative desert tortoise density patterns.

  4. Status of the desert tortoise in Red Rock Canyon State Park

    USGS Publications Warehouse

    Berry, Kristin H.; Keith, Kevin; Bailey, Tracy Y.

    2008-01-01

    We surveyed for desert tortoises, Gopherus agassizii, in the western part of Red Rock Canyon State Park and watershed in eastern Kern County, California, between 2002 and 2004. We used two techniques: a single demographic plot (~4 km2 ) and 37 landscape plots (1-ha each). We estimated population densities of tortoises to be between 2.7 and 3.57/km2 and the population in the Park to be 108 tortoises. We estimated the death rate at 67% for subadults and adults during the last 4 yrs. Mortality was high for several reasons: gunshot deaths, avian predation, mammalian predation, and probably disease. Historic and recent anthropogenic impacts from State Highway 14, secondary roads, trash, cross-country vehicle tracks, and livestock have contributed to elevated death rates and degradation of habitat. We propose conservation actions to reduce mortality.

  5. Seroepidemiology of upper respiratory tract disease in the desert tortoise of California

    USGS Publications Warehouse

    Brown, Mary B.; Berry, Kristin H.; Schumacher, Isabella M.; Nagy, Kenneth A.; Christopher, Mary M.; Klein, Paul A.

    1999-01-01

    Several factors have combined with an upper respiratory tract disease (URTD) to produce declines on some population numbers of desert tortoises (Gopherus agassizii) in the western USA. This study was designed to determine the seroepidemiology of URTD in a population of wild adult tortoises at the Desert Tortoise Research Natural Area (DTNA) study site in Kern County (California, USA). Prior to initiation of the study, there was a dramatic decline in the number of individuals in this population. At each individual time point, samples were obtained from 12 to 20 tortoises with radiotransmitters during winter, spring, summer, and fall from 1992 through 1995. During the course of the study, 35 animals were sampled at one or more times. Only 10 animals were available for consistent monitoring throughout the 4 yr period. Specific antibody (Ab) levels to Mycoplasma agassizii were determined for individual tortoises by an enzyme-linked immunosorbent assay (ELISA) test. Specific Ab levels were not influenced by the gender of the tortoise. Levels of Ab and distribution of ELISA+, ELISA– and suspect animals were not consistently affected by season within a single year or for a season among the study years. Significantly more tortoises presented with clinical signs in 1992 and 1995. The profile of ELISA+ animals with clinical signs shifted from 5% (1992) to 42% (1995). In 1992, 52% of tortoises lacked clinical signs and were ELISA–. In 1995, this category accounted for only 19% of tortoises. Based on the results of this study, we conclude that URTD was present in this population as evidenced by the presence of ELISA+ individual animals, and that the infectious agent is still present as evidenced by seroconversion of previously ELISA– animals during the course of the study. There is evidence to suggest that animals may remain ELISA+ without showing overt disease, a clinical pattern consistent with the chronic nature of most mycoplasmal infections. Further, there are

  6. A Pasteurella sp associated with respiratory disease in captive desert tortoises.

    PubMed

    Snipes, K P; Biberstein, E L; Fowler, M E

    1980-11-01

    Bacteria isolated from captive healthy desert tortoises were compared with bacteria from captive tortoises with respiratory illness and with bacteria from free-ranging tortoises from the Mojave Desert. Major differences were not observed among these groups when bacteria from the mouth, nares, trachea, lungs, and cloaca were compared. Frequently encountered organisms in all 3 groups included: coagulase-negative, catalase-positive, gram-positive cocci; Corynebacterium sp; members of Enterobacteriaceae, including Proteus spp; and a bacterium apparently belonging to the genus Pasteurella. The Pasteurella sp was consistently found to be associated with respiratory lesions in captive tortoises with signs of respiratory disease but was also found to be part of the gastrointestinal and nasal flora of healthy tortoises. It was hypothesized that respiratory disease in captive desert tortoises involves a commensal bacterium with the potential to be an opportunistic pathogen when the tortoise is stressed by a captive environment.

  7. Translocation as a conservation tool for Agassiz's desert tortoises: survivorship, reproduction, and movements

    USGS Publications Warehouse

    Nussear, K.E.; Tracy, C.R.; Medica, P.A.; Wilson, D.S.; Marlow, R.W.; Corn, P.S.

    2012-01-01

    We translocated 120 Agassiz's desert tortoises to 5 sites in Nevada and Utah to evaluate the effects of translocation on tortoise survivorship, reproduction, and habitat use. Translocation sites included several elevations, and extended to sites with vegetation assemblages not typically associated with desert tortoises in order to explore the possibility of moving animals to upper elevation areas. We measured survivorship, reproduction, and movements of translocated and resident animals at each site. Survivorship was not significantly different between translocated and resident animals within and among sites, and survivorship was greater overall during non-drought years. The number of eggs produced by tortoises was similar for translocated and resident females, but differed among sites. Animals translocated to atypical habitat generally moved until they reached vegetation communities more typical of desert tortoise habitat. Even within typical tortoise habitat, tortoises tended to move greater distances in the first year after translocation than did residents, but their movements in the second or third year after translocation were indistinguishable from those of resident tortoises. Our data show that tortoises translocated into typical Mojave desert scrub habitats perform well; however, the large first-year movements of translocated tortoises have important management implications. Projects that employ translocations must consider how much area will be needed to contain translocated tortoises and whether roads need fencing to prevent the loss of animals.

  8. Reducing predation by common ravens on desert tortoises in the Mojave and Colorado Deserts

    USGS Publications Warehouse

    Boarman, William I.

    2002-01-01

    intended to provide a basis for a long-term reduction in raven impacts. The recommendations fall into four basic categories. (1) Modify anthropogenic sources of food, water, and nesting substrates to reduce their use by ravens. This includes modifying landfill operations, septage containment practices, livestock management, and other commercial and private practices that help facilitate raven survival and dispersal by providing food and water. Most of these measures are long-term actions deigned to reduce the carrying capacity of the desert for ravens. This action is critical and must be done over very large areas. (2)Lethal removal of ravens by shooting or euthanizing following live trapping. Specific ravens known to prey on tortoises would be targeted as well as all ravens found foraging within specific high-priority desert tortoise management zones (e.g., Desert Tortoise Natural Areas, DTNA). These actions would primarily be deployed on a short-term emergency basis to give specific tortoise populations a necessary boost until other measures become fully implemented and achieve their goals. (3) Conduct research on raven ecology, raven behavior, and methods to reduce raven predation on tortoises. Results of these studies would be used to design future phases of the raven management program. (4) All actions should be approached within an adaptive management framework. As such monitor, actions should be designed as experiments so that monitoring of actions will yield reliable and scientifically sound results. Coordinating and oversight teams should be convened to facilitate cooperation and coordination among agencies and to ensure that the actions are being implemented effectively. Recommendations made herein were developed to help recover tortoise populations by reducing raven predation on juvenile tortoises. If the recommendations made are implemented in concert with actions reducing other causes of mortality, ill health, and lowered reproductive output, they

  9. Habitat drives dispersal and survival of translocated juvenile desert tortoises

    USGS Publications Warehouse

    Nafus, Melia G.; Esque, Todd; Averill-Murray, Roy C.; Nussear, Kenneth E.; Swaisgood, Ronald R.

    2017-01-01

    5.Synthesis and applications. Resource managers using translocations as a conservation tool should prioritize acquiring data linking habitat to fitness. In particular, for species that depend on avoiding detection, refuges such as burrows and habitat that improved concealment had notable ability to improve survival and dispersal. Our study on juvenile Mojave desert tortoises showed that refuge availability or the distributions of habitat appropriate for concealment are important considerations for identifying translocation sites for species highly dependent on crypsis, camouflage, or other forms of habitat matching.

  10. Effects of climatic variation on field metabolism and water relations of desert tortoises

    USGS Publications Warehouse

    Henen, B.T.; Peterson, C.C.; Wallis, I.R.; Berry, K.H.; Nagy, K.A.

    1998-01-01

    We used the doubly labeled water method to measure the field metabolic rates (FMRs, in kJ kg-1 day-1) and water flux rates (WIRs, in ml H2O kg-1 day-1) of adult desert tortoises (Gopherus agassizii) in three parts of the Mojave Desert in California over a 3.5-year period, in order to develop insights into the physiological responses of this threatened species to climate variation among sites and years. FMR, WIR, and the water economy index (WEI, in ml H2O kJ-1, an indicator of drinking of free water) differed extensively among seasons, among study sites, between sexes, and among years. In high-rainfall years, males had higher FMRs than females. Average daily rates of energy and water use by desert tortoises were extraordinarily variable: 28-fold differences in FMR and 237-fold differences in WIR were measured. Some of this variation was due to seasonal conditions, with rates being low during cold winter months and higher in the warm seasons. However, much of the variation was due to responses to year-to-year variation in rainfall. Annual spring peaks in FMR and WIR were higher in wet years than in drought years. Site differences in seasonal patterns were apparently due to geographic differences in rainfall patterns (more summer rain at eastern Mojave sites). In spring 1992, during an El Nino (ENSO) event, the WEI was greater than the maximal value obtainable from consuming succulent vegetation, indicating copious drinking of rainwater at that time. The physiological and behavioral flexibility of desert tortoises, evident in individuals living at all three study sites, appears central to their ability to survive droughts and benefit from periods of resource abundance. The strong effects of the El Nino (ENSO) weather pattern on tortoise physiology, reproduction, and survival elucidated in this and other studies suggest that local manifestations of global climate events could have a long-term influence on the tortoise populations in the Mojave Desert.

  11. Effects of climatic variation on field metabolism and water relations of desert tortoises.

    PubMed

    Henen, Brian T; Peterson, Charles C; Wallis, Ian R; Berry, Kristin H; Nagy, Kenneth A

    1998-12-01

    We used the doubly labeled water method to measure the field metabolic rates (FMRs, in kJ kg(-1 )day(-1)) and water flux rates (WIRs, in ml H2O kg(-1 )day(-1)) of adult desert tortoises (Gopherus agassizii) in three parts of the Mojave Desert in California over a 3.5-year period, in order to develop insights into the physiological responses of this threatened species to climate variation among sites and years. FMR, WIR, and the water economy index (WEI, in ml H2O kJ(-1), an indicator of drinking of free water) differed extensively among seasons, among study sites, between sexes, and among years. In high-rainfall years, males had higher FMRs than females. Average daily rates of energy and water use by desert tortoises were extraordinarily variable: 28-fold differences in FMR and 237-fold differences in WIR were measured. Some of this variation was due to seasonal conditions, with rates being low during cold winter months and higher in the warm seasons. However, much of the variation was due to responses to year-to-year variation in rainfall. Annual spring peaks in FMR and WIR were higher in wet years than in drought years. Site differences in seasonal patterns were apparently due to geographic differences in rainfall patterns (more summer rain at eastern Mojave sites). In spring 1992, during an El Niño (ENSO) event, the WEI was greater than the maximal value obtainable from consuming succulent vegetation, indicating copious drinking of rainwater at that time. The physiological and behavioral flexibility of desert tortoises, evident in individuals living at all three study sites, appears central to their ability to survive droughts and benefit from periods of resource abundance. The strong effects of the El Niño (ENSO) weather pattern on tortoise physiology, reproduction, and survival elucidated in this and other studies suggest that local manifestations of global climate events could have a long-term influence on the tortoise populations in the Mojave

  12. PCR primers for microsatellite loci in the desert tortoise (Gopherus agassizii, Testudinidae)

    USGS Publications Warehouse

    Edwards, T.; Goldberg, C.S.; Kaplan, M.E.; Schwalbe, C.R.; Swann, D.E.

    2003-01-01

    The desert tortoise, Gopherus agassizii, is a threatened species native to the North American desert southwest and is recognized as having distinct Mojave and Sonoran populations. We identified six polymorphic microsatellite loci in the desert tortoise. All six loci were polymorphic in Sonoran samples. Five of the loci were variable in Mojave samples with varying degrees of amplification success. Two of the loci exhibited low allelic variation (2-3 alleles) while four were highly variable (8-27 alleles).

  13. Validation and Development of a Certification Program for Using K9s to Survey Desert Tortoises

    DTIC Science & Technology

    2011-08-01

    calibrated and motivated as it works. Because of the cryptic nature of desert tortoises in combination with being particularly vulnerable to being...hatchling and juvenile tortoises where nests recently hatched or in the vicinity of numerous females of reproductive age. DTK9 teams would be useful to...locate tortoises for studies involving health assessments, genetic surveys, and identifying gravid females , among others. They may be fielded in

  14. The northern boundary of the desert tortoise range on the Nevada Test Site

    SciTech Connect

    Rautenstrauch, K.R.; Brown, G.A.; Goodwin, R.G.

    1994-12-01

    A study was conducted in 1993 to more accurately define the northern boundary of the range of desert tortoises (Gopherus agassizii) on the Nevada Test Site. Eighty-six transects totaling 338.2 km were walked along this boundary and 53 tortoise signs were recorded. Tortoise signs were found all along the northern edge of Jackass and Frenchman flats. Signs were found north of those valleys only in the Calico Hills at the south end of Topopah Valley and in the CP Hills at the extreme southern end of Yucca Flat. A revised map of the range of desert tortoises on NTS is presented. This information can be used by the US Department of Energy to determine whether activities conducted along or near this boundary will affect desert tortoises.

  15. Management and research of desert tortoises for the Yucca Mountain Project

    SciTech Connect

    Rautenstrauch, K.R.; Cox, M.K.; Doerr, T.B.; Green, R.A.; Mueller, J.M.; O`Farrell, T.P.; Rakestraw, D.L.

    1991-04-01

    A program has been developed for the Yucca Mountain Project (YMP) to manage and study the desert tortoise (Gopherus agassizi), a threatened species that occurs at low densities at Yucca Mountain. The goals of this program are to better understand the biology and status of the desert tortoise population at Yucca Mountain, assess impacts on tortoises of site characterization (SC) activities, and minimize those impacts. The first steps we took to develop this program were to compile the available information on tortoise biology at Yucca Mountain, ascertain what information was lacking, and identify the potential impacts on tortoises of SC. We then developed a technical design for identifying and mitigating direct and cumulative impacts and providing information on tortoise biology. Interrelated studies were developed to achieve these objectives. The primary sampling unit for the impact monitoring studies is radiomarked tortoises. Three populations of tortoises will be sampled: individuals isolated from disturbances (control), individuals near major SC activities (direct effects treatment and worst-case cumulative effects treatment), and individuals from throughout Yucca Mountain (cumulative effects treatment). Impacts will be studied by measuring and comparing survival, reproduction, movements, habitat use, health, and diet of these tortoises. A habitat quality model also will be developed and the efficacy of mitigation techniques, such as relocating tortoises, will be evaluated. 29 refs.

  16. Management and research of desert tortoises for the Yucca Mountain Project

    SciTech Connect

    Rautenstrauch, K.R.; Cox, M.K.; Doerr, T.B.; Green, R.A.; Mueller, J.M.; O`Farrell, T.P.; Rakestraw, D.L.

    1991-12-31

    A program has been developed for the Yucca Mountain Project (YMP) to manage and study the desert tortoise (Gopherus agassizi), a threatened species that occurs at low densities at Yucca Mountain. The goals of this program are to better understand the biology and status of the desert tortoise population at Yucca Mountain, assess impacts on tortoises of site characterization (SC) activities, and minimize those impacts. The first steps we took to develop this program were to compile the available information on the biology of tortoises at Yucca Mountain, ascertain what information was lacking, and identify the potential impacts on tortoises of SC. We then developed a technical design that can be used to identify and mitigate direct and cumulative impacts and provide information on tortoise biology. Interrelated studies were developed to achieve these objectives. The primary sampling unit for the impact monitoring studies is radiomarked tortoises. Three populations of tortoises will be sampled: Individuals isolated from disturbances (control), individuals near major SC activities (direct effects treatment and worst-case cumulative effects treatment), and individuals from throughout Yucca Mountain (cumulative effects treatment). Impacts will be studied by measuring and comparing survival, reproduction, movements, habitat use, health, and diet of these tortoises. A habitat quality model also will be developed and the efficacy of mitigation techniques, such as relocating tortoises, will be evaluated.

  17. Assessing age in the desert tortoise Gopherus agassizii: Testing skeletochronology with individuals of known age

    USGS Publications Warehouse

    Curtin, A.J.; Zug, G.R.; Medica, P.A.; Spotila, J.R.

    2008-01-01

    Eight desert tortoises Gopherus agassizii from a long-term mark-recapture study in the Mojave Desert, Nevada, USA, afforded an opportunity to examine the accuracy of skeletochronological age estimation on tortoises from a seasonal, yet environmentally erratic environment. These 8 tortoises were marked as hatchlings or within the first 2 yr of life, and their carcasses were salvaged from predator kills. Using d blind protocol, 2 skeletochronological protocols (correction-factor and ranking) provided age estimates for a set of 4 bony elements (humerus, scapula, femur, ilium) from these tortoises of known age. The age at death of the tortoises ranged from 15 to 50 yr. The most accurate protocol - ranking using the growth layers within each of the 4 elements - provided estimates from 21 to 47 yr, with the highest accuracy from the ilia. The results indicate that skeletochronological age estimation provides a reasonably accurate method for assessing the age at death of desert tortoises and, if used with a large sample of individuals, will provide a valuable tool for examining age-related mortality parameters in desert tortoise and likely in other gopher tortoises (Gopherus). ?? Inter-Research 2008.

  18. Evaluation of evidence supporting the effectiveness of desert tortoise recovery actions

    USGS Publications Warehouse

    Boarman, William I.; Kristan, William B.

    2006-01-01

    As a federally threatened species, the desert tortoise's (Gopherus agassizii) recovery is required under the Endangered Species Act (ESA). According to the criteria established by the Desert Tortoise Recovery Plan (U.S. Fish and Wildlife Service 1994) for delisting the tortoise from ESA protection, the species as a whole will be considered recovered when tortoises have exhibited a statistically significant upward trend for at least one tortoise generation (25 years), enough habitat is protected to allow persistence, provisions are in place to maintain discrete population growth rates at or above 1.0, regulatory measures are in place to ensure continued management of tortoise habitat, and there is no longer reason to believe that the species will require ESA protection in the future. Just as species extinction can be thought of as the cumulative extinction of all populations, species recovery can be thought of as recovery of constituent populations; management efforts for recovery generally are implemented and assessed at the population level. A recent review of the Desert Tortoise Recovery Plan, including an exhaustive literature search, has been compiled by the Desert Tortoise Recovery Plan Assessment Committee (Tracy et al. 2004).

  19. Effects of subsidized predators, resource variability, and human population density on desert tortoise populations in the Mojave Desert, USA

    USGS Publications Warehouse

    Esque, Todd C.; Nussear, Kenneth E.; Drake, K. Kristina; Walde, Andrew D.; Berry, Kristin H.; Averill-Murray, Roy C.; Woodman, A. Peter; Boarman, William I.; Medica, Phil A.; Mack, Jeremy S.; Heaton, Jill S.

    2010-01-01

    Understanding predator–prey relationships can be pivotal in the conservation of species. For 2 decades, desert tortoise Gopherus agassizii populations have declined, yet quantitative evidence regarding the causes of declines is scarce. In 2005, Ft. Irwin National Training Center, California, USA, implemented a translocation project including 2 yr of baseline monitoring of desert tortoises. Unusually high predation on tortoises was observed after translocation occurred. We conducted a retrospective analysis of predation and found that translocation did not affect the probability of predation: translocated, resident, and control tortoises all had similar levels of predation. However, predation rates were higher near human population concentrations, at lower elevation sites, and for smaller tortoises and females. Furthermore, high mortality rates were not limited to the National Training Center. In 2008, elevated mortality (as high as 43%) occurred throughout the listed range of the desert tortoise. Although no temporal prey base data are available for analysis from any of the study sites, we hypothesize that low population levels of typical coyote Canis latrans prey (i.e. jackrabbits Lepus californicus and other small animals) due to drought conditions influenced high predation rates in previous years. Predation may have been exacerbated in areas with high levels of subsidized predators. Many historical reports of increased predation, and our observation of a range-wide pattern, may indicate that high predation rates are more common than generally considered and may impact recovery of the desert tortoise throughout its range.

  20. The distribution and abundance of desert tortoises on the Nevada Test Site

    SciTech Connect

    Not Available

    1991-01-01

    This report presents the results of transect studies conducted from 1981--1986 to determine the distribution and abundance of desert tortoises (Gopherus agassizii) on the Nevada Test Site (NTS) and summarizes the current understanding of the distribution of this species on NTS. Seven hundred fifty-nine transect having a total length of 1,190.7 km were walked and 380 sign of tortoises were counted. The abundance of tortoises on NTS is low to very low relative to the other areas within this species' range. Tortoises appear to be more abundant on NTS on the bajadas and foothills of limestone and dolomite mountains than on mountains of volcanic origin. Sign of tortoises were found were 880 to 1600 m and sign was more abundant at higher elevations (>1200 m) than has been reported previously for Nevada. The scale of classification of vegetation associations available for NTS is too large to be useful for predicting tortoise abundance. Tortoises were found only in approximately the southern third of NTS. They probably do not occur in Yucca Flat or anywhere else north of the Control Point. A map of the northern boundary of the range of desert tortoises on NTS is presented and additional studies of the distribution and abundance of tortoises on NTS are recommended. 30 refs., 9 figs., 4 tabs.

  1. Comparison of intraosseous and peripheral venous fluid dynamics in the desert tortoise (Gopherus agassizii).

    PubMed

    Young, Benjamin D; Stegeman, Nadia; Norby, Bo; Heatley, J Jill

    2012-03-01

    The efficacy of intraosseous catheterization has not been described previously in the desert tortoise (Gopherus agassizii). The goal of this study was to describe and compare the efficacy of four intraosseous catheter sites (humerus, femur, plastocarapacial junction [bridge], and gular region of the plastron) to jugular catheterization. Five adult tortoises were catheterized in each of the sites at least once. The distribution of a bolus injection of radiopharmaceutical (technetium-99m-diethylenetriaminepentaacidic acid [99mTc -DTPA]) was monitored via gamma camera over 2-min periods at five time intervals over 24 min. Compared to jugular catheterization, the humerus and femur sites provided the next best vascular access, with 84.4 and 61.8% of activity reaching the systemic circulation by 7 min, respectively. The bridge and gular catheter sites were less effective with only 41.9 and 40.8% systemic activity, respectively. Intraosseous catheters were no more technically difficult to place than jugular catheters and were less commonly dislodged, making them a viable option for vascular access in tortoises.

  2. The relative abundance of desert tortoises on the Nevada Test Site within ecological landform units

    SciTech Connect

    Woodward, R.; Rautenstrauch, K.R.; Hall, D.B.; Ostler, W.K.

    1998-09-01

    Sign-survey transects were sampled in 1996 to better determine the relative abundance of desert tortoises on the Nevada Test Site (NTS). These transects were sampled within ecological land-form units (ELUs), which are small, ecologically homogeneous units of land. Two-hundred and six ELUs were sampled by walking 332 transects totaling 889 kilometers (km). These ELUs covered 528 km{sup 2}. Two-hundred and eight-one sign were counted. An average of 0.32 sign was found per km walked. Seventy percent of the area sampled had a very low abundance of tortoises, 29% had a low abundance, and 1% had a moderate abundance. A revised map of the relative abundance of desert tortoise on the NTS is presented. Within the 1,330 km{sup 2} of desert tortoise habitat on the NTS, 49% is classified as having no tortoises or a very low abundance, 18% has a low or moderate abundance, 12% is unclassified land being used by the Yucca Mountain Site Characterization Project, and the remaining 21% still has an unknown abundance of desert tortoises. Based on the results of this work, the amount of tortoise habitat previously classified as having an unknown or low-moderate abundance, and on which clearance surveys and on-site monitoring was required, has been reduced by 20%.

  3. The Relative Abundance of Desert Tortoises on the Nevada Test Site within Ecological Landform Units

    SciTech Connect

    Woodward, Roy; Rautenstrauch, Kurt R.; Hall, Derek B.; Ostler, W. Kent

    1998-09-01

    Sign-survey transects were sampled in 1996 to better determine the relative abundance of desert tortoises on the Nevada Test Site (NTS). These transects were sampled within ecological land-form units (ELUs), which are small, ecologically homogeneous units of land. Two-hundred and six ELUs were sampled by walking 332 transects totaling 889 kilometers (km) (552 miles [mi]). These ELUs covered 528 km{sup 2} (204 mi{sup 2}). Two-hundred and eighty-one sign were counted. An average of 0.32 sign was found per km walked. Seventy percent of the area sampled had a very low abundance of tortoises, 29 percent had a low abundance, and 1 percent had a moderate abundance. A revised map of the relative abundance of desert tortoise on the NTS is presented. Within the 1,330 km{sup 2} (514 mi{sup 2}) of desert tortoise habitat on the NTS, 49 percent is classified as having no tortoises or a very low abundance, 18 percent has a low or moderate abundance, 12 percent is unclassified land being used by the Yucca Mountain Site Characterization Project, and the remaining 21 percent still has an unknown abundance of desert tortoises. Based on the results of this work, the amount of tortoise habitat previously classified as having an unknown or low-moderate abundance, and on which clearance surveys and on-site monitoring was required, has been reduced by 20 percent.

  4. Distance to human populations influences epidemiology of respiratory disease in desert tortoises

    USGS Publications Warehouse

    Berry, Kristin H.; Ashley A. Coble (formerly Emerson), no longer USGS; Yee, Julie L.; Mack, Jeremy S.; Perry, William M.; Anderson, Kemp M.; Brown, Mary B.

    2014-01-01

    We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if they were positive by culture and/or DNA identification or positive or suspect for specific antibody for either of the two pathogens. We used covariates of habitat (vegetation, elevation, slope, and aspect), tortoise size and sex, distance from another test-positive tortoise, and anthropogenic variables (distances to roads, agricultural areas, playas, urban areas, and centroids of human-populated census blocks). We used both logistic regression models and regression trees to evaluate the 2 species of Mycoplasma separately. The prevalence of test-positive tortoises was low: 1.49% (15/1,004) for M. agassizii and 2.89% (29/1,004) for M. testudineum. The spatial distributions of test-positive tortoises for the 2 Mycoplasma species showed little overlap; only 2 tortoises were test-positive for both diseases. However, the spatial distributions did not differ statistically between the 2 species. We consistently found higher prevalence of test-positive tortoises with shorter distances to centroids of human-populated census blocks. The relationship between distance to human-populated census blocks and tortoises that are test-positive for M. agassizii and potentially M. testudineum may be related to release or escape of captive tortoises because the prevalence of M. agassizii in captive tortoises is high. Our findings have application to other species of chelonians where both domestic captive and wild populations exist. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  5. Return to the wild: Translocation as a tool in conservation of the desert tortoise (Gopherus agassizii)

    USGS Publications Warehouse

    Field, K.J.; Tracy, C.R.; Medica, P.A.; Marlow, R.W.; Corn, P.S.

    2007-01-01

    Translocation could be used as a tool in conservation of the threatened Mojave Desert Tortoise (Gopherus agassizii) by moving individuals from harm's way and into areas where they could contribute to conservation of the species. Numerous factors may affect the success of translocations, including the conditions experienced by tortoises in holding facilities while awaiting translocation. The tortoises available for our translocation study had been provided supplemental water during their years spent in a captive holding facility, potentially inducing carelessness in water conservation. In addition to generally investigating the efficacy of translocation, we compared the effects of continuing with the effects of ceasing the holding facility's water supplementation regimen. After exposure to one of the two water regimens, all tortoises were given the opportunity to hydrate immediately prior to release. We examined behavior, body mass, carapace length, movement, and mortality of tortoises for two activity seasons following release to the wild. Water supplementation was correlated with high rates of carapace growth and distant movements by males after release. Lengthy movements following translocation may be problematic for conservation planning, but this should be evaluated in light of the goals and circumstances of each translocation project. Although the mortality rate was 21.4% in 1997, data suggest that drought conditions at the site rather than the translocation itself negatively affected the tortoises. None of the tortoises died during their second season at the site. Our results indicate that translocation should be considered a useful tool in conservation of the Desert Tortoise.

  6. Long-term growth of Desert Tortoises (Gopherus agassizii) in a southern Nevada population

    USGS Publications Warehouse

    Medica, P.A.; Nussear, Kenneth E.; Esque, Todd C.; Saethre, Mary B.

    2012-01-01

    Knowledge of growth rates, age at maturity, and longevity are important aspects of a species life history and are directly applicable to life table creation and population viability analyses. We measured the growth of a cohort of 17 semi-wild Desert Tortoises (Gopherus agassizii) located in Rock Valley, Nevada over a 47-yr period beginning in 1963. The tortoises were initially marked as hatchling and juvenile animals between the years 1963 and 1965 and ranged in size from 47 to 77 mm in plastron length. We assigned ages of 1-4 yr to the tortoises at initial capture based on their body size. These tortoises were recaptured, measured, and weighed approximately annually since their initial capture. Growth of male and female tortoises did not differ significantly until animals reached the age of 23-25 yr. Annual tortoise growth was correlated with the production of ephemeral vegetation, while accounting for size, sex, and repeated measurements of the animals as well as the interval between measurements. However, the production of ephemeral plants was likewise highly correlated (non-linearly) with winter rainfall. Stochastic predation events between 2003 and 2007 decimated this cohort of tortoises. The average age of the long-term surviving tortoises from this cohort was 43 yr with a range of 39-47 yr. Twelve of the tortoises survived to the age of 39 yr and 11 of the 12 reached 40 yr.

  7. Soluble scute proteins of healthy and ill desert tortoises (Gopherus agassizii)

    USGS Publications Warehouse

    Homer, B.L.; Li, C.; Berry, K.H.; Denslow, N.D.; Jacobson, E.R.; Sawyer, R.H.; Williams, J.E.

    2001-01-01

    Objectives - To characterize protein composition of shell scute of desert tortoises and to determine whether detectable differences could be used to identify healthy tortoises from tortoises with certain illnesses. Animals - 20 desert tortoises. Procedures - Complete postmortem examinations were performed on all tortoises. Plastron scute proteins were solubilized, scute proteins were separated by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and proteins were analyzed, using densitometry. Two-dimensional immobilized pH gradient-PAGE (2D IPG-PAGE) and immunoblot analysis, using polyclonal antisera to chicken-feather ?? keratin and to alligator-scale ?? keratin, were conducted on representative samples. The 14-kd proteins were analyzed for amino acid composition. Results - The SDS-PAGE and densitometry revealed 7 distinct bands, each with a mean relative protein concentration of > 1 %, ranging from 8 to 47 kd, and a major protein component of approximately 14 kd that constituted up to 75% of the scute protein. The 2D IPG-PAGE revealed additional distinct 62-and 68-kd protein bands. On immunoblot analysis, the 14-, 32-, and 45-kd proteins reacted with both antisera. The 14-kd proteins had an amino acid composition similar to that of chicken ?? keratins. There was a substantial difference in the percentage of the major 14-kd proteins from scute of ill tortoises with normal appearing shells, compared with 14-kd proteins of healthy tortoises. Conclusions and Clinical Relevance - The major protein components of shell scute of desert tortoises have amino acid composition and antigenic features of ?? keratins. Scute protein composition may be altered in tortoises with certain systemic illnesses.

  8. The effect of research activities and winter precipitation on voiding behaviour of Agassiz’s desert tortoises (Gopherus agassizii)

    USGS Publications Warehouse

    Agha, Mickey; Murphy, Mason O.; Lovich, Jeffrey E.; Ennen, Joshua R.; Oldham, Christian R.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Austin, Meaghan; Madrak, Sheila V.; Loughran, Caleb L.; Tennant, Laura A.; Price, Steven J.

    2015-01-01

    Implications: This study has demonstrated that common handling practices on desert tortoise may cause voiding behaviour. These results suggest that in order to minimise undesirable behavioural responses in studied desert tortoise populations, defined procedures or protocols must be followed by the investigators to reduce contact period to the extent feasible.

  9. Gopherus agassizii (Agassiz’s desert tortoise). scute dysecdysis/scute sloughing

    USGS Publications Warehouse

    Nussear, Kenneth E.; Drake, Karla K.; Medica, Phil A.; Esque, Todd C.

    2012-01-01

    Desert tortoises with scute injuries due to fire or disease related processes can result in loss of the scute. These animals appear to function normally, and can replace the scute material with a keratinized layer that covers the bone. This paper describes a tortoise with severe scute loss from a wildfire in 2005, and an animal that lost its scute for unknown reasons. Both animals appeared to be healthy in all other aspects, and lived for many years afterward.

  10. Reproductive effort and reproductive nutrition of female desert tortoises: essential field methods.

    PubMed

    Henen, Brian Thomas

    2002-02-01

    I used three innovative, nondestructive field methods (gas dilution, doubly labeled water and radiography) to measure individual energy and water budgets of wild, female desert tortoises (Gopherus agassizii). With these budgets, I evaluated whether body reserves help females produce eggs independent of rainfall and food availability. Female desert tortoises used large seasonal and annual changes in metabolism and body water, protein and energy reserves to survive and produce eggs. Although lipid reserves are important to female desert tortoises, nitrogen or crude protein appears to be the primary limiting resource for producing eggs. By reducing metabolic rates 90%, females conserved enough body reserves to produce eggs during extreme drought conditions; this is an effective bet-hedging reproductive pattern in an extreme and unpredictable environment.

  11. Managing a subsidized predator population: Reducing common raven predation on desert tortoises

    USGS Publications Warehouse

    Boarman, W.I.

    2003-01-01

    Human communities often are an inadvertent source of food, water, and other resources to native species of wildlife. Because these resources are more stable and predictable than those in a natural environment, animals that subsist on them are able to increase in numbers and expand their range, much to the detriment of their competitors and species they prey upon. In the Mojave Desert, common ravens (Corvus corax) have benefited from human-provided resources to increase in population size precipitously in recent years. This trend has caused concern because ravens prey on juvenile desert tortoises (Gopherus agassizii), a federally threatened species. In this paper, I discuss management strategies to reduce raven predation on desert tortoises. The recommendations fall into three categories: (1) managing raven populations by reducing access to anthropogenic resources; (2) removing offending ravens or other birds in specially targeted tortoise management zones; and (3) continuing research on raven ecology, raven behavior, and methods of reducing raven predation on tortoises. I also recommend approaching the problem within an adaptive management framework: management efforts should first be employed as scientific experiments - with replicates and controls - to yield an unbiased assessment of their effectiveness. Furthermore, these strategies should be implemented in concert with actions that reduce other causes of desert tortoise mortality to aid the long-term recovery of their populations. Overall, the approaches outlined in this paper are widely applicable to the management of subsidized predators, particularly where they present a threat to a declining species of prey.

  12. Biogeographic perspective of speciation among desert tortoises in the genus Gopherus: a preliminary evaluation

    USGS Publications Warehouse

    Edwards, Taylor; Vaughn, Mercy; Meléndez Torres, Cristina; Karl, Alice E.; Rosen, Philip C.; Berry, Kristin H.; Murph, Robert W.

    2013-01-01

    The enduring processes of time, climate, and adaptation have sculpted the distribution of organisms we observe in the Sonoran Desert. One such organism is Morafka’s desert tortoise, Gopherus morafkai. We apply a genomic approach to identify the evolutionary processes driving diversity in this species and present preliminary findings and emerging hypotheses. The Sonoran Desert form of the tortoise exhibits a continuum of genetic similarity spanning 850 km of Sonoran desertscrub extending from Empalme, Sonora, to Kingman, Arizona. However, at the ecotone between desertscrub and foothills thornscrub we identify a distinct, Sinaloan lineage and this occurrence suggests a more complex evolutionary history for G. morafkai. By using multiple loci from throughout the tortoise’s genome, we aim to determine if divergence between these lineages occurred in allopatry, and further to investigate for signatures of past or current genetic introgression. This international, collaborative project will assist state and federal agencies in developing management strategies that best preserve the evolutionary potential of Morafka’s desert tortoise. Ultimately, an understanding of the evolutionary history of desert tortoises will not only clarify the forces that have driven the divergence in this group, but also contribute to our knowledge of the biogeographic history of the Southwestern deserts and how diversity is maintained within them.

  13. Sex differences in plasma corticosterone in desert tortoises, Gopherus agassizii, during the reproductive cycle.

    PubMed

    Lance, V A; Grumbles, J S; Rostal, D C

    2001-04-15

    Blood samples from 30 female and 20 male adult desert tortoises, Gopherus agassizii, were collected at monthly intervals during the annual reproductive cycle (April to October). Plasma corticosterone and the sex steroids in each of the samples were analyzed by radioimmunoassay. Mean corticosterone levels in males were significantly higher than in females (P < 0.001) in every month. Male tortoises showed a marked seasonal pattern in plasma corticosterone with a highly significant peak in July, August, September, and October that corresponded with a similar peak in plasma testosterone. Testosterone and corticosterone in the male showed a highly significant correlation (P < 0.0001). The pattern of corticosterone in the female was less marked, with a significant peak in May during the mating and nesting season, but no association with the peak in estradiol in late summer was apparent. The highest levels of corticosterone in the males were associated with the peak in spermatogenesis and intense male-male combat. These results support similar data from other reptiles that suggest increased glucocorticoid secretion during periods of increased activity and metabolism.

  14. Ecological energetics of the desert tortoise (Gopherus Agassizii): Effects of rainfall and drought

    SciTech Connect

    Peterson, C.C.

    1996-09-01

    To elucidate ecological effects of variation in the temporal distribution of a limiting resource (water in the Mojave Desert), energetics of two free-living populations of desert tortoises (Gopherus [=Xerobates] agassizii) were studied concurrently over 18 mo with use of doubly-labeled water. Field metabolic rates (FMR) and feeding rates were highly variable. This variability was manifested at several levels, including seasonal changes within populations, year-to-year differences within populations, and differences between populations. Underlying observed patterns and contrasts was considerable variation among individuals. Much of the variation in energetic variables was associated with a single climatic variable, rainfall. Seasonal, annual, and interpopulation differences in FMR and foraging rates corresponded to differences in availability of free-standing water from rainstorms. Some differences among individuals were apparently due to differences in proclivity or ability to drink. Tortoises had very low FMRs relative to other reptiles, allowed them to tolerate long periods of chronic energy shortage during a drought. Calculations suggested that tortoises experienced a net loss of energy shortage during a drought and tortoises experienced a net loss of energy on their spring diet of succulent annual plants. If so, tortoises require drier forage to accrue an energy profit, emphasizing reliance on drinking rainwater. Further, it suggests that growth (as protein deposition) and net acquisition of energy may be temporally decoupled in desert tortoises, with potential consequences for geographic variation in life history. Energy acquisition and expenditure in desert tortoises are strongly constrained by the contingencies of rainfall, both indirectly through effects on availability and quality of food, and directly through reliance on free-standing water for drinking, which is apparently necessary for achieving a net annual energy profit. 61 refs., 5 figs., 5 tabs.

  15. Long-term post-fire effects on spatial ecology and reproductive output of female Agassiz’s desert tortoises (Gopherus agassizii) at a wind energy facility near Palm Springs, California, USA

    USGS Publications Warehouse

    Lovich, Jeffrey E.; Ennen, Joshua R.; Madrak, Sheila V.; Loughran, Caleb L.; Meyer, Katherin P.; Arundel, Terence R.; Bjurlin, Curtis D.

    2011-01-01

    We studied the long-term response of a cohort of eight female Agassiz’s desert tortoises (Gopherus agassizii) during the first 15 years following a large fire at a wind energy generation facility near Palm Springs, California, USA. The fire burned a significant portion of the study site in 1995. Tortoise activity areas were mapped using minimum convex polygons for a proximate post-fire interval from 1997 to 2000, and a long-term post-fire interval from 2009 to 2010. In addition, we measured the annual reproductive output of eggs each year and monitored the body condition of tortoises over time. One adult female tortoise was killed by the fire and five tortoises bore exposure scars that were not fatal. Despite predictions that tortoises would make the short-distance movements from burned to nearby unburned habitats, most activity areas and their centroids remained in burned areas for the duration of the study. The percentage of activity area burned did not differ significantly between the two monitoring periods. Annual reproductive output and measures of body condition remained statistically similar throughout the monitoring period. Despite changes in plant composition, conditions at this site appeared to be suitable for survival of tortoises following a major fire. High productivity at the site may have buffered tortoises from the adverse impacts of fire if they were not killed outright. Tortoise populations at less productive desert sites may not have adequate resources to sustain normal activity areas, reproductive output, and body conditions following fire.

  16. The desert tortoise trichotomy: Mexico hosts a third, new sister-species of tortoise in the Gopherus morafkai-G. agassizii group.

    PubMed

    Edwards, Taylor; Karl, Alice E; Vaughn, Mercy; Rosen, Philip C; Torres, Cristina Meléndez; Murphy, Robert W

    2016-01-01

    Desert tortoises (Testudines; Testudinidae; Gopherus agassizii group) have an extensive distribution throughout the Mojave, Colorado, and Sonoran desert regions. Not surprisingly, they exhibit a tremendous amount of ecological, behavioral, morphological and genetic variation. Gopherus agassizii was considered a single species for almost 150 years but recently the species was split into the nominate form and Morafka's desert tortoise, Gopherus morafkai, the latter occurring south and east of the Colorado River. Whereas a large body of literature focuses on tortoises in the United States, a dearth of investigations exists for Mexican animals. Notwithstanding, Mexican populations of desert tortoises in the southern part of the range of Gopherus morafkai are distinct, particularly where the tortoises occur in tropical thornscrub and tropical deciduous forest. Recent studies have shed light on the ecology, morphology and genetics of these southern 'desert' tortoises. All evidence warrants recognition of this clade as a distinctive taxon and herein we describe it as Gopherus evgoodei sp. n. The description of the new species significantly reduces and limits the distribution of Gopherus morafkai to desertscrub habitat only. By contrast, Gopherus evgoodei sp. n. occurs in thornscrub and tropical deciduous forests only and this leaves it with the smallest range of the three sister species. We present conservation implications for the newly described Gopherus evgoodei, which already faces impending threats.

  17. Modeling Habitat of the Desert Tortoise (Gopherus agassizii) in the Mojave and Parts of the Sonoran Deserts of California, Nevada, Utah, and Arizona

    USGS Publications Warehouse

    Nussear, Kenneth E.; Esque, Todd C.; Inman, Richard D.; Gass, Leila; Thomas, Kathryn A.; Wallace, Cynthia S.A.; Blainey, Joan B.; Miller, David M.; Webb, Robert H.

    2009-01-01

    Habitat modeling is an important tool used to simulate the potential distribution of a species for a variety of basic and applied questions. The desert tortoise (Gopherus agassizii) is a federally listed threatened species in the Mojave Desert and parts of the Sonoran Desert of California, Nevada, Utah, and Arizona. Land managers in this region require reliable information about the potential distribution of desert tortoise habitat to plan conservation efforts, guide monitoring activities, monitor changes in the amount and quality of habitat available, minimize and mitigate disturbances, and ultimately to assess the status of the tortoise and its habitat toward recovery of the species. By applying information from the literature and our knowledge or assumptions of environmental variables that could potentially explain variability in the quality of desert tortoise habitat, we developed a quantitative habitat model for the desert tortoise using an extensive set of field-collected presence data. Sixteen environmental data layers were converted into a grid covering the study area and merged with the desert tortoise presence data that we gathered for input into the Maxent habitat-modeling algorithm. This model provides output of the statistical probability of habitat potential that can be used to map potential areas of desert tortoise habitat. This type of analysis, while robust in its predictions of habitat, does not account for anthropogenic changes that may have altered habitat with relatively high potential into areas with lower potential.

  18. When desert tortoises are rare: Testing a new protocol for assessing status

    USGS Publications Warehouse

    Keith, Kevin; Berry, Kristin H.; Weigand, James F.

    2008-01-01

    We developed and tested a new protocol for sampling populations of the desert tortoise, Gopherus agassizii, a state- and federally listed species, in areas where population densities are very low, historical data are sparse, and anthropogenic uses may threaten the well-being of tortoise populations and habitat. We conducted a 3-year (2002–2004) survey in Jawbone-Butterbredt Area of Critical Environmental Concern and Red Rock Canyon State Park in the western Mojave Desert of California where the status was previously unknown. We stratified the study area and used 751, 1-ha plots to evaluate 187.7 km2 of habitat, a 4% sample. Tortoise sign was found on 31 of the 751 plots (4.1%) in two limited areas: ~14 km2 on the Kiavah Apron and ~40 km2 in the Red Rock Canyon watershed.

  19. Quantitative PCR method for detection of mycoplasma spp. DNA in nasal lavage samples from the desert tortoise (Gopherus agassizii).

    PubMed

    duPre', S A; Tracy, C R; Hunter, K W

    2011-08-01

    Mycoplasma agassizii and M. testudineum have been associated with upper respiratory tract disease (URTD) in the threatened desert tortoise (Gopherus agassizii). Because microbiological culture methods have proven difficult to employ in wild desert tortoises, our goal was to develop a sensitive and specific qPCR method for detecting and quantifying mycoplasma DNA in nasal lavage fluid collected in the field. Primers for 16S ribosomal RNA gene sequences specific for M. agassizii and M. testudineum were designed, together with primers that recognize conserved sequences of both microorganisms. Standard curves generated with DNA extracted from known numbers of mycoplasma cells revealed a lower detection limit of approximately 5fg. The qPCR method did not recognize normal flora DNA, and nasal lavage fluid contained no interfering substances. Nasal lavage samples collected from 20 captive desert tortoises housed at the Desert Tortoise Conservation Center (Clark County, Nevada, USA) revealed the presence of M. agassizii DNA in 100% of the tortoises. Concentrations ranged from a low of 6pg ml(-1) to a high of 72,962pg ml(-1). Only one of the tortoises was positive for M. testudineum. Interestingly, not all of the qPCR positive tortoises showed evidence of seroconversion, suggesting that they were colonized but not infected. This new quantitative method will provide a critical tool for managing threatened populations of the desert tortoise.

  20. The desert tortoise trichotomy: Mexico hosts a third, new sister-species of tortoise in the Gopherus morafkai–G. agassizii group

    PubMed Central

    Edwards, Taylor; Karl, Alice E.; Vaughn, Mercy; Rosen, Philip C.; Torres, Cristina Meléndez; Murphy, Robert W.

    2016-01-01

    Abstract Desert tortoises (Testudines; Testudinidae; Gopherus agassizii group) have an extensive distribution throughout the Mojave, Colorado, and Sonoran desert regions. Not surprisingly, they exhibit a tremendous amount of ecological, behavioral, morphological and genetic variation. Gopherus agassizii was considered a single species for almost 150 years but recently the species was split into the nominate form and Morafka’s desert tortoise, Gopherus morafkai, the latter occurring south and east of the Colorado River. Whereas a large body of literature focuses on tortoises in the United States, a dearth of investigations exists for Mexican animals. Notwithstanding, Mexican populations of desert tortoises in the southern part of the range of Gopherus morafkai are distinct, particularly where the tortoises occur in tropical thornscrub and tropical deciduous forest. Recent studies have shed light on the ecology, morphology and genetics of these southern ‘desert’ tortoises. All evidence warrants recognition of this clade as a distinctive taxon and herein we describe it as Gopherus evgoodei sp. n. The description of the new species significantly reduces and limits the distribution of Gopherus morafkai to desertscrub habitat only. By contrast, Gopherus evgoodei sp. n. occurs in thornscrub and tropical deciduous forests only and this leaves it with the smallest range of the three sister species. We present conservation implications for the newly described Gopherus evgoodei, which already faces impending threats. PMID:27006625

  1. Modeling population response to anthropogenic threats for a long-lived reptile, the desert tortoise

    EPA Science Inventory

    Background/Question/Methods The decline in desert tortoise population densities and abundances since the 1970s has been attributed to numerous threats, leading scientists, land managers, and conservationists to describe the plight of the species as a “death by a thousand cuts.” ...

  2. Application of diagnostic tests for mycoplasmal infections of desert and gopher tortoises with management recommendations

    USGS Publications Warehouse

    Brown, D.R.; Schumacher, Isabella M.; Mclaughlin, Grace S.; Wendland, L.D.; Brown, Mary E.; Klein, P.A.; Jacobson, E.R.

    2002-01-01

    Mycoplasmosis is a transmissible upper respiratory tract disease that has affected plans for management and conservation of wild desert and gopher tortoises in the United States. Although impact of mycoplasmosis on populations of desert and gopher tortoises is unknown, increased prevalence of seropositive animals as well as field observations of clinically ill tortoises have occurred in association with declining populations. In order to help in the identification of potentially infected animals, three tests have been developed to diagnose mycoplasmal infections of tortoises: 1) direct mycoplasmal culture; 2) detection of mycolplasmal chromosomal DNA by polymerase chain reaction (PCR); and 3) detection of anti-Mycoplasma antibodies in tortoise plasma by enzyme-linked immunosorbent assay (ELISA). Each test provides different, complementary information that collectively can be used to define tortoise mycoplasmal infection status. The types of samples required, the predictive value, interpretation, and cost vary among tests. These assays have been used for epidemiological surveys and in decision making for relocation, repatriation, or captive management of tortoises to minimize the risk of outbreaks of mycoplasmal respiratory disease and spread of the causative agent of this disease. Certain features of mycoplasmal infections of tortoises and other animals create a diagnostic dilemma. Multiple Mycoplasma species can cause respiratory disease with identical clinical presentations. Further, individual strains of a given species may vary with respect to their virulence potential, and some species may be commensals rather than pathogens. Current diagnostic tests may not differentiate among mycoplasmal species or strains or permit determination of pathogenicity of individual isolates. Thus, the information provided by testing is not a simple 'positive' vs. 'negative' issue. While these tests provide much needed information on the exposure of tortoise populations to

  3. Using motion-sensor camera technology to infer seasonal activity and thermal niche of the desert tortoise (Gopherus agassizii)

    USGS Publications Warehouse

    Agha, Mickey; Augustine, Benjamin; Lovich, Jeffrey E.; Delaney, David F.; Sinervo, Barry; Murphy, Mason O.; Ennen, Joshua R.; Briggs, Jessica R.; Cooper, Robert J.; Price, Steven J.

    2015-01-01

    Understanding the relationships between environmental variables and wildlife activity is an important part of effective management. The desert tortoise (Gopherus agassizii), an imperiled species of arid environments in the southwest US, may have increasingly restricted windows for activity due to current warming trends. In summer 2013, we deployed 48 motion sensor cameras at the entrances of tortoise burrows to investigate the effects of temperature, sex, and day of the year on the activity of desert tortoises. Using generalized estimating equations, we found that the relative probability of activity was associated with temperature (linear and quadratic), sex, and day of the year. Sex effects showed that male tortoises are generally more active than female tortoises. Temperature had a quadratic effect, indicating that tortoise activity was heightened at a range of temperatures. In addition, we found significant support for interactions between sex and day of the year, and sex and temperature as predictors of the probability of activity. Using our models, we were able to estimate air temperatures and times (days and hours) that were associated with maximum activity during the study. Because tortoise activity is constrained by environmental conditions such as temperature, it is increasingly vital to conduct studies on how tortoises vary their activity throughout the Sonoran Desert to better understand the effects of a changing climate.

  4. Using motion-sensor camera technology to infer seasonal activity and thermal niche of the desert tortoise (Gopherus agassizii).

    PubMed

    Agha, Mickey; Augustine, Benjamin; Lovich, Jeffrey E; Delaney, David; Sinervo, Barry; Murphy, Mason O; Ennen, Joshua R; Briggs, Jessica R; Cooper, Robert; Price, Steven J

    2015-01-01

    Understanding the relationships between environmental variables and wildlife activity is an important part of effective management. The desert tortoise (Gopherus agassizii), an imperiled species of arid environments in the southwest US, may have increasingly restricted windows for activity due to current warming trends. In summer 2013, we deployed 48 motion sensor cameras at the entrances of tortoise burrows to investigate the effects of temperature, sex, and day of the year on the activity of desert tortoises. Using generalized estimating equations, we found that the relative probability of activity was associated with temperature (linear and quadratic), sex, and day of the year. Sex effects showed that male tortoises are generally more active than female tortoises. Temperature had a quadratic effect, indicating that tortoise activity was heightened at a range of temperatures. In addition, we found significant support for interactions between sex and day of the year, and sex and temperature as predictors of the probability of activity. Using our models, we were able to estimate air temperatures and times (days and hours) that were associated with maximum activity during the study. Because tortoise activity is constrained by environmental conditions such as temperature, it is increasingly vital to conduct studies on how tortoises vary their activity throughout the Sonoran Desert to better understand the effects of a changing climate.

  5. A Microcantilever Sensor Array for the Detection and Inventory of Desert Tortoises

    SciTech Connect

    Venedam, R. J.; Dillingham, T. R.

    2008-07-01

    We have designed and tested a portable instrument consisting of a small infrared camera coupled with an array of piezoresistive microcantilever sensors that is used to provide real-time, non-invasive data on desert tortoise den occupancy. The piezoresistive microcantilever (PMC) sensors are used to obtain a chemical “signature” of tortoise presence from the air deep within the dens, and provide data in cases where the camera cannot extend deep enough into the den to provide visual evidence of tortoise presence. The infrared camera was used to verify the PMC data during testing, and in many cases, such as shallower dens, may be used to provide exact numbers on den populations.

  6. Guidelines for the field evaluation of desert tortoise health and disease

    USGS Publications Warehouse

    Berry, Kristin H.; Christopher, Mary M.

    2001-01-01

    Field evaluation of free-ranging wildlife requires the systematic documentation of a variety of environmental conditions and individual parameters of health and disease, particularly in the case of rare or endangered species. In addition, defined criteria are needed for the humane salvage of ill or dying animals. The purpose of this paper is to describe, in detail, the preparation, procedures, and protocols we developed and tested for the field evaluation of wild desert tortoises (Gopherus agassizii). These guidelines describe: preparations for the field, including developing familiarity with tortoise behavior and ecology, and preparation of standardized data sheets; journal notes to document background data on weather conditions, temperature, rainfall, locality, and historic and recent human activities; procedures to prevent the spread of disease and parasites; data sheets for live tortoises to record tortoise identification, location, sex, body measurements and activity; health profile forms for documenting and grading physical abnormalities of tortoise posture and movements, general condition (e.g., lethargy, cachexia), external parasites, and clinical abnormalities associated with shell and upper respiratory diseases; permanent photographic records for the retrospective analysis of progression and regression of upper respiratory and eye diseases, analysis of shell lesions and evaluation of growth and age; and indications and methods for salvaging ill or dying tortoises for necropsy evaluation. These guidelines, tested on 5,000 to 20,000 tortoises over a 10 to 27 yr period, were designed to maximize acquisition of data for demographic, ecological, health and disease research projects; to reduce handling and stress of individual animals; to avoid spread of infectious disease; to promote high quality and consistent data sets; and to reduce the duration and number of field trips. The field methods are adapted for desert tortoise life cycle, behavior, anatomy

  7. Impacts of upper respiratory tract disease on olfactory behavior of the Mojave desert tortoise.

    PubMed

    Germano, Jennifer; Van Zerr, Vanessa E; Esque, Todd C; Nussear, Ken E; Lamberski, Nadine

    2014-04-01

    Upper respiratory tract disease (URTD) caused by Mycoplasma agassizii is considered a threat to desert tortoise populations that should be addressed as part of the recovery of the species. Clinical signs can be intermittent and include serous or mucoid nasal discharge and respiratory difficulty when nares are occluded. This nasal congestion may result in a loss of the olfactory sense. Turtles are known to use olfaction to identify food items, predators, and conspecifics; therefore, it is likely that URTD affects not only their physical well-being but also their behavior and ability to perform necessary functions in the wild. To determine more specifically the impact nasal discharge might have on free-ranging tortoises (Gopherus agassizii), we compared the responses of tortoises with and without nasal discharge and both positive and negative for M. agassizii antibodies to a visually hidden olfactory food stimulus and an empty control. We found that nasal discharge did reduce sense of smell and hence the ability to locate food. Our study also showed that moderate chronic nasal discharge in the absence of other clinical signs did not affect appetite in desert tortoises.

  8. Impacts of upper respiratory tract disease on olfactory behavior of the Mojave desert tortoise

    USGS Publications Warehouse

    Germano, Jennifer; Van Zerr, Vanessa E.; Esque, Todd C.; Nussear, Ken E.; Lamberski, Nadine

    2014-01-01

    Upper respiratory tract disease (URTD) caused by Mycoplasma agassizii is considered a threat to desert tortoise populations that should be addressed as part of the recovery of the species. Clinical signs can be intermittent and include serous or mucoid nasal discharge and respiratory difficulty when nares are occluded. This nasal congestion may result in a loss of the olfactory sense. Turtles are known to use olfaction to identify food items, predators, and conspecifics; therefore, it is likely that URTD affects not only their physical well-being but also their behavior and ability to perform necessary functions in the wild. To determine more specifically the impact nasal discharge might have on free-ranging tortoises (Gopherus agassizii), we compared the responses of tortoises with and without nasal discharge and both positive and negative for M. agassizii antibodies to a visually hidden olfactory food stimulus and an empty control. We found that nasal discharge did reduce sense of smell and hence the ability to locate food. Our study also showed that moderate chronic nasal discharge in the absence of other clinical signs did not affect appetite in desert tortoises.

  9. Diet of desert tortoises at Yucca Mountain, Nevada, and implications for habitat reclamation

    SciTech Connect

    Rakestraw, D.L.; Holt, E.A.; Rautenstrauch, K.R.

    1995-12-01

    The diet of desert tortoises at Yucca Mountain was assessed during 1992 to 1995 using a combination of feeding observations and scat analysis. Feeding observation data (1993 through 1995) showed that tortoises fed on a wide variety of items. The most frequently eaten items were forbs and annual grasses. These two forage groups comprised more than 90% of all bites taken. Analysis of scat (1992 and 1993) also showed that grasses and forbs were the most common groups, making up more than 80% of the composition of scat. Yearly differences between proportions of species in the diet were observed and were most likely attributable to differences in plant productivity, which is linked to rainfall patterns. Non-native species were an important component of the diet in all years, accounting for 13 to 50% of all bites observed and 6 to 24% of scat contents. A list of all items encountered in the diet is provided. To facilitate reclamation of desert tortoise habitat disturbed by the Yucca Mountain Site Characterization Project, native forage species that should be included in reclamation seed mixes, when feasible, were identified. Although shrubs make up only a small proportion of the diet, they should also be included in reclamation efforts because they provide habitat structure. Tortoise cover sites, and microhabitats amenable to seed germination and seedling establishment. In addition, non-native species should not be planted on reclaimed sites and, if necessary, sites should be recontoured and soil compaction reduced prior to planting.

  10. Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline.

    PubMed

    Sieg, Annette E; Gambone, Megan M; Wallace, Bryan P; Clusella-Trullas, Susana; Spotila, James R; Avery, Harold W

    2015-05-01

    Desert resource environments (e.g. microclimates, food) are tied to limited, highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants. Typically, enhanced growth rates, reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short-lived animals. We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises (Gopherus agassizii), long-lived and large-bodied ectotherms, at opposite ends of a 250-m elevation-related rainfall cline within Ivanpah Valley in the eastern Mojave Desert, California, USA. Biophysical operative environments in both the upper-elevation, "Cima," and the lower-elevation, "Pumphouse," plots corresponded with daily and seasonal patterns of incident solar radiation. Cima received 22% more rainfall and contained greater perennial vegetative cover, which conferred 5°C-cooler daytime shaded temperatures. In a monitored average rainfall year, Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage. Enhanced resource availability in Cima was associated with larger-bodied females producing larger eggs, while still producing the same number of eggs as Pumphouse females. However, reproductive success was lower in Cima because 90% of eggs were depredated versus 11% in Pumphouse, indicating that predatory interactions produced counter-gradient variation in reproductive success across the rainfall cline. Land-use impacts on deserts (e.g. solar energy generation) are increasing rapidly, and conservation strategies designed to protect and recover threatened desert inhabitants, such as desert tortoises, should incorporate these strong ecosystem-level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts.

  11. Turbines and terrestrial vertebrates: variation in tortoise survivorship between a wind energy facility and an adjacent undisturbed wildland area in the desert southwest (USA)

    USGS Publications Warehouse

    Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Augustine, Benjamin J.; Arundel, Terry; Murphy, Mason O.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David F.; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V.; Price, Steven J.

    2015-01-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises (Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18 year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility scale wind energy on long-lived terrestrial vertebrates.

  12. Turbines and Terrestrial Vertebrates: Variation in Tortoise Survivorship Between a Wind Energy Facility and an Adjacent Undisturbed Wildland Area in the Desert Southwest (USA)

    NASA Astrophysics Data System (ADS)

    Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Augustine, Benjamin; Arundel, Terence R.; Murphy, Mason O.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V.; Price, Steven J.

    2015-08-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises ( Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18-year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability, and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility-scale wind energy on long-lived terrestrial vertebrates.

  13. Turbines and Terrestrial Vertebrates: Variation in Tortoise Survivorship Between a Wind Energy Facility and an Adjacent Undisturbed Wildland Area in the Desert Southwest (USA).

    PubMed

    Agha, Mickey; Lovich, Jeffrey E; Ennen, Joshua R; Augustine, Benjamin; Arundel, Terence R; Murphy, Mason O; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V; Price, Steven J

    2015-08-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises (Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18-year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability, and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility-scale wind energy on long-lived terrestrial vertebrates.

  14. Short-Term Space-Use Patterns of Translocated Mojave Desert Tortoise in Southern California

    PubMed Central

    Farnsworth, Matthew L.; Dickson, Brett G.; Zachmann, Luke J.; Hegeman, Ericka E.; Cangelosi, Amanda R.; Jackson, Thomas G.; Scheib, Amanda F.

    2015-01-01

    Increasingly, renewable energy comprises a larger share of global energy production. Across the western United States, public lands are being developed to support renewable energy production. Where there are conflicts with threatened or endangered species, translocation can be used in an attempt to mitigate negative effects. For the threatened Mojave desert tortoise (Gopherus agassizii), we sought to compare habitat- and space-use patterns between short-distance translocated, resident, and control groups. We tested for differences in home range size based on utilization distributions and used linear mixed-effects models to compare space-use intensity, while controlling for demographic and environmental variables. In addition, we examined mean movement distances as well as home range overlap between years and for male and female tortoises in each study group. During the first active season post-translocation, home range size was greater and space-use intensity was lower for translocated tortoises than resident and control groups. These patterns were not present in the second season. In both years, there was no difference in home range size or space-use intensity between control and resident groups. Translocation typically resulted in one active season of questing followed by a second active season characterized by space-use patterns that were indistinguishable from control tortoises. Across both years, the number of times a tortoise was found in a burrow was positively related to greater space-use intensity. Minimizing the time required for translocated tortoises to exhibit patterns similar to non-translocated individuals may have strong implications for conservation by reducing exposure to adverse environmental conditions and predation. With ongoing development, our results can be used to guide future efforts aimed at understanding how translocation strategies influence patterns of animal space use. PMID:26352691

  15. Short-Term Space-Use Patterns of Translocated Mojave Desert Tortoise in Southern California.

    PubMed

    Farnsworth, Matthew L; Dickson, Brett G; Zachmann, Luke J; Hegeman, Ericka E; Cangelosi, Amanda R; Jackson, Thomas G; Scheib, Amanda F

    2015-01-01

    Increasingly, renewable energy comprises a larger share of global energy production. Across the western United States, public lands are being developed to support renewable energy production. Where there are conflicts with threatened or endangered species, translocation can be used in an attempt to mitigate negative effects. For the threatened Mojave desert tortoise (Gopherus agassizii), we sought to compare habitat- and space-use patterns between short-distance translocated, resident, and control groups. We tested for differences in home range size based on utilization distributions and used linear mixed-effects models to compare space-use intensity, while controlling for demographic and environmental variables. In addition, we examined mean movement distances as well as home range overlap between years and for male and female tortoises in each study group. During the first active season post-translocation, home range size was greater and space-use intensity was lower for translocated tortoises than resident and control groups. These patterns were not present in the second season. In both years, there was no difference in home range size or space-use intensity between control and resident groups. Translocation typically resulted in one active season of questing followed by a second active season characterized by space-use patterns that were indistinguishable from control tortoises. Across both years, the number of times a tortoise was found in a burrow was positively related to greater space-use intensity. Minimizing the time required for translocated tortoises to exhibit patterns similar to non-translocated individuals may have strong implications for conservation by reducing exposure to adverse environmental conditions and predation. With ongoing development, our results can be used to guide future efforts aimed at understanding how translocation strategies influence patterns of animal space use.

  16. Molecular methods to detect Mycoplasma spp. And Testudinid herpesvirus 2 in desert tortoises (Gopherus agassizii) and implications for disease management.

    PubMed

    Braun, Josephine; Schrenzel, Mark; Witte, Carmel; Gokool, Larisa; Burchell, Jennifer; Rideout, Bruce A

    2014-10-01

    Abstract Mycoplasmas are an important cause of upper respiratory tract disease (URTD) in desert tortoises (Gopherus agassizii) and have been a main focus in attempts to mitigate disease-based population declines. Infection risk can vary with an animal's population of origin, making screening tests popular tools for determining infection status in individuals and populations. To provide additional methods for investigating URTD we developed quantitative PCR (qPCR) assays specific for agents causing clinical signs of URTD: Mycoplasma agassizii, Mycoplasma testudineum, and Testudinid herpesvirus 2 (TeHV2) and tested necropsied desert tortoises housed at the Desert Tortoise Conservation Center in Las Vegas, Nevada, USA, as well as wild desert tortoises (n=3), during 2010. Findings were compared with M. agassizii enzyme-linked immunosorbent assay (ELISA) data. Based on qPCR, the prevalence of M. agassizii was 75% (33/44) and the prevalence of TeHV2 was 48% (20/42) in the evaluated population. Both agents were also present in the wild tortoises. Mycoplasma testudineum was not detected. The M. agassizii ELISA and qPCR results did not always agree. More tortoises were positive for M. agassizii by nasal mucosa testing than by nasal flush. Our findings suggest that mycoplasmas are not the only agents of concern and that a single M. agassizii ELISA or nasal flush qPCR alone failed to identify all potentially infected animals in a population. Caution should be exercised in using these tests for disposition decisions.

  17. Nest guarding by female Agassiz's desert tortoise (Gopherus agassizii) at a wind-energy facility near Palm Springs, California

    USGS Publications Warehouse

    Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Wilcox, Ethan

    2013-01-01

    We observed behavior consistent with nest-guarding in Agassiz's desert tortoise (Gopherus agassizii) at two nests in a large wind-energy-generation facility near Palm Springs, California, locally known as the Mesa Wind Farm. As researchers approached the nests, female desert tortoises moved to the entrance of their burrows and positioned themselves sideways, directly over their nests. One female stretched her limbs outward and wedged herself into the burrow (her plastron directly above the nest). Guarding of nests is rarely observed in Agassiz's desert tortoise but can occur as a result of attempted predation on eggs by Gila monsters (Heloderma suspectum) or in direct response to the perceived threat posed by researchers. This is the first report of nest-guarding for G. agassizii in the Sonoran Desert ecosystem of California.

  18. Making molehills out of mountains: landscape genetics of the Mojave desert tortoise

    USGS Publications Warehouse

    Hagerty, Bridgette E.; Nussear, Kenneth E.; Esque, Todd C.; Tracy, C. Richard

    2010-01-01

    Heterogeneity in habitat often influences how organisms traverse the landscape matrix that connects populations. Understanding landscape connectivity is important to determine the ecological processes that influence those movements, which lead to evolutionary change due to gene flow. Here, we used landscape genetics and statistical models to evaluate hypotheses that could explain isolation among locations of the threatened Mojave desert tortoise (Gopherus agassizii). Within a causal modeling framework, we investigated three factors that can influence landscape connectivity: geographic distance, barriers to dispersal, and landscape friction. A statistical model of habitat suitability for the Mojave desert tortoise, based on topography, vegetation, and climate variables, was used as a proxy for landscape friction and barriers to dispersal. We quantified landscape friction with least-cost distances and with resistance distances among sampling locations. A set of diagnostic partial Mantel tests statistically separated the hypotheses of potential causes of genetic isolation. The best-supported model varied depending upon how landscape friction was quantified. Patterns of genetic structure were related to a combination of geographic distance and barriers as defined by least-cost distances, suggesting that mountain ranges and extremely low-elevation valleys influence connectivity at the regional scale beyond the tortoises' ability to disperse. However, geographic distance was the only influence detected using resistance distances, which we attributed to fundamental differences between the two ways of quantifying friction. Landscape friction, as we measured it, did not influence the observed patterns of genetic distances using either quantification. Barriers and distance may be more valuable predictors of observed population structure for species like the desert tortoise, which has high dispersal capability and a long generation time.

  19. Protection benefits desert tortoise (Gopherus agassizii) abundance: the influence of three management strategies on a threatened species

    USGS Publications Warehouse

    Berry, Kristin H.; Lyren, Lisa M.; Yee, Julie L.; Bailey, Tracy Y.

    2014-01-01

    We surveyed an area of ∼260 km2 in the western Mojave Desert to evaluate relationships between condition of Agassiz's Desert Tortoise populations (Gopherus agassizii) and habitat on lands that have experienced three different levels of management and protection. We established 240 1-ha plots using random sampling, with 80 plots on each of the three types of managed lands. We conducted surveys in spring 2011 and collected data on live tortoises, shell-skeletal remains, other signs of tortoises, perennial vegetation, predators, and evidence of human use. Throughout the study area and regardless of management area, tortoise abundance was positively associated with one of the more diverse associations of perennial vegetation. The management area with the longest history of protection, a fence, and legal exclusion of livestock and vehicles had significantly more live tortoises and lower death rates than the other two areas. Tortoise presence and abundance in this protected area had no significant positive or negative associations with predators or human-related impacts. In contrast, the management area with a more recent exclusion of livestock, limited vehicular traffic, and with a recent, partial fence had lower tortoise densities and high death rates. Tortoise abundance here was negatively associated with vehicle tracks and positively associated with mammalian predators and debris from firearms. The management area with the least protection—unfenced, with uncontrolled vehicle use, sheep grazing, and high trash counts—also had low tortoise densities and high death rates. Tortoise abundance was negatively associated with sheep grazing and positively associated with trash and mammalian predator scat.cat.

  20. Mycoplasma agassizii sp., nov., isolated from the upper respiratory tract of the desert tortoise (Gopherus agassizii) and the gopher tortoise (Gopherus polyphemus).

    USGS Publications Warehouse

    Brown, Mary E.; Brown, D.R.; Kelin, P.A.; McLaughlin, G.S.; Schumacher, Isabella M.; Jacobson, E.R.; Adams, H.P.; Tully, J.G.

    2001-01-01

    Biochemical, serological and molecular genetic studies were performed on seven mycoplasma isolates that were recovered from the upper respiratory tract of clinically ill desert tortoises. The isolates were serologically related to each other but serologically distinct from previously described species. Unique mycoplasma species-specific 16S rRNA nucleotide sequences were found in the proposed type strain. The name Mycoplasma agassizii is proposed for these isolates. The type strain is PS6T (=ATCC 700616T) which caused upper respiratory tract disease (URTD) in experimentally infected tortoises.

  1. Desert tortoise (Gopherus agassizii) dietary specialization decreases across a precipitation gradient.

    PubMed

    Murray, Ian W; Wolf, Blair O

    2013-01-01

    We studied the plant resource use between and within populations of desert tortoise (Gopherus agassizii) across a precipitation gradient in the Sonoran Desert of Arizona. The carbon and nitrogen stable isotope values in animal tissues are a reflection of the carbon and nitrogen isotope values in diet, and consequently represent a powerful tool to study animal feeding ecology. We measured the δ(13)C and δ(15)N values in the growth rings on the shells of tortoises in different populations to characterize dietary specialization and track tortoise use of isotopically distinct C4/CAM versus C3 plant resources. Plants using C3 photosynthesis are generally more nutritious than C4 plants and these trait differences can have important growth and fitness consequences for consumers. We found that dietary specialization decreases in successively drier and less vegetated sites, and that broader population niche widths are accompanied by an increase in the dietary variability between individuals. Our results highlight how individual consumer plant resource use is bounded under a varying regime of precipitation and plant productivity, lending insight into how intra-individual dietary specialization varies over a spatial scale of environmental variability.

  2. A highway's road-effect zone for desert tortoises (Gopherus agassizii)

    USGS Publications Warehouse

    Boarman, W.I.; Sazaki, M.

    2006-01-01

    Roads and highways can affect populations of animals directly (e.g. due to road mortality) and indirectly (e.g. due to fragmentation of habitat and proliferation of non-native or predatory species). We investigated the effect of roads on threatened desert tortoise (Gopherus agassizii) populations in the Mojave Desert, California, and attempted to determine the width of the road-effect zone by counting tortoise signs along transects at 0, 400, 800, and 1600 m from the edge of a highway. Mean sign count was 0.2/km at 0 m, 4.2/km at 400 m, 5.7/km at 800 m, and 5.4/km at 1600 m from the highway edge. The differences between all pairs of distances, except 800 and 1600 m, were statistically significant, suggesting that tortoise populations in our study area are depressed in a zone extending at least 400 m from roadways. We speculate that the major cause for this depression zone is road mortality.

  3. Desert Tortoise (Gopherus agassizii) Dietary Specialization Decreases across a Precipitation Gradient

    PubMed Central

    Murray, Ian W.; Wolf, Blair O.

    2013-01-01

    We studied the plant resource use between and within populations of desert tortoise (Gopherus agassizii) across a precipitation gradient in the Sonoran Desert of Arizona. The carbon and nitrogen stable isotope values in animal tissues are a reflection of the carbon and nitrogen isotope values in diet, and consequently represent a powerful tool to study animal feeding ecology. We measured the δ13C and δ15N values in the growth rings on the shells of tortoises in different populations to characterize dietary specialization and track tortoise use of isotopically distinct C4/CAM versus C3 plant resources. Plants using C3 photosynthesis are generally more nutritious than C4 plants and these trait differences can have important growth and fitness consequences for consumers. We found that dietary specialization decreases in successively drier and less vegetated sites, and that broader population niche widths are accompanied by an increase in the dietary variability between individuals. Our results highlight how individual consumer plant resource use is bounded under a varying regime of precipitation and plant productivity, lending insight into how intra-individual dietary specialization varies over a spatial scale of environmental variability. PMID:23840495

  4. Problems with sampling desert tortoises: A simulation analysis based on field data

    USGS Publications Warehouse

    Freilich, J.E.; Camp, R.J.; Duda, J.J.; Karl, A.E.

    2005-01-01

    The desert tortoise (Gopherus agassizii) was listed as a U.S. threatened species in 1990 based largely on population declines inferred from mark-recapture surveys of 2.59-km2 (1-mi2) plots. Since then, several census methods have been proposed and tested, but all methods still pose logistical or statistical difficulties. We conducted computer simulations using actual tortoise location data from 2 1-mi2 plot surveys in southern California, USA, to identify strengths and weaknesses of current sampling strategies. We considered tortoise population estimates based on these plots as "truth" and then tested various sampling methods based on sampling smaller plots or transect lines passing through the mile squares. Data were analyzed using Schnabel's mark-recapture estimate and program CAPTURE. Experimental subsampling with replacement of the 1-mi2 data using 1-km2 and 0.25-km2 plot boundaries produced data sets of smaller plot sizes, which we compared to estimates from the 1-mi 2 plots. We also tested distance sampling by saturating a 1-mi 2 site with computer simulated transect lines, once again evaluating bias in density estimates. Subsampling estimates from 1-km2 plots did not differ significantly from the estimates derived at 1-mi2. The 0.25-km2 subsamples significantly overestimated population sizes, chiefly because too few recaptures were made. Distance sampling simulations were biased 80% of the time and had high coefficient of variation to density ratios. Furthermore, a prospective power analysis suggested limited ability to detect population declines as high as 50%. We concluded that poor performance and bias of both sampling procedures was driven by insufficient sample size, suggesting that all efforts must be directed to increasing numbers found in order to produce reliable results. Our results suggest that present methods may not be capable of accurately estimating desert tortoise populations.

  5. Effectiveness of post-fire seeding in desert tortoise Critical Habitat following the 2005 Southern Nevada Fire Complex

    USGS Publications Warehouse

    DeFalco, Lesley; Drake, Karla K.; Scoles-Sciulla, S. J.; Bauer, Kyla L.

    2010-01-01

    In June 2005, lightning strikes ignited multiple wildfires in southern Nevada. The Southern Nevada Fire Complex burned more than 32,000 acres of designated desert tortoise Critical Habitat and an additional 403,000 acres of Mojave Desert habitat characterized as potentially suitable for the tortoise. Mortalities of desert tortoises were observed after the fires, but altered habitat is likely to prolong and magnify the impacts of wildfire on desert tortoise populations. To accelerate the re-establishment of plants commonly used by tortoises for food and shelter, the Bureau of Land Management (BLM) distributed seeds of native annual and perennial species in burned areas within desert tortoise Critical Habitat. The U.S. Geological Survey (USGS) established monitoring plots to evaluate broadcast seeding as a means to restore habitat and tortoise activity compared with natural recovery. Within the standard three-year Emergency and Stabilization Response (ESR) monitoring timeline, seeding augmented perennial seed banks by four to six-fold within a year of seed applications compared with unseeded areas. By the end of the three-year monitoring period, seedling densities of seeded perennial species were 33% higher in seeded areas than in unseeded areas, particularly for the disturbance-adapted desert globemallow (Sphaeralcea ambigua) and desert marigold (Baileya multiradiata). Seeded annuals, in contrast, did not increase significantly in seed banks or biomass production, likely due to low seeding rates of these species. Production of non-native annuals that helped carry the fires was not reduced by seeding efforts but instead was strongly correlated with site-specific rainfall, as were native annual species. The short-term vegetation changes measured in seeded areas were not yet associated with a return of tortoise activity to unburned levels. By focusing on a combination of native species that can withstand disturbance conditions, including species that are found in

  6. Inferring social structure and its drivers from refuge use in the desert tortoise, a relatively solitary species

    USGS Publications Warehouse

    Sah, Pratha; Nussear, Kenneth E.; Esque, Todd C.; Aiello, Christina M.; Hudson, Peter J.; Bansal, Shweta

    2016-01-01

    For several species, refuges (such as burrows, dens, roosts, nests) are an essential resource for protection from predators and extreme environmental conditions. Refuges also serve as focal sites for social interactions, including mating, courtship, and aggression. Knowledge of refuge use patterns can therefore provide information about social structure, mating, and foraging success, as well as the robustness and health of wildlife populations, especially for species considered to be relatively solitary. In this study, we construct networks of burrow use to infer social associations in a threatened wildlife species typically considered solitary—the desert tortoise. We show that tortoise social networks are significantly different than null networks of random associations, and have moderate spatial constraints. We next use statistical models to identify major mechanisms behind individual-level variation in tortoise burrow use, popularity of burrows in desert tortoise habitat, and test for stressor-driven changes in refuge use patterns. We show that seasonal variation has a strong impact on tortoise burrow switching behavior. On the other hand, burrow age and topographical condition influence the number of tortoises visiting a burrow in desert tortoise habitat. Of three major population stressors affecting this species (translocation, drought, disease), translocation alters tortoise burrow switching behavior, with translocated animals visiting fewer unique burrows than residents. In a species that is not social, our study highlights the importance of leveraging refuge use behavior to study the presence of and mechanisms behind non-random social structure and individual-level variation. Our analysis of the impact of stressors on refuge-based social structure further emphasizes the potential of this method to detect environmental or anthropogenic disturbances.

  7. Arsenic Species in Scute (Shell Plate) and Lung Tissues of Desert Tortoises

    NASA Astrophysics Data System (ADS)

    Foster, A. L.; Berry, K.; Jacobson, E. R.; Rytuba, J. J.

    2009-12-01

    The desert tortoise (Gopherus agassizii) is federally listed as a threatened species, and its numbers have been in decline for at least two decades. Portions of protected desert tortoise habitats coincide with anthropogenic features such as historic mines and military bases that are potential sources of ingested or inhaled arsenic. Previous studies of necropsied desert tortoise specimens collected from the Mojave Desert have shown a statistically significant link between elevated tissue levels of arsenic (As) and the occurrence of clinical disease states. Synchrotron-based, microbeam X-ray absorption fine structure spectroscopy (XAFS) and X-ray fluorescence mapping (XRF) were the primary techniques used to identify As species in these tissues. Specimens have been analyzed from a mining-impacted area (Kelly-Rand Mining district, Kern County), and from sites on or adjacent to military bases (National Training Center, Ft Irwin, and Edwards AFB). XRF maps showed that scute sections sliced perpendicular to the exposed surface contain one or more diffuse bands of As(III) coordinated by oxygen instead of sulfur. This As(III) species is identical in all individuals, suggesting that it represents metabolized As. In contrast, the exterior surface and edges of scute sections contained As-rich particles of varying oxidation state and species, suggesting an exogenous origin. Particles contained reduced As in sulfides (Cu sulfide or arsenide) and As(V) in ferric sulfates and/or ferric arsenates. XAFS spectra of many As(V)-rich particles were close visual matches to spectra of known arsenic-bearing minerals or phases such as scorodite, jarosite, and arsenic adsorbed to iron (hydr)oxides. At least one, and more commonly 3-5 exogeneous As-rich particles were found in the formalin-preserved lung tissue sections examined, suggesting that such particles were relatively common. Pentavalent As was observed in forms similar to those encountered on scute sections. As(III) was observed in

  8. Spatially explicit decision support for selecting translocation areas for Mojave desert tortoises

    USGS Publications Warehouse

    Heaton, Jill S.; Nussear, Kenneth E.; Esque, Todd C.; Inman, Richard D.; Davenport, Frank; Leuteritz, Thomas E.; Medica, Philip A.; Strout, Nathan W.; Burgess, Paul A.; Benvenuti, Lisa

    2008-01-01

    Spatially explicit decision support systems are assuming an increasing role in natural resource and conservation management. In order for these systems to be successful, however, they must address real-world management problems with input from both the scientific and management communities. The National Training Center at Fort Irwin, California, has expanded its training area, encroaching U.S. Fish and Wildlife Service critical habitat set aside for the Mojave desert tortoise (Gopherus agassizii), a federally threatened species. Of all the mitigation measures proposed to offset expansion, the most challenging to implement was the selection of areas most feasible for tortoise translocation. We developed an objective, open, scientifically defensible spatially explicit decision support system to evaluate translocation potential within the Western Mojave Recovery Unit for tortoise populations under imminent threat from military expansion. Using up to a total of 10 biological, anthropogenic, and/or logistical criteria, seven alternative translocation scenarios were developed. The final translocation model was a consensus model between the seven scenarios. Within the final model, six potential translocation areas were identified.

  9. Economic analysis of critical habitat designation for the desert tortoise (Mojave population)

    USGS Publications Warehouse

    Schamberger, Mel; MacGillvray, Timothy J.; Draper, Dirk D.

    1993-01-01

    The U.S. Fish and Wildlife Service emergency 1isted the Mojave population of the desert tortoise as endangered on August 4, 1989. The Mojave population formally was listed as threatened on April 2, 1990. The Endangered Species Act of 1973, as amended, requires that the economic benefits and costs and other relevant effects of critical habitat designation be considered. The Secretary of the Interior may exclude from designation areas where the costs of designation are greater than the benefits, unless the exclusion would result in extinction of the species. Desert tortoises are threatened by an accumulation of human-and disease-related mortality accompanied by habitat destruction, degradation, and fragmentation. Many desert tortoises are illegally collected for pets, food, and commercial trade. Others are accidentally struck and killed by vehicles on roads and highways or are killed by gunshot or vehicles traveling off-highway. Raven predation on hatchling desert tortoises has increased as raven populations in the desert have risen. An upper respiratory tract disease is suspected to be a major cause of mortality in the western Mojave Desert. This presumably incurable affliction presumably is thought to be spread through the release of infected tortoises into the desert. The Service has proposed designating critical habitat in nine counties within four states. The 12 critical habitat units encompass 6.4 million acres of land, more than 80% federally owned. This region is economically and demographically diverse. Most of the land is sparsely settled and characterized as a hot desert ecosystem. Major industries in the region include entertainment and lodging (primarily in Las Vegas), property development to accommodate the rapid population growth, and services. Millions of rural acres in the region are leased by the federal government for livestock grazing and used for mining. Overall economic benefits to the affected states derived from cattle and sheep grazing in the

  10. Effects of wind energy production on growth, demography, and survivorship of a Desert Tortoise (Gopherus agassizii) population in Southern California with comparisons to natural populations

    USGS Publications Warehouse

    Lovich, J.E.; Ennen, J.R.; Madrak, S.; Meyer, K.; Loughran, C.; Bjurlin, C.; Arundel, T.; Turner, W.; Jones, C.; Groenendaal, G.M.

    2011-01-01

    We studied a Desert Tortoise (Gopherus agassizii) population at a large wind energy generation facility near Palm Springs, California over six field seasons from 1997 to 2010. We compared growth and demographic parameters to populations living in less disturbed areas; as well as populations of the closely-related and newly-described G. morafkai elsewhere in the Sonoran Desert of Arizona. We marked 69 individuals of all size classes and estimated a population size of 96 tortoises, or about 15.4/km2. Growth rates for males were lower than reported elsewhere, although maximum body size was larger. The smallest female with shelled eggs was 221 mm and males mature at over 200 mm. Mean male size was greater than that of females. The adult sex ratio was not significantly different from unity. Size frequency histograms were similar over time and when compared to most, but not all, G. morafkai populations in the Sonoran Desert. For a cohort of adult females, we estimated mortality at 8.4% annually due, in part, to site operations. This value was low in comparison to many other populations during the same time period. Other than possible differences in growth rate of males and the high survivorship of females, there appear to be few differences between this population and those in more natural areas. The high productivity of food plants at the site and its limited public access may contribute to the overall stability of the population. However, the effects of utility-scale renewable energy development on tortoises in other, less productive, areas are unknown. Additional research (especially controlled and replicated before and after studies) is urgently needed to address this deficiency because of forecasted expansion of utility-scale renewable energy development in the future.

  11. A quantitative PCR method for assessing the presence of Pasteurella testudinis DNA in nasal lavage samples from the desert tortoise (Gopherus agassizii).

    PubMed

    duPre', S A; Tracy, C R; Sandmeier, F C; Hunter, K W

    2012-12-01

    Pasteurella testudinis has been associated with upper respiratory tract disease (URTD) in the threatened desert tortoise (Gopherus agassizii). Our goal was to develop a sensitive and specific qPCR method for detecting DNA from P. testudinis in nasal lavage fluid collected from desert tortoises in the field. Probes for 16S ribosomal RNA and RNA polymerase β-subunit (rpoB) genes were designed. A standard curve generated with DNA extracted from known numbers of bacterial cells determined by flow cytometry revealed a lower detection limit of 50 fg/ml (10 bacteria/ml). The nasal lavage fluid contained no interfering substances, and the qPCR method did not recognize normal flora DNA. The nasal lavage samples from 20 desert tortoises captured in Clark County, Nevada, USA in 2007 and housed at the Desert Tortoise Conservation Center, were all positive for P. testudinis DNA by qPCR. Another set of 19 lavage samples collected in 2010 from wild desert tortoises in the Mojave Desert were tested and 84% were positive for P. testudinis DNA. Fully validated, this qPCR method will provide a means of determining colonization rate. When used in conjunction with serological methods and clinical evaluations, both infection rate and disease rate can be determined for this potential URTD pathogen. This new assay provides an important tool for managing the threatened populations of the Mojave Desert tortoise.

  12. Effect of venipuncture sites on hematologic and clinical biochemical values in desert tortoises (Gopherus agassizii).

    PubMed

    Gottdenker, N L; Jacobson, E R

    1995-01-01

    Paired blood samples were collected from the postoccipital venous plexus and jugular vein of desert tortoises (Gopherus agassizii) for hematologic and plasma biochemical analyses. Comparison of hematologic values revealed significantly (P < or = 0.05) lower PCV, RBC count, WBC count, and hemoglobin values for samples obtained from the occipital site. When comparisons were made between plasma biochemical values for the 2 sites, significant (P < or = 0.05) differences were measured for: glucose, potassium, chloride, uric acid, calcium, phosphorous, total protein, albumin, globulin, alkaline phosphatase, aspartate transaminase, alanine transaminase, and total cholesterol. Significant differences between hematologic and plasma biochemical values from the occipital region samples vs jugular vein samples were attributed to hemodilution of the occipital region samples with extravascular fluid or lymph or both.

  13. Radiotelemetry Study of a Desert Tortoise Population: Sand Hill Training Mea, Marine Corps Air Ground Combat Center, Twentynine Palms, California

    DTIC Science & Technology

    1998-05-01

    have dramatically declined, making it economically feasible to extend the utility and applications of this important field technique. The most...increases the probability of local extinctions from inbreeding depression, loss of heterosis (decreased genetic variability), and genetic drift (the...USACERLTR-98/39 57 Bürge, B.L., "Daily and Seasonal Behavior, and Areas Utilized by the Desert Tortoise Gopherus Agassizii in Southern Nevada," The

  14. Turtles and culverts, and alternative energy development: an unreported but potentially significant mortality threat to the desert tortoise (Gopherus agassizii)

    USGS Publications Warehouse

    Lovich, J.E.; Ennen, J.R.; Madrak, S.; Grover, B.

    2011-01-01

    Culverts are often used to increase the permeability of roaded landscapes for wildlife, including turtles. Although the benefits of culverts as safe passages for turtles are well documented, under some conditions culverts can entrap them and cause mortality. Here we report a culvert-related mortality in the federally threatened desert tortoise (Gopherus agassizii) at a wind energy facility in California and offer simple recommendations to mitigate the negative effects of culverts for wildlife in general.

  15. A genetic assessment of the recovery units for the mojave population of the desert tortoise, Gopherus agassizii

    USGS Publications Warehouse

    Murphy, R.W.; Berry, K.H.; Edwards, T.; McLuckie, A.M.

    2007-01-01

    In the 1994 Recovery Plan for the Mojave population of the desert tortoise, Gopherus agassizii, the US Fish and Wildlife Service established 6 recovery units by using the best available data on habitat use, behavior, morphology, and genetics. To further assess the validity of the recovery units, we analyzed genetic data by using mitochondrial deoxyribonucleic acid (mtDNA) sequences and nuclear DNA microsatellites. In total, 125 desert tortoises were sampled for mtDNA and 628 for microsatellites from 31 study sites, representing all recovery units and desert regions throughout the Mojave Desert in California and Utah, and the Colorado Desert of California. The mtDNA revealed a great divergence between the Mojave populations west of the Colorado River and those occurring east of the river in the Sonoran Desert of Arizona. Some divergence also occurred between northern and southern populations within the Mojave population. The microsatellites indicated a low frequency of private alleles and a significant correlation between genetic and geographic distance among 31 sample sites, which was consistent with an isolation-by-distance population structure. Regional genetic differentiation was complementary to the recovery units in the Recovery Plan. Most allelic frequencies in the recovery units differed. An assignment test correctly placed most individuals to their recovery unit of origin. Of the 6 recovery units, the Northeastern and the Upper Virgin River units showed the greatest differentiation; these units may have been relatively more isolated than other areas and should be managed accordingly. The Western Mojave Recovery Unit, by using the new genetic data, was redefined along regional boundaries into the Western Mojave, Central Mojave, and Southern Mojave recovery units. Large-scale translocations of tortoises and habitat disturbance throughout the 20th century may have contributed to the observed patterns of regional similarity. ?? 2007 Chelonian Research

  16. Surveys for desert tortoise on the proposed site of a high-level nuclear waste repository at the Nevada Test Site

    SciTech Connect

    Collins, E.; Sauls, M.L.; O`Farrell, T.P.

    1983-12-31

    The National Waste Terminal Storage Program is a national search for suitable sites to isolate commercial spent nuclear fuel or high-level radioactive waste. The Nevada Nuclear Waste Storage Investigation (NNWSI) managed by the U.S. Department of Energy (DOE), Nevada Operations Office, was initiated to study the suitability of a portion of Yucca Mountain on the DOE`s Nevada Test Site (NTS) as a location for such a repository. EG and G was contracted to provide information concerning the ecosystems encountered on the site. A comprehensive literature survey was conducted to evaluate the status and completeness of the existing biological information for the previously undisturbed area. Site specific studies were begun in 1981 when preliminary field surveys confirmed the presence of the desert tortoise (Gopherus agassizi) within the project area FY82 studies were designed to determine the overall distribution and abundance of the tortoise within the area likely to be impacted by NNWSI activities. The Yucca Mountain area of the Nevada Test Site is situated close to the northern range limit of the desert tortoise. Prior to the 1982 surveys, the desert tortoise was reported from only nine locations on NTS. A known population had been under study in Rock Valley about 25 miles southeast of the project area. However, the distribution and population densities of tortoise in the southwest portion of NTS were virtually unknown. Results of our surveys indicate that desert tortoise can be expected, albeit in small numbers, in a wide range of Mojavean and Transitional habitats.

  17. Comparative water relations of adult and juvenile tortoise beetles: differences among sympatric species.

    PubMed

    Hull-Sanders, Helen M; Appel, Arthur G; Eubanks, Micky D

    2003-08-01

    Relative abundance of two sympatric tortoise beetles varies between drought and 'wet' years. Differing abilities to conserve water may influence beetle survival in changing environments. Cuticular permeability (CP), percentage of total body water (%TBW), rate of water loss and percentage of body lipid content were determined for five juvenile stages and female and male adults of two sympatric species of chrysomelid beetles, the golden tortoise beetle, Charidotella bicolor (F.) and the mottled tortoise beetle, Deloyala guttata (Olivier). There were significant differences in %TBW and lipid content among juvenile stages. Second instars had the greatest difference in CP (37.98 and 11.13 microgcm(-2)h(-1)mmHg(-1) for golden and mottled tortoise beetles, respectively). Mottled tortoise beetles had lower CP and greater %TBW compared with golden tortoise beetles, suggesting that they can conserve a greater amount of water and may tolerate drier environmental conditions. This study suggests that juvenile response to environmental water stress may differentially affect the survival of early instars and thus affect the relative abundance of adult beetles in the field. This is supported by the low relative abundance of golden tortoise beetle larvae in a drought year and the higher abundance in two 'wet' years.

  18. Abundance and distribution of selected elements in soils, stream sediments, and selected forage plants from desert tortoise habitats in the Mojave and Colorado deserts, USA

    USGS Publications Warehouse

    Chaffee, M.A.; Berry, K.H.

    2006-01-01

    A baseline and background chemical survey was conducted in southeastern California, USA, to identify potential sources of toxicants in natural and anthropogenically-altered habitats of the threatened desert tortoise (Gopherus agassizii). Soil, stream sediment, and plant samples were collected from six tortoise habitat study areas in the Mojave and Colorado deserts and analysed for up to 66 different elements. The chemical analyses provided new information on the abundances and distributions of selected elements in this region. Soil, stream-sediment, and plant analyses showed distinct variations in bulk chemistries from locality to locality. Variations were, in general, consistent with the many types of exposed rock units in the region, their highly variable bulk mineralogies, and chemical contents. Of elements in soils that might have been toxic to tortoises, only As seemed to be anomalous region-wide. Some soil and plant anomalies were clearly anthropogenic. In the Rand and Atolia mining districts, soil anomalies for As, Au, Cd, Hg, Sb, and(or) W and plant anomalies for As, Sb, and(or) W extend as far as ???15 km outward from the present area of mining; soils containing anomalous Hg were found at least 6 km away from old piles of tailings. The anomalous concentrations of As and Hg may have been the source of elevated levels of these elements found in ill tortoises from the region. In the Goldstone mining district, soil anomalies extended several km from the mining area. These areas probably represented anthropogenic surface contamination of dust redistributed by wind, vehicles, and rainfall. One of two study areas transected by a paved road (Chemehuevi Valley) showed weakly elevated levels of Pb, which extended as far as ???22 m from the pavement edge and were probably related to vehicle exhaust. No soil or plant samples from historically used military areas (Goldstone, Goffs, Chemehuevi Valley, Chuckwalla Bench) contained anomalous concentrations of the elements

  19. Factors affecting the thermal environment of Agassiz’s Desert Tortoise (Gopherus agassizii) cover sites in the Central Mojave Desert during periods of temperature extremes

    USGS Publications Warehouse

    Mack, Jeremy S.; Berry, Kristin H.; Miller, David; Carlson, Andrea S.

    2015-01-01

    Agassiz's Desert Tortoises (Gopherus agassizii) spend >95% of their lives underground in cover sites that serve as thermal buffers from temperatures, which can fluctuate >40°C on a daily and seasonal basis. We monitored temperatures at 30 active tortoise cover sites within the Soda Mountains, San Bernardino County, California, from February 2004 to September 2006. Cover sites varied in type and structural characteristics, including opening height and width, soil cover depth over the opening, aspect, tunnel length, and surficial geology. We focused our analyses on periods of extreme temperature: in summer, between July 1 and September 1, and winter, between November 1 and February 15. With the use of multivariate regression tree analyses, we found cover-site temperatures were influenced largely by tunnel length and subsequently opening width and soil cover. Linear regression models further showed that increasing tunnel length increased temperature stability and dampened seasonal temperature extremes. Climate change models predict increased warming for southwestern North America. Cover sites that buffer temperature extremes and fluctuations will become increasingly important for survival of tortoises. In planning future translocation projects and conservation efforts, decision makers should consider habitats with terrain and underlying substrate that sustain cover sites with long tunnels and expanded openings for tortoises living under temperature extremes similar to those described here or as projected in the future.

  20. Threats to desert tortoise populations: a critical review of the literature

    USGS Publications Warehouse

    Boarman, William I.

    2002-01-01

    Decision in resource management are generally based on a combination of sociopolitical, economic, and environmental factors, and may be biased by personal values. These three components often contradict each other resulting in controversy. Controversies can usually be reduced when solid scientific evidence is used to support or refute a decision. However, it is important to recognize that data often do little to alter antagonists' positions when differences in values are the bases if the dispute. But, supporting data can make the decision more defensible, both legally and ethically, especially if the data supporting all opposing viewpoints are included in the decision-making process. Resource management decisions must be made using the best scientific information currently available. However, scientific data vary in two important measures of quality: reliability and validity. The reliability of the data is a measure of the degree to which the observations or conclusion can be repeated. Validity of the data is a measure of the degree to which the observation or conclusion reflects what actually occurs in nature. How the data are collected strongly affects the reliability of validity of ecological conclusions that can be made. Research data potentially relevant to management come from different sources, and the source often provides clues to the reliability and, to a certain extent, validity of data. Understanding the quality of data being used to make management decisions helps to separate the philosophical or value-based aspects of arguments from the objective ones, thus helping to clarify the decisions and judgments that need to be made. The West Mojave Plan is a multispecies, bioregional plan for the management of natural resources within a 9.4 million-acre area of the Mojave Desert in California. The plan addresses the legal requirements for the recovery of the desert tortoise (Gopherus agazzizii), a threatened species, but also covers an additional

  1. Not putting all their eggs in one basket: bet-hedging despite extraordinary annual reproductive output of desert tortoises

    USGS Publications Warehouse

    Lovich, Jeffrey E.; Ennen, Joshua R.; Yackulic, Charles B.; Meyer-Wilkins, Kathie; Agha, Mickey; Loughran, Caleb L.; Bjurlin, Curtis; Austin, Meaghan; Madrak, Sheila V.

    2015-01-01

    Bet-hedging theory makes the counter-intuitive prediction that, if juvenile survival is low and unpredictable, organisms should consistently reduce short-term reproductive output to minimize the risk of reproductive failure in the long-term. We investigated the long-term reproductive output of an Agassiz's desert tortoise (Gopherus agassizii) population and conformance to a bet-hedging strategy of reproduction in an unpredictable but comparatively productive environment. Most females reproduced every year, even during periods of low precipitation and poor germination of food plants, and the mean percentage of reproducing females did not differ significantly on an annual basis. Although mean annual egg production (clutch size × clutch frequency) differed significantly among years, mean clutch size and mean clutch frequency remained relatively constant. During an El Niño year, mean annual egg production and mean annual clutch frequency were the highest ever reported for this species. Annual egg production was positively influenced by maternal body size but clutch size and clutch frequency were not. Our long-term results confirm earlier conclusions based on short-term research that desert tortoises have a bet-hedging strategy of producing small clutches almost every year. The risk of long-term reproductive failure is minimized in unpredictable environments, both through time by annually producing multiple small clutches over a long reproductive lifespan, even in years of low resource availability, and through space by depositing multiple annual clutches in different locations. The extraordinary annual reproductive output of this population appears to be the result of a typically high but unpredictable biomass of annual food plants at the site relative to tortoise habitat in dryer regions. Under the comparatively productive but unpredictable conditions, tortoises conform to predictions of a bet-hedging strategy of reproduction with relatively small but consistent

  2. Range-Wide Monitoring of the Mojave Desert Tortoise (Gopherus Agassizii): 2008 and 2009

    DTIC Science & Technology

    2012-09-01

    quality assurance and quality control .................................. 24  Tortoise encounter rate and development of detection functions ...encounter rates and detection functions .............................................................. 50  Proportion of tortoises that are available for...the Pinto Mountains, Joshua Tree, Chuckwalla, and Chocolate Mountain monitoring strata

  3. Mycoplasmal upper respiratory tract disease across the range of the threatened Mojave Desert tortoise: associations with thermal regime and natural antibodies.

    PubMed

    Sandmeier, Franziska C; Tracy, C Richard; Hagerty, Bridgette E; DuPré, Sally; Mohammadpour, Hamid; Hunter, Kenneth

    2013-03-01

    Most research of upper respiratory tract disease (mycoplasmal URTD) in the threatened Mojave Desert tortoise (Gopherus agassizii) has worked under the hypothesis that the pathogen, Mycoplasma agassizii, has a relatively consistent and predictable effect on tortoise populations across their natural range. In contrast, we hypothesized that multiple factors influence the prevalence of disease and analyzed biological and environmental variables that vary significantly across the Mojave Desert. We used multiple regression models to analyze associations between mycoplasmal URTD and the genetic structure of 24 tortoise populations, levels of natural antibody (NAb) to M. agassizii in tortoises (one component of the innate immune system), precipitation, and colder thermal regimes. We detected a significant, positive association between mean levels of NAb and seroprevalence to M. agassizii. We hypothesized that NAbs may provide tolerance to mycoplasmal infections and that more tolerant populations may act as host reservoirs of disease. We also detected significant associations between colder winters and mycoplasmal URTD, suggesting that colder winters may depress tortoise immune resistance against M. agassizii or enhance conditions for the growth of M. agassizii.

  4. Female Agassiz’s desert tortoise activity at a wind energy facility in southern California: The influence of an El Niño event

    USGS Publications Warehouse

    Ennen, Josh R.; Meyer-Wilkins, Kathie; Lovich, Jeffrey

    2012-01-01

    We compared spring-summer activity of adult female Agassiz’s Desert Tortoises (Gopherus agassizii) among three consecutive years (1997, 1998, and 1999) that differed dramatically in winter rainfall and annual plant production at a wind energy facility in the Sonoran Desert of southern California. Winter rainfall was approximately 71%, 190%, and 17% of the long-term average (October-March = 114 mm) for this area in water years (WY) 1997, 1998, and 1999, respectively. The substantial precipitation caused by an El Niño Southern Oscillation (ENSO) event in WY 1998 produced a generous annual food plant supply (138.2 g dry biomass/ m2) in the spring. Primary production of winter annuals during below average rainfall years (WY 1997 and WY 1999) was reduced to 98.3 and 0.2 g/m2, respectively. Mean rates of movement and mean body condition indices (mass/length) did not differ significantly among the years. The drought year following ENSO (WY 1999) was statistically similar to ENSO in every other measured value, while WY 1997 (end of a two year drought) was statistically different from ENSO using activity area, minimum number of burrows used, and percentage of non-movements. Our data suggest that female G. agassizii activity can be influenced by environmental conditions in previous years.

  5. Disease dynamics during wildlife translocations: disruptions to the host population and potential consequences for transmission in desert tortoise contact networks

    USGS Publications Warehouse

    Aiello, Christina M.; Nussear, Kenneth E.; Walde, Andrew D.; Esque, Todd C.; Emblidge, Patrick G.; Sah, Pratha; Bansal, S.; Hudson, Peter J.

    2014-01-01

    Wildlife managers consider animal translocation a means of increasing the viability of a local population. However, augmentation may disrupt existing resident disease dynamics and initiate an outbreak that would effectively offset any advantages the translocation may have achieved. This paper examines fundamental concepts of disease ecology and identifies the conditions that will increase the likelihood of a disease outbreak following translocation. We highlight the importance of susceptibility to infection, population size and population connectivity – a characteristic likely affected by translocation but not often considered in risk assessments – in estimating outbreak risk due to translocation. We then explore these features in a species of conservation concern often translocated in the presence of infectious disease, the Mojave Desert tortoise, and use data from experimental tortoise translocations to detect changes in population connectivity that may influence pathogen transmission. Preliminary analyses comparing contact networks inferred from spatial data at control and translocation plots and infection simulation results through these networks suggest increased outbreak risk following translocation due to dispersal-driven changes in contact frequency and network structure. We outline future research goals to test these concepts and aid managers in designing effective risk assessment and intervention strategies that will improve translocation success.

  6. Laser ablation ICP-MS profiling and semiquantitative determination of trace element concentrations in desert tortoise shells: Documenting the uptake of elemental toxicants

    USGS Publications Warehouse

    Seltzer, M.D.; Berry, K.H.

    2005-01-01

    The outer keratin layer (scute) of desert tortoise shells consists of incrementally grown laminae in which various bioaccumulated trace elements are sequestered during scute deposition. Laser ablation ICP-MS examination of laminae in scutes of dead tortoises revealed patterns of trace elemental distribution from which the chronology of elemental uptake can be inferred. These patterns may be of pathologic significance in the case of elemental toxicants such as arsenic, which has been linked to both shell and respiratory diseases. Laser ablation transects, performed along the lateral surfaces of sectioned scutes, offered the most successful means of avoiding exogenous contamination that was present on the scute exterior. Semiquantitative determination of elemental concentrations was achieved using sulfur, a keratin matrix element, as an internal standard. The results presented here highlight the potential of laser ablation ICP-MS as a diagnostic tool for investigating toxic element uptake as it pertains to tortoise morbidity and mortality.

  7. A new species of Isospora Schneider, 1881 (Apicomplexa: Eimeriidae) from Morafka's desert tortoise Gopherus morafkai (Testudines: Testudinidae).

    PubMed

    Hnida, John A

    2015-11-01

    Isospora gopheri n. sp. (Apicomplexa: Eimeriidae) is described from 5 of 28 (18%) Morafka's desert tortoise Gopherus morafkai Murphy, Berry, Edwards, Leviton, Lathrop & Readle, housed by the Phoenix Herpetological Society, Maricopa County, Arizona, USA. Sporulated oöcysts of this new species were spheroidal to subspheroidal, 20-27 × 19-27 (23.0 × 21.7) µm, with a smooth, bi-layered wall and 1-3 polar granules; an oöcyst residuum was absent. Sporocysts were elongate-ovoidal to ellipsoidal, 13-18 × 9-12 (15.9 × 10.2) µm, with a Stieda body, sub-Stieda body and sporocyst residuum; sporozoites were banana-shaped with an ellipsoidal posterior refractile body and a spheroidal anterior refractile body. This is both the first coccidian to be described from this host species and only the second reported from the host genus.

  8. Hematological values for adult eastern Hermann's tortoise (Testudo hermanni boettgeri) in semi-natural conditions.

    PubMed

    Bielli, Mattia; Nardini, Giordano; Di Girolamo, Nicola; Savarino, Paolo

    2015-01-01

    Hermann's tortoise (Testudo hermanni) is considered near threatened in the wild but, by contrast, it is one of the most popular pet tortoises in Europe. Scant data is reported in the veterinary literature on hematological values for T. hermanni and, to our knowledge, none focused on the subspecies boettgeri (eastern Hermann's tortoise). Published reports are based on small sample populations, and confusion arises when comparing the sampling sites, the anticoagulants, and the counting methods used. The purpose of the current study was to establish the normal mean values and reference intervals for the main hematological parameters for captive adult T. hermanni boettgeri and to evaluate the reliability of a semiautomated blood analyzer for red blood cell count and hematocrit determination. Blood values were determined in 23 adult tortoises using a Neubauer chamber with Natt and Herrick solution; red blood cells and hematocrit were also measured using a semiautomated blood analyzer. Statistical analysis included descriptive statistics, differences between sexes, and agreement between the counting methods. Reference intervals were calculated with the robust method. Wilcoxon signed rank test with continuity correction was used to investigate differences between sexes, and Bland-Altman analysis was performed to compare manual versus semiautomated values. Red blood cells, hematocrit, and hemoglobin determinations were significantly higher in males than in females. White blood cell counts did not show any sex variability. The agreement of manual versus semiautomated determination was considered acceptable for clinical use.

  9. Shaping species with ephemeral boundaries: The distribution and genetic structure of desert tortoise (Gopherus morafkai) in the Sonoran Desert region

    USGS Publications Warehouse

    Edwards, Taylor; Vaughn, Mercy; Rosen, Philip C.; Torres, Ma. Cristina Melendez; Karl, Alice E.; Culver, Melanie; Murphy, Robert W.

    2015-01-01

    The historically shifting ecotone between tropical deciduous forest and Sonoran desertscrub appears to be a boundary that fostered divergence between parapatric lineages of tortoises. The sharp genetic cline between the two lineages suggests that periods of isolation in temporary refugia due to Pleistocene climatic cycling influenced divergence. Despite incomplete reproductive isolation, the Sonoran and Sinaloan lineages of G. morafkai are on separate evolutionary trajectories.

  10. Desert Tortoise Head-start Program at Twentynine Palms Marine Base

    DTIC Science & Technology

    2013-04-02

    in the bird netting have allowed entry to a roadrunner, a burrowing owl and an antelope ground squirrel, and some tortoise mortality occurred before...discovered. The earlier surprising discoveries at the Edwards AFB facility of predation on eggs and hatchlings by Antelope ground squirrels and then by...closed. No predatory birds have since been seen inside. In 2012, we saw an antelope ground squirrel inside Enclosure #4, and there were some

  11. Gopher Tortoise Survey Handbook

    DTIC Science & Technology

    2009-03-01

    Paspalum notatum) pasture, a sand ridge with sand live oak scrub, and a patch of mature longleaf pine designated in the above figure as tortoise habitat...The work was completed under the direction of the Ecological Process Branch (CN-N) of the Installations Division (CN), Construction Engineer- ing...patterns of desert tortoises at multiple spatial scales. Chelonian Conservation and Biology 4:366–379. Martin, P. L., and J. L. Layne. 1987

  12. Studies of reproductive output of the desert tortoise at Joshua Tree National Park, the Mojave National Preserve, and comparative sites

    USGS Publications Warehouse

    Lovich, J.E.; Medica, P.; Avery, H.; Meyer, K.; Bowser, G.; Brown, A.

    1999-01-01

    The stability of any population is a function of how many young are produced and how many survive to reproduce. Populations with low reproductive output and high mortality will decline until such time as deaths and births are at least balanced. Monitoring populations of sensitive species is particularly important to ensure that conditions do not favor decline or extinction. Turtles, including tortoises, are characterized by life history traits that make them slow to adapt to rapid changes in mortality and habitat alteration. Long life spans (in excess of 50 years), late maturity, and widely variable nest success are traits that allowed turtles to outlive the dinosaurs, but they are poorly adapted for life in the rapidly changing modern world. Increased mortality of young and adults can seriously tip the delicate balance required for turtles to survive.

  13. Applications of GIS, Advanced Sensors and Habitat Modeling in Support of Desert Tortoise Line Distance, Sampling and Translocation Studies Related to the Proposed Expansion of the Ft. Irwin NTC

    DTIC Science & Technology

    2008-09-25

    Range Workshop in San Antonio, TX. Hurd, Wendy. (2006). Designing a Geodatabase : Using the Nest Survey Data for the Raven Management Project. Desert...program (the Desert Tortoise Project; DTP), was designed to improve terrestrial science and to explore and apply a variety of information science...are those of the author(s) and should not contrued as an official Department of the Army position, policy or decision, unless so designated by other

  14. Nest site characteristics, nesting movements, and lack of long-term nest site fidelity in Agassiz's desert tortoises at a wind energy facility in southern California

    USGS Publications Warehouse

    Lovich, Jeffrey E.; Agha, Mickey; Yackulic, Charles B.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Ennen, Joshua R.; Arundel, Terry R.; Austin, Meaghan

    2014-01-01

    Nest site selection has important consequences for maternal and offspring survival and fitness. Females of some species return to the same nesting areas year after year. We studied nest site characteristics, fidelity, and daily pre-nesting movements in a population of Agassiz’s desert tortoises (Gopherus agassizii) at a wind energy facility in southern California during two field seasons separated by over a decade. No females returned to the same exact nest site within or between years but several nested in the same general area. However, distances between first and second clutches within a year (2000) were not significantly different from distances between nests among years (2000 and 2011) for a small sample of females, suggesting some degree of fidelity within their normal activity areas. Environmental attributes of nest sites did not differ significantly among females but did among years due largely to changes in perennial plant structure as a result of multiple fires. Daily pre-nesting distances moved by females decreased consistently from the time shelled eggs were first visible in X-radiographs until oviposition, again suggesting some degree of nest site selection. Tortoises appear to select nest sites that are within their long-term activity areas, inside the climate-moderated confines of one of their self-constructed burrows, and specifically, at a depth in the burrow that minimizes exposure of eggs and embryos to lethal incubation temperatures. Nesting in “climate-controlled” burrows and nest guarding by females relaxes some of the constraints that drive nest site selection in other oviparous species.

  15. Nevada Test Site tortoise population monitoring study. Final report

    SciTech Connect

    Mueller, J.M.; Zander, K.K.

    1994-12-01

    A Tortoise Population Monitoring Study was initiated to determine and monitor the density of desert tortoises (Gopherus agassizii) on the Nevada Test Site. Quadrat sampling was conducted following methodology described in the Draft Desert Tortoise Recovery Plan (FWS, 1993). So few tortoises were found that densities could not be calculated. Based on estimates of capture probabilities and densities from other studies, it was determined that 1-km{sup 2} (0.4 mi{sup 2}) plots did not contain enough tortoises for estimating densities with the Recovery Plan methods. It was recommended that additional surveys on the Nevada Test Site using those methods not be conducted. Any future efforts to monitor desert tortoise densities should start by identifying other possible methods, determining their relative power to detect changes, and estimating their cost.

  16. A 30-year chronosequence of burned areas in Arizona: effects of wildfires on vegetation in Sonoran Desert Tortoise (Gopherus morafkai) habitats

    USGS Publications Warehouse

    Shryock, Daniel F.; Esque, Todd C.; Chen, Felicia C.

    2015-01-01

    Fire is widely regarded as a key evolutionary force in fire-prone ecosystems, with effects spanning multiple levels of organization, from species and functional group composition through landscape-scale vegetation structure, biomass, and diversity (Pausas and others, 2004; Bond and Keeley 2005; Pausas and Verdu, 2008). Ecosystems subjected to novel fire regimes may experience profound changes that are difficult to predict, including persistent losses of vegetation cover and diversity (McLaughlin and Bowers, 1982; Brown and Minnich, 1986; Brooks, 2012), losses to seed banks (Esque and others, 2010a), changes in demographic processes (Esque and others, 2004; DeFalco and others, 2010), increased erosion (Soulard and others, 2013), changes in nutrient availability (Esque and others, 2010b), increased dominance of invasive species (Esque and others, 2002; Brooks and others, 2004), and transitions to alternative community states (Davies and others, 2012). In the deserts of the Southwestern United States, fire size and frequency have increased substantially over the last several decades because of an invasive grass/fire feedback cycle (Schmid and Rogers, 1988; D’Antonio and Vitousek, 1992; Swantek and others, 1999; Brooks and Matchett, 2006; Esque and others, 2010a), in which invasive annual species are able to establish fuel loads capable of sustaining large-scale wildfires following years of high rainfall (Esque and Schwalbe, 2002). Native perennial vegetation is not well-adapted to fire in these environments, and widespread, physiognomically dominant species such as creosote bush (Larrea tridentata), Joshua tree (Yucca brevifolia), giant saguaro cactus (Carnegiea gigantea), and paloverde (Parkinsonia spp.) may be reduced or eliminated (Brown and Minnich, 1986; Esque and others, 2006; DeFalco and others, 2010), potentially affecting wildlife populations including the Sonoran and federally threatened Mojave Desert Tortoises (Gopherus morafkai and Gopherus agassizii

  17. Daily energy expenditure in free-ranging Gopher Tortoises (Gopherus polyphemus)

    USGS Publications Warehouse

    Jodice, P.G.R.; Epperson, D.M.; Visser, G. Henk

    2006-01-01

    Studies of ecological energetics in chelonians are rare. Here, we report the first measurements of daily energy expenditure (DEE) and water influx rates (WIRs) in free-ranging adult Gopher Tortoises (Gopherus polyphemus). We used the doubly labeled water (DLW) method to measure DEE in six adult tortoises during the non-breeding season in south-central Mississippi, USA. Tortoise DEE ranged from 76.7-187.5 kj/day and WIR ranged from 30.6-93.1 ml H2O/day. Daily energy expenditure did not differ between the sexes, but DEE was positively related to body mass. Water influx rates varied with the interaction of sex and body mass. We used a log/log regression model to assess the allometric relationship between DEE and body mass for Gopher Tortoises, Desert Tortoises (Gopherus agassizii), and Box Turtles (Terrapene carolina), the only chelonians for which DEE has been measured. The slope of this allometric model (0.626) was less than that previously calculated for herbivorous reptiles (0.813), suggesting that chelonians may expend energy at a slower rate per unit of body mass compared to other herbivorous reptiles. We used retrospective power analyses and data from the DLW isotope analyses to develop guidelines for sample sizes and duration of measurement intervals, respectively, for larger-scale energetic studies in this species. ?? 2006 by the American Society of Ichthyologists and Herpetologists.

  18. Are captive tortoises a reservoir for conservation? An assessment of genealogical affiliation of captive Gopherus agassizii to local, wild populations

    USGS Publications Warehouse

    Berry, Kristin H.; Edwards, Taylor

    2013-01-01

    The conservation of tortoises poses a unique situation because several threatened species are commonly kept as pets within their native ranges. Thus, there is potential for captive populations to be a reservoir for repatriation efforts. We assess the utility of captive populations of the threatened Agassiz’s desert tortoise (Gopherus agassizii) for recovery efforts based on genetic affinity to local areas. We collected samples from 130 captive desert tortoises from three desert communities: two in California (Ridgecrest and Joshua Tree) and the Desert Tortoise Conservation Center (Las Vegas) in Nevada. We tested all samples for 25 short tandem repeats and sequenced 1,109 bp of the mitochondrial genome. We compared captive genotypes to a database of 1,258 Gopherus samples, including 657 wild caught G. agassizii spanning the full range of the species. We conducted population assignment tests to determine the genetic origins of the captive individuals. For our total sample set, only 44 % of captive individuals were assigned to local populations based on genetic units derived from the reference database. One individual from Joshua Tree, California, was identified as being a Morafka’s desert tortoise, G. morafkai, a cryptic species which is not native to the Mojave Desert. Our data suggest that captive desert tortoises kept within the native range of G. agassizii cannot be presumed to have a genealogical affiliation to wild tortoises in their geographic proximity. Precautions should be taken before considering the release of captive tortoises into the wild as a management tool for recovery.

  19. Morphometrics, sexual dimorphism, and growth in the Angonoka tortoise (Geochelone yniphora) of western Madagascar

    USGS Publications Warehouse

    Smith, Lora L.; Pedrono, Miguel; Dorazio, Robert M.; Bishko, Jack

    2001-01-01

    The most recent description of the morphology of the rare endemic Madagascar tortoise,Geochelone yniphora was based on fewer than 20 specimens. We collected morphological data for 200 free‐ranging tortoises from five populations over a four‐year period. Tortoises ranged in size from 43.5 mm carapace length at hatching to a maximum of 481 mm in an adult male. We were able to develop a logistic regression model to predict the sex of adult tortoises in one of the five populations using principal component analysis; the model correctly predicted the sex of 25 of 26 adult tortoises. Growth of 40 tortoises was monitored and as in other chelonians, the annual relative growth rate decreased with age. The relative growth rate in adults was approximately 5% per year as compared to approximately 16% in juveniles. Juvenile tortoises accrued one scute growth layer per year.

  20. Body size development of captive and free-ranging Leopard tortoises (Geochelone pardalis).

    PubMed

    Ritz, Julia; Hammer, Catrin; Clauss, Marcus

    2010-01-01

    The growth and weight development of Leopard tortoise hatchings (Geochelone pardalis) kept at the Al Wabra Wildlife Preservation (AWWP), Qatar, was observed for more than four years, and compared to data in literature for free-ranging animals on body weight or carapace measurements. The results document a distinctively faster growth in the captive animals. Indications for the same phenomenon in other tortoise species (Galapagos giant tortoises, G. nigra; Spur-thighed tortoises, Testudo graeca; Desert tortoises, Gopherus agassizi) were found in the literature. The cause of the high growth rate most likely is the constant provision with highly digestible food of low fiber content. Increased growth rates are suspected to have negative consequences such as obesity, high mortality, gastrointestinal illnesses, renal diseases, "pyramiding," fibrous osteodystrophy or metabolic bone disease. The apparently widespread occurrence of high growth rates in intensively managed tortoises underlines how easily ectothermic animals can be oversupplemented with nutrients.

  1. Field Verification of the Prediction Model on Desert Locust Adult Phase Status From Density and Vegetation

    PubMed Central

    Cissé, S.; Ghaout, S.; Babah Ebbe, M. A; Kamara, S; Piou, C.

    2016-01-01

    Previous studies investigated the effect of vegetation on density thresholds of adult Desert Locust gregarization from historical data in Mauritania. We examine here the prediction of locust phase based on adult density and vegetation conditions using the statistical model from Cisse et al. compared with actual behavior of Desert Locust adults observed in the field in Mauritania. From the 130 sites where adult locusts were found, the model predicted the phase of Desert Locust adults with a relatively small error of prediction of 6.1%. Preventive locust control should be rational, based on a risk assessment. The staff involved in implementation of the preventive control strategy needs specific indicators for when or where chemical treatment should be done. In this respect, we show here that the statistical model of Cisse et al. may be appropriate. PMID:27432351

  2. Field Verification of the Prediction Model on Desert Locust Adult Phase Status From Density and Vegetation.

    PubMed

    Cissé, S; Ghaout, S; Babah Ebbe, M A; Kamara, S; Piou, C

    2016-01-01

    Previous studies investigated the effect of vegetation on density thresholds of adult Desert Locust gregarization from historical data in Mauritania. We examine here the prediction of locust phase based on adult density and vegetation conditions using the statistical model from Cisse et al. compared with actual behavior of Desert Locust adults observed in the field in Mauritania. From the 130 sites where adult locusts were found, the model predicted the phase of Desert Locust adults with a relatively small error of prediction of 6.1%. Preventive locust control should be rational, based on a risk assessment. The staff involved in implementation of the preventive control strategy needs specific indicators for when or where chemical treatment should be done. In this respect, we show here that the statistical model of Cisse et al. may be appropriate.

  3. Response of Gopher Tortoises to Habitat Manipulation by Prescribed Burning: Can Forested Areas Adjacent to Training Areas Be Improved

    DTIC Science & Technology

    2006-04-01

    Herpetology , 26: 158–165. Dietlein, N.E., and R. Franz (1979) Status and habits of Gopherus polyphemus. In Proceedings, 1979 Symposium of the Desert Tortoise...Nesting and hatchling ecology of Gopher Tortoises (Gopherus polyphemus) in southern Mississippi. Journal of Herpetology , 37: 315–324. 38 ERDC/CERL TR-06

  4. Upper Respiratory Tract Disease in the Gopher Tortoise Is Caused by Mycoplasma agassizii†

    PubMed Central

    Brown, M. B.; McLaughlin, G. S.; Klein, P. A.; Crenshaw, B. C.; Schumacher, I. M.; Brown, D. R.; Jacobson, E. R.

    1999-01-01

    Upper respiratory tract disease (URTD) has been observed in a number of tortoise species, including the desert tortoise (Gopherus agassizii) and the gopher tortoise (Gopherus polyphemus). Clinical signs of URTD in gopher tortoises are similar to those in desert tortoises and include serous, mucoid, or purulent discharge from the nares, excessive tearing to purulent ocular discharge, conjunctivitis, and edema of the eyelids and ocular glands. The objectives of the present study were to determine if Mycoplasma agassizii was an etiologic agent of URTD in the gopher tortoise and to determine the clinical course of the experimental infection in a dose-response infection study. Tortoises were inoculated intranasally with 0.5 ml (0.25 ml/nostril) of either sterile SP4 broth (control group; n = 10) or 108 color-changing units (CCU) (total dose) of M. agassizii 723 (experimental infection group; n = 9). M. agassizii caused clinical signs compatible with those observed in tortoises with natural infections. Clinical signs of URTD were evident in seven of nine experimentally infected tortoises by 4 weeks postinfection (p.i.) and in eight of nine experimentally infected tortoises by 8 weeks p.i. In the dose-response experiments, tortoises were inoculated intranasally with a low (101 CCU; n = 6), medium (103 CCU; n = 6), or high (105 CCU; n = 5) dose of M. agassizii 723 or with sterile SP4 broth (n = 10). At all time points p.i. in both experiments, M. agassizii could be isolated from the nares of at least 50% of the tortoises. All of the experimentally infected tortoises seroconverted, and levels of antibody were statistically higher in infected animals than in control animals for all time points of >4 weeks p.i. (P < 0.0001). Control tortoises in both experiments did not show clinical signs, did not seroconvert, and did not have detectable M. agassizii by either culture or PCR at any point in the study. Histological lesions were compatible with those observed in tortoises with

  5. Lichens On Galapagos Giant Tortoises.

    PubMed

    Hendrickson, J R; Weber, W A

    1964-06-19

    The association of Physcia picta with the giant Galdpagos tortoise is believed to be the first reported occurrence of lichens on land animals. The habitat is restricted to specific sites on the carapace of male tortoises.

  6. Mass spectral determination of phenylacetonitrile (PAN) levels in body tissues of adult desert locust, Schistocerca gregaria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Wings and legs of the gregarious desert locust, Schistocerca gregaria have been shown to be release sites of phenylacetonitrile (PAN), the major adult male-produced pheromone. However, there is limited information on the distribution of PAN within the locust. Here we show, using gas chromatograph...

  7. Mycoplasmosis and upper respiratory tract disease of tortoises: a review and update

    USGS Publications Warehouse

    Jacobson, Elliott R.; Brown, Mary B.; Wendland, Lori; Brown, Daniel R.; Klein, Paul A.; Christopher, Mary M.; Berry, Kristin H.

    2014-01-01

    Tortoise mycoplasmosis is one of the most extensively characterized infectious diseases of chelonians. A 1989 outbreak of upper respiratory tract disease (URTD) in free-ranging Agassiz's desert tortoises (Gopherus agassizii) brought together an investigative team of researchers, diagnosticians, pathologists, immunologists and clinicians from multiple institutions and agencies. Electron microscopic studies of affected tortoises revealed a microorganism in close association with the nasal mucosa that subsequently was identified as a new species, Mycoplasma agassizii. Over the next 24 years, a second causative agent, Mycoplasma testudineum, was discovered, the geographic distribution and host range of tortoise mycoplasmosis were expanded, diagnostic tests were developed and refined for antibody and pathogen detection, transmission studies confirmed the pathogenicity of the original M. agassizii isolate, clinical (and subclinical) disease and laboratory abnormalities were characterized, many extrinsic and predisposing factors were found to play a role in morbidity and mortality associated with mycoplasmal infection, and social behavior was implicated in disease transmission. The translation of scientific research into management decisions has sometimes led to undesirable outcomes, such as euthanasia of clinically healthy tortoises. In this article, we review and assess current research on tortoise mycoplasmosis, arguably the most important chronic infectious disease of wild and captive North American and European tortoises, and update the implications for management and conservation of tortoises in the wild.

  8. Habitat characteristics of North American tortoises: chapter 9

    USGS Publications Warehouse

    Nussear, Kenneth E.; Tuberville, Tracey D.

    2014-01-01

    North American tortoises are distributed in semi-arid and temperate deserts and coastal regions of the southern United States and Mexico. The five species currently recognized each have specific habitat requirements, which they fulfill through their selection of, and interaction with unique habitat constituents. In this chapter we discuss the physiographic and geological associations, perennial and annual vegetation components, shelter sites, and climatic conditions associated with the species’ habitats, as well as the potential threats to their habitat.

  9. Sulawesi tortoise adenovirus-1 in two impressed tortoises (Manouria impressa) and a Burmese star tortoise (Geochelone platynota).

    PubMed

    Schumacher, Vanessa L; Innis, Charles J; Garner, Michael M; Risatti, Guillermo R; Nordhausen, Robert W; Gilbert-Marcheterre, Kelly; Wellehan, James F X; Childress, April L; Frasca, Salvatore

    2012-09-01

    Sulawesi tortoise adenovirus-1 (STAdV-1) is a newly discovered virus infecting endangered and threatened tortoises. It was initially described from a confiscated group of 105 Sulawesi tortoises (Indotestudo forsteni) obtained by the Turtle Survival Alliance and distributed to five sites with available veterinary care across the United States. In a 3-yr period from the initial outbreak, one multi-species collection that rehabilitated and housed adenovirus-infected Sulawesi tortoises experienced deaths in impressed tortoises (Manouria impressa) and a Burmese star tortoise (Geochelone platynota). Impressed tortoises that died had evidence of systemic viral infection with histopathologic features of adenovirus. Adenovirus was identified by consensus nested polymerase chain reaction (PCR) testing and subsequent sequencing of PCR products. Sequencing indicated that the adenovirus infecting these impressed tortoises and Burmese star tortoise was STAdV-1. In one impressed tortoise, viral infection was confirmed using transmission electron microscopy. In situ hybridization using a semiautomated protocol and fluorescein-labeled riboprobe identified STAdV-1 inclusions in spleen, liver, kidney, and testis of one impressed tortoise. The impact of this virus on captive and wild populations of tortoises is unknown; however, these findings indicate that STAdV-1 can be transmitted to and can infect other tortoise species, the impressed tortoise and Burmese star tortoise, when cohabitated with infected Sulawesi tortoises.

  10. Assessing the potential to restore historic grazing ecosystems with tortoise ecological replacements.

    PubMed

    Griffiths, Christine J; Zuël, Nicolas; Jones, Carl G; Ahamud, Zairabee; Harris, Stephen

    2013-08-01

    The extinction of large herbivores, often keystone species, can dramatically modify plant communities and impose key biotic thresholds that may prevent an ecosystem returning to its previous state and threaten native biodiversity. A potentially innovative, yet controversial, landscape-based long-term restoration approach is to replace missing plant-herbivore interactions with non-native herbivores. Aldabran giant (Aldabrachelys gigantea) and Madagascan radiated (Astrochelys radiata) tortoises, taxonomically and functionally similar to the extinct Mauritian giant tortoises (Cylindraspis spp.), were introduced to Round Island, Mauritius, in 2007 to control the non-native plants that were threatening persistence of native species. We monitored the response of the plant community to tortoise grazing for 11 months in enclosures before the tortoises were released and, compared the cost of using tortoises as weeders with the cost of using manual labor. At the end of this period, plant biomass; vegetation height and cover; and adult, seedling, flower, and seed abundance were 3-136 times greater in adjacent control plots than in the tortoise enclosures. After their release, the free-roaming tortoises grazed on most non-native plants and significantly reduced vegetation cover, height, and seed production, reflecting findings from the enclosure study. The tortoises generally did not eat native species, although they consumed those native species that increased in abundance following the eradication of mammalian herbivores. Our results suggest that introduced non-native tortoises are a more cost-effective approach to control non-native vegetation than manual weeding. Numerous long-term outcomes (e.g., change in species composition and soil seed bank) are possible following tortoise releases. Monitoring and adaptive management are needed to ensure that the replacement herbivores promote the recovery of native plants.

  11. Equivalency of Galápagos giant tortoises used as ecological replacement species to restore ecosystem functions.

    PubMed

    Hunter, Elizabeth A; Gibbs, James P; Cayot, Linda J; Tapia, Washington

    2013-08-01

    Loss of key plant-animal interactions (e.g., disturbance, seed dispersal, and herbivory) due to extinctions of large herbivores has diminished ecosystem functioning nearly worldwide. Mitigating for the ecological consequences of large herbivore losses through the use of ecological replacements to fill extinct species' niches and thereby replicate missing ecological functions has been proposed. It is unknown how different morphologically and ecologically a replacement can be from the extinct species and still provide similar functions. We studied niche equivalency between 2 phenotypes of Galápagos giant tortoises (domed and saddlebacked) that were translocated to Pinta Island in the Galápagos Archipelago as ecological replacements for the extinct saddlebacked giant tortoise (Chelonoidis abingdonii). Thirty-nine adult, nonreproductive tortoises were introduced to Pinta Island in May 2010, and we observed tortoise resource use in relation to phenotype during the first year following release. Domed tortoises settled in higher, moister elevations than saddlebacked tortoises, which favored lower elevation arid zones. The areas where the tortoises settled are consistent with the ecological conditions each phenotype occupies in its native range. Saddlebacked tortoises selected areas with high densities of the arboreal prickly pear cactus (Opuntia galapageia) and mostly foraged on the cactus, which likely relied on the extinct saddlebacked Pinta tortoise for seed dispersal. In contrast, domed tortoises did not select areas with cactus and therefore would not provide the same seed-dispersal functions for the cactus as the introduced or the original, now extinct, saddlebacked tortoises. Interchangeability of extant megaherbivores as replacements for extinct forms therefore should be scrutinized given the lack of equivalency we observed in closely related forms of giant tortoises. Our results also demonstrate the value of trial introductions of sterilized individuals to test

  12. Enriching tortoises: assessing color preference.

    PubMed

    Passos, Luiza F; Mello, Humberto Espirito Santo; Young, Robert John

    2014-01-01

    Environmental enrichment is a principle that is used to enhance the quality of care for nonhuman animals in captivity. To achieve this, it is necessary to understand the animal's needs. This study focused on color preference to provide food stimuli as a source of environmental enrichment for the tortoise, Chelonoidis denticulata. During this study, the stimuli green-, blue-, yellow-, and red-colored bananas and plaster blocks were randomly offered to the tortoises. Analysis of the data showed that the tortoises had a preference for the stimuli dyed with colors red and yellow over the other presented colors. It was possible to conclude that presenting food in different colors stimulated the animals to evaluate their environment and make choices in relation to their color preference. Thus, this experiment introduced an element of choice into their lives, beyond identifying color food preferences for the tortoises. The element of choice is known to be important to animal welfare.

  13. Infestation of the spur-thighed tortoise (Testudo graeca) by Hyalomma aegyptium in Tunisia.

    PubMed

    Gharbi, Mohamed; Rjeibi, Mohamed Ridha; Rouatbi, Mariem; Mabrouk, Moez; Mhadhbi, Moez; Amairia, Safa; Amdouni, Yosra; Boussaadoun, Mohamed Anis

    2015-04-01

    We examined 210 spur-thighed tortoises (Testudo graeca) for the presence of ticks in Tunisia during May 2014. A total number of 602 adult ticks were collected and identified leading to the estimation of parasitological indicators. All the ticks belonged to a single species: Hyalomma aegyptium. The mean infestation prevalence was 66.2%, mean overall infestation intensity and abundance were 4.33 and 2.86 ticks/tortoise respectively. Our survey showed that tortoises were significantly more infested by male ticks than females (p<0.001). The ticks were mainly present in the posterior limbs compared to other body regions (p<0.05). There was no significance variation of length and weight of tortoises according to sex (p<0.05). There was a significant correlation between the tortoises' size (length and weight) and tick infestation. This study showed high tick burdens of spur-thighed tortoises in Tunisia; further investigations are needed to determine exactly the role of this tick species in the transmission of different zoonotic pathogens.

  14. Cryptosporidiosis caused by two distinct species in Russian tortoises and a pancake tortoise.

    PubMed

    Griffin, Chris; Reavill, Drury R; Stacy, Brian A; Childress, April L; Wellehan, James F X

    2010-05-28

    Cryptosporidiosis in squamates is well documented, but there is very limited information available on cryptosporidiosis in testudines. We describe three cases of cryptosporidiosis in tortoises with associated pathology. Two Russian tortoises (Agrionemys [Testudo] horsfieldii) and a pancake tortoise (Malacochersus tornieri), all from separate collections, were found dead. At necropsy, two had histological evidence of intestinal cryptosporidiosis and one had gastric cryptosporidiosis. Consensus Cryptosporidium sp. PCR and sequencing was used to identify the Cryptosporidium sp. present in these three tortoises. In the juvenile Russian tortoise with gastric cryptosporidiosis, the organism had 98% homology with a previously reported sequence from an Indian star tortoise isolate. A second chelonian Cryptosporidium sp. was identified in the pancake tortoise and the second Russian tortoise. This sequence was 100% identical to a shorter gene sequence previously reported in a marginated tortoise. This is the first report coordinating pathology with Cryptosporidium characterization in chelonians. The two Cryptosporidium sp. found in tortoises segregate according to site of infection, and there may be further differences in pathology, host range, and transmission. These Cryptosporidium sp. appear to be able to infect diverse tortoise host species. This may be an under-recognized problem in tortoises.

  15. Using Range-Wide Abundance Modeling to Identify Key Conservation Areas for the Micro-Endemic Bolson Tortoise (Gopherus flavomarginatus)

    PubMed Central

    Ureña-Aranda, Cinthya A.; Rojas-Soto, Octavio; Martínez-Meyer, Enrique; Yáñez-Arenas, Carlos; Landgrave Ramírez, Rosario; Espinosa de los Monteros, Alejandro

    2015-01-01

    A widespread biogeographic pattern in nature is that population abundance is not uniform across the geographic range of species: most occurrence sites have relatively low numbers, whereas a few places contain orders of magnitude more individuals. The Bolson tortoise Gopherus flavomarginatus is endemic to a small region of the Chihuahuan Desert in Mexico, where habitat deterioration threatens this species with extinction. In this study we combined field burrows counts and the approach for modeling species abundance based on calculating the distance to the niche centroid to obtain range-wide abundance estimates. For the Bolson tortoise, we found a robust, negative relationship between observed burrows abundance and distance to the niche centroid, with a predictive capacity of 71%. Based on these results we identified four priority areas for the conservation of this microendemic and threatened tortoise. We conclude that this approach may be a useful approximation for identifying key areas for sampling and conservation efforts in elusive and rare species. PMID:26115482

  16. Using Range-Wide Abundance Modeling to Identify Key Conservation Areas for the Micro-Endemic Bolson Tortoise (Gopherus flavomarginatus).

    PubMed

    Ureña-Aranda, Cinthya A; Rojas-Soto, Octavio; Martínez-Meyer, Enrique; Yáñez-Arenas, Carlos; Landgrave Ramírez, Rosario; Espinosa de los Monteros, Alejandro

    2015-01-01

    A widespread biogeographic pattern in nature is that population abundance is not uniform across the geographic range of species: most occurrence sites have relatively low numbers, whereas a few places contain orders of magnitude more individuals. The Bolson tortoise Gopherus flavomarginatus is endemic to a small region of the Chihuahuan Desert in Mexico, where habitat deterioration threatens this species with extinction. In this study we combined field burrows counts and the approach for modeling species abundance based on calculating the distance to the niche centroid to obtain range-wide abundance estimates. For the Bolson tortoise, we found a robust, negative relationship between observed burrows abundance and distance to the niche centroid, with a predictive capacity of 71%. Based on these results we identified four priority areas for the conservation of this microendemic and threatened tortoise. We conclude that this approach may be a useful approximation for identifying key areas for sampling and conservation efforts in elusive and rare species.

  17. Body condition and habitat use by Hermann's tortoises in burnt and intact habitats

    PubMed Central

    Lecq, S.; Ballouard, J.-M.; Caron, S.; Livoreil, B.; Seynaeve, V.; Matthieu, L.-A.; Bonnet, X.

    2014-01-01

    In Mediterranean regions, fires threaten terrestrial tortoises. Nevertheless, varying proportions of adults survive fire; these surviving individuals can play a central role for population recovery. The regions devastated by fire often include important habitat of Hermann's tortoises (Testudo hermanni hermanni), so assessing the ability of survivors to persist is essential for conserving the species. Body-condition indices provide an integrative estimate of how well individuals cope with environmental variations and impacts, including fires. Between 2002 and 2009, we monitored Hermann's tortoises in intact and burnt habitats in southeastern France. In summer 2003, a strong fire ravaged half of the surveyed zone, providing an opportunity to compare body condition of tortoises between intact and burnt areas over time. Six years later, the impact of fire on vegetation was still marked; large trees were abundant in the intact area, whereas open shrub vegetation prevailed in the burnt area. In both areas, the mean body condition of tortoises fluctuated over time; however, there were no differences between the two areas. A radio-tracking experiment demonstrated that individuals from each area were residents, and not vagrants commuting between areas. We also assessed changes in body condition and microhabitat use in radio-tracked individuals. We found no significant differences between the tortoises living in the burnt and intact areas, despite subtle differences in habitat use. In conclusion: (i) surviving tortoises in an area ravaged by fire can maintain their body condition like individuals living in an intact area, and thus, individuals from burnt areas should not be translocated to supposedly better areas; and (ii) depopulated burnt areas are likely to be appropriate for population-augmentation programmes. PMID:27293640

  18. Genetic and morphometric assessment of an unusual tortoise (Gopherus agassizii) population in the Black Mountains of Arizona

    USGS Publications Warehouse

    McLuckie, A.M.; Lamb, T.; Schwalbe, C.R.; Mccord, R.D.

    1999-01-01

    Under recent regulatory designation of the U.S. Fish and Wildlife Service, desert tortoises (Gopherus agassizii) occurring east and south of the Colorado River constitute the Sonoran population, whereas those to the west and north form the Mojave population. These management units, distinguished by significant genetic, morphometric, and ecological differences, represent deep phylogenetic subdivisions within G. agassizii and are of high conservation value. We provide genetic and morphological profiles for an unusual tortoise population inhabiting the Black Mountains of Arizona, some 40 km east of the Colorado River. Both mitochondrial (mt) DNA and morphometric analyses revealed predominately Mojavean features: ten of eleven Black Mountain tortoises possessed Mojave mtDNA markers, and 24 of 37 animals exhibited Mojave morphometric phenotypes. Our results indicate west-to-east movement of tortoises across the Colorado River, though how or when a Mojave lineage became established in the Black Mountains is difficult to ascertain. Active dispersal, river meander, and human transport (early or modern peoples) serve as plausible explanations. Future management of the Black Mountain tortoises should emphasize the population's Mojavean affinities.

  19. Sonoran Desert: Fragile Land of Extremes

    USGS Publications Warehouse

    Produced and Directed by Wessells, Stephen

    2003-01-01

    'Sonoran Desert: Fragile Land of Extremes' shows how biologists with the U.S. Geological Survey work with other scientists in an effort to better understand native plants and animals such as desert tortoises, saguaro cacti, and Gila monsters. Much of the program was shot in and around Saguaro National Park near Tucson, Arizona. Genetic detective work, using DNA, focuses on understanding the lives of tortoises. Studies of saguaros over many decades clarify how these amazing plants reproduce and thrive in the desert. Threats from fire, diseases in tortoises, and a growing human population motivate the scientists. Their work to identify how these organisms live and survive is a crucial step for the sound management of biological resources on public lands. This 28-minute program, USGS Open-File Report 03-305, was shot entirely in high definition video and produced by the USGS Western Ecological Research Center and Southwest Biological Science Center; produced and directed by Stephen Wessells, Western Region Office of Communications.

  20. Digesta retention time in the Galápagos tortoise (Chelonoidis nigra).

    PubMed

    Sadeghayobi, Elham; Blake, Stephen; Wikelski, Martin; Gibbs, James; Mackie, Roderick; Cabrera, Fredy

    2011-12-01

    The retention time of food in the digestive tract of animals has important implications for digestive physiology. Retention time impacts digestive efficiency and among herbivores affects plant-animal interactions including herbivory and seed dispersal. Poorly studied yet iconic Galápagos tortoises are large-bodied generalist herbivores and ecosystem engineers which migrate seasonally. Potentially variable digesta retention times due to strong seasonal and altitudinal temperature gradients may influence tortoise seed dispersal abilities and rates of herbivory. We fed captive adult tortoises living in semi-natural conditions on Galápagos with inert particles and seeds from locally available fruits to determine whether seed size and ambient temperature influenced retention time. Median retention time varied from 6 to 28days, with a mode of 12days. Seed size had no effect on any of our measures of retention time, but ambient temperature was inversely correlated with retention times. Long retention time facilitates long distance seed dispersal by Galápagos tortoises, which may improve effectiveness. The effect of temperature, which may double from hot lowlands to cold highlands through the seasonal cycle, on tortoise digesta retention time will strongly influence seed dispersal efficiency and may influence patterns of food selection and migration in this species.

  1. Hepatitis associated with herpes viral infection in the tortoise (Testudo horsfieldii).

    PubMed

    Hervás, J; Sánchez-Cordón, P J; de Chacón Lara, F; Carrasco, L; Gómez-Villamandos, J C

    2002-03-01

    Herpesvirus infection in tortoises is largely characterized by the development of respiratory clinical signs. Usually lesions develop in the respiratory, oral pharyngeal, intestinal tract and are accompanied by cutaneous and ocular lesions. In chelonids affected by herpesvirus, systemic-type lesions in organs such as the liver and spleen are commonly observed. In this paper we describe a case of multifocal necrotic hepatitis associated with herpesviruses in an adult female land tortoise of the species Testudo horsfieldii. This article is the first description of a viral hepatitis in Testudo spp. with lesions compatible with herpesvirus infection, with no clinical signs or lesions in the respiratory system, oral cavity or other organs.

  2. The dependence of Hyalomma aegyptium on its tortoise host Testudo graeca in Algeria.

    PubMed

    Tiar, G; Tiar-Saadi, M; Benyacoub, S; Rouag, R; Široký, P

    2016-09-01

    Hyalomma aegyptium (Linnaeus, 1758) (Ixodida: Ixodidae) has recently been confirmed as a carrier of numerous pathogenic, including zoonotic, agents. Four environmentally distinct regions of Algeria, located between the humid coastal zone and the arid Saharan Atlas range, were selected in order to compare differences in tick abundance among localities, and the correlations between tick abundance and host population characteristics and other environmental conditions. Sampling was carried out during May and early June in 2010-2012. A total of 1832 H. aegyptium were removed from 201 tortoises. Adult ticks accounted for 52% of the collection. In the pre-adult stages, larvae were dominant. Data on prevalence, intensity (mean ± standard deviation, range) and abundance of tick infestation were calculated for each locality. Locally, prevalences reached 100%. The sex ratio was biased in favour of males (4.2). Intensities of infestation differed significantly among the localities studied for all developmental stages of the tick. The intensity of infestation by adult ticks was positively correlated to the size of the tortoise and with tortoise population density in the habitat. However, findings for immature tick stages were independent of both variables. No significant correlations between infestation intensities and the climatic parameters tested were found. Immature ticks were observed to prefer the front parts of their tortoise hosts, whereas the majority of adults were attached to the rear parts.

  3. Biogeography of Parasitic Nematode Communities in the Galápagos Giant Tortoise: Implications for Conservation Management

    PubMed Central

    Fournié, Guillaume; Goodman, Simon J.; Cruz, Marilyn; Cedeño, Virna; Vélez, Alberto; Patiño, Leandro; Millins, Caroline; Gibbons, Lynda M.; Fox, Mark T.; Cunningham, Andrew A.

    2015-01-01

    The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host. PMID:26332126

  4. Biogeography of Parasitic Nematode Communities in the Galápagos Giant Tortoise: Implications for Conservation Management.

    PubMed

    Fournié, Guillaume; Goodman, Simon J; Cruz, Marilyn; Cedeño, Virna; Vélez, Alberto; Patiño, Leandro; Millins, Caroline; Gibbons, Lynda M; Fox, Mark T; Cunningham, Andrew A

    2015-01-01

    The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host.

  5. Detection of antibodies against paramyxoviruses in tortoises.

    PubMed

    Rösler, Reinhild; Abbas, Maha Diekan; Papp, Tibor; Marschang, Rachel E

    2013-06-01

    Sera from a total of 202 tortoises from six countries and nine species were tested for antibodies against four different reptilian paramyxoviruses (ferlaviruses, ferlaVs) by hemagglutination inhibition (HI) test. The viruses used were a tortoise PMV (tPMV) and three squamatid PMV isolates, each belonging to a different subgroup of ferlaV within the genus Ferlavirus. HI tests revealed that antibodies against ferlaVs occurred regularly in the tested samples (5.5%). One and a half percent of the tested samples have measurable antibody titers against the group A isolate, 3% had antibodies against the group B isolate, and 1% had antibodies against the group C isolate. The significantly highest number of positive reactions was detected against the tortoise isolate (5%). Most of the animals that tested positive for one of the snake isolates also tested positive in HI assays with the tortoise isolate. Of the samples from different origins, the sera from Great Britain showed the highest percentage of positive tested animals (10.3%, n = 39), followed by those from Spain (10%, n = 10), while none of the samples from Madagascar or Italy scored positive. Since in most cases animals from one country came from the same collection, this does not represent the real prevalence of ferlaV in tortoises in these countries but rather indicates that ferlaVs occur in a number of different countries and tortoise species.

  6. Desert Tortoise series data report: 1983 pressurized ammonia spills

    SciTech Connect

    Goldwire, H.C. Jr.; McRae, T.G.; Johnson, G.W.; Hipple, D.L.; Koopman, R.P.; McClure, J.W.; Morris, L.K.; Cederwall, R.T.

    1985-12-01

    A series of four pressurized ammonia spills up to 60 m/sup 3/ in size were performed at Frenchman Flat in Nevada as a part of a joint government-industry study. This data report presents a description of how the tests were conducted and the data from the tests.

  7. Vegetation dynamics drive segregation by body size in Galapagos tortoises migrating across altitudinal gradients.

    PubMed

    Blake, Stephen; Yackulic, Charles B; Cabrera, Fredy; Tapia, Washington; Gibbs, James P; Kümmeth, Franz; Wikelski, Martin

    2013-03-01

    Seasonal migration has evolved in many taxa as a response to predictable spatial and temporal variation in the environment. Individual traits, physiology and social state interact with environmental factors to increase the complexity of migratory systems. Despite a huge body of research, the ultimate causes of migration remain unclear. A relatively simple, tractable system - giant tortoises on Santa Cruz Island, Galapagos, was studied to elucidate the roles of environmental variation and individual traits in a partial migratory system. Specifically, we asked: (i) do Galapagos tortoises undergo long-distance seasonal migrations? (ii) is tortoise migration ultimately driven by gradients in forage quality or temperature; and (iii) how do sex and body size influence migration patterns? We recorded the daily locations of 17 GPS-tagged tortoises and walked a monthly survey along the altitudinal gradient to characterize the movements and distribution of tortoises of different sizes and sexes. Monthly temperature and rainfall data were obtained from weather stations deployed at various altitudes, and the Normalized Difference Vegetation Index was used as a proxy for forage quality. Analyses using net displacement or daily movement characteristics did not agree on assigning individuals as either migratory or non-migratory; however, both methods suggested that some individuals were migratory. Adult tortoises of both sexes move up and down an altitudinal gradient in response to changes in vegetation dynamics, not temperature. The largest tagged individuals all moved, whereas only some mid-sized individuals moved, and the smallest individuals never left lowland areas. The timing of movements varied with body size: large individuals moved upward (as lowland forage quality declined) earlier in the year than did mid-sized individuals, while the timing of downward movements was unrelated to body size and occurred as lowland vegetation productivity peaked. Giant tortoises are

  8. Negative impacts of invasive plants on conservation of sensitive desert wildlife

    USGS Publications Warehouse

    Drake, K. Kristina; Bowen, Lizabeth; Nussear, Kenneth E.; Esque, Todd C.; Berger, Andrew J.; Custer, Nathan; Waters, Shannon C.; Johnson, Jay D.; Miles, A. Keith; Lewison, Rebecca L.

    2016-01-01

    Habitat disturbance from development, resource extraction, off-road vehicle use, and energy development ranks highly among threats to desert systems worldwide. In the Mojave Desert, United States, these disturbances have promoted the establishment of nonnative plants, so that native grasses and forbs are now intermixed with, or have been replaced by invasive, nonnative Mediterranean grasses. This shift in plant composition has altered food availability for Mojave Desert tortoises (Gopherus agassizii), a federally listed species. We hypothesized that this change in forage would negatively influence the physiological ecology, immune competence, and health of neonatal and yearling tortoises. To test this, we monitored the effects of diet on growth, body condition, immunological responses (measured by gene transcription), and survival for 100 captive Mojave tortoises. Tortoises were assigned to one of five diets: native forbs, native grass, invasive grass, and native forbs combined with either the native or invasive grass. Tortoises eating native forbs had better body condition and immune functions, grew more, and had higher survival rates (>95%) than tortoises consuming any other diet. At the end of the experiment, 32% of individuals fed only native grass and 37% fed only invasive grass were found dead or removed from the experiment due to poor body conditions. In contrast, all tortoises fed either the native forb or combined native forb and native grass diets survived and were in good condition. Health and body condition quickly declined for tortoises fed only the native grass (Festuca octoflora) or invasive grass (Bromus rubens) with notable loss of fat and muscle mass and increased muscular atrophy. Bromus rubens seeds were found embedded in the oral mucosa and tongue in most individuals eating that diet, which led to mucosal inflammation. Genes indicative of physiological, immune, and metabolic functions were transcribed at lower levels for individuals fed B

  9. Localizing Tortoise Nests by Neural Networks.

    PubMed

    Barbuti, Roberto; Chessa, Stefano; Micheli, Alessio; Pucci, Rita

    2016-01-01

    The goal of this research is to recognize the nest digging activity of tortoises using a device mounted atop the tortoise carapace. The device classifies tortoise movements in order to discriminate between nest digging, and non-digging activity (specifically walking and eating). Accelerometer data was collected from devices attached to the carapace of a number of tortoises during their two-month nesting period. Our system uses an accelerometer and an activity recognition system (ARS) which is modularly structured using an artificial neural network and an output filter. For the purpose of experiment and comparison, and with the aim of minimizing the computational cost, the artificial neural network has been modelled according to three different architectures based on the input delay neural network (IDNN). We show that the ARS can achieve very high accuracy on segments of data sequences, with an extremely small neural network that can be embedded in programmable low power devices. Given that digging is typically a long activity (up to two hours), the application of ARS on data segments can be repeated over time to set up a reliable and efficient system, called Tortoise@, for digging activity recognition.

  10. Localizing Tortoise Nests by Neural Networks

    PubMed Central

    2016-01-01

    The goal of this research is to recognize the nest digging activity of tortoises using a device mounted atop the tortoise carapace. The device classifies tortoise movements in order to discriminate between nest digging, and non-digging activity (specifically walking and eating). Accelerometer data was collected from devices attached to the carapace of a number of tortoises during their two-month nesting period. Our system uses an accelerometer and an activity recognition system (ARS) which is modularly structured using an artificial neural network and an output filter. For the purpose of experiment and comparison, and with the aim of minimizing the computational cost, the artificial neural network has been modelled according to three different architectures based on the input delay neural network (IDNN). We show that the ARS can achieve very high accuracy on segments of data sequences, with an extremely small neural network that can be embedded in programmable low power devices. Given that digging is typically a long activity (up to two hours), the application of ARS on data segments can be repeated over time to set up a reliable and efficient system, called Tortoise@, for digging activity recognition. PMID:26985660

  11. Ancient tortoise hunting in the southwest Pacific

    PubMed Central

    Hawkins, Stuart; Worthy, Trevor H.; Bedford, Stuart; Spriggs, Matthew; Clark, Geoffrey; Irwin, Geoff; Best, Simon; Kirch, Patrick

    2016-01-01

    We report the unprecedented Lapita exploitation and subsequent extinction of large megafauna tortoises (?Meiolania damelipi) on tropical islands during the late Holocene over a 281,000 km2 region of the southwest Pacific spanning from the Vanuatu archipelago to Viti Levu in Fiji. Zooarchaeological analyses have identified seven early archaeological sites with the remains of this distinctive hornless tortoise, unlike the Gondwanan horned meiolaniid radiation to the southwest. These large tortoise radiations in the Pacific may have contributed to the rapid dispersal of early mobile Neolithic hunters throughout southwest Melanesia and on to western Polynesia. Subsequent rapid extinctions of these terrestrial herbivorous megafauna are likely to have led to significant changes in ecosystems that help explain changes in current archaeological patterns from Post-Lapita contexts in the region. PMID:27922064

  12. Ancient tortoise hunting in the southwest Pacific

    NASA Astrophysics Data System (ADS)

    Hawkins, Stuart; Worthy, Trevor H.; Bedford, Stuart; Spriggs, Matthew; Clark, Geoffrey; Irwin, Geoff; Best, Simon; Kirch, Patrick

    2016-12-01

    We report the unprecedented Lapita exploitation and subsequent extinction of large megafauna tortoises (?Meiolania damelipi) on tropical islands during the late Holocene over a 281,000 km2 region of the southwest Pacific spanning from the Vanuatu archipelago to Viti Levu in Fiji. Zooarchaeological analyses have identified seven early archaeological sites with the remains of this distinctive hornless tortoise, unlike the Gondwanan horned meiolaniid radiation to the southwest. These large tortoise radiations in the Pacific may have contributed to the rapid dispersal of early mobile Neolithic hunters throughout southwest Melanesia and on to western Polynesia. Subsequent rapid extinctions of these terrestrial herbivorous megafauna are likely to have led to significant changes in ecosystems that help explain changes in current archaeological patterns from Post-Lapita contexts in the region.

  13. Analysis and Assessment of Impacts on Biodiversity: Investigating Alternative Futures for the California Mojave Desert

    DTIC Science & Technology

    2004-07-01

    cactus, annual forbs, grasses, and wildflowers. Desert Tortoises live in burrows where they may spend 95% of their lives, and where they estivate in...squirrel will estivate in a burrow until conditions improve. While running it holds its tail over it back exposing the white underside. It is

  14. Observations on the female reproductive cycle of captive giant tortoises (Geochelone spp.) using ultrasound scanning.

    PubMed

    Casares, M; Rübel, A; Honegger, R E

    1997-09-01

    The reproductive activities of one adult female Galápagos tortoise (Geochelone nigra) and three adult female Aldabra tortoises (Geochelone gigantea) were monitored over 2 yr using ultrasound scanning. A nonrestraining technique of tactile stimulation was used for all examinations. Developing, preovulatory, and atretic ovarian follicles, as well as eggs at various stages of shell deposition, were identified and measured. In G. nigra, follicles became preovulatory at a diameter of 40-42 mm and eggs were laid 34-84 days (mean = 55.6, n = 5) after the thin-shelled eggs were first detected in the oviducts. Geochelone nigra was capable of retaining eggs, with the shell already formed, until the next breeding season. No eggs have been produced by G. gigantea during their stay in Zürich Zoo although follicles of 38-40 mm have been observed frequently in two animals.

  15. Giant Galapagos tortoises walk without inverted pendulum mechanical-energy exchange.

    PubMed

    Zani, Peter A; Gottschall, Jinger S; Kram, Rodger

    2005-04-01

    Animals must perform mechanical work during walking, but most conserve substantial mechanical energy via an inverted-pendulum-like mechanism of energy recovery in which fluctuations of kinetic energy (KE) and gravitational potential energy (GPE) are of similar magnitude and 180 degrees out of phase. The greatest energy recovery typically occurs at intermediate speeds. Tortoises are known for their slow speeds, which we anticipated would lead to small fluctuations in KE. To have an effective exchange of mechanical energy using the inverted-pendulum mechanism, tortoises would need to walk with only small changes in GPE corresponding to vertical center-of-mass (COM) fluctuations of < 0.5 mm. Thus, we hypothesized that giant Galapagos tortoises would not conserve substantial mechanical energy using the inverted-pendulum mechanism. We studied five adult giant Galapagos tortoises Geochelone elephantopus (mean mass=142 kg; range= 103-196 kg). Walking speed was extremely slow (0.16+/-0.052 m s(-1); mean +/- 1 s.d.). The fluctuations in kinetic energy (8.1+/-3.98 J stride(-1)) were only one-third as large as the fluctuations in gravitational potential energy (22.7+/-8.04 J stride(-1)). In addition, these energies fluctuated nearly randomly and were only sporadically out of phase. Because of the dissimilar amplitudes and inconsistent phase relationships of these energies, tortoises conserved little mechanical energy during steady walking, recovering only 29.8+/-3.77% of the mechanical energy (range=13-52%). Thus, giant Galapagos tortoises do not utilize effectively an inverted-pendulum mechanism of energy conservation. Nonetheless, the mass-specific external mechanical work required per distance (0.41+/-0.092 J kg(-1) m(-1)) was not different from most other legged animals. Other turtle species use less than half as much metabolic energy to walk as other terrestrial animals of similar mass. It is not yet known if Galapagos tortoises are economical walkers. Nevertheless

  16. Biology and medicine of turtles and tortoises.

    PubMed

    Mautino, M; Page, C D

    1993-11-01

    Turtles and tortoises are unique reptiles that are gaining popularity as pets. Their anatomy and defense posture hinder, but do not preclude, clinical assessment and performance of routine diagnostic and therapeutic procedures by the clinician. A basic working knowledge of chelonian taxonomy, anatomy, physiology, husbandry, common diseases, and therapeutics will enable the veterinarian to provide health care to this order of reptiles.

  17. Digestive parameters and water turnover of the leopard tortoise.

    PubMed

    McMaster, Megan K; Downs, Colleen T

    2008-09-01

    Leopard tortoises (Stigmochelys pardalis) experience wide fluctuations in environmental conditions and unpredictable availability of food and water within the Nama-Karoo biome. It was hypothesised that tortoises fed two diets differing in preformed water and fibre content would have differing food intake, gut transit rate, assimilation efficiency, faecal and urinary water loss, and urine concentrations. It was predicted that tortoises fed these contrasting diets would attempt to maintain energy and water balance by altering their digestive parameters. Leopard tortoises fed lucerne (Medicago sativa) had a low food intake coupled with long gut transit times, which resulted in the lowest amount of faecal energy and faecal water lost. Tortoises fed tomatoes (Solanum lycopersicum) had higher food intake and faster gut transit times, but more energy and water was lost in the faeces. However, daily energy assimilated and assimilation efficiency were comparable between tortoises fed the two diets. Urine osmolality was significantly different between tortoises on the two diets. Results indicate that leopard tortoises can adjust parameters such as transit rate, food intake, water loss and urine osmolality to maintain body mass, water and energy balance in response to a high fibre, low water content and a low fibre, high water content diet. This study suggests that this digestive flexibility allows leopard tortoises in the wild to take advantage of unpredictable food and water resources.

  18. 42 CFR 71.52 - Turtles, tortoises, and terrapins.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Turtles, tortoises, and terrapins. 71.52 Section 71..., INSPECTION, LICENSING FOREIGN QUARANTINE Importations § 71.52 Turtles, tortoises, and terrapins. (a) Definitions. As used in this section the term: Turtles includes all animals commonly known as...

  19. 42 CFR 71.52 - Turtles, tortoises, and terrapins.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Turtles, tortoises, and terrapins. 71.52 Section 71..., INSPECTION, LICENSING FOREIGN QUARANTINE Importations § 71.52 Turtles, tortoises, and terrapins. (a) Definitions. As used in this section the term: Turtles includes all animals commonly known as...

  20. 42 CFR 71.52 - Turtles, tortoises, and terrapins.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Turtles, tortoises, and terrapins. 71.52 Section 71..., INSPECTION, LICENSING FOREIGN QUARANTINE Importations § 71.52 Turtles, tortoises, and terrapins. (a) Definitions. As used in this section the term: Turtles includes all animals commonly known as...

  1. 42 CFR 71.52 - Turtles, tortoises, and terrapins.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Turtles, tortoises, and terrapins. 71.52 Section 71..., INSPECTION, LICENSING FOREIGN QUARANTINE Importations § 71.52 Turtles, tortoises, and terrapins. (a) Definitions. As used in this section the term: Turtles includes all animals commonly known as...

  2. 42 CFR 71.52 - Turtles, tortoises, and terrapins.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Turtles, tortoises, and terrapins. 71.52 Section 71..., INSPECTION, LICENSING FOREIGN QUARANTINE Importations § 71.52 Turtles, tortoises, and terrapins. (a) Definitions. As used in this section the term: Turtles includes all animals commonly known as...

  3. Detection of Mycoplasma agassizii in the Texas Tortoise (Gopherus berlandieri)

    USGS Publications Warehouse

    Guthrie, Amanda L.; White, C. LeAnn; Brown, Mary B.; deMaar, Thomas W.

    2013-01-01

    Mycoplasma agassizii causes upper respiratory tract disease (URTD) in Texas tortoises (Gopherus berlandieri). To determine exposure to and shedding of M. agassizii, we collected blood samples and nasal swabs from 40 free-ranging Texas tortoises on public and private lands in Texas, USA, from May to October 2009. We used an enzyme-linked immunosorbent assay (ELISA) to detect M. agassizii–specific antibodies. Eleven (28%) tortoises were antibody positive, three (8%) were suspect, and the remaining 26 (65%) were negative. Nasal lavage samples were collected from 35 of the 40 tortoises for M. agassizii culture and PCR to detect shedding of M. agassizii. Current infection with M. agassizii was confirmed in one tortoise that had mild clinical signs of URTD and was positive by ELISA (antibody titer >512), PCR, and culture. The clinical isolate was confirmed as M. agassizii by restriction fragment length polymorphism and immunobinding.

  4. Study of the carapace shape and growth in two Galápagos tortoise lineages.

    PubMed

    Chiari, Ylenia; Claude, Julien

    2011-03-01

    Galápagos tortoises possess two main shell forms, domed and saddleback, that correlate with the biogeographic history of this species group. However, the lack of description of morphological shell variation within and among populations has prevented the understanding of the contribution of evolutionary forces and the potential role of ontogeny in shaping morphological shell differences. Here, we analyze two lineages of Galápagos tortoises inhabiting Santa Cruz Island by applying geometric morphometrics in combination with a photogrammetry 3D reconstruction method on a set of tortoises of different ages (from juvenile to adult). The aim of this study is to describe morphological features on the carapace that could be used for taxonomic recognition by taking into account confounding factors, such as the morphological changes occurring during growth. Our results indicate that despite the shared similarities of growth patterns and of morphological changes observed during growth, the two lineages and the different sexes can be distinguished on the basis of distinct carapace features. Lineages differ by the shape of the vertebral (especially concerning their width) and pleural scutes, with one lineage having a more compressed carapace shape, whereas the other possesses a carapace that is more elongated and expanded toward the sides as well as an higher positioning of the first vertebral scute. Furthermore, females have a more elongated and wider carapace shape than males. Finally, carapace shape changes with growth, with vertebral scutes becoming narrower and pleural scutes becoming larger during late ontogeny.

  5. Desert Communities.

    ERIC Educational Resources Information Center

    NatureScope, 1985

    1985-01-01

    Provides: (1) background information on desert communities, their similarities, and differences; (2) student activities on this topic; and (3) ready-to-copy student pages with pictures of desert animals and plants. Each activity includes objective(s), recommended age level(s), subject area(s), list of materials needed, and procedures. (DH)

  6. Testing Taxon Tenacity of Tortoises: evidence for a geographical selection gradient at a secondary contact zone

    PubMed Central

    Edwards, Taylor; Berry, Kristin H; Inman, Richard D; Esque, Todd C; Nussear, Kenneth E; Jones, Cristina A; Culver, Melanie

    2015-01-01

    We examined a secondary contact zone between two species of desert tortoise, Gopherus agassizii and G. morafkai. The taxa were isolated from a common ancestor during the formation of the Colorado River (4–8 mya) and are a classic example of allopatric speciation. However, an anomalous population of G. agassizii comes into secondary contact with G. morafkai east of the Colorado River in the Black Mountains of Arizona and provides an opportunity to examine reinforcement of species' boundaries under natural conditions. We sampled 234 tortoises representing G. agassizii in California (n - 103), G. morafkai in Arizona (n - 78), and 53 individuals of undetermined assignment in the contact zone including and surrounding the Black Mountains. We genotyped individuals for 25 STR loci and determined maternal lineage using mtDNA sequence data. We performed multilocus genetic clustering analyses and used multiple statistical methods to detect levels of hybridization. We tested hypotheses about habitat use between G. agassizii and G. morafkai in the region where they co-occur using habitat suitability models. Gopherus agassizii and G. morafkai maintain independent taxonomic identities likely due to ecological niche partitioning, and the maintenance of the hybrid zone is best described by a geographical selection gradient model. PMID:26045959

  7. Testing taxon tenacity of tortoises: evidence for a geographical selection gradient at a secondary contact zone

    USGS Publications Warehouse

    Edwards, Taylor; Berry, Kristin H.; Inman, Richard D.; Esque, Todd C.; Nussear, Kenneth E.; Jones, Cristina A.; Culver, Melanie

    2015-01-01

    We examined a secondary contact zone between two species of desert tortoise, Gopherus agassizii and G. morafkai. The taxa were isolated from a common ancestor during the formation of the Colorado River (4-8 mya) and are a classic example of allopatric speciation. However, an anomalous population of G. agassizii comes into secondary contact with G. morafkai east of the Colorado River in the Black Mountains of Arizona and provides an opportunity to examine reinforcement of species' boundaries under natural conditions. We sampled 234 tortoises representing G. agassizii in California (n = 103), G. morafkai in Arizona (n = 78), and 53 individuals of undetermined assignment in the contact zone including and surrounding the Black Mountains. We genotyped individuals for 25 STR loci and determined maternal lineage using mtDNA sequence data. We performed multilocus genetic clustering analyses and used multiple statistical methods to detect levels of hybridization. We tested hypotheses about habitat use between G. agassizii and G. morafkai in the region where they co-occur using habitat suitability models. Gopherus agassizii and G. morafkai maintain independent taxonomic identities likely due to ecological niche partitioning, and the maintenance of the hybrid zone is best described by a geographical selection gradient model.

  8. Gastrointestinal parasitic burdens in UK tortoises: a survey of tortoise owners and potential risk factors.

    PubMed

    Hedley, J; Eatwell, K; Shaw, D J

    2013-11-30

    Despite gastrointestinal parasites being commonly diagnosed in captive tortoises throughout the UK, there is a lack of data regarding the prevalence. The aims of this study were to investigate the prevalence of gastrointestinal parasites in tortoises in the UK, and to investigate the factors affecting the prevalence of these parasites. Owners were invited to submit a faecal sample from their tortoise in conjunction with a completed questionnaire covering details of signalment and husbandry. Data from the questionnaires were analysed at the end of the study. Faecal analysis was performed on samples from Testudo hermanni, Testudo graeca and Testudo horsfieldii. This involved examination of direct wet preparations, a modified McMaster technique, passive NaCl flotation and Cryptosporidium staining. Of the 142 samples used, 130 were examined by the first three methods. 49 per cent were positive for one or more parasites. Of the positive samples, 67 per cent were positive for oxyurids, 28 per cent were positive for ascarids and 28 per cent were positive for protozoa (Balantidium, Nyctotherus or flagellates). Only 1/113 (0.8 per cent) samples was positive for Cryptosporidium. The most important risk factors for parasites were sex (F) and length of time (<5 years) in owner's possession. This survey showed that gastrointestinal parasites are frequently detected in the faecal samples of captive tortoises in the UK, but their prevalence may be influenced by various factors including sex, length of time owned, age and species.

  9. The dazed and confused identity of Agassiz's land tortoise, Gopherus agassizii (Testudines, Testudinidae) with the description of a new species, and its consequences for conservation

    USGS Publications Warehouse

    Murphy, R.W.; Berry, K.H.; Edwards, T.; Leviton, A.E.; Lathrop, A.; Riedle, J.D.

    2011-01-01

    We investigate a cornucopia of problems associated with the identity of the desert tortoise, Gopherus agassizii (Cooper). The date of publication is found to be 1861, rather than 1863. Only one of the three original cotypes exists, and it is designated as the lectotype of the species. Another cotype is found to have been destroyed in the 1906 San Francisco earthquake and subsequent fire. The third is lost. The lectotype is genetically confirmed to be from California, and not Arizona, USA as sometimes reported. Maternally, the holotype of G. lepidocephalus (Ottley & Vel??zques Solis. 1989) from the Cape Region of Baja California Sur, Mexico is also from the Mojavian population of the desert tortoise, and not from Tiburon Island, Sonora, Mexico as previously proposed. A suite of characters serve to diagnose tortoises west and north of the Colorado River, the Mojavian population, from those east and south of the river in Arizona, USA, and Sonora and Sinaloa, Mexico, the Sonoran population. Species recognition is warranted and because G. lepidocephalus is from the Mojavian population, no names are available for the Sonoran species. Thus, a new species, Gopherus morafkai sp. n., is named and this action reduces the distribution of G. agassizii to only 30% of its former range. This reduction has important implications for the conservation and protection of G. agassizii, which may deserve a higher level of protection. ?? Robert W. Murphy et al.

  10. The dazed and confused identity of Agassiz's land tortoise, Gopherus agassizii (Testudines, Testudinidae) with the description of a new species, and its consequences for conservation

    USGS Publications Warehouse

    Murphy, Robert K.; Berry, Kristin; Edwards, Taylor; Leviton, Alan E.; Lathrop, Amy; Riedle, J. Daren

    2011-01-01

    We investigate a cornucopia of problems associated with the identity of the desert tortoise, Gopherus agassizii Cooper. The date of publication is found to be 1861, rather than 1863. Only one of the three original cotypes exists, and it is designated as the lectotype of the species. Another cotype is found to have been destroyed in the 1906 San Francisco earthquake and subsequent fire. The third is lost. The lectotype is genetically confirmed to be from California, and not Arizona, USA as sometimes reported. Maternally, the holotype of G. lepidocephalus Ottley et Velázques Solis, 1989 from the Cape Region of Baja California Sur, Mexico is also from the Mojavian population of the desert tortoise, and not from Tiburon Island, Sonora, Mexico as previously proposed. A suite of characters serve to diagnose tortoises west and north of the Colorado River, the Mojavian population, from those east and south of the river in Arizona, USA and Sonora and Sinaloa, Mexico, the Sonoran population. Species recognition is warranted and because G. lepidocephalus is from the Mojavian population no names are available for the Sonoran species. Thus, a new species, Gopherus morafkai sp. n., is named and this action reduces the distribution of G. agassizii to only 30% of its former range. This reduction has important implications for the conservation and protection of G. agassizii, which may deserve a higher level of protection.

  11. The dazed and confused identity of Agassiz's land tortoise, Gopherus agassizii (Testudines, Testudinidae) with the description of a new species, and its consequences for conservation.

    PubMed

    Murphy, Robert W; Berry, Kristin H; Edwards, Taylor; Leviton, Alan E; Lathrop, Amy; Riedle, J Daren

    2011-01-01

    We investigate a cornucopia of problems associated with the identity of the desert tortoise, Gopherus agassizii (Cooper). The date of publication is found to be 1861, rather than 1863. Only one of the three original cotypes exists, and it is designated as the lectotype of the species. Another cotype is found to have been destroyed in the 1906 San Francisco earthquake and subsequent fire. The third is lost. The lectotype is genetically confirmed to be from California, and not Arizona, USA as sometimes reported. Maternally, the holotype of Gopherus lepidocephalus (Ottley & Velázques Solis. 1989) from the Cape Region of Baja California Sur, Mexico is also from the Mojavian population of the desert tortoise, and not from Tiburon Island, Sonora, Mexico as previously proposed. A suite of characters serve to diagnose tortoises west and north of the Colorado River, the Mojavian population, from those east and south of the river in Arizona, USA, and Sonora and Sinaloa, Mexico, the Sonoran population. Species recognition is warranted and because Gopherus lepidocephalus is from the Mojavian population, no names are available for the Sonoran species. Thus, a new species, Gopherus morafkaisp. n., is named and this action reduces the distribution of Gopherus agassizii to only 30% of its former range. This reduction has important implications for the conservation and protection of Gopherus agassizii, which may deserve a higher level of protection.

  12. The dazed and confused identity of Agassiz’s land tortoise, Gopherus agassizii (Testudines, Testudinidae) with the description of a new species, and its consequences for conservation

    PubMed Central

    Murphy, Robert W.; Berry, Kristin H.; Edwards, Taylor; Leviton, Alan E.; Lathrop, Amy; Riedle, J. Daren

    2011-01-01

    Abstract We investigate a cornucopia of problems associated with the identity of the desert tortoise, Gopherus agassizii (Cooper). The date of publication is found to be 1861, rather than 1863. Only one of the three original cotypes exists, and it is designated as the lectotype of the species. Another cotype is found to have been destroyed in the 1906 San Francisco earthquake and subsequent fire. The third is lost. The lectotype is genetically confirmed to be from California, and not Arizona, USA as sometimes reported. Maternally, the holotype of Gopherus lepidocephalus (Ottley & Velázques Solis. 1989) from the Cape Region of Baja California Sur, Mexico is also from the Mojavian population of the desert tortoise, and not from Tiburon Island, Sonora, Mexico as previously proposed. A suite of characters serve to diagnose tortoises west and north of the Colorado River, the Mojavian population, from those east and south of the river in Arizona, USA, and Sonora and Sinaloa, Mexico, the Sonoran population. Species recognition is warranted and because Gopherus lepidocephalus is from the Mojavian population, no names are available for the Sonoran species. Thus, a new species, Gopherus morafkai sp. n., is named and this action reduces the distribution of Gopherus agassizii to only 30% of its former range. This reduction has important implications for the conservation and protection of Gopherus agassizii, which may deserve a higher level of protection. PMID:21976992

  13. Cryptosporidium testudinis sp. n., Cryptosporidium ducismarci Traversa, 2010 and Cryptosporidium tortoise genotype III (Apicomplexa: Cryptosporidiidae) in tortoises.

    PubMed

    Jezkova, Jana; Horcickova, Michaela; Hlaskova, Lenka; Sak, Bohumil; Kvetonova, Dana; Novak, Jan; Hofmannova, Lada; McEvoy, John; Kvac, Martin

    2016-10-14

    Understanding of the diversity of species of Cryptosporidium Tyzzer, 1910 in tortoises remains incomplete due to the limited number of studies on these hosts. The aim of the present study was to characterise the genetic diversity and biology of cryptosporidia in tortoises of the family Testudinidae Batsch. Faecal samples were individually collected immediately after defecation and were screened for presence of cryptosporidia by microscopy using aniline-carbol-methyl violet staining, and by PCR amplification and sequence analysis targeting the small subunit rRNA (SSU), Cryptosporidium oocyst wall protein (COWP) and actin genes. Out of 387 faecal samples from 16 tortoise species belonging to 11 genera, 10 and 46 were positive for cryptosporidia by microscopy and PCR, respectively. All samples positive by microscopy were also PCR positive. Sequence analysis of amplified genes revealed the presence of the Cryptosporidium tortoise genotype I (n = 22), C. ducismarci Traversa, 2010 (n = 23) and tortoise genotype III (n = 1). Phylogenetic analyses of SSU, COWP and actin gene sequences revealed that Cryptosporidium tortoise genotype I and C. ducismarci are genetically distinct from previously described species of Cryptosporidium. Oocysts of Cryptosporidium tortoise genotype I, measuring 5.8-6.9 µm × 5.3-6.5 µm, are morphologically distinguishable from C. ducismarci, measuring 4.4-5.4 µm × 4.3-5.3 µm. Oocysts of Cryptosporidium tortoise genotype I and C. ducismarci obtained from naturally infected Russian tortoises (Testudo horsfieldii Gray) were infectious for the same tortoise but not for Reeve's turtles (Mauremys reevesii [Gray]), common garter snake (Thamnophis sirtalis [Linnaeus]), zebra finches (Taeniopygia guttata [Vieillot]) and SCID mice (Mus musculus Linnaeus). The prepatent period was 11 and 6 days post infection (DPI) for Cryptosporidium tortoise genotype I and C. ducismarci, respectively; the patent period was longer than 200 days for both cryptosporidia

  14. Tick (Amblyomma chabaudi) infestation of endemic tortoises in southwest Madagascar and investigation of tick-borne pathogens.

    PubMed

    Ehlers, Julian; Ganzhorn, Jörg U; Silaghi, Cornelia; Krüger, Andreas; Pothmann, Daniela; Ratovonamana, R Yedidya; Veit, Alexandra; Keller, Christian; Poppert, Sven

    2016-03-01

    Little is known about the role of endemic ticks as vectors for bacterial and protozoan pathogens for animals and humans in Madagascar and their interaction in anthropogenic habitats where humans, their livestock and native Malagasy species (vectors and hosts) come into more frequent contact than in natural forest ecosystems. The aims of the study were (1) to test whether habitat degradation is associated with increased infestation of tortoises by ticks and (2) to investigate whether ticks carried Babesia, Borrelia or Rickettsia species that might be pathogenic for humans and livestock. We studied hard ticks of two endemic Malagasy tortoises, Astrochelys radiata and Pyxis arachnoides in March and April 2013 in southwest Madagascar. Two tortoise habitats were compared, the National Park of Tsimanampetsotsa and the adjacent degraded pasture and agricultural land at the end of the wet season. Ticks were screened for protozoan and bacterial pathogens via PCR on DNA isolated from ticks using genus-specific primers. Only one out of 42 A. radiata collected from both habitats had ticks. The low prevalence did not allow further analyses of the effect of habitat degradation. Forty-two P. arachnoides were found in the anthropogenic habitat and 36 individuals in the national park. Tick infestation rates of P. arachnoides differed significantly between the two study sites. Tortoises inside the park had lower tick prevalence than outside (8 of 36 (22%) versus 32 of 42 individuals (76%)) and infected animals tended to have fewer ticks inside than outside the park. All ticks collected in both habitats were adults of the ixodid tick Amblyomma chabaudi, which is supposed to be a host-specific tick of P. arachnoides. Screening for Borrelia sp. and Babesia sp. was negative in all ticks. But all A. chabaudi ticks were infected with Rickettsia africae, known to cause spotted fever in humans. Thus, habitat degradation seems to be linked to higher infestation of tortoises with ticks with

  15. Evolutionary divergency of giant tortoises in Gal?pagos

    USGS Publications Warehouse

    Fritts, T.H.

    1984-01-01

    The giant tortoises in the Galapagos Archipelago diverge considerably in size, and in shape and other carapace characteristics. The saddleback morphotype is known only from insular faunas lacking large terrestrial predators (i.e. Galapagos and Mauritius) and in Galapagos is associated with xeric habitats where vertical feeding range and vertical reach in agonistic encounters are adaptive. The large domed morphotype is associated with relatively cool, mesic habitats where intraspecific competition for food and other resources may be less intense than in xeric habitats. Other external characteristics that differ between tortoise populations are also correlated with ecological variation. Tortoises have radiated into a mosaic of ecological conditions in the Galapagos but critical data are lacking on the role of genetic and environmental controls on phenotypic variation. Morphological divergence in tortoises is potentially a better indicator of present ecological conditions than of evolutionary relationships.

  16. Desert Dermatoses (Thar Desert, India)

    PubMed Central

    Chatterjee, Col Manas

    2017-01-01

    Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is, therefore, important to survival. Infections are the most common conditions seen among this population, and among them, fungal infections are the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis, and skin tumors are found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions. PMID:28216726

  17. Desert Dermatoses (Thar Desert, India).

    PubMed

    Chatterjee, Col Manas

    2017-01-01

    Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is, therefore, important to survival. Infections are the most common conditions seen among this population, and among them, fungal infections are the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis, and skin tumors are found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions.

  18. Modeling Fog Oil Obscurant Smoke Penetration into Simulated Tortoise Burrows

    DTIC Science & Technology

    2006-11-01

    requested by a petition in January 2006 (Save Our Big Scrub, Inc. and Wild South 2006 ). At least 18 military bases are known to have gopher tortoises...Wilson et al . 1997). Among the training activities that occur in or near the gopher tortoise habitat is troop preparedness training and the field...dispersion characteristics, and safety (Eberhard et al . 1989). SGF-2 fog oil (FO) is the obscurant used most frequently for military training

  19. Habitat Selection by the Gopher Tortoise (Gopherus polyphemus)

    DTIC Science & Technology

    2007-03-01

    distribution. Herpetological Review 32:191. Clark, E.E. 2003. Relocation and population modeling for gopher tortoise recovery. M.S. Thesis...Gopherus polyphemus in northern Florida. Journal of Herpetology 26:158-165. Diemer, J.E. 1992b. Demography of the tortoise Gopherus polyphemus...in northern Florida. Journal of Herpetology 26:281-289. ERDC/CERL TR-07-1 33 Dozier, J., and J. Stowe. 1999. Tillman Sand Ridge Heritage

  20. Thar Desert

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This ASTER sub-scene covers an area of 12 x 15 km in NW India in the Thar Desert. The sand dunes of the Thar Desert constantly shift and take on new shapes. Located in northwestern India and eastern Pakistan, the desert is bounded on the south by a salt marsh known as the Rann of Kutch, and on the west by the Indus River plain. About 800 kilometers long and about 490 kilometers wide, the desert's terrain is mainly rolling sandhills with scattered growths of shrub and rock outcroppings. Only about 12 to 25 centimeters of rain fall on the desert each year, and temperatures rise as high as 52 degrees Celsius. Much of the population is pastoral, raising sheep for their wool. The image is located at 24.4 degrees north latitude and 69.3 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  1. On Effective Potential in Tortoise Coordinate

    NASA Astrophysics Data System (ADS)

    Ganjali, M. A.

    2012-08-01

    In this paper, we study the field dynamics in Tortoise coordinate where the equation of motion of a scalar can be written as Schrodinger-like form. We obtain a general form for effective potential by finding the Schrodinger equation for scalar and spinor fields and study its global behavior in some black hole backgrounds in three dimension such as BTZ black holes, new type black holes and black holes with no horizon. Especially, we study the asymptotic behavior of potential at infinity, horizons and origin and find that its asymptotic in BTZ and new type solution is completely different from that of vanishing horizon solution. In fact, potential for vanishing horizon goes to a fixed quantity at infinity, while in BTZ and new type black hole we have an infinite barrier.

  2. Haemoproteus (Apicomplexa: Haemoproteidae) of tortoises and turtles.

    PubMed Central

    Lainson, R; Naiff, R D

    1998-01-01

    It is the general opinion that the haemoproteid blood parasites of chelonians belong to the genus Haemoproteus. Different specific names have long been assigned to this parasite in birds, but some past authorities have accepted only a single species, H. metchnikovi, for all those haemoproteids recorded in a wide range of chelonian genera throughout the world. In the present study, a comparison of one such organism in the tortoise Geochelone denticulata with another in the river turtle Peltocephalus dumerilianus, from Amazonian Brazil, has revealed clear morphological differences. These distinguish the parasites from each other, H. metchnikovi and the other named species of chelonian Haemoproteus for which adequate descriptions are available. We have assigned to them the names Haemoproteus geochelonis n.sp. and Haemoproteus peltocephali n.sp. PMID:9675908

  3. Discovering Deserts.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1985-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Discovering Deserts." Contents are organized into the following…

  4. Desert Survivors!

    ERIC Educational Resources Information Center

    Horton, Jessica; Friedenstab, Steve

    2013-01-01

    This article describes a special third-grade classroom unit based on the reality show "Survivor." The goal of this engaging and interactive unit was to teach students about physical and behavioral adaptations that help animals survive in various desert biomes. The activity combines research, argument, and puppet play over one week of…

  5. COMPARISON OF TOTAL LEUKOCYTE QUANTIFICATION METHODS IN FREE-LIVING GALAPAGOS TORTOISES (CHELONOIDIS SPP.).

    PubMed

    Sheldon, Julie D; Stacy, Nicole I; Blake, Stephen; Cabrera, Fredy; Deem, Sharon L

    2016-03-01

    Reptile hematologic data provide important health information for conservation efforts of vulnerable wildlife species such as the Galapagos tortoise (Chelonoidis spp.). Given the reported discrepancies between manual leukocyte counts for nonmammalian species, two manual leukocyte quantification methods, the Natt and Herrick's (NH) and the Eopette (EO), were compared to white blood cell (WBC) estimates from blood films of 42 free-living, clinically healthy, adult female Galapagos tortoises. To investigate the effects of delay in sample processing, estimated WBC counts and leukocyte differentials were compared for blood films prepared at time of collection under field conditions (T0) to blood films prepared from samples that were stored for 18-23 hr at 4°C in the laboratory (T1). Passing-Bablok regression analysis revealed no constant or proportional error between the NH and WBC estimates (T0 and T1) with slopes of 1.1 and 0.9, respectively. However both constant and proportional errors were present between EO and WBC estimates (T0 and T1) with slopes of 3.1 and 2.7, respectively. Bland Altman plots also showed agreement between the NH and WBC estimates where the points fell within the confidence-interval limit lines and were evenly distributed about the mean. In contrast, the EO and WBC estimate comparisons showed numerous points above the upper limit line, especially at higher concentrations. WBC estimates obtained from T0 and T1 films were in agreement, whereas heterophil and monocyte percentages based on differentials were not. Cell morphology and preservation were superior in T0 blood films because thrombocytes exhibited swelling after storage, becoming difficult to differentiate from lymphocytes. In this study, the highest quality and most reliable hematologic data in Galapagos tortoises were obtained by combining immediate blood film preparation with the NH leukocyte quantification method and a confirmatory WBC estimate from the blood film.

  6. Wildlife DNA forensics against crime: resolution of a case of tortoise theft.

    PubMed

    Mucci, Nadia; Mengoni, Chiara; Randi, Ettore

    2014-01-01

    A paternity test was used to investigate a robbery case involving captive individuals of Greek tortoise (Testudo graeca). Six tortoises were allegedly stolen from a private breeder and offered for sale on the web by the supposed thief. The stolen tortoises were confiscated by the rangers of the State Forestry Corps (CFS). A panel of 14 autosomal microsatellite loci was used to genotype the seized tortoises and ten individuals assumed to be legally owned by the breeder. Kinship analyses reliably reconstructed the tortoise pedigree, demonstrating parent-offspring relationships among the owned and the stolen tortoises. As correctly declared by the breeder, four of the six stolen individuals belonged to the same family group of the ten legally owned tortoises. Results indicate that genetic identification procedures can provide valuable evidence and give useful support against illegal wildlife traffic.

  7. A novel herpesvirus of the proposed genus Chelonivirus from an asymptomatic bowsprit tortoise (Chersina angulata).

    PubMed

    Bicknese, Elizabeth J; Childress, April L; Wellehan, James F X

    2010-06-01

    A wild-caught Bowsprit tortoise (Chersina angulata) was received into quarantine and appeared clinically normal. Oral swabs for consensus herpesvirus polymerase chain reaction (PCR) and sequencing were obtained during routine quarantine, and a novel herpesvirus was identified. Comparative sequence analysis shows that this virus is a member of the subfamily Alphaherpesvirinae in the proposed genus Chelonivirus. Host/virus co-evolution appears to be common amongst herpesviruses and their hosts, and the most significant disease is typically seen when herpesviruses jump to related host species. Previous studies have found some diversity of herpesviruses in tortoises. This report expands the number of known herpesviruses of tortoises. It is reasonable to expect that there will be significantly different clinical consequences of different tortoise herpesviruses in different species, and that identification of host/virus relationships will aid in clinical management of tortoise collections. Further work is needed to determine the clinical implications of this and other tortoise herpesviruses in different tortoise species.

  8. Hormonal profiles of captive Galapagos tortoises (Chelonoidis nigra).

    PubMed

    Branson, Maile A; Atkinson, Shannon; Ramos, Meg Ferrell

    2016-05-01

    Monthly blood samples, daily mating observations from Galapagos tortoises (Chelonoidis nigra), and local rainfall and temperature were collected at the Honolulu Zoo as part of a fertility evaluation. Testosterone concentrations were measured for males (n = 6), two of which were seen copulating and were considered sexually active. Estrone sulfate and progesterone concentrations were measured for female tortoises (n = 9), two of which nested and only one had laid eggs. Testosterone profiles were similar for both sexually active and sexually inactive males, both of which were positively correlated with temperature but not rainfall. Peak testosterone concentrations (12.0 ± 1.4 ng/ml sexually active animals vs. 14.4 ± 2.4 ng/ml sexually inactive animals) occurred at the end of the nesting season, from April to July. Estrone sulfate concentrations were similar for nesting (n = 2) and non-nesting (n = 7) female tortoises, rising from non-detectable concentrations (September), and increasing to peak concentrations during the nesting season. Progesterone concentrations remained low and spiked (9.44 ng/ml) only for the female that nested and laid eggs. Testosterone was negatively correlated with mating behavior, and the male tortoises were likely capable of spermatogenesis even though only two of them engaged in mating behavior. The female tortoises were not senescent, as the estrone sulfate concentrations likely reflected waves of ovarian follicular activity. Endocrine parameters were not in synchrony with rainfall, and a disconnect between the timing of reproductive events and the environmental milieu may help to explain the poor fertility of these tortoises. Zoo Biol. 35:237-245, 2016. © 2016 Wiley Periodicals, Inc.

  9. Cytochemical characteristics of blood cells from Brazilian tortoises (Testudines: Testudinidae).

    PubMed

    Martins, G S; Alevi, K C C; Azeredo-Oliveira, M T V; Bonini-Domingos, C R

    2016-03-18

    The hematology of wild and captive animals is essential for obtaining details about species and represents a simple method of diagnosing disease and determining prognosis. Few studies have described the morphology of chelonian blood cells, which are more common in sea and freshwater turtle species. Thus, in order to further our understanding and recognition of different chelonian cells types, the present study aimed to describe blood cells from the two species of Brazilian tortoises, Chelonoidis carbonarius and C. denticulatus. Cytochemical analysis of tortoise blood tissue with Panótico®, made it possible to describe all the of the chelonian cell types (with the exception of thrombocytes): erythrocytes, agranular leukocytes (monocytes and lymphocytes), and granular leukocytes (eosinophils, heterophils, basophils, and azurophils). These data are of high importance for establishing hematological profiles of Brazilian tortoises and reptiles. Therefore, based on our results and on comparative analyses with data from the literature for other reptile species, we can conclude that the blood cells described for Brazilian tortoises are found in all species of reptiles that have been analyzed thus far, and may be characterized and used as a comparative parameter between different groups to evaluate the health status of these animals.

  10. The Tortoise Transformation as a Prospect for Life Extension.

    PubMed

    Murphy, Timothy F

    2015-12-01

    The value of extending the human lifespan remains a key philosophical debate in bioethics. In building a case against the extension of the species-typical human life, Nicolas Agar considers the prospect of transforming human beings near the end of their lives into Galapagos tortoises, which would then live on decades longer. A central question at stake in this transformation is the persistence of human consciousness as a condition of the value of the transformation. Agar entertains the idea that consciousness could persist in some measure, but he thinks little is to be gained from the transformation because the experiences available to tortoises pale in comparison to those available to human beings. Moreover, he thinks persisting human consciousness and values would degrade over time, being remade by tortoise needs and environment. The value available in the transformation would not, then, make the additional years of life desirable. Agar's account does not, however, dispose of the tortoise transformation as a defensible preference. Some people might still want this kind of transformation for symbolic reasons, but it would probably be better that no human consciousness persist, since that consciousness would be inexpressible as such. Even so, it is not irrational to prefer various kinds of lifespan extension even if they involve significant modifications to human consciousness and values.

  11. 76 FR 52363 - Tortoise Power and Energy Infrastructure Fund, Inc. and Tortoise Capital Advisors, L.L.C.; Notice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ...: Notice of application under section 6(c) of the Investment Company Act of 1940 (``Act'') for an exemption... an order to permit a registered closed-end investment company to make periodic distributions of long... preferred stock that such investment company may issue. Applicants: Tortoise Power and Energy...

  12. Estimating Occupancy of Gopher Tortoise (Gorpherus polyphemus) Burrows in Coastal Scrub and Slash Pine Flatwoods

    NASA Technical Reports Server (NTRS)

    Breininger, David R.; Schmalzer, Paul A.; Hinkle, C. Ross

    1991-01-01

    One hundred twelve plots were established in coastal scrub and slash pine flatwoods habitats on the John F. Kennedy Space Center (KSC) to evaluate relationships between the number of burrows and gopher tortoise (Gopherus polyphemus) density. All burrows were located within these plots and were classified according to tortoise activity. Depending on season, bucket trapping, a stick method, a gopher tortoise pulling device, and a camera system were used to estimate tortoise occupancy. Correction factors (% of burrows occupied) were calculated by season and habitat type. Our data suggest that less than 20% of the active and inactive burrows combined were occupied during seasons when gopher tortoises were active. Correction factors were higher in poorly-drained areas and lower in well-drained areas during the winter, when gopher tortoise activity was low. Correction factors differed from studies elsewhere, indicating that population estimates require correction factors specific to the site and season to accurately estimate population size.

  13. Femoral head and neck excision arthroplasty in a leopard tortoise (Stigmochelys pardalis).

    PubMed

    Naylor, Adam D

    2013-12-01

    Cases of femoral head and neck excision arthroplasty are infrequently reported in reptiles, and details of surgical technique and clinical outcome in chelonia are lacking. An adult female leopard tortoise (Stigmochelys pardalis) was presented with chronic non-weight-bearing lameness of the left hind limb. Examination and radiography were consistent with coxofemoral luxation, and as a result of the chronic presentation, surgical intervention was recommended. A cranial approach to the joint via the prefemoral fossa afforded good surgical exposure. A depressed lytic acetabular lesion was noted during the procedure, postulated to be a result of abnormal wear from the luxated femoral head. A fiberglass prop was used during recovery to allow extension of the limb without full weight-bearing. Lameness persisted postoperatively, but limb usage significantly improved.

  14. Mycoplasma and herpesvirus PCR detection in tortoises with rhinitis-stomatitis complex in Spain.

    PubMed

    Salinas, María; Francino, Olga; Sánchez, Armand; Altet, Laura

    2011-01-01

    Chelonid herpesvirus (ChHV) and mycoplasmal infections cause similar clinical signs in terrestrial tortoises and may be the most important causative agents of rhinitis-stomatitis complex, a common disease in captive tortoises worldwide. Currently, diagnosis of ChHV and Mycoplasma spp. infections is most often based on serologic testing. However, serologic results only detect past exposure, and the specificity of these tests can be reduced due to antigenic cross-reactions with other pathogens. Molecular-based techniques could help to define the causative agent and to better manage infected tortoises. Using polymerase chain reaction, we analyzed 63 tortoises (59 spur-thighed tortoise, Testudo graeca; three Greek tortoise, Testudo ibera; and one Russian tortoise, Agryonemys horsfieldii) with clinical signs of rhinitis-stomatitis complex to identify the causative agent. Molecular evidence of ChHV type I (24%), type II (3%), and Mycoplasma agassizii (6%) infections, as well as coinfection of Mycoplasma-ChHV and both types of ChHV, were detected. Both ChHV and M. agassizii are considered pathogenic in captive tortoises and both are a threat to wild populations. However, neither agent was detected from most of the symptomatic tortoises we evaluated, indicating that other agents could be involved in the rhinitis-stomatitis complex.

  15. Host contact and shedding patterns clarify variation in pathogen exposure and transmission in threatened tortoise Gopherus agassizii: implications for disease modelling and management.

    PubMed

    Aiello, Christina M; Nussear, Kenneth E; Esque, Todd C; Emblidge, Patrick G; Sah, Pratha; Bansal, Shweta; Hudson, Peter J

    2016-05-01

    Most directly transmitted infections require some form of close contact between infectious and susceptible hosts to spread. Often disease models assume contacts are equal and use mean field estimates of transmission probability for all interactions with infectious hosts. Such methods may inaccurately describe transmission when interactions differ substantially in their ability to cause infection. Understanding this variation in transmission risk may be critical to properly model and manage some infectious diseases. In this study, we investigate how varying exposure and transmission may be key to understanding disease dynamics in the threatened desert tortoise Gopherus agassizii. We created heterogeneity in Mycoplasma agassizii exposure (the putative bacterial agent of a respiratory disease) by varying the duration of interactions between naturally infected and uninfected captive desert tortoises. Using qPCR, we identified new infections and compared models of transmission probability as a function of contact duration and pathogen load. We then examined the contact patterns of a wild tortoise population using proximity loggers to identify heterogeneity in contact duration. The top-ranked model predicting M. agassizii transmission included a dose term defined as the product of the number of days in proximity to an infected host and the infection level of that host. Models predicted low transmission probability for short interactions, unless the infectious host had a high load of M. agassizii: such hosts were predicted to transmit infection at higher rates with any amount of contact. We observed predominantly short-lived interactions in a free-ranging tortoise population and thus, expect transmission patterns in this population to vary considerably with the frequency and duration of high infection levels. Mean field models may misrepresent natural transmission patterns in this and other populations depending on the distribution of high-risk contact and shedding

  16. Desert Voices: Southwestern Children's Literature.

    ERIC Educational Resources Information Center

    Polette, Keith

    1997-01-01

    Examines three books with different ways of writing about the desert. Discusses: "Here Is the Southwestern Desert" by Madeline Dunphy, "The Desert Is My Mother" by Pat Mora, and "The Desert Mermaid" by Alberto Blanco. (PA)

  17. Fungal keratitis in a gopher tortoise (Gopherus polyphemus).

    PubMed

    Myers, Debbie A; Isaza, Ramiro; Ben-Shlomo, Gil; Abbott, Jeffrey; Plummer, Caryn E

    2009-09-01

    A free-ranging gopher tortoise (Gopherus polyphemus) presented for trauma and blindness. Fibrinous exudate obscured visualization of the globes. This exudative crust extended from the conjunctival fornices through the palpebral fissure and was manually removed. Ophthalmic examination revealed bilateral corneal ulcerations and scarring and phthisis bulbi of the left globe. Histology of the crust revealed a necrotic conjunctivitis with intralesional fungal hyphae. Culture of the corneal ulcer of the left eye isolated moderate growth of a mixed fungal flora consisting of Curvularia sp. and Aspergillus sp. Miconazole ophthalmic solution was administered and the ulcers in both eyes healed, but corneal edema continued. After 2 mo of treatment with miconazole, tramadol, acetylcysteine, hypertonic saline ointment, artificial tears, and hypertonic saline flushes, the right eye was normal with only a small scar. The left eye remained phthisical. This is the first report of fungal keratitis in a wild reptile and a gopher tortoise.

  18. Field Test of Gopher Tortoise (Gopherus Polyphemus) Population Estimation Techniques

    DTIC Science & Technology

    2008-04-01

    27 Tables 1 Comparison of models fitted to line transect data ................................................................22 2 Estimated...tortoise (GT) is a U.S. Fish and Wildlife Service (USFWS) listed TES species in the south-western portion of its range, which extends west from the...Tombigbee and Mobile rivers in Alabama, Mississippi, and Louisiana (Carthy et al. 2005). East of these rivers, Federal protection does not extend

  19. Phylogeography and history of giant Galápagos tortoises.

    PubMed

    Caccone, Adalgisa; Gentile, Gabriele; Gibbs, James P; Frirts, Thomas H; Snell, Howard L; Betts, Jessica; Powell, Jeffrey R

    2002-10-01

    We examined the phylogeography and history of giant Galápagos tortoise populations based on mitochondrial DNA sequence data from 161 individuals from 21 sampling sites representing the 11 currently recognized extant taxa. Molecular clock and geological considerations indicate a founding of the monophyletic Galápagos lineage around 2-3 million years ago, which would allow for all the diversification to have occurred on extant islands. Founding events generally occurred from geologically older to younger islands with some islands colonized more than once. Six of the 11 named taxa can be associated with monophyletic maternal lineages. One, Geochelone porteri on Santa Cruz Island, consists of two distinct populations connected by the deepest node in the archipelago-wide phylogeny, whereas tortoises in northwest Santa Cruz are closely related to those on adjacent Pinzón Island. Volcan Wolf, the northernmost volcano of Isabela Island, consists of both a unique set of maternal lineages and recent migrants from other islands, indicating multiple colonizations possibly due to human transport or multiple colonization and partial elimination through competition. These genetic findings are consistent with the mixed morphology of tortoises on this volcano. No clear genetic differentiation between two taxa on the two southernmost volcanoes of Isabela was evident. Extinction of crucial populations by human activities confounds whether domed versus saddleback carapaces of different populations are mono- or polyphyletic. Our findings revealed a complex phylogeography and history for this tortoise radiation within an insular environment and have implications for efforts to conserve these endangered biological treasures.

  20. Intestinal parasites of the gopher tortoise (Gopherus polyphemus) from eight populations in Georgia.

    PubMed

    McGuire, Jessica L; Miller, Elizabeth A; Norton, Terry M; Raphael, Bonnie L; Spratt, Jeffrey S; Yabsley, Michael J

    2013-12-01

    The gopher tortoise (Gopherus polyphemus), one of five tortoise species endemic in the USA, was recently classified as a candidate for federal listing as a threatened species. Fecal samples collected from 117 tortoises from eight sites in Georgia were examined for endoparasites using a combination of sedimentation and flotation. Samples from an island population were examined for parasitic oocysts and ova only by flotation, protozoan cysts by trichrome-stained direct smear, and Cryptosporidium by direct immunofluorescence assay and ProSpecT rapid assay. A total of 99 tortoises (85, range 0-100%) was infected with pinworms (Alaeuris spp.), 47 (40, 0-86%) with cestodes (Oochorstica sp.), 34 (41, 0-74%) with Chapiniella spp., 2 (3, 0-33%) with Eimeria paynei, and a single tortoise each with a capillarid and ascarid (1%). On the island, Entamoeba was detected in one tortoise (2%) while Cryptosporidium oocysts were detected in eight (17%). In conclusion, at least eight species of parasites were detected including Cryptosporidium, a possible pathogen of tortoises. Interestingly, we detected spatial variation in the distribution of several parasites among populations suggesting additional work should be conducted across a gradient of tortoise densities, land use, and habitat characteristics.

  1. Endoscopy-guided ectopic egg removal from the urinary bladder in a leopard tortoise (Stigmochelys pardalis).

    PubMed

    Mans, Christoph; Foster, Jonathan D

    2014-06-01

    Egg retention in the urinary bladder of a leopard tortoise was diagnosed by radiography and confirmed by cystoscopy. The egg was removed with a modified polypectomy snare, aided by a flexible endoscope and insufflation. No complications occurred during the procedures and the tortoise made a complete recovery.

  2. The ecological consequences of megafaunal loss: giant tortoises and wetland biodiversity.

    PubMed

    Froyd, Cynthia A; Coffey, Emily E D; van der Knaap, Willem O; van Leeuwen, Jacqueline F N; Tye, Alan; Willis, Katherine J

    2014-02-01

    The giant tortoises of the Galápagos have become greatly depleted since European discovery of the islands in the 16th Century, with populations declining from an estimated 250 000 to between 8000 and 14 000 in the 1970s. Successful tortoise conservation efforts have focused on species recovery, but ecosystem conservation and restoration requires a better understanding of the wider ecological consequences of this drastic reduction in the archipelago's only large native herbivore. We report the first evidence from palaeoecological records of coprophilous fungal spores of the formerly more extensive geographical range of giant tortoises in the highlands of Santa Cruz Island. Upland tortoise populations on Santa Cruz declined 500-700 years ago, likely the result of human impact or possible climatic change. Former freshwater wetlands, a now limited habitat-type, were found to have converted to Sphagnum bogs concomitant with tortoise loss, subsequently leading to the decline of several now-rare or extinct plant species.

  3. Lineage identification and genealogical relationships among captive Galápagos tortoises.

    PubMed

    Benavides, Edgar; Russello, Michael; Boyer, Donal; Wiese, Robert J; Kajdacsi, Brittney; Marquez, Lady; Garrick, Ryan; Caccone, Adalgisa

    2012-01-01

    Genetic tools have become a critical complement to traditional approaches for meeting short- and long-term goals of ex situ conservation programs. The San Diego Zoo (SDZ) harbors a collection of wild-born and captive-born Galápagos giant tortoises (n = 22) of uncertain species designation and unknown genealogical relationships. Here, we used mitochondrial DNA haplotypic data and nuclear microsatellite genotypic data to identify the evolutionary lineage of wild-born and captive-born tortoises of unknown ancestry, to infer levels of relatedness among founders and captive-born tortoises, and assess putative pedigree relationships assigned by the SDZ studbook. Assignment tests revealed that 12 wild-born and five captive-born tortoises represent five different species from Isabela Island and one species from Santa Cruz Island, only five of which were consistent with current studbook designations. Three wild-born and one captive-born tortoise were of mixed ancestry. In addition, kinship analyses revealed two significant first-order relationship pairs between wild-born and captive-born tortoises, four second-order relationships (half-sibling) between wild-born and captive tortoises (full-sibs or parent-offspring), and one second-order relationship between two captive-born tortoises. Of particular note, we also reconstructed a first-order relationship between two wild-born individuals, violating the founder assumption. Overall, our results contribute to a worldwide effort in identifying genetically important Galápagos tortoises currently in captivity while revealing closely related founders, reconstructing genealogical relationships, and providing detailed management recommendations for the SDZ tortoises.

  4. Are Wildlife Detector Dogs or People Better at Finding Desert Tortoises (Gopherus Agassizii)?

    DTIC Science & Technology

    2008-02-01

    discriminate them from non-termite material. Journal of Economic Entomology 96:1259-1266. Cablk, M.E., and J.S. Heaton. 2006. Accuracy and...K. Castellano, and D. Hopkins. 1992. A multidisciplinary approach to the detection of clandestine graves. Journal of Forensic Sciences 37: 1445

  5. Validation and Development of a Certification Program for Using K9s to Survey Desert Tortoises

    DTIC Science & Technology

    2011-08-01

    identifier. M’ = male and ‘F’ = female . DTK9 veteran indicates the dog had prior deployment as DTK9. Origin is the handler’s home state where initial...team data with pass/fail designation. Team is unique identifier. ‘M’ = male and ‘F’ = female . DTK9 veteran indicates the dog had prior deployment as...recognition was used to make a choice to investigate further, the dog’s determination of whether or not the target was ‘tortoise’ appeared to be confirmed

  6. Validation and Development of a Certification Program for Using K9s to Survey Desert Tortoises

    DTIC Science & Technology

    2013-08-01

    43 Table 11. DTK9 team data. Team is unique identifier. M’ = male and ‘F’ = female . DTK9 veteran indicates...identifier. ‘M’ = male and ‘F’ = female . DTK9 veteran indicates the dog had prior deployment as DTK9. Group identifies pass (P) or fail (F) of Phase I...were observed when the dog was typically upwind of the object. However when visual recognition was used to make a choice to investigate further, the

  7. Surveillance for upper respiratory tract disease and Mycoplasma in free-ranging gopher tortoises (Gopherus polyphemus) in Georgia, USA.

    PubMed

    McGuire, Jessica L; Smith, Lora L; Guyer, Craig; Lockhart, J Mitchell; Lee, Gregory W; Yabsley, Michael J

    2014-10-01

    Abstract Upper respiratory tract disease (URTD) in the gopher tortoise (Gopherus polyphemus) is highly contagious and has been implicated in the reduction of populations throughout the range. With the exception of a few limited studies, the prevalence of URTD in Georgia, USA tortoise populations is poorly known. We found that exposure to Mycoplasma agassizii and Mycoplasma testudineum, associated with URTD, varied geographically among 11 Georgia tortoise populations. The prevalence of antibodies to M. agassizii in individual populations was either very low (0-3%, n=7 populations) or very high (96-100%, n=4 populations), whereas there was variation in the prevalence of antibodies to M. testudineum among populations (20-61%, n=10) with only one site being negative. Five sites had tortoises with antibodies to both pathogens, and these were the only sites where we observed tortoises with clinical signs consistent with URTD. We did not find tortoises with clinical signs of URTD at sites with tortoises with antibodies only to M. testudineum, which provides evidence that this organism may be of limited pathogenicity for gopher tortoises. Collectively, these data indicate that both M. agassizii and M. testudineum are present in Georgia populations of gopher tortoises and that clinical disease is apparent in populations where both pathogens are present. Additional research is needed to better understand the role of these two pathogens, and other potential pathogens, in the overall health of tortoise populations, especially if future conservation efforts involve translocation of tortoises.

  8. Genetic Assessments and Parentage Analysis of Captive Bolson Tortoises (Gopherus flavomarginatus) Inform Their “Rewilding” in New Mexico

    PubMed Central

    Edwards, Taylor; Cox, Elizabeth Canty; Buzzard, Vanessa; Wiese, Christiane; Hillard, L. Scott; Murphy, Robert W.

    2014-01-01

    The Bolson tortoise (Gopherus flavomarginatus) is the first species of extirpated megafauna to be repatriated into the United States. In September 2006, 30 individuals were translocated from Arizona to New Mexico with the long-term objective of restoring wild populations via captive propagation. We evaluated mtDNA sequences and allelic diversity among 11 microsatellite loci from the captive population and archived samples collected from wild individuals in Durango, Mexico (n = 28). Both populations exhibited very low genetic diversity and the captive population captured roughly 97.5% of the total wild diversity, making it a promising founder population. Genetic screening of other captive animals (n = 26) potentially suitable for reintroduction uncovered multiple hybrid G. flavomarginatus×G. polyphemus, which were ineligible for repatriation; only three of these individuals were verified as purebred G. flavomarginatus. We used these genetic data to inform mate pairing, reduce the potential for inbreeding and to monitor the maintenance of genetic diversity in the captive population. After six years of successful propagation, we analyzed the parentage of 241 hatchlings to assess the maintenance of genetic diversity. Not all adults contributed equally to successive generations. Most yearly cohorts of hatchlings failed to capture the diversity of the parental population. However, overlapping generations of tortoises helped to alleviate genetic loss because the entire six-year cohort of hatchlings contained the allelic diversity of the parental population. Polyandry and sperm storage occurred in the captives and future management strategies must consider such events. PMID:25029369

  9. Resource Selection Probability Functions for Gopher Tortoise: Providing a Management Tool Applicable Across the Species' Range

    NASA Astrophysics Data System (ADS)

    Kowal, Virginia A.; Schmolke, Amelie; Kanagaraj, Rajapandian; Bruggeman, Douglas

    2014-03-01

    The gopher tortoise ( Gopherus polyphemus) is protected by conservation policy throughout its range. Efforts to protect the species from further decline demand detailed understanding of its habitat requirements, which have not yet been rigorously defined. Current methods of identifying gopher tortoise habitat typically rely on coarse soil and vegetation classifications, and are prone to over-prediction of suitable habitat. We used a logistic resource selection probability function in an information-theoretic framework to understand the relative importance of various environmental factors to gopher tortoise habitat selection, drawing on nationwide environmental datasets, and an existing tortoise survey of the Ft. Benning military base. We applied the normalized difference vegetation index (NDVI) as an index of vegetation density, and found that NDVI was strongly negatively associated with active burrow locations. Our results showed that the most parsimonious model included variables from all candidate model types (landscape features, topography, soil, vegetation), and the model groups describing soil or vegetation alone performed poorly. These results demonstrate with a rigorous quantitative approach that although soil and vegetation are important to the gopher tortoise, they are not sufficient to describe suitable habitat. More widely, our results highlight the feasibility of constructing highly accurate habitat suitability models from data that are widely available throughout the species' range. Our study shows that the widespread availability of national environmental datasets describing important components of gopher tortoise habitat, combined with existing tortoise surveys on public lands, can be leveraged to inform knowledge of habitat suitability and target recovery efforts range-wide.

  10. Resource selection probability functions for gopher tortoise: providing a management tool applicable across the species' range.

    PubMed

    Kowal, Virginia A; Schmolke, Amelie; Kanagaraj, Rajapandian; Bruggeman, Douglas

    2014-03-01

    The gopher tortoise (Gopherus polyphemus) is protected by conservation policy throughout its range. Efforts to protect the species from further decline demand detailed understanding of its habitat requirements, which have not yet been rigorously defined. Current methods of identifying gopher tortoise habitat typically rely on coarse soil and vegetation classifications, and are prone to over-prediction of suitable habitat. We used a logistic resource selection probability function in an information-theoretic framework to understand the relative importance of various environmental factors to gopher tortoise habitat selection, drawing on nationwide environmental datasets, and an existing tortoise survey of the Ft. Benning military base. We applied the normalized difference vegetation index (NDVI) as an index of vegetation density, and found that NDVI was strongly negatively associated with active burrow locations. Our results showed that the most parsimonious model included variables from all candidate model types (landscape features, topography, soil, vegetation), and the model groups describing soil or vegetation alone performed poorly. These results demonstrate with a rigorous quantitative approach that although soil and vegetation are important to the gopher tortoise, they are not sufficient to describe suitable habitat. More widely, our results highlight the feasibility of constructing highly accurate habitat suitability models from data that are widely available throughout the species' range. Our study shows that the widespread availability of national environmental datasets describing important components of gopher tortoise habitat, combined with existing tortoise surveys on public lands, can be leveraged to inform knowledge of habitat suitability and target recovery efforts range-wide.

  11. Contributions of Private Landowners to the Conservation of the Gopher Tortoise ( Gopherus polyphemus)

    NASA Astrophysics Data System (ADS)

    Underwood, Vicki J.; Ober, Holly K.; Miller, Deborah L.; Munn, Ian A.

    2012-04-01

    Private landowners play a pivotal role in determining whether or not rare species persist in regions where privately owned land is extensive. The range of the gopher tortoise ( Gopherus polyphemus) is confined to the Southeastern U.S., a region predominantly under private ownership, and thus the status of this species is largely dependent upon land management decisions made by private landowners. We sent an anonymous mail survey to 2,584 individuals to examine factors affecting gopher tortoise occurrence on private lands in Mississippi (adjusted response rate of 23%). Few respondents (19%) reported currently having tortoises on their property, although many had them in the past (30%). Tortoises were persisting primarily on larger properties with longleaf pine that were not managed chiefly for timber production. In general, respondents were largely unaware of habitat requirements of tortoises or effects of various land management practices on them, and few reported using management techniques that benefit tortoises, such as prescribed burning. Most respondents (57%) knew of wildlife incentive programs, but were hesitant to enroll because they did not want to commit to managing their property in a particular manner (34%). We suggest actions that could improve the likelihood of tortoise persistence in this region, as well as changes that could be made to incentive programs to increase landowner participation. These suggestions should be relevant to the conservation of other rare species on private lands in other regions.

  12. Contributions of private landowners to the conservation of the gopher tortoise (Gopherus polyphemus).

    PubMed

    Underwood, Vicki J; Ober, Holly K; Miller, Deborah L; Munn, Ian A

    2012-04-01

    Private landowners play a pivotal role in determining whether or not rare species persist in regions where privately owned land is extensive. The range of the gopher tortoise (Gopherus polyphemus) is confined to the Southeastern U.S., a region predominantly under private ownership, and thus the status of this species is largely dependent upon land management decisions made by private landowners. We sent an anonymous mail survey to 2,584 individuals to examine factors affecting gopher tortoise occurrence on private lands in Mississippi (adjusted response rate of 23%). Few respondents (19%) reported currently having tortoises on their property, although many had them in the past (30%). Tortoises were persisting primarily on larger properties with longleaf pine that were not managed chiefly for timber production. In general, respondents were largely unaware of habitat requirements of tortoises or effects of various land management practices on them, and few reported using management techniques that benefit tortoises, such as prescribed burning. Most respondents (57%) knew of wildlife incentive programs, but were hesitant to enroll because they did not want to commit to managing their property in a particular manner (34%). We suggest actions that could improve the likelihood of tortoise persistence in this region, as well as changes that could be made to incentive programs to increase landowner participation. These suggestions should be relevant to the conservation of other rare species on private lands in other regions.

  13. Origin and evolutionary relationships of giant Galápagos tortoises.

    PubMed

    Caccone, A; Gibbs, J P; Ketmaier, V; Suatoni, E; Powell, J R

    1999-11-09

    Perhaps the most enduring debate in reptile systematics has involved the giant Galápagos tortoises (Geochelone nigra), whose origins and systematic relationships captivated Charles Darwin and remain unresolved to this day. Here we report a phylogenetic reconstruction based on mitochondrial DNA sequences from Galápagos tortoises and Geochelone from mainland South America and Africa. The closest living relative to the Galápagos tortoise is not among the larger-bodied tortoises of South America but is the relatively small-bodied Geochelone chilensis, or Chaco tortoise. The split between G. chilensis and the Galápagos lineage probably occurred 6 to 12 million years ago, before the origin of the oldest extant Galápagos island. Our data suggest that the four named southern subspecies on the largest island, Isabela, are not distinct genetic units, whereas a genetically distinct northernmost Isabela subspecies is probably the result of a separate colonization. Most unexpectedly, the lone survivor of the abingdoni subspecies from Pinta Island ("Lonesome George") is very closely related to tortoises from San Cristobal and Espanola, the islands farthest from the island of Pinta. To rule out a possible recent transplant of Lonesome George, we sequenced DNA from three tortoises collected on Pinta in 1906. They have sequences identical to Lonesome George, consistent with his being the last survivor of his subspecies. This finding may provide guidance in finding a mate for Lonesome George, who so far has failed to reproduce.

  14. Status and distribution of the angonoka tortoise (Geochelone yniphora) of western Madagascar

    USGS Publications Warehouse

    Smith, Lora L.; Reid, Don; Robert, Bourou; Joby, Mahatoly; Clement, Sibo

    1999-01-01

    From 1993 to 1995, field surveys were conducted in western Madagascar to assess the current status of the angonoka tortoise (Geochelone yniphora) in the wild. Tortoise presence was documented at 10 of 11 localities surveyed. These localities represent at least five populations, all within a 30-km radius of Baly Bay, near the town of Soalala. The populations occur on fragments of habitat ranging from <50 to 4–6000 ha in size. One hundred and forty-five tortoises were marked in the five populations. Hatchling or juvenile tortoises were observed in all populations, indicating that reproduction was occurring. Most of the 145 tortoises (68%) were marked on Cape Sada, where monthly surveys were conducted. The tortoise density on the c. 150 ha peninsula was 0.66 tortoises/ha. The remains of 22 dead juveniles were found on Cape Sada over the 2-year period. This evidence, combined with the low number of juveniles in intermediate size classes in the Cape Sada population suggests that juvenile mortality may be high.

  15. Comparison of paramyxovirus isolates from snakes, lizards and a tortoise.

    PubMed

    Marschang, Rachel E; Papp, Tibor; Frost, Jens W

    2009-09-01

    Previously uncharacterized paramyxovirus (PMV) isolates from four snakes, three lizards and a tortoise were compared based on partial sequences of the L, HN, and U genes. Analysis of the sequences supported the classification of all reptilian PMVs in a separate genus (Ferlavirus) in the subfamily Paramyxovirinae. Within each of the gene segments, the squamatid isolates could be divided into two groups with a sequence divergence of 0.3-15.6% nt (0-6.8% aa) within the groups and 19.5-22.3% nt (5-7.4% aa) between the groups for the L gene, and 0.9-15.4% nt (0-6.9% aa) within the groups and 18.2-22.5% nt (4.4-9.5% aa) between the groups for the HN gene while higher values of 0.4-17.1% nt (0-13.3% aa) within the groups and 28.9-31.3% nt (25.5-27.8% aa) between the groups were found for the U gene. Isolates from lizards were found in both groups. There was no host species specificity in the grouping of the isolates from snakes and lizards. However, the L gene sequence obtained from the tortoise isolate differed significantly from the sequences obtained from the snake and lizard isolates. This isolate showed divergence values of 24.2-27% nt (18.5-20.9% aa) compared to the squamatid sequences. The tortoise isolate clustered together with the other reptilian PMVs, but not into any of the squamatid groups on the phylogenetic tree. It is hypothesized that this chelonian PMV has a more unique genome sequence as neither HN nor U gene parts could be amplified using newly designed consensus nested PCRs.

  16. The Welfare Implications of Using Exotic Tortoises as Ecological Replacements

    PubMed Central

    Griffiths, Christine J.; Zuël, Nicolas; Tatayah, Vikash; Jones, Carl G.; Griffiths, Owen; Harris, Stephen

    2012-01-01

    Background Ecological replacement involves the introduction of non-native species to habitats beyond their historical range, a factor identified as increasing the risk of failure for translocations. Yet the effectiveness and success of ecological replacement rely in part on the ability of translocatees to adapt, survive and potentially reproduce in a novel environment. We discuss the welfare aspects of translocating captive-reared non-native tortoises, Aldabrachelys gigantea and Astrochelys radiata, to two offshore Mauritian islands, and the costs and success of the projects to date. Methodology/Principal Findings Because tortoises are long-lived, late-maturing reptiles, we assessed the progress of the translocation by monitoring the survival, health, growth, and breeding by the founders. Between 2000 and 2011, a total of 26 A. gigantea were introduced to Ile aux Aigrettes, and in 2007 twelve sexually immature A. gigantea and twelve male A. radiata were introduced to Round Island, Mauritius. Annual mortality rates were low, with most animals either maintaining or gaining weight. A minimum of 529 hatchlings were produced on Ile aux Aigrettes in 11 years; there was no potential for breeding on Round Island. Project costs were low. We attribute the success of these introductions to the tortoises’ generalist diet, habitat requirements, and innate behaviour. Conclusions/Significance Feasibility analyses for ecological replacement and assisted colonisation projects should consider the candidate species’ welfare during translocation and in its recipient environment. Our study provides a useful model for how this should be done. In addition to serving as ecological replacements for extinct Mauritian tortoises, we found that releasing small numbers of captive-reared A. gigantea and A. radiata is cost-effective and successful in the short term. The ability to release small numbers of animals is a particularly important attribute for ecological replacement projects since

  17. Allometric and temporal scaling of movement characteristics in Galapagos tortoises

    USGS Publications Warehouse

    Bastille-Rousseau, Guillaume; Yackulic, Charles B.; Frair, Jacqueline L.; Cabrera, Freddy; Blake, Stephen

    2016-01-01

    Understanding how individual movement scales with body size is of fundamental importance in predicting ecological relationships for diverse species. One-dimensional movement metrics scale consistently with body size yet vary over different temporal scales. Knowing how temporal scale influences the relationship between animal body size and movement would better inform hypotheses about the efficiency of foraging behaviour, the ontogeny of energy budgets, and numerous life-history trade-offs.We investigated how the temporal scaling of allometric patterns in movement varies over the course of a year, specifically during periods of motivated (directional and fast movement) and unmotivated (stationary and tortuous movement) behaviour. We focused on a recently diverged group of species that displays wide variation in movement behaviour – giant Galapagos tortoises (Chelonoidis spp.) – to test how movement metrics estimated on a monthly basis scaled with body size.We used state-space modelling to estimate seven different movement metrics of Galapagos tortoises. We used log-log regression of the power law to evaluate allometric scaling for these movement metrics and contrasted relationships by species and sex.Allometric scaling of movement was more apparent during motivated periods of movement. During this period, allometry was revealed at multiple temporal intervals (hourly, daily and monthly), with values observed at daily and monthly intervals corresponding most closely to the expected one-fourth scaling coefficient, albeit with wide credible intervals. We further detected differences in the magnitude of scaling among taxa uncoupled from observed differences in the temporal structuring of their movement rates.Our results indicate that the definition of temporal scales is fundamental to the detection of allometry of movement and should be given more attention in movement studies. Our approach not only provides new conceptual insights into temporal attributes in one

  18. Allometric and temporal scaling of movement characteristics in Galapagos tortoises.

    PubMed

    Bastille-Rousseau, Guillaume; Yackulic, Charles B; Frair, Jacqueline L; Cabrera, Freddy; Blake, Stephen

    2016-09-01

    Understanding how individual movement scales with body size is of fundamental importance in predicting ecological relationships for diverse species. One-dimensional movement metrics scale consistently with body size yet vary over different temporal scales. Knowing how temporal scale influences the relationship between animal body size and movement would better inform hypotheses about the efficiency of foraging behaviour, the ontogeny of energy budgets, and numerous life-history trade-offs. We investigated how the temporal scaling of allometric patterns in movement varies over the course of a year, specifically during periods of motivated (directional and fast movement) and unmotivated (stationary and tortuous movement) behaviour. We focused on a recently diverged group of species that displays wide variation in movement behaviour - giant Galapagos tortoises (Chelonoidis spp.) - to test how movement metrics estimated on a monthly basis scaled with body size. We used state-space modelling to estimate seven different movement metrics of Galapagos tortoises. We used log-log regression of the power law to evaluate allometric scaling for these movement metrics and contrasted relationships by species and sex. Allometric scaling of movement was more apparent during motivated periods of movement. During this period, allometry was revealed at multiple temporal intervals (hourly, daily and monthly), with values observed at daily and monthly intervals corresponding most closely to the expected one-fourth scaling coefficient, albeit with wide credible intervals. We further detected differences in the magnitude of scaling among taxa uncoupled from observed differences in the temporal structuring of their movement rates. Our results indicate that the definition of temporal scales is fundamental to the detection of allometry of movement and should be given more attention in movement studies. Our approach not only provides new conceptual insights into temporal attributes in one

  19. Demographic Outcomes and Ecosystem Implications of Giant Tortoise Reintroduction to Española Island, Galapagos

    PubMed Central

    Gibbs, James P.; Hunter, Elizabeth A.; Shoemaker, Kevin T.; Tapia, Washington H.; Cayot, Linda J.

    2014-01-01

    Restoration of extirpated species via captive breeding has typically relied on population viability as the primary criterion for evaluating success. This criterion is inadequate when species reintroduction is undertaken to restore ecological functions and interactions. Herein we report on the demographic and ecological outcomes of a five-decade-long population restoration program for a critically endangered species of “ecosystem engineer”: the endemic Española giant Galapagos tortoise (Chelonoidis hoodensis). Our analysis of complementary datasets on tortoise demography and movement, tortoise-plant interactions and Española Island’s vegetation history indicated that the repatriated tortoise population is secure from a strictly demographic perspective: about half of tortoises released on the island since 1975 were still alive in 2007, in situ reproduction is now significant, and future extinction risk is low with or without continued repatriation. Declining survival rates, somatic growth rates, and body condition of repatriates suggests, however, that resources for continued population growth are increasingly limited. Soil stable carbon isotope analyses indicated a pronounced shift toward woody plants in the recent history of the island’s plant community, likely a legacy of changes in competitive relations between woody and herbaceous plants induced by now-eradicated feral goats and prolonged absence of tortoises. Woody plants are of concern because they block tortoise movement and hinder recruitment of cactus–a critical resource for tortoises. Tortoises restrict themselves to remnant cactus patches and areas of low woody plant density in the center of the island despite an apparent capacity to colonize a far greater range, likely because of a lack of cactus elsewhere on the island. We conclude that ecosystem-level criteria for success of species reintroduction efforts take much longer to achieve than population-level criteria; moreover, reinstatement of

  20. Demographic outcomes and ecosystem implications of giant tortoise reintroduction to Española Island, Galapagos.

    PubMed

    Gibbs, James P; Hunter, Elizabeth A; Shoemaker, Kevin T; Tapia, Washington H; Cayot, Linda J

    2014-01-01

    Restoration of extirpated species via captive breeding has typically relied on population viability as the primary criterion for evaluating success. This criterion is inadequate when species reintroduction is undertaken to restore ecological functions and interactions. Herein we report on the demographic and ecological outcomes of a five-decade-long population restoration program for a critically endangered species of "ecosystem engineer": the endemic Española giant Galapagos tortoise (Chelonoidis hoodensis). Our analysis of complementary datasets on tortoise demography and movement, tortoise-plant interactions and Española Island's vegetation history indicated that the repatriated tortoise population is secure from a strictly demographic perspective: about half of tortoises released on the island since 1975 were still alive in 2007, in situ reproduction is now significant, and future extinction risk is low with or without continued repatriation. Declining survival rates, somatic growth rates, and body condition of repatriates suggests, however, that resources for continued population growth are increasingly limited. Soil stable carbon isotope analyses indicated a pronounced shift toward woody plants in the recent history of the island's plant community, likely a legacy of changes in competitive relations between woody and herbaceous plants induced by now-eradicated feral goats and prolonged absence of tortoises. Woody plants are of concern because they block tortoise movement and hinder recruitment of cactus--a critical resource for tortoises. Tortoises restrict themselves to remnant cactus patches and areas of low woody plant density in the center of the island despite an apparent capacity to colonize a far greater range, likely because of a lack of cactus elsewhere on the island. We conclude that ecosystem-level criteria for success of species reintroduction efforts take much longer to achieve than population-level criteria; moreover, reinstatement of

  1. Structural and physical evidence for an endocuticular gold reflector in the tortoise beetle, Charidotella ambita.

    PubMed

    Pasteels, Jacques M; Deparis, Olivier; Mouchet, Sébastien R; Windsor, Donald M; Billen, Johan

    2016-11-01

    Charidotella ambita offers a unique opportunity for unambiguously locating its gold reflector by comparing the structure of reflecting and non-reflecting cuticle of the elytron and pronotum. Using light microscopy and TEM, the reflector was located underneath the macrofiber endocuticle just above the epidermis. The reflector is a multilayer comprising up to 50 bilayers alternating high and low density layers parallel to the surface of the cuticle. It is chirped, i.e., showing a progressive decrease in layer thickness from approximately 150 nm-100 nm across its depth. The high density layers in contact with the endocuticle fuse to the last macrofiber when the reflector is interrupted by a trabecula, demonstrating their cuticular nature. Simulated reflectance spectra from models of the multilayer matched the reflection spectra measured on the major gold patch of the elytron of living specimens. Previous reports in adult insects exhibiting metallic colors located their reflector in the upper strata and structures of the cuticle, i.e., epicuticle, exocuticle, scales and hairs. Thus, the endocuticular location of the reflector in C. ambita (and other tortoise beetles) appears unique for adult insects. Gold reflection appears in C. ambita only when the synthesis of the macrolayer endocuticle is complete, which may take up to 2 weeks. The development of the gold reflector coincides with the start of mating behavior, possibly suggesting a signaling function in conspecific recognition once sexual maturity has been reached.

  2. Ecology of a population of subsidized predators: Common ravens in the central Mojave Desert, California

    USGS Publications Warehouse

    Boarman, W.I.; Patten, M.A.; Camp, R.J.; Collis, S.J.

    2006-01-01

    Human subsidies have resulted in the rapid growth of populations of common ravens (Corvus corax) in the Mojave Desert. This is a management concern because ravens prey on threatened desert tortoises (Gopherus agassizii). We conducted weekly counts for 29 months at 10 sites on the US Army's National Training Center, Fort Irwin, California to evaluate factors affecting the distribution of ravens. Raven abundance varied seasonally, diurnally, and with human abundance. It was greatest near resource subsidies, specifically the landfill and sewage ponds. Although other studies have documented heavy use of landfills by ravens, the use of sewage ponds had not been previously reported in the published literature. We suggest that raven management should focus on reducing access to anthropogenic resources. ?? 2006.

  3. Tortoise Coordinate Transformation on Apparent Horizon of a Dynamical Black Hole

    NASA Astrophysics Data System (ADS)

    Liu, Xianming; Zhao, Zheng; Liu, Wenbiao

    Thinking of Hawking radiation calculation from a Schwarzschild black hole using Damour-Ruffini method, some key requirements of the tortoise coordinate transformation are pointed out. Extending these requirements to a dynamical black hole, a dynamical tortoise coordinate transformation is proposed. Under this new dynamical tortoise coordinate transformation, Hawking radiation from a Vaidya black hole can be got successfully using Damour-Ruffini method. Moreover, we also find that the radiation should be regarded as originating from the apparent horizon rather than the event horizon at least from the viewpoint of the first law of thermodynamics.

  4. Hawking radiation temperatures in non-stationary Kerr black holes with different tortoise coordinate transformations

    NASA Astrophysics Data System (ADS)

    Lan, X. G.; Jiang, Q. Q.; Wei, L. F.

    2012-04-01

    We apply the Damour-Ruffini-Sannan method to study the Hawking radiations of scalar and Dirac particles in non-stationary Kerr black holes under different tortoise coordinate transformations. We found that all the relevant Hawking radiation spectra show still the blackbody ones, while the Hawking temperatures are strongly related to the used tortoise coordinate transformations. The properties of these dependences are discussed analytically and numerically. Our results imply that proper selections of tortoise coordinate transformations should be important in the studies of Hawking radiations and the correct selection would be given by the experimental observations in the future.

  5. Hawking radiation of Kerr-Newman black hole in different tortoise coordinate transformations

    NASA Astrophysics Data System (ADS)

    Ibungochouba Singh, T.

    2013-10-01

    Hawking radiation effect of Maxwell’s electromagnetic fields in the Kerr-Newman black hole space-time is investigated using two different tortoise coordinate transformations. It has been shown that the new tortoise coordinate transformation produces constant term ξ in the expression of surface gravity and Hawking temperature. If ξ is set to zero, the surface gravity and Hawking temperature will be equal to those obtained from the old tortoise coordinate transformation. This indicates that new transformation is more reliable and accurate. The black body radiant spectrum of photon displays a new spin-rotation coupling effect.

  6. Comparative abundance and population structure of sympatric Afrotropical tortoises in six rainforest areas: the differential effects of ``traditional veneration'' and of ``subsistence hunting'' by local people

    NASA Astrophysics Data System (ADS)

    Luiselli, Luca

    2003-07-01

    Hinge-back tortoises are actively hunted by human populations in sub-Saharan Africa, and are currently threatened in wide areas of their ranges. The wide wetlands and moist rainforests of the Niger Delta (southeastern Nigeria, west Africa) house three sympatric species of hinge-back tortoises: Kinixys erosa, K. homeana, and K. belliana nogueyi. These tortoises are subjected to strong hunting pressure for several reasons (mainly domestic consumption), but in a few places in Bayelsa and Rivers States (eastern axis of the Niger Delta), they are traditionally venerated as "holy animals" bringing happiness. These few places may represent ideal laboratories for monitoring the effects of hundreds of years of "traditional conservation" on the wild populations of a tropical reptile. Here, I compare the apparent abundance, sex ratio, body sizes, microhabitats, and seasonal occurrence of free-ranging Kinixys populations inhabiting three of these "traditional sanctuaries" with the same ecological aspects of conspecifics from three neighbouring areas where the tortoises are actively hunted. K. homeana was the most common species at all sites, followed by K. erosa, whereas K. belliana was extremely rare. Adult sex ratio did not depart significantly from equality both in K. erosa and in K. homeana, and was not influenced by locality or by type of "management" (veneration or harvesting). The frequency of juveniles of K. homeana was significantly higher in areas with traditional veneration than in areas of harvesting, but the same pattern was not observed in K. erosa. There was a significant decrease in terms of the number of observed specimens between areas of traditional protection and areas of usual harvesting in all species, and this trend was more obvious in K. homeana than in K. erosa. The ratio "number of observed erosa/number of observed homeana" was not dependent on the presence of traditional veneration. Mean body sizes were not different in harvest areas and in

  7. Drawing a line in the sand: Effectiveness of off-highway vehicle management in California's Sonoran desert.

    PubMed

    Custer, Nathan A; DeFalco, Lesley A; Nussear, Kenneth E; Esque, Todd C

    2017-05-15

    Public land policies manage multiple uses while striving to protect vulnerable plant and wildlife habitats from degradation; yet the effectiveness of such policies are infrequently evaluated, particularly for remote landscapes that are difficult to monitor. We assessed the use and impacts of recreational vehicles on Mojave Desert washes (intermittent streams) in the Chemehuevi Desert Wildlife Management Area (DWMA) of southern California. Wash zones designated as open and closed to off-highway vehicle (OHV) activity were designed in part to protect Mojave desert tortoise (Gopherus agassizii) habitat while allowing recreation in designated areas. OHV tracks were monitored in washes located near access roads during winter and early spring holidays - when recreation is typically high - and at randomly dispersed locations away from roads. Washes near access roads had fewer vehicle tracks within closed than open zones; further away from roads, OHV tracks were infrequent and their occurrence was not different between wash designations. Washes were in better condition in closed zones following major holidays as indicated by less vegetation damage, presence of trash, and wash bank damage. Furthermore, the frequency of washes with live tortoises and their sign was marginally greater in closed than open wash zones. Collectively, these results suggest that low impacts to habitats in designated closed wash zones reflect public compliance with federal OHV policy and regulations in the Chemehuevi DWMA during our study. Future monitoring to contrast wash use and impacts during other seasons as well as in other DWMAs will elucidate spatial and temporal patterns of recreation in these important conservation areas.

  8. Efficacy of oxfendazole and fenbendazole against tortoise (Testudo hermanni) oxyurids.

    PubMed

    Giannetto, S; Brianti, E; Poglayen, G; Sorgi, C; Capelli, G; Pennisi, M G; Coci, G

    2007-04-01

    Thirty-six tortoises (Testudo hermanni) with naturally acquired oxyurids infections were used to assess the anthelmintic efficacy of oxfendazole (Dolthene; Merial) and fenbendazole (Panacur; Hoechst Roussel Vet). Animals were randomly assigned to three groups (A, B, and C) based on sex and weight. Animals in group A (seven males and six females) were orally treated with oxfendazole at dose rate of 66 mg/kg, group B animals (nine males and eight females) were orally treated with fenbendazole at dose rate of 100 mg/kg, and group C animals (three males and three females) were not treated and served as controls. All animals were individually stabled in plexiglas boxes under controlled conditions of temperature, humidity, and light beginning 7 days pretreatment and continuing for the duration of the trial. Individual tortoises feces were examined daily by the McMaster technique and drugs efficacy was assessed by the fecal eggs count reduction (FECR) test. Both drugs showed 100% of FECR. However, oxfendazole reached this level 12 days after treatment, whereas 31 days after treatment were necessary to obtain the same stable result with fenbendazole. The two drugs were well tolerated by all the animals and no adverse reactions were observed after treatment.

  9. Lineage fusion in Galápagos giant tortoises.

    PubMed

    Garrick, Ryan C; Benavides, Edgar; Russello, Michael A; Hyseni, Chaz; Edwards, Danielle L; Gibbs, James P; Tapia, Washington; Ciofi, Claudio; Caccone, Adalgisa

    2014-11-01

    Although many classic radiations on islands are thought to be the result of repeated lineage splitting, the role of past fusion is rarely known because during these events, purebreds are rapidly replaced by a swarm of admixed individuals. Here, we capture lineage fusion in action in a Galápagos giant tortoise species, Chelonoidis becki, from Wolf Volcano (Isabela Island). The long generation time of Galápagos tortoises and dense sampling (841 individuals) of genetic and demographic data were integral in detecting and characterizing this phenomenon. In C. becki, we identified two genetically distinct, morphologically cryptic lineages. Historical reconstructions show that they colonized Wolf Volcano from Santiago Island in two temporally separated events, the first estimated to have occurred ~199 000 years ago. Following arrival of the second wave of colonists, both lineages coexisted for approximately ~53 000 years. Within that time, they began fusing back together, as microsatellite data reveal widespread introgressive hybridization. Interestingly, greater mate selectivity seems to be exhibited by purebred females of one of the lineages. Forward-in-time simulations predict rapid extinction of the early arriving lineage. This study provides a rare example of reticulate evolution in action and underscores the power of population genetics for understanding the past, present and future consequences of evolutionary phenomena associated with lineage fusion.

  10. [The anatomy of the heart of tortoises (Testudinidae)].

    PubMed

    Prütz, Maike; Hungerbühler, Stephan; Fehr, Michael; Mathes, Karina

    2016-01-01

    25 formalin-fixed hearts of different tortoise species (Testudinidae) underwent gross-anatomical examination. The aim of the study was to illustrate the specific anatomy of the heart of these species in comparison to the data available in the literature. The examined tortoises showed the well-known basic structure of a reptile heart with two atria and a ventricle composed of three interconnected chambers. The right atrium was consistently slightly larger than the left atrium. The atrioventricular (AV-) valves emerged as double-flap valves, whereby the lateral leaflets were only present in a rudimentary form. Neither papillary muscles nor chordae tendineae could be detected macroscopically. A vertical septum in order to subdivide the dorsal chambers was missing. However, the muscular ridge between Cavum venosum and Cavum pulmonale was well developed. The Cavum pulmonale represented itself as the smallest chamber respectively rather as a small passageway to the Truncus pulmonalis. Apart from two-parted aortic valves also multicuspidated valves of the Truncus pulmonalis could be visualized.

  11. The evolution of island gigantism and body size variation in tortoises and turtles.

    PubMed

    Jaffe, Alexander L; Slater, Graham J; Alfaro, Michael E

    2011-08-23

    Extant chelonians (turtles and tortoises) span almost four orders of magnitude of body size, including the startling examples of gigantism seen in the tortoises of the Galapagos and Seychelles islands. However, the evolutionary determinants of size diversity in chelonians are poorly understood. We present a comparative analysis of body size evolution in turtles and tortoises within a phylogenetic framework. Our results reveal a pronounced relationship between habitat and optimal body size in chelonians. We found strong evidence for separate, larger optimal body sizes for sea turtles and island tortoises, the latter showing support for the rule of island gigantism in non-mammalian amniotes. Optimal sizes for freshwater and mainland terrestrial turtles are similar and smaller, although the range of body size variation in these forms is qualitatively greater. The greater number of potential niches in freshwater and terrestrial environments may mean that body size relationships are more complicated in these habitats.

  12. Rhabdomyosarcoma in a terrestrial tortoise (Geochelone nigra) in Nigeria: a case report.

    PubMed

    Eyarefe, Oghenemega D; Antia, Richard E; Oguntoye, Cecilia O; Abiola, Olusoji O; Alaka, Olugbenga O; Ogunsola, John O

    2012-11-30

    A skeletal muscle tumour (rhabdomysarcoma) was diagnosed in a 4-year-old captive female terrestrial tortoise (Geochelone nigra) weighing 7 kg presented at the Veterinary Teaching Hospital, University of Ibadan, Ibadan, Nigeria. The tumour was located at the anterior right portion of the body and ventral to the carapace. The location of the tumour prevented the tortoise from extending its head from the body. The tumour was a sessile, smooth white mass, with a soft myxomatous consistency. The histological features that were diagnostic of rhabdomyosarcoma included a sparse population of haphazardly arranged spindle-shaped cells within a homogenous matrix (anisocytosis), occasional tumour giant and binucleate cells, and some well differentiated myofibrils with cross striations within the cytoplasm. The paucity of information on tumours in the land tortoise was the reason for this report, which appears to be the first report of rhabdomyosarcoma in the tortoise.

  13. [Polymorphism of the 12S rRNA gene and phylogeography of the Central Asian tortoises Agrionemys horsfieldii gray, 1844].

    PubMed

    Vasil'ev, V A; Bondarenko, D A; Peregortsev, E A; Voronov, A S; Ryskov, A P; Semenova, S K

    2008-06-01

    Based on intraspecific polymorphism of 12S rRNA gene, genetic variation of isolated populations of the Central Asian tortoise, Agrionemys horsfieldii, was for the first time investigated on a large part of the species distribution range, encompassing Uzbekistan, southern Kazakhstan, and northern and eastern Iran. In 59 tortoises, four haplotypes were discovered, including two (AH1 and AH2), described earlier. Haplotype AH1 was detected in 52 tortoises, inhabiting southern Kazakhstan and Uzbekistan. Haplotype AH2 was found in four tortoises from the border territory between Uzbekistan, Tajikistan, and Afghanistan. Two novel haplotypes, AH3 and AH4, were detected in the three tortoises from Iran. Based on nucleotide substitutions in the 12S rDNA sequence, the possible divergence time between the tortoises from different parts of the range was estimated. Possible pathways of the formation of modern intraspecific groups of A. horsfieldii are discussed.

  14. The dominance of introduced plant species in the diets of migratory Galapagos tortoises increases with elevation on a human-occupied island

    USGS Publications Warehouse

    Blake, Stephen; Guézou, Anne; Deem, Sharon L.; Yackulic, Charles B.; Cabrera, Fredy

    2015-01-01

    The distribution of resources and food selection are fundamental to the ecology, life history, physiology, population dynamics, and conservation of animals. Introduced plants are changing foraging dynamics of herbivores in many ecosystems often with unknown consequences. Galapagos tortoises, like many herbivores, undertake migrations along elevation gradients driven by variability in vegetation productivity which take them into upland areas dominated by introduced plants. We sought to characterize diet composition of two species of Galapagos tortoises, focussing on how the role of introduced forage species changes over space and the implications for tortoise conservation. We quantified the distribution of tortoises with elevation using GPS telemetry. Along the elevation gradient, we quantified the abundance of introduced and native plant species, estimated diet composition by recording foods consumed by tortoises, and assessed tortoise physical condition from body weights and blood parameter values. Tortoises ranged between 0 and 429 m in elevation over which they consumed at least 64 plant species from 26 families, 44 percent of which were introduced species. Cover of introduced species and the proportion of introduced species in tortoise diets increased with elevation. Introduced species were positively selected for by tortoises at all elevations. Tortoise physical condition was either consistent or increased with elevation at the least biologically productive season on Galapagos. Santa Cruz tortoises are generalist herbivores that have adapted their feeding behavior to consume many introduced plant species that has likely made a positive contribution to tortoise nutrition. Some transformed habitats that contain an abundance of introduced forage species are compatible with tortoise conservation.

  15. Effects of factors of prolonged space flight on conditions of tortoise skeleton

    NASA Technical Reports Server (NTRS)

    Stupakon, G. P.; Volozhin, A. I.; Korzhenyants, V. A.; Yagodovskiy, V. S.; Polyakov, A. N.; Korolev, V. V.; Elivanov, V. A.

    1980-01-01

    After a 60-90 day space flight mild osteoporosis developed in the epiphyses and metaphyses of long tubular bones of tortoises, which was not attributed to reduced mineral saturation of the preserved bone tissue microstructures. The diminished strength of the cancellous bone of the epiphyses in tortoises after space flight was due to the reduced properties of its structure. The strength of the compact substance did not change under the effect of weightlessness.

  16. New Tortoise Coordinate and Hawking Radiation of Dirac Particles in a Non-stationary Kerr-Newman Black Hole

    NASA Astrophysics Data System (ADS)

    Lan, Xiao-Gang

    2012-04-01

    The Hawking effect of Dirac particles in a non-stationary Kerr-Newman black hole is investigated using an improved Damour-Ruffini method with a new tortoise coordinate transformation. In contrast with the old tortoise coordinate, the new one satisfies the dimensional requirement. It is interesting to note that the Hawking emission spectrum remains a blackbody one with a correction term ξ existing in the Hawking temperature. Compared with the old tortoise coordinate transformation, our results appears more accurate and reliable.

  17. Case report of systemic coccidiosis in a radiated tortoise (Geochelone radiata).

    PubMed

    Schmidt, Volker; Dyachenko, Viktor; Aupperle, Heike; Pees, Michael; Krautwald-Junghanns, Maria-Elisabeth; Daugschies, Arwid

    2008-02-01

    More than 30 species of coccidian parasites have been described in Chelonidae (tortoises and turtles). Eimeria spp. are apparently the most common coccidia in chelonians. Findings of Caryospora cheloniae, Isospora sp., and Mantonella sp. have also been published, but reports about systemic coccidiosis are rare. We describe a case of a coccidiosis diagnosed cytologically in a radiated tortoise (Geochelone radiata) which was captive-bred in Germany. Infection was systemic and involved the lymphoid system. Intracytoplasmatic stages of parasite development were identified cytologically, histologically, and ultrastructurally. The systemic coccidiosis was associated with variable degrees of inflammation in the different organs and contributed substantially to the cause of death in this tortoise. Fragments of coccidian 18S- and 28S-rRNA from the tortoise liver were sequenced; the 18S-rRNA sequence had the highest identity to intranuclear coccidia described previously in a travancore tortoise (Intestudo forstenii) and a leopard tortoise (Geochelone pardalis). The analysis of maximum likelihood phylogenetic tree showed relation to species of the order Sarcocystidae. The biology of these coccidia and the route of infection in this case remained unclear.

  18. Gopher Tortoise (Gopherus polyphemus) Densities in Coastal Scrub and Slash Pine Flatwoods in Florida

    NASA Technical Reports Server (NTRS)

    Breininger, David R.; Schmalzer, Paul A.; Hinkle, C. Ross

    1994-01-01

    Densities of gopher tortoises were compared with habitat characteristics in scrub and in flatwood habitats on the Kennedy Space Center, Florida. Tortoises were distributed widely among habitat types and did not have higher densities in well-drained (oak-palmetto) than in poorly-drained (saw palmetto) habitats. Fall densities of tortoises ranged from a mean of 2.7 individuals/ha in disturbed habitat to 0.0 individuals/ha in saw palmetto habitat. Spring densities of tortoises ranged from a mean of 2.5 individuals/ha in saw palmetto habitat to 0.7 individuals/ha in oak-palmetto habitat. Densities of tortoises were correlated positively with the percent herbaceous cover, an indicator of food resources. Plots were divided into three burn classes; these were areas burned within three years, burned four to seven years, and unburned for more than seven years prior to the study. Relationships between densities of tortoises and time-since-fire classes were inconsistent.

  19. Operational Aspects of Desert Shield and Desert Storm

    DTIC Science & Technology

    1992-03-12

    Battalion (MIB), 3d Armored Division leading up to and during Desert Shield and Desert Storm. This paper represents the personal assessment of the author...DESERT SHIELD A$DDESERT STORM ...J BY Lieutenant Colonel Henry C. Shirah United States Army DISTRIBUTION STATEMENT A: Approved for public release...Classification) OPERATIONAL ASPECTS OF DESERT SHIELD AND DESERT STORM 12. PERSONAL AUTHOR(S) 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year

  20. Deserts : geology and resources

    USGS Publications Warehouse

    Walker, Alta S.

    1996-01-01

    Approximately one-third of the Earth's land surface is desert, arid land with meager rainfall that supports only sparse vegetation and a limited population of people and animals. Deserts stark, sometimes mysterious worlds have been portrayed as fascinating environments of adventure and exploration from narratives such as that of Lawrence of Arabia to movies such as "Dune." These arid regions are called deserts because they are dry. They may be hot, they may be cold. They may be regions of sand or vast areas of rocks and gravel peppered with occasional plants. But deserts are always dry. Deserts are natural laboratories in which to study the interactions of wind and sometimes water on the arid surfaces of planets. They contain valuable mineral deposits that were formed in the arid environment or that were exposed by erosion. Because deserts are dry, they are ideal places for human artifacts and fossils to be preserved. Deserts are also fragile environments. The misuse of these lands is a serious and growing problem in parts of our world.

  1. What is Desert RATS?

    NASA Video Gallery

    The mission manager and test coordinators for the 2011 mission explain why Desert RATS was started 14 years ago, questions being studied in this year's activities, technologies being tested and the...

  2. Origin and evolutionary relationships of giant Galápagos tortoises

    PubMed Central

    Caccone, Adalgisa; Gibbs, James P.; Ketmaier, Valerio; Suatoni, Elizabeth; Powell, Jeffrey R.

    1999-01-01

    Perhaps the most enduring debate in reptile systematics has involved the giant Galápagos tortoises (Geochelone nigra), whose origins and systematic relationships captivated Charles Darwin and remain unresolved to this day. Here we report a phylogenetic reconstruction based on mitochondrial DNA sequences from Galápagos tortoises and Geochelone from mainland South America and Africa. The closest living relative to the Galápagos tortoise is not among the larger-bodied tortoises of South America but is the relatively small-bodied Geochelone chilensis, or Chaco tortoise. The split between G. chilensis and the Galápagos lineage probably occurred 6 to 12 million years ago, before the origin of the oldest extant Galápagos island. Our data suggest that the four named southern subspecies on the largest island, Isabela, are not distinct genetic units, whereas a genetically distinct northernmost Isabela subspecies is probably the result of a separate colonization. Most unexpectedly, the lone survivor of the abingdoni subspecies from Pinta Island (“Lonesome George”) is very closely related to tortoises from San Cristóbal and Española, the islands farthest from the island of Pinta. To rule out a possible recent transplant of Lonesome George, we sequenced DNA from three tortoises collected on Pinta in 1906. They have sequences identical to Lonesome George, consistent with his being the last survivor of his subspecies. This finding may provide guidance in finding a mate for Lonesome George, who so far has failed to reproduce. PMID:10557302

  3. 77 FR 14514 - TGP Granada, LLC v. Public Service Company of New Mexico; Tortoise Capital Resources Corp...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission TGP Granada, LLC v. Public Service Company of New Mexico; Tortoise Capital... against the Public Service Company of New Mexico (PNM) and Tortoise Capital Resources Corp....

  4. Checklist of tortoise beetles (Coleoptera, Chrysomelidae, Cassidinae) from Colombia with new data and description of a new species

    PubMed Central

    Borowiec, Lech; Świętojańska, Jolanta

    2015-01-01

    Abstract A new tortoise beetle species, Cyrtonota abrili, is described from the Antioquia and Caldas departments in Colombia. New faunistic data are provided for 87 species, including 16 new additions to the country’s fauna. A checklist of the known 238 species of tortoise beetles recorded from Colombia is given. PMID:26448702

  5. The ecological consequences of megafaunal loss: giant tortoises and wetland biodiversity

    PubMed Central

    Froyd, Cynthia A; Coffey, Emily E D; Knaap, Willem O; Leeuwen, Jacqueline F N; Tye, Alan; Willis, Katherine J; Sax, Dov

    2014-01-01

    The giant tortoises of the Galápagos have become greatly depleted since European discovery of the islands in the 16th Century, with populations declining from an estimated 250 000 to between 8000 and 14 000 in the 1970s. Successful tortoise conservation efforts have focused on species recovery, but ecosystem conservation and restoration requires a better understanding of the wider ecological consequences of this drastic reduction in the archipelago's only large native herbivore. We report the first evidence from palaeoecological records of coprophilous fungal spores of the formerly more extensive geographical range of giant tortoises in the highlands of Santa Cruz Island. Upland tortoise populations on Santa Cruz declined 500–700 years ago, likely the result of human impact or possible climatic change. Former freshwater wetlands, a now limited habitat-type, were found to have converted to Sphagnum bogs concomitant with tortoise loss, subsequently leading to the decline of several now-rare or extinct plant species. PMID:24382356

  6. Visual and response-based navigation in the tortoise (Geochelone carbonaria).

    PubMed

    Wilkinson, Anna; Coward, Sacha; Hall, Geoffrey

    2009-11-01

    Much research has investigated spatial cognition in mammals and birds. Evidence suggests that the hippocampus plays a critical role in this; however, reptiles do not possess a hippocampus. It has been proposed that the reptilian medial cortex plays a similar role, yet little behavioral research has directly investigated this. Consequently, this study examined the role of extramaze cues in spatial navigation by the red-footed tortoise (Geochelone carbonaria) using an eight-arm radial maze. In Experiment 1 the maze was surrounded by a black curtain on which geometrical shapes were attached. After the tortoise reached above-chance performance we introduced test sessions in which the cues were removed. Performance was unaffected by cue removal. The tortoise appeared to have developed a "turn-by-one-arm" strategy. In a second experiment the curtain was removed and the tortoise was allowed access to a rich-cue environment. The use of the turn-by-one-arm strategy was significantly reduced and the tortoise appeared to be using the extramaze cues to navigate around the apparatus. This type of response-based strategy, and the specific contexts in which it was used, has not been observed in mammals and birds, suggesting that the mechanisms served by the reptilian medial cortex do not parallel exactly those of the hippocampus.

  7. Touchscreen performance and knowledge transfer in the red-footed tortoise (Chelonoidis carbonaria).

    PubMed

    Mueller-Paul, Julia; Wilkinson, Anna; Aust, Ulrike; Steurer, Michael; Hall, Geoffrey; Huber, Ludwig

    2014-07-01

    In recent years red-footed tortoises have been shown to be proficient in a number of spatial cognition tasks that involve movement of the animal through space (e.g., the radial maze). The present study investigated the ability of the tortoise to learn a spatial task in which the response required was simply to touch a stimulus presented in a given position on a touchscreen. We also investigated the relation between this task and performance in a different spatial task (an arena, in which whole-body movement was required). Four red-footed tortoises learned to operate the touchscreen apparatus, and two learned the simple spatial discrimination. The side-preference trained with the touchscreen was maintained when behaviour was tested in a physical arena. When the contingencies in the arena were then reversed, the tortoises learned the reversal but in a subsequent test did not transfer it to the touchscreen. Rather they chose the side that had been rewarded originally on the touchscreen. The results show that red-footed tortoises are able to operate a touchscreen and can successfully solve a spatial two-choice task in this apparatus. There was some indication that the preference established with the touchscreen could transfer to an arena, but with subsequent training in the arena independent patterns of choice were established that could be evoked according to the test context.

  8. Morphometrics parallel genetics in a newly discovered and endangered taxon of Galápagos tortoise.

    PubMed

    Chiari, Ylenia; Hyseni, Chaz; Fritts, Tom H; Glaberman, Scott; Marquez, Cruz; Gibbs, James P; Claude, Julien; Caccone, Adalgisa

    2009-07-17

    Galápagos tortoises represent the only surviving lineage of giant tortoises that exhibit two different types of shell morphology. The taxonomy of Galápagos tortoises was initially based mainly on diagnostic morphological characters of the shell, but has been clarified by molecular studies indicating that most islands harbor monophyletic lineages, with the exception of Isabela and Santa Cruz. On Santa Cruz there is strong genetic differentiation between the two tortoise populations (Cerro Fatal and La Reserva) exhibiting domed shell morphology. Here we integrate nuclear microsatellite and mitochondrial data with statistical analyses of shell shape morphology to evaluate whether the genetic distinction and variability of the two domed tortoise populations is paralleled by differences in shell shape. Based on our results, morphometric analyses support the genetic distinction of the two populations and also reveal that the level of genetic variation is associated with morphological shell shape variation in both populations. The Cerro Fatal population possesses lower levels of morphological and genetic variation compared to the La Reserva population. Because the turtle shell is a complex heritable trait, our results suggest that, for the Cerro Fatal population, non-neutral loci have probably experienced a parallel decrease in variability as that observed for the genetic data.

  9. Microsatellite analysis of genetic divergence among populations of giant Galápagos tortoises.

    PubMed

    Ciofi, Claudio; Milinkovitch, Michel C; Gibbs, James P; Caccone, Adalgisa; Powell, Jeffrey R

    2002-11-01

    Giant Galápagos tortoises represent an interesting model for the study of patterns of genetic divergence and adaptive differentiation related to island colonization events. Recent mitochondrial DNA work elucidated the evolutionary history of the species and helped to clarify aspects of nomenclature. We used 10 microsatellite loci to assess levels of genetic divergence among and within island populations. In particular, we described the genetic structure of tortoises on the island of Isabela, where discrimination of different taxa is still subject of debate. Individual island populations were all genetically distinct. The island of Santa Cruz harboured two distinct populations. On Isabela, populations of Volcan Wolf, Darwin and Alcedo were significantly different from each other. On the other hand, Volcan Wolf showed allelic similarity with the island of Santiago. On Southern Isabela, lower genetic divergence was found between Northeast Sierra Negra and Volcan Alcedo, while patterns of gene flow were recorded among tortoises of Cerro Azul and Southeast Sierra Negra. These tortoises have endured heavy exploitation during the last three centuries and recently attracted much concern due to the current number of stochastic and deterministic threats to extant populations. Our study complements previous investigation based on mtDNA diversity and provides further information that may help devising tortoise management plans.

  10. Desert Shield/Storm Logistics

    DTIC Science & Technology

    1993-04-15

    Wc This document may not be retee for open publiarion until it has bm deaed by the Vproprnite military service or gmeanen agency. DESERT SHIELD /STORM...capture what had occurred during Operations DESERT SHIELD and STORM, the commanders of the Division Support Command of the 24th Infantry Division...Mechanized) held a ful. day of discussion centering on what occurted during Operation DESERT STORM and its preceding operation, DESERT SHIELD . The entire

  11. Desert Shield and Desert Storm Emerging Observations

    DTIC Science & Technology

    1991-10-07

    becomes much more apparent over relatively flat terrain. d. Recommended or Ongoing Action. The M577 CPV is scheduled to yo through a system conversion to...STORM Vehicle exchange policy at maintenanfce points. 9? 40115 4f996 (0017?) DESERT STORM Fretracide, peor ommunication. poor flank ceerdihutien. 24...02413 fll% yo (00M) DEIil SIONM Distribut ion of Wcom arM Iaf amon units 4??44 INAI8 (002 n) TILSll STORM Pro-combat trainfig V4 14145 U’,411 (00276

  12. Lessons from the Desert

    DTIC Science & Technology

    1993-04-14

    involvement in Operations DESERT SHIELD and STORM. The 498th was a unique unit, well-suited for the gamut of operations conducted by the 2AD (FWD) during its...Division (Forward), during that unit’s involvement in Operations DESERT SHIELD and STORM. The 498th was a unique unit, well-suited for the gamut of...well-suited fir the gamut of operations conducted by 2AD (FWD) during its stay in Southwest Asia (SWA) . I commanded the 498th Support Battalion from

  13. Tantalizing tortoises and the Darwin-Galápagos legend.

    PubMed

    Sulloway, Frank J

    2009-01-01

    During his historic Galápagos visit in 1835, Darwin spent nine days making scientific observations and collecting specimens on Santiago (James Island). In the course of this visit, Darwin ascended twice to the Santiago highlands. There, near springs located close to the island's summit, he conducted his most detailed observations of Galápagos tortoises. The precise location of these springs, which has not previously been established, is here identified using Darwin's own writings, satellite maps, and GPS technology. Photographic evidence from excursions to the areas where Darwin climbed, including repeat photography over a period of four decades, offers striking evidence of the deleterious impact of feral mammals introduced after Darwin's visit. Exploring the impact that Darwin's Santiago visit had on his thinking--especially focusing on his activities in the highlands--raises intriguing questions about the depth of his understanding of the evolutionary evidence he encountered while in the Galápagos. These questions and related insights provide further evidence concerning the timing of Darwin's conversion to the theory of evolution, which, despite recent claims to the contrary, occurred only after his return to England.

  14. New tortoise coordinate transformation and Hawking's radiation in de Sitter space

    NASA Astrophysics Data System (ADS)

    Ibohal, N.; Ibungochouba, T.

    2013-01-01

    Hawking's radiation effect of Klein-Gordon equation, Dirac particles and Maxwell's electromagnetic fields in the non-stationary rotating de Sitter cosmological space-time is investigated by using a new method of generalized tortoise coordinate transformation. It is found that the new transformation produces constant additional terms in the expressions of the surface gravities and the Hawking's temperatures. If the constant terms are set to zero, then the surface gravities and Hawking's temperatures will be equal to those obtained from the old generalized tortoise coordinate transformations. This shows that the new transformations are more reasonable. The Fermionic spectrum of Dirac particles displays a new spin-rotation coupling effect.

  15. On the Thermal Property of Arbitrarily Accelerating Charged Black Hole with a New Tortoise Coordinate Transformation

    NASA Astrophysics Data System (ADS)

    Zhenfeng, Niu; Wenbiao, Liu

    2006-07-01

    After a new tortoise coordinate transformation is adopted, the entropy and non-thermal radiation of an arbitrarily accelerating charged black hole are discussed as an example of non-stationary black holes. The same cut-off relation is chosen as static case, which is independent of space-time, and then the entropy of the non-stationary black hole is also proportional to the area of its event horizon. Meanwhile, the crossing of the particle energy levels near the event horizon is studied, the representative of the maximum value of the crossing energy levels is the same as the usual tortoise coordinate transformation.

  16. Thesis Abstract Morphological and phylogeographic analysis of Brazilian tortoises (Testudinidae).

    PubMed

    Silva, T L; Venancio, L P R; Bonini-Domingos, C R

    2015-12-29

    The discriminative potentials of biogeography, vocalization, morphology, cytogenetics, hemoglobin, and molecular profiling of cytochrome b as taxonomic techniques for differentiating Brazilian tortoises were evaluated in this study. In Brazil, two species of tortoises are described, Chelonoidis carbonarius and Chelonoidis denticulatus. However, in the present study, some animals that were initially recognized based on morphological characters and coloring did not correspond to the typical pattern of C. carbonarius; these animals were classified as morphotypes 1 and 2. It was proposed that these morphotypes are differentiated species, and they should not be considered as a single taxonomic unit with C. carbonarius. Tortoises analyzed were provided by the National Institute for Amazonian Research (INPA); the Emilio Goeldi Museum, PA; municipal zoos in São José do Rio Preto, SP, and Araçatuba, SP; and the Reginaldo Uvo Leone breeding farm for Wild and Exotic Animals, Tabapuã, SP. Based on the data obtained using biogeographic evaluation of specimens in the literature, it was found that C. carbonarius is distributed in the Northeast Region of Brazil, and no animal of this pattern was observed in the investigated collections. On the other hand, C. denticulatus is found in all the states of the Legal Amazonia. In addition, isolated individual records of this species exist in the Atlantic Forest in Espírito Santo and Rio de Janeiro and in the Midwest Region composed of the states of Goiás, Mato Grosso, and Mato Grosso do Sul. In the Northeast Region, C. denticulatus occurs in the State of Bahia. Morphotype 1 has a wider geographical distribution than C. carbonarius, possibly because of several distribution reports associated with C. carbonarius, indicating erroneous association of morphotype 1 as a single taxonomic unit with C. carbonarius. Morphotype 2 is found only in the states of Pará, Maranhão, and Piauí. These biogeographic data indicate that the

  17. Mojave Desert Diary

    ERIC Educational Resources Information Center

    Breed, Allen F.

    1974-01-01

    This is an account of a trip to the Mojave Desert sponsored by the California Youth Authority's Community Parole Center for wards who are selected on the basis of their potential for growth and their ability to make a connection between what they do in the wilderness and what they do on the streets. (PD)

  18. Nest desertion and cowbird parasitism: evidence for evolved responses and evolutionary lag.

    PubMed

    Hosoi; Rothstein

    2000-04-01

    Nest desertion with subsequent renesting is a frequently cited response to parasitism by the brown-headed cowbird, Molothrus ater, yet the role of desertion as an antiparasite defence is widely debated. To determine whether desertion represents an evolutionary response to brown-headed cowbird parasitism, we searched the primary literature, yielding data on the desertion frequencies of 60 host populations from 35 species. Species were categorized according to three habitat types (forest, intermediate and nonforest). Because cowbirds prefer open habitat and rarely penetrate deeply into forests, nonforest species have long been exposed to widespread cowbird parasitism, whereas forest species have not. However, due to increased forest fragmentation, forest species are being increasingly exposed to extensive parasitism. The frequency of desertion of parasitized nests was significantly higher in nonforest than forest species, suggesting that the latter experience evolutionary lag. We also considered whether desertion is affected by predation frequency, degree of current or recent sympatry with cowbirds, parasitism frequency, length of host laying season, phylogenetic relationships, and potential cost of cowbird parasitism. None of these variables created biases that could account for the observed difference in desertion frequencies of nonforest and forest species. However, species that incur large costs when parasitized had higher desertion rates among nonforest species but not among forest species. These results indicate that increased nest desertion is an evolved response to cowbird parasitism, as one would otherwise expect no relationship between desertion frequency and thezx costs and length of exposure to cowbird parasitism. Although nearly all hosts have eggs easily distinguished from cowbird eggs, few or none desert in response to cowbird eggs. Instead, desertion may be a response to adult cowbirds. The scarcity of species that desert in response to cowbird eggs

  19. A study of Desert Dermatoses in the Thar Desert Region

    PubMed Central

    Chatterjee, Manas; Vasudevan, Biju

    2015-01-01

    Introduction: Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is therefore important to survival. This original article focuses on dermatoses occurring in a population in the Thar desert of India, predominantly located in Rajasthan. Materials and Methods: This is a descriptive study involving various dermatoses seen in patients residing in the Thar desert region over a duration of 3 years. Results: Infections were the most common condition seen among this population and among them fungal infections were the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis and skin tumors were found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. Conclusion: The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions. The concept of desert dermatology needs to be understood in more details to provide better care to those suffering from desert dermatoses and this article is a step forward in this regard. PMID:25657392

  20. 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.

  1. Heavy absorption chillers: The Tortoise technology that can win

    SciTech Connect

    Irwin, F.E.

    1995-06-01

    Why has Absorption taken over 200 years to become a viable technology and secondarily what is the long term potential for heavy absorption technology? A third interesting question may be as some knowledgeable people in the North America industry have professed, is there a Window of Opportunity which was presented by the electric vapor compressor refrigerant issue which will be the last chance for absorption? Of course we know that absorption is not a new technology in 1994. It is however being rediscovered in many parts of the world by specifiers and engineers who are otherwise totally familiar with HVAC systems technology. As has been well documented in Japan, absorption heavy systems have been dominant for some time to the point that over 90% of the new units installed in the heavy systems category are absorption. Further by now 50% of the installed heavy systems tonnage in the country are absorption chillers. It did not take the electric vapor compressor refrigerant issue to make this huge market for absorption and there aren`t too many people in the HVAC business in Japan that view absorption as the {open_quotes}Tortoise technology.{close_quotes} If we only understood what the drivers were in Japan to create this absorption market then perhaps we could understand and possibly predict the long term potential for the technology in other markets of the world. We could actually go to work and look for markets that mirror the prevailing conditions in Japan. There will be those amongst us who will tell you that Japan is a unique market in almost every product category and most certainly with respect to heavy chiller systems.

  2. Uruburuella testudinis sp. nov., isolated from tortoise (Testudo).

    PubMed

    Kuhnert, Peter; Thomann, Andreas; Brodard, Isabelle; Haefeli, Willi; Korczak, Bożena M

    2015-04-01

    A polyphasic taxonomic analysis was carried out on 11 uncommon Gram-stain-negative, non-motile, catalase- and oxidase-positive, but indole-negative, bacterial strains isolated from tortoises. Phenotypically and genetically they represented a homogeneous group of organisms most closely related to, but distinct from, Uruburuella suis. In a reconstructed 16S rRNA gene tree they clustered on a monophyletic branch next to U. suis with gene similarities between strains of 99.5-100%, and of up to 98.2% with U. suis . DNA-DNA hybridization indicated the organisms represented a novel species with only 40% DNA-DNA similarity with U. suis . Partial sequencing of rpoB resulted in two subclusters confirming the 16S rRNA gene phylogeny; both genes allowed clear separation and identification of the novel species. Furthermore, they could be unambiguously identified by matrix-assisted laser desorption ionization time-of-flight MS, where, again, they formed a highly homogeneous cluster separate from U. suis and other members of the family Neisseriaceae . The major fatty acids were C(16 : 0) and summed feature C(16 : 1)ω7c/iso-C(15 : 0) 2-OH. The DNA G+C content was 54.4 mol%. Based on phenotypic and genetic data we propose classifying these organisms as representatives of a novel species named Uruburuella testudinis sp. nov. The type strain is 07_OD624(T) ( = DSM 26510(T) = CCUG 63373(T)).

  3. If Animals Could Talk: Bald Eagle, Bear, Florida Panther, Gopher Tortoise, Indigo Snake, Manatee, Otter, Raccoon.

    ERIC Educational Resources Information Center

    Pinellas County District School Board, Clearwater, FL.

    In this series of booklets, eight Florida animals describe their appearance, habitats, food, behavior, and relationships with humans. Each entry is written for elementary students from the animal's point of view and includes a bibliography. Contained are the life stories of the bald eagle, black bear, Florida panther, gopher tortoise, Eastern…

  4. Do Handling and Transport Stress Influence Adrenocortical Response in the Tortoises (Testudo hermanni)?

    PubMed Central

    Medica, Pietro; Ferlazzo, Adriana

    2014-01-01

    The goal of this study was to analyze circulating cortisol levels from tortoises (Testudo hermanni) to establish reference intervals and to develop guidelines for the interpretation of the effect of handling and transport stress. Blood samples were obtained from the caudal venous from 23 healthy juvenile tortoises (9 males and 14 females), aged 8–20 years, in basal condition, four weeks prior to and four weeks following handling and short transportation. The study was carried out on the experimental group: 10 tortoises, 4 males and 6 females, and on a control group: 13 tortoises, 5 males and 8 females. Compared to basal values, circulating cortisol concentrations was higher after handling and transport (+286%; P < 0.001), with an increase of +246% (P < 0.001) in males, +236% (P < 0.005) in females, +370% (P < 0.005) in subjects aged 8–12 years, and +240% (P < 0.001) in subjects aged 13–20 years. These observations support the hypotheses that cortisol may act to mediate the effects of handling and transport stress in this species and that four weeks following handling and transport were insufficient to restore their homeostasis. PMID:24977048

  5. Low tortoise abundances in pine forest plantations in forest-shrubland transition areas.

    PubMed

    Rodríguez-Caro, Roberto C; Oedekoven, Cornelia S; Graciá, Eva; Anadón, José D; Buckland, Stephen T; Esteve-Selma, Miguel A; Martinez, Julia; Giménez, Andrés

    2017-01-01

    In the transition between Mediterranean forest and the arid subtropical shrublands of the southeastern Iberian Peninsula, humans have transformed habitat since ancient times. Understanding the role of the original mosaic landscapes in wildlife species and the effects of the current changes as pine forest plantations, performed even outside the forest ecological boundaries, are important conservation issues. We studied variation in the density of the endangered spur-thighed tortoise (Testudo graeca) in three areas that include the four most common land types within the species' range (pine forests, natural shrubs, dryland crop fields, and abandoned crop fields). Tortoise densities were estimated using a two-stage modeling approach with line transect distance sampling. Densities in dryland crop fields, abandoned crop fields and natural shrubs were higher (>6 individuals/ha) than in pine forests (1.25 individuals/ha). We also found large variation in density in the pine forests. Recent pine plantations showed higher densities than mature pine forests where shrub and herbaceous cover was taller and thicker. We hypothesize that mature pine forest might constrain tortoise activity by acting as partial barriers to movements. This issue is relevant for management purposes given that large areas in the tortoise's range have recently been converted to pine plantations.

  6. Thinking and Writing Mathematically: "Achilles and the Tortoise" as an Algebraic Word Problem.

    ERIC Educational Resources Information Center

    Martinez, Joseph G. R.

    2001-01-01

    Introduces Hogben's adaptation of Zeno's paradox, "Achilles and the Tortoise", as a thinking and writing exercise. Emphasizes engaging students' imagination with creative, thought-provoking problems and involving students in evaluating their word problem-solving strategies. Describes the paradox, logical solutions, and students' mathematical…

  7. Fermions Tunneling from Non-Stationary Dilaton-Maxwell Black Hole via General Tortoise Coordinate Transformation

    NASA Astrophysics Data System (ADS)

    Lin, Kai; Yang, Shu-Zheng

    2009-10-01

    Fermions tunneling of the non-stationary Dilaton-Maxwell black hole is investigated with general tortoise coordinate transformation. The Dirac equation is simplified by semiclassical approximation so that the Hamilton-Jacobi equation is generated. Finally the tunneling rate and the Hawking temperature is calculated.

  8. Fermions Tunneling from Bardeen-Vaidya Black Hole via General Tortoise Coordinate Transformation

    NASA Astrophysics Data System (ADS)

    Kai, Lin; Shuzheng, Yang

    In this paper, we research on the scalar field particles and 1/2 spin fermions tunneling from the event horizon of Bardeen-Vaidya black hole by semiclassical method and general tortoise coordinate transformation, and obtain the Hawking temperature and tunneling rate near the event horizon.

  9. Ancient mitochondrial DNA and morphology elucidate an extinct island radiation of Indian Ocean giant tortoises (Cylindraspis).

    PubMed Central

    Austin, J. J.; Arnold, E. N.

    2001-01-01

    Ancient mitochondrial DNA sequences were used for investigating the evolution of an entire clade of extinct vertebrates, the endemic tortoises (Cylindraspis) of the Mascarene Islands in the Indian Ocean. Mitochondrial DNA corroborates morphological evidence that there were five species of tortoise with the following relationships: Cylindraspis triserrata ((Cylindraspis vosmaeri and Cylindraspis peltastes) (Cylindraspis inepta and Cylindraspis indica)). Phylogeny indicates that the ancestor of the group first colonized Mauritius where speciation produced C. triserrata and the ancestor of the other species including a second sympatric Mauritian form, C. inepta. A propagule derived from this lineage colonized Rodrigues 590 km to the east, where a second within-island speciation took place producing the sympatric C. vosmaeri and C. peltastes. A recent colonization of Réunion 150 km to the southwest produced C. indica. In the virtual absence of predators, the defensive features of the shells of Mascarene tortoises were largely dismantled, apparently in two stages. 'Saddlebacked' shells with high fronts evolved independently on all three islands. This and other features, such as a derived jaw structure and small body size, may be associated with niche differentiation in sympatric species and may represent a striking example of parallel differentiation in a large terrestrial vertebrate. The history of Mascarene tortoises contrasts with that of the Galápagos, where only a single species is present and surviving populations are genetically much more similar. However, they too show some reduction in anti-predator mechanisms and multiple development of populations with saddlebacked shells. PMID:11749704

  10. Occurrence of Camallanus trispinosus in a captive Indian star tortoise (Geochelone elegans).

    PubMed

    Jeyathilakan, N; Raman, M; Jayathangaraj, M G

    2015-03-01

    Camallanoids are spirurid round worms known to occur in stomach and intestine of lower vertebrate animals such as fishes and reptiles. This paper records the occurrence of Camallanus trispinosus in a captive Indian star tortoise of Guindy snake park, Chennai, India for the first time during necropsy and identified on the basis of morphology of male and female worms, including eggs.

  11. Hematologic and plasma biochemical changes associated with fenbendazole administration in Hermann's tortoises (testudo hermanni).

    PubMed

    Neiffer, Donald L; Lydick, Dianna; Burks, Kyle; Doherty, Donna

    2005-12-01

    Toxicosis associated with benzimidazole anthelmintics has been reported with increasing frequency in zoologic collections. Clinical signs, clinicopathologic abnormalities, and gross and histologic lesions are primarily the result of damage to the gastrointestinal and hematopoietic systems. Profound leukopenia, especially granulocytopenia, is the most common and severe clinicopathologic change associated with benzimidazole administration. Death usually occurs from overwhelming systemic bacterial and/or fungal infections secondary to severe immunosuppression. In this 125-day study, six male Hermann's tortoises (Testudo hermanni) were treated orally with two 5-day courses of fenbendazole 2 wk apart at a dosage of 50 mg/kg. Serial blood samples were used to assess hematologic and plasma biochemical changes before, during, and following the treatment period. Although the tortoises remained healthy, blood sampling indicated an extended heteropenia with transient hypoglycemia, hyperuricemia, hyperphosphatemia, and equivocal hyperproteinemia/hyperglobulinemia, which were considered to be in response to fenbendazole administration. Changes in several other clinicopathologic parameters appeared to correlate with fenbendazole administration. The hematologic and biochemical changes seen in the healthy animals in this study should be considered when treating compromised tortoises with fenbendazole. Hematologic and plasma biochemical status of tortoises/reptiles should be determined before treatment and monitored during the treatment period. The risk of mortality of an individual from nematode infection should be assessed relative to the potential for metabolic alteration and secondary septicemia following damage to hematopoietic and gastrointestinal systems by fenbendazole.

  12. A molecular phylogeny of four endangered Madagascar tortoises based on MtDNA sequences.

    PubMed

    Caccone, A; Amato, G; Gratry, O C; Behler, J; Powell, J R

    1999-06-01

    Four of the five tortoise species in Madagascar, Pyxis arachnoides, P. planicauda, Geochelone radiata, and G. yniphora, are endemic and on the verge of extinction. Their phylogenetic relationships remain controversial and unresolved. Here we address the phylogeny of this group using DNA sequences for the 12S and 16S rDNA and cyt b genes in mitochondrial DNA. As outgroups we used two species of Geochelone, pardalis (mainland Africa) and nigra (Galápagos), as well as a more distant North American tortoise, Gopherus polyphemus. We conclude that the two Pyxis species are sister taxa and are imbedded in the genus Geochelone, rendering this latter genus paraphyletic. There is moderate support for the sister status of the two Madagascar Geochelone and for the monophyletic origin of all four endemics, suggesting a single colonization of the island. The separation of Madagascar from other land masses (90-165 mya) predates the origin of the endemic tortoises (estimated to be 14-22 mya). This suggests founding by rafting, a process known to have occurred with other tortoises. The derived morphological divergence of the Pyxis species in a relatively short period of time (13-20 my) stands in contrast to the notoriously slow rate of morphological evolution in most lineages of Chelonia.

  13. Ancient mitochondrial DNA and morphology elucidate an extinct island radiation of Indian Ocean giant tortoises (Cylindraspis).

    PubMed

    Austin, J J; Arnold, E N

    2001-12-22

    Ancient mitochondrial DNA sequences were used for investigating the evolution of an entire clade of extinct vertebrates, the endemic tortoises (Cylindraspis) of the Mascarene Islands in the Indian Ocean. Mitochondrial DNA corroborates morphological evidence that there were five species of tortoise with the following relationships: Cylindraspis triserrata ((Cylindraspis vosmaeri and Cylindraspis peltastes) (Cylindraspis inepta and Cylindraspis indica)). Phylogeny indicates that the ancestor of the group first colonized Mauritius where speciation produced C. triserrata and the ancestor of the other species including a second sympatric Mauritian form, C. inepta. A propagule derived from this lineage colonized Rodrigues 590 km to the east, where a second within-island speciation took place producing the sympatric C. vosmaeri and C. peltastes. A recent colonization of Réunion 150 km to the southwest produced C. indica. In the virtual absence of predators, the defensive features of the shells of Mascarene tortoises were largely dismantled, apparently in two stages. 'Saddlebacked' shells with high fronts evolved independently on all three islands. This and other features, such as a derived jaw structure and small body size, may be associated with niche differentiation in sympatric species and may represent a striking example of parallel differentiation in a large terrestrial vertebrate. The history of Mascarene tortoises contrasts with that of the Galápagos, where only a single species is present and surviving populations are genetically much more similar. However, they too show some reduction in anti-predator mechanisms and multiple development of populations with saddlebacked shells.

  14. The phylogeny of Mediterranean tortoises and their close relativesbased on complete mitochondrial genome sequences from museumspecimens

    SciTech Connect

    Parham, James F.; Macey, J. Robert; Papenfuss, Theodore J.; Feldman, Chris R.; Turkozan, Oguz; Polymeni, Rosa; Boore, Jeffrey

    2005-04-29

    As part of an ongoing project to generate a mitochondrial database for terrestrial tortoises based on museum specimens, the complete mitochondrial genome sequences of 10 species and a {approx}14 kb sequence from an eleventh species are reported. The sampling of the present study emphasizes Mediterranean tortoises (genus Testudo and their close relatives). Our new sequences are aligned, along with those of two testudinoid turtles from GenBank, Chrysemys picta and Mauremys reevesii, yielding an alignment of 14,858 positions, of which 3,238 are parsimony informative. We develop a phylogenetic taxonomy for Testudo and related species based on well-supported, diagnosable clades. Several well-supported nodes are recovered, including the monophyly of a restricted Testudo, T. kleinmanni + T. marginata (the Chersus clade), and the placement of the enigmatic African pancake tortoise (Malacochersustornieri) within the predominantly Palearctic greater Testudo group (Testudona tax. nov.). Despite the large amount of sequence reported, there is low statistical support for some nodes within Testudona and Sowe do not propose names for those groups. A preliminary and conservative estimation of divergence times implies a late Miocene diversification for the testudonan clade (6-12 million years ago), matching their first appearance in the fossil record. The multi-continental distribution of testudonan turtles can be explained by the establishment of permanent connections between Europe, Africa, and Asia at this time. The arrival of testudonan turtles to Africa occurred after one or more initial tortoise invasions gave rise to the diverse (>25 species) 'Geochelone complex.'Two unusual genomic features are reported for the mtDNA of one tortoise, M. tornieri: (1) nad4 has a shift of reading frame that we suggest is resolved by translational frameshifting of the mRNA on the ribosome during protein synthesis and (2) there are two copies of the control region and trnF, with the latter

  15. Deserts of China

    USGS Publications Warehouse

    Walker, Alta S.

    1982-01-01

    Improving arid land quality requires an understanding of the original state of the land and its relationship to wind, water, and plant regimes, as well as understanding of interactions within the present ecosystem.  Chinese scientists and local residents have made significant advances in improving arid environments in gobi and sandy deserts and in less arid sandy lands.  Wind patterns are being changed by planting forest belts to protect oases and sandy lands, and on a smaller scale by planting grasses and shrubs or constructing straw grids.  Research on reclamation of deserts is now focusing on how sand-fixing plants may be adapted to local environments, and how the resources of grazing land and water may be effectively exploited without being overused.

  16. Southwestern desert resources

    USGS Publications Warehouse

    Halvorson, William L.; van Riper, Charles; Schwalbe, Cecil R.

    2010-01-01

    The southwestern deserts stretch from southeastern California to west Texas and then south to central Mexico. The landscape of this region is known as basin and range topography featuring to "sky islands" of forest rising from the desert lowlands which creates a uniquely diverse ecology. The region is further complicated by an international border, where governments have caused difficulties for many animal populations. This book puts a spotlight on individual research projects which are specific examples of work being done in the area and when they are all brought together, to shed a general light of understanding the biological and cultural resources of this vast region so that those same resources can be managed as effectively and efficiently as possible. The intent is to show that collaborative efforts among federal, state agency, university, and private sector researchers working with land managers, provides better science and better management than when scientists and land managers work independently.

  17. Aquaporins in desert rodent physiology.

    PubMed

    Pannabecker, Thomas L

    2015-08-01

    Desert rodents face a sizeable challenge in maintaining salt and water homeostasis due to their life in an arid environment. A number of their organ systems exhibit functional characteristics that limit water loss above that which occurs in non-desert species under similar conditions. These systems include renal, pulmonary, gastrointestinal, nasal, and skin epithelia. The desert rodent kidney preserves body water by producing a highly concentrated urine that reaches a maximum osmolality nearly three times that of the common laboratory rat. The precise mechanism by which urine is concentrated in any mammal is unknown. Insights into the process may be more apparent in species that produce highly concentrated urine. Aquaporin water channels play a fundamental role in water transport in several desert rodent organ systems. The role of aquaporins in facilitating highly effective water preservation in desert rodents is only beginning to be explored. The organ systems of desert rodents and their associated AQPs are described.

  18. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  19. Episodic death across species of desert shrubs.

    PubMed

    Miriti, Maria N; Rodríguez-Buriticá, Susana; Wright, S Joseph; Howe, Henry F

    2007-01-01

    Extreme events shape population and community trajectories. We report episodic mortality across common species of thousands of long-lived perennials individually tagged and monitored for 20 years in the Colorado Desert of California following severe regional drought. Demographic records from 1984 to 2004 show 15 years of virtual stasis in populations of adult shrubs and cacti, punctuated by a 55-100% die-off of six of the seven most common perennial species. In this episode, adults that experienced reduced growth in a lesser drought during 1984-1989 failed to survive the drought of 2002. The significance of this event is potentially profound because population dynamics of long-lived plants can be far more strongly affected by deaths of adults, which in deserts potentially live for centuries, than by seedling births or deaths. Differential mortality and rates of recovery during and after extreme climatic events quite likely determine the species composition of plant and associated animal communities for at least decades. The die-off recorded in this closely monitored community provides a unique window into the mechanics of this process of species decline and replacement.

  20. Survey of Yucca Mountain, Forty-Mile Canyon, and Jackass Flats in Nye County, Nevada for desert tortoise, Gopherus agassizii

    SciTech Connect

    Medica, P.A.; O`Farrell, T.P.; Collins, E.

    1981-10-01

    The objective of this brief survey was to determine if G. agassizii is present west of Forty-Mile Canyon in the Yucca Mountain.. area, or along the major access roads which lead through Jackass Flats to Forty-Mile Canyon and Yucca Mountain

  1. Benefits of protective fencing to plant and rodent communities of the western Mojave Desert, California

    NASA Astrophysics Data System (ADS)

    Brooks, Matthew L.

    1995-01-01

    Human disturbance in the western Mojave Desert takes many forms. The most pervasive are livestock grazing and off-highway vehicle use. Over the past few decades several areas within this region have been fenced to preclude human disturbance. These areas provide opportunities to study the impact of human activities in a desert ecosystem. This paper documents the response of plant and small mammal populations to fencing constructed between 1978 and 1979 at the Desert Tortoise Research Natural Area, Kern County, California. Aboveground live annual plant biomass was generally greater inside than outside the fenced plots during April 1990, 1991, and 1992. The alien grass Schismus barbatus was a notable exception, producing more biomass in the unprotected area. Forb biomass was greater than that of alien annual grasses inside the fence during all three years of the study. Outside the fence, forb biomass was significantly higher than that of alien grasses only during spring 1992. Percent cover of perennial shrubs was higher inside the fence than outside, while no significant trend was detected in density. There was als more seed biomass inside the fence; this may have contributed to the greater diversity and density of Merriam's kangaroo rats ( Dipodomys merriami), long-tailed pocket mice ( Chaetodipus formosus), and southern grasshopper mice ( Onychomys torridus) in the protected area. These results show that protection from human disturbance has many benefits, including greater overall community biomass and diversity. The significance and generality of these results can be further tested by studying other exclosures of varying age and configurations in different desert regions of the southwestern United States.

  2. Exploring conservation discourses in the Galapagos Islands: A case study of the Galapagos giant tortoises.

    PubMed

    Benitez-Capistros, Francisco; Hugé, Jean; Dahdouh-Guebas, Farid; Koedam, Nico

    2016-10-01

    Conservation discourses change rapidly both at global and local scales. To be able to capture these shifts and the relationships between humans and nature, we focused on a local and iconic conservation case: the Galapagos giant tortoises (Chelonoidis spp.). We used the Q methodology to contextualize conservation for science and decision making and to explore the multidimensionality of the conservation concept in Galapagos. The results indicate four prevailing discourses: (1) Multi-actor governance; (2) giant tortoise and ecosystems conservation; (3) community governance; and (4) market and tourism centred. These findings allow us to identify foreseeable points of disagreement, as well as areas of consensus, and to discuss the implication of the findings to address socio-ecological conservation and sustainability challenges. This can help the different involved stakeholders (managers, scientists and local communities) to the design and apply contextualized conservation actions and policies to contribute to a better sustainable management of the archipelago.

  3. Hematological and pathological features of massive hepatic necrosis in two radiated tortoises (Astrochelys radiata)

    PubMed Central

    KIDO, Nobuhide; ITAGAKI, Iori; KIRYU, Daisuke; OMIYA, Tomoko; ONO, Kaori

    2016-01-01

    Two radiated tortoises (Astrochelys radiata) exhibited anorexia and hypokinesia. In both cases, hematological and serum biochemical examinations revealed high alkaline phosphatase levels, moderately high aspartate aminotransferase levels and white blood cell counts approximately within the normal range. Despite being treated, the tortoises died 9 and 43 days after the first clinical examination. Gross pathological examinations revealed that the livers of both animals were extremely swollen and contained pale yellow necrotic tissue. Histopathological assessment revealed that the livers contained a massive area of hepatic necrosis surrounded by migration of macrophages and multinucleated giant cells. In one of the cases, severe fibrosis was observed. The present study provides reference information for similar cases in the future. PMID:27746414

  4. A cryptic taxon of Galápagos tortoise in conservation peril.

    PubMed

    Russello, Michael A; Glaberman, Scott; Gibbs, James P; Marquez, Cruz; Powell, Jeffrey R; Caccone, Adalgisa

    2005-09-22

    As once boldly stated, 'bad taxonomy can kill', highlighting the critical importance of accurate taxonomy for the conservation of endangered taxa. The concept continues to evolve almost 15 years later largely because most legal protections aimed at preserving biological diversity are based on formal taxonomic designations. In this paper we report unrecognized genetic divisions within the giant tortoises of the Galápagos. We found three distinct lineages among populations formerly considered a single taxon on the most populous and accessible island of Santa Cruz; their diagnosability, degree of genetic divergence and phylogenetic placement merit the recognition of at least one new taxon. These results demonstrate the fundamental importance of continuing taxonomic investigations to recognize biological diversity and designate units of conservation, even within long-studied organisms such as Galápagos tortoises, whose evolutionary heritage and contribution to human intellectual history warrant them special attention.

  5. A cryptic taxon of Galápagos tortoise in conservation peril

    PubMed Central

    Russello, Michael A; Glaberman, Scott; Gibbs, James P; Marquez, Cruz; Powell, Jeffrey R; Caccone, Adalgisa

    2005-01-01

    As once boldly stated, ‘bad taxonomy can kill’, highlighting the critical importance of accurate taxonomy for the conservation of endangered taxa. The concept continues to evolve almost 15 years later largely because most legal protections aimed at preserving biological diversity are based on formal taxonomic designations. In this paper we report unrecognized genetic divisions within the giant tortoises of the Galápagos. We found three distinct lineages among populations formerly considered a single taxon on the most populous and accessible island of Santa Cruz; their diagnosability, degree of genetic divergence and phylogenetic placement merit the recognition of at least one new taxon. These results demonstrate the fundamental importance of continuing taxonomic investigations to recognize biological diversity and designate units of conservation, even within long-studied organisms such as Galápagos tortoises, whose evolutionary heritage and contribution to human intellectual history warrant them special attention. PMID:17148189

  6. [Several features of the metabolism of the fast and slow muscles of Emys orbicularis tortoises].

    PubMed

    Lebedinskaia, I I; Ogorodnikova, L G

    1978-01-01

    In skeletal muscles of the tortoise E. orbicularis, studies have been made on the content of glycogen, lactic acid, on the activity of glucose-6-phosphatase and phosphorylase. Histochemical studies were made on the lipid content. Experiments were performed on fast and slow bundles from mm. iliofibularis, testo cervicalis and retractor capitis. For comparison, the same indices of carbohydrate metabolism were investigated in fast m. plantaris and slow m. soleus of rats. In rats, slow muscles exhibit aerobic metabolism, in fast muscles--anaerobic one. In tortoises, slow muscles exhibit intermediate type of metabolism. Fast muscles show an anaerobic type or metabolism which is less intensive than anaerobic metabolism in slow muscles. Significant differences in some of the indices of carbohydrate metabolism were found in muscles which perform different functions in the organism.

  7. Russian tortoises (Agrionemys horsfieldi) as a potential reservoir for Salmonella spp.

    PubMed

    Nowakiewicz, Aneta; Ziółkowska, Grażyna; Zięba, Przemysław; Stępniewska, Katarzyna; Tokarzewski, Stanisław

    2012-04-01

    A total of 80 Russian tortoises brought in Poland were examined for presence of Salmonella. Salmonella was detected in 15 out of all the animals tested (18.75%). Of the total of 56 strains, 30 (53.57%) belonged to Salmonella enterica subsp. enterica (I) and 26 to Salmonella enterica subsp. salamae (II). The predominant serotype within subspecies I was S. Newport, which is one of the most serotypes causing salmonellosis in humans and warm-blooded animals. In vitro determination of the susceptibility of Salmonella to the 10 medicinal preparations showed that all tested strains were sensitive to norfloxacin, sulfamethoxazole with trimethoprim, florfenicol, gentamicin, tetracycline and ampicillin, resistance was noted only to amoxicillin with clavulanic acid (12 strains), and intermediate sensitivity to colistin (7 strains), enrofloxacin (2 strains) and cephalexin (5 strains). These studies confirmed that Russian tortoises are a significant reservoir for Salmonella and may represent a potential source of infection for humans.

  8. Desert landscape irrigation

    SciTech Connect

    Quinones, R.

    1995-06-01

    Industrialization can take place in an arid environment if a long term, overall water management program is developed. The general rule to follow is that recharge must equal or exceed use. The main problem encountered in landscape projects is that everyone wants a lush jungle setting, tall shade trees, ferns, with a variety of floral arrangements mixed in. What we want, what we can afford, and what we get are not always the same. Vegetation that requires large quantities of water are not native to any desert. Surprisingly; there are various types of fruit trees, and vegetables that will thrive in the desert. Peaches, plums, nut trees, do well with drip irrigation as well as tomatoes. Shaded berry plans will also do well, the strawberry being one. In summary; if we match our landscape to our area, we can then design our irrigation system to maintain our landscape and grow a variety of vegetation in any arid or semiarid environment. The application of science and economics to landscaping has now come of age.

  9. Tortoises as a dietary supplement: A view from the Middle Pleistocene site of Qesem Cave, Israel

    NASA Astrophysics Data System (ADS)

    Blasco, Ruth; Rosell, Jordi; Smith, Krister T.; Maul, Lutz Christian; Sañudo, Pablo; Barkai, Ran; Gopher, Avi

    2016-02-01

    Dietary reconstructions can offer an improved perspective on human capacities of adaptation to the environment. New methodological approaches and analytical techniques have led to a theoretical framework for understanding how human groups used and adapted to their local environment. Faunal remains provide an important potential source of dietary information and allow study of behavioural variation and its evolutionary significance. Interest in determining how hominids filled the gaps in large prey availability with small game or what role small game played in pre-Upper Palaeolithic societies is an area of active research. Some of this work has focused on tortoises because they represent an important combination of edible and non-edible resources that are easy to collect if available. The exploitation of these slow-moving animals features prominently in prey choice models because the low handling costs of these reptiles make up for their small body size. Here, we present new taphonomic data from two tortoise assemblages extracted from the lower sequence of the Middle Pleistocene site of Qesem Cave, Israel (420-300 ka), with the aim of assessing the socio-economic factors that may have led to the inclusion of this type of resource in the human diets. We show that hominid damage on large tortoise specimens from Qesem Cave is not unusual and that evidence such as cut marks, percussion marks and consistent patterns of burning suggests established sequences of processing, including cooking in the shell, defleshing, and direct percussion to access the visceral content. These matters make it possible not only to assess the potential role of tortoises as prey, but also to evaluate collecting behaviour in the resource acquisition systems and eco-social strategies at the Acheulo-Yabrudian Cultural Complex (AYCC) in the southern Levant.

  10. The whole world put between to shells: The cosmic symbolism of tortoises and turtles.

    NASA Astrophysics Data System (ADS)

    Rappengluck, M.

    Since the Bronze Age turtles and tortoise were related to a cosmic symbolism by ancient cultures in different parts of the world, with a certain concentration in the northern hemisphere. The paper attempts to categorize aspects of the cosmic turtle symbolism, using mainly an ethnoastronomical approach, partly supported by archaeological evidences. As a result a set of concepts can be identified, which are related to cosmologic, cosmogonic, biological and psychological aspects.

  11. Tortoise coordinate and Hawking effect in a dynamical Kerr black hole

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Zhao, Zheng; Liu, Wenbiao

    2011-02-01

    Hawking effect from a dynamical Kerr black hole is investigated using the improved Damour-Ruffini method with a new tortoise coordinate transformation. Hawking temperature of the black hole can be obtained point by point at the event horizon. It is found that Hawking temperatures of different points on the surface are different. Moreover, the temperature does not turn to zero while the dynamical black hole turns to an extreme one.

  12. General Tortoise Coordinate Transformation in a Dynamical Kerr-Newman Black Hole

    NASA Astrophysics Data System (ADS)

    Liu, Xian-Ming; Cheng, Su-Jun; Liu, Wen-Biao

    2012-02-01

    Under the extended dynamical tortoise coordinate transformation, Damour-Ruffini method has been applied to calculate the charged particles' Hawking radiation from the apparent horizon of a dynamical Kerr-Newman black hole. It is shown that Hawking radiation is still purely thermal black body spectrum. Moreover, the temperature of Hawking radiation is corresponding to the apparent horizon surface gravity and the first law of thermodynamics can also be constructed successfully on the apparent horizon in the dynamical Kerr-Newman black hole.

  13. Mast cell tumour in a giant Galapagos tortoise (Geochelone nigra vicina).

    PubMed

    Santoro, M; Stacy, B A; Morales, J A; Gastezzi-Arias, P; Landazuli, S; Jacobson, E R

    2008-01-01

    A well-differentiated cutaneous mast cell tumour was diagnosed in a subadult female giant Galapagos tortoise. The tumour was a pedunculated, verrucose mass located near the base of the neck. The histological features, which were diagnostic for a mast cell tumour, included abundant intracytoplasmic granules that were stained metachromatically with Giemsa and toluidine blue stains. Mast cell tumours are rare in reptiles, and this is the first description of a mast cell tumour in a chelonian.

  14. Genetic studies of freshwater turtle and tortoises: a review of the past 70 years

    USGS Publications Warehouse

    FitzSimmons, Nancy N.; Hart, Kristen M.

    2007-01-01

    Powerful molecular techniques have been developed over many decades for resolving genetic relationships, population genetic structure, patterns of gene flow, mating systems, and the amount of genetic diversity in animals. Genetic studies of turtles were among the earliest and the rapid application of new genetic tools and analytical techniques is still apparent in the literature on turtles. At present, of the 198 freshwater turtles and tortoises that are listed as not extinct by the IUCN Red List, 69 species worldwide are listed as endangered or critically endangered, and an additional 56 species are listed as vulnerable. Of the ca. 300 species of the freshwater turtles and tortoises in the world, ca. 42% are considered to be facing a high risk extinction, and there is a need to focus intense conservation attention on these species. This includes a need to (i) assess our current state of knowledge regarding the application of genetics to studies of freshwater turtles and tortoises and (ii) determine future research directions. Here, we review all available published studies for the past 70 years that were written in English and used genetic markers (e.g. karyotypes, allozymes, DNA loci) to better understand the biology of freshwater turtles and tortoises. We review the types of studies conducted in relation to the species studied and quantify the countries where the studies were performed. We rack the changing use of different genetic markers through time and report on studies focused on aspects of molecular evolution within turtle genomes. We address the usefulness of particular genetic markers to answer phylogenetic questions and present data comparing population genetic structure and mating systems across species. We draw specific attention to whether authors have considered issues to turtle conservation in their research or provided new insights that have been translated into recommendations for conservation management.

  15. Nest site characteristics and nesting success of the Western Burrowing Owl in the eastern Mojave Desert

    USGS Publications Warehouse

    Longshore, Kathleen M.; Crowe, Dorothy E.

    2013-01-01

    We evaluated nest site selection at two spatial scales (microsite, territory) and reproductive success of Western Burrowing Owls (Athene cunicularia hypugaea) at three spatial scales (microsite, territory, landscape) in the eastern Mojave Desert. We used binary logistic regression within an information-theoretic approach to assess factors influencing nest site choice and nesting success. Microsite-scale variables favored by owls included burrows excavated by desert tortoise (Gopherus agassizii), burrows with a large mound of excavated soil at the entrance, and a greater number of satellite burrows within 5 m of the nest burrow. At the territory scale, owls preferred patches with greater cover of creosote bush (Larrea tridentata) within 50 m of the nest burrow. An interaction between the presence or absence of a calcic soil horizon layer over the top of the burrow (microsite) and the number of burrows within 50 m (territory) influenced nest site choice. Nesting success was influenced by a greater number of burrows within 5 m of the nest burrow. Total cool season precipitation was a predictor of nesting success at the landscape scale. Conservation strategies can rely on management of habitat for favored and productive nesting sites for this declining species.

  16. Dominance and environmental correlates of alien annual plants in the Mojave Desert, USA

    USGS Publications Warehouse

    Brooks, M.L.; Berry, K.H.

    2006-01-01

    Land managers are concerned about the negative effects of alien annual plants on native plants, threatened and endangered species such as the desert tortoise (Gopherus agassizii), and ecosystem integrity in the Mojave Desert. Management of alien plants is hampered by a lack of information regarding the dominance and environmental correlates of these species. The results of this study indicate that alien plant species comprised a small fraction of the total annual plant flora, but most of the annual plant community biomass. When rainfall was high in 1995, aliens comprised 6% of the flora and 66% of the biomass. When rainfall was low in 1999, aliens comprised 27% of the flora and 91% of the biomass. Bromus rubens, Schismus spp. (S. arabicus and S. barbatus), and Erodium cicutarium were the predominant alien species during both years, comprising 99% of the alien biomass. B. rubens was more abundant in relatively mesic microhabitats beneath shrub canopies and at higher elevations above 800-1000 m, whereas Schismus spp. and E. cicutarium were more abundant in the relatively arid interspaces between shrubs, and, for Schismus spp., at lower elevations as well. Disturbance variables were more reliable indicators of alien dominance than were productivity or native plant diversity variables, although relationships often varied between years of contrasting rainfall. The strongest environmental correlates occurred between dirt road density and alien species richness and biomass of E. cicutarium, and between frequency and size of fires and biomass of B. rubens.

  17. Evidence of Fluconazole-Resistant Candida Species in Tortoises and Sea Turtles.

    PubMed

    Brilhante, Raimunda Sâmia Nogueira; Rodrigues, Pedro Henrique de Aragão; de Alencar, Lucas Pereira; Riello, Giovanna Barbosa; Ribeiro, Joyce Fonteles; de Oliveira, Jonathas Sales; Castelo-Branco, Débora de Souza Collares Maia; Bandeira, Tereza de Jesus Pinheiro Gomes; Monteiro, André Jalles; Rocha, Marcos Fábio Gadelha; Cordeiro, Rossana de Aguiar; Moreira, José Luciano Bezerra; Sidrim, José Júlio Costa

    2015-12-01

    The aim of this study was to evaluate the antifungal susceptibility of Candida spp. recovered from tortoises (Chelonoidis spp.) and sea turtles (Chelonia mydas, Caretta caretta, Lepidochelys olivacea, Eretmochelys imbricata). For this purpose, material from the oral cavity and cloaca of 77 animals (60 tortoises and 17 sea turtles) was collected. The collected specimens were seeded on 2% Sabouraud dextrose agar with chloramphenicol, and the identification was carried out by morphological and biochemical methods. Sixty-six isolates were recovered from tortoises, out of which 27 were C. tropicalis, 27 C. famata, 7 C. albicans, 4 C. guilliermondii and 1 C. intermedia, whereas 12 strains were obtained from sea turtles, which were identified as Candida parapsilosis (n = 4), Candida guilliermondii (n = 4), Candida tropicalis (n = 2), Candida albicans (n = 1) and Candida intermedia (n = 1). The minimum inhibitory concentrations for amphotericin B, itraconazole and fluconazole ranged from 0.03125 to 0.5, 0.03125 to >16 and 0.125 to >64, respectively. Overall, 19 azole-resistant strains (14 C. tropicalis and 5 C. albicans) were found. Thus, this study shows that Testudines carry azole-resistant Candida spp.

  18. Low tortoise abundances in pine forest plantations in forest-shrubland transition areas

    PubMed Central

    Rodríguez-Caro, Roberto C.; Oedekoven, Cornelia S.; Graciá, Eva; Anadón, José D.; Buckland, Stephen T.; Esteve-Selma, Miguel A.; Martinez, Julia; Giménez, Andrés

    2017-01-01

    In the transition between Mediterranean forest and the arid subtropical shrublands of the southeastern Iberian Peninsula, humans have transformed habitat since ancient times. Understanding the role of the original mosaic landscapes in wildlife species and the effects of the current changes as pine forest plantations, performed even outside the forest ecological boundaries, are important conservation issues. We studied variation in the density of the endangered spur-thighed tortoise (Testudo graeca) in three areas that include the four most common land types within the species’ range (pine forests, natural shrubs, dryland crop fields, and abandoned crop fields). Tortoise densities were estimated using a two-stage modeling approach with line transect distance sampling. Densities in dryland crop fields, abandoned crop fields and natural shrubs were higher (>6 individuals/ha) than in pine forests (1.25 individuals/ha). We also found large variation in density in the pine forests. Recent pine plantations showed higher densities than mature pine forests where shrub and herbaceous cover was taller and thicker. We hypothesize that mature pine forest might constrain tortoise activity by acting as partial barriers to movements. This issue is relevant for management purposes given that large areas in the tortoise’s range have recently been converted to pine plantations. PMID:28273135

  19. Tropical ancient DNA reveals relationships of the extinct Bahamian giant tortoise Chelonoidis alburyorum.

    PubMed

    Kehlmaier, Christian; Barlow, Axel; Hastings, Alexander K; Vamberger, Melita; Paijmans, Johanna L A; Steadman, David W; Albury, Nancy A; Franz, Richard; Hofreiter, Michael; Fritz, Uwe

    2017-01-11

    Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1 000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galápagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galápagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact.

  20. Recovery of a nearly extinct Galápagos tortoise despite minimal genetic variation.

    PubMed

    Milinkovitch, Michel C; Kanitz, Ricardo; Tiedemann, Ralph; Tapia, Washington; Llerena, Fausto; Caccone, Adalgisa; Gibbs, James P; Powell, Jeffrey R

    2013-02-01

    A species of Galápagos tortoise endemic to Española Island was reduced to just 12 females and three males that have been bred in captivity since 1971 and have produced over 1700 offspring now repatriated to the island. Our molecular genetic analyses of juveniles repatriated to and surviving on the island indicate that none of the tortoises sampled in 1994 had hatched on the island versus 3% in 2004 and 24% in 2007, which demonstrates substantial and increasing reproduction in situ once again. This recovery occurred despite the parental population having an estimated effective population size <8 due to a combination of unequal reproductive success of the breeders and nonrandom mating in captivity. These results provide guidelines for adapting breeding regimes in the parental captive population and decreasing inbreeding in the repatriated population. Using simple morphological data scored on the sampled animals, we also show that a strongly heterogeneous distribution of tortoise sizes on Española Island observed today is due to a large variance in the number of animals included in yearly repatriation events performed in the last 40 years. Our study reveals that, at least in the short run, some endangered species can recover dramatically despite a lack of genetic variation and irregular repatriation efforts.

  1. Phylogeny, Diversity, Distribution, and Host Specificity of Haemoproteus spp. (Apicomplexa: Haemosporida: Haemoproteidae) of Palaearctic Tortoises.

    PubMed

    Javanbakht, Hossein; Kvičerová, Jana; Dvořáková, Nela; Mikulíček, Peter; Sharifi, Mozafar; Kautman, Matej; Maršíková, Aneta; Široký, Pavel

    2015-01-01

    A complex wide-range study on the haemoproteid parasites of chelonians was carried out for the first time. Altogether, 811 samples from four tortoise species from an extensive area between western Morocco and eastern Afghanistan and between Romania and southern Syria were studied by a combination of microscopic and molecular-genetic methods. Altogether 160 Haemoproteus-positive samples were gathered in the area between central Anatolia and eastern Afghanistan. According to variability in the cytochrome b gene, two monophyletic evolutionary lineages were distinguished; by means of microscopic analysis it was revealed that they corresponded to two previously described species-Haemoproteus anatolicum and Haemoproteus caucasica. Their distribution areas overlap only in a narrow strip along the Zagros Mts. range in Iran. This fact suggests the involvement of two different vector species with separated distribution. Nevertheless, no vectors were confirmed. According to phylogenetic analyses, H. caucasica represented a sister group to H. anatolicum, and both of them were most closely related to H. pacayae and H. peltocephali, described from South American river turtles. Four unique haplotypes were revealed in the population of H. caucasica, compared with seven haplotypes in H. anatolicum. Furthermore, H. caucasica was detected in two tortoise species, Testudo graeca and Testudo horsfieldii, providing evidence that Haemoproteus is not strictly host-specific to the tortoise host species.

  2. Recovery of a nearly extinct Galápagos tortoise despite minimal genetic variation

    PubMed Central

    Milinkovitch, Michel C; Kanitz, Ricardo; Tiedemann, Ralph; Tapia, Washington; Llerena, Fausto; Caccone, Adalgisa; Gibbs, James P; Powell, Jeffrey R

    2013-01-01

    A species of Galápagos tortoise endemic to Española Island was reduced to just 12 females and three males that have been bred in captivity since 1971 and have produced over 1700 offspring now repatriated to the island. Our molecular genetic analyses of juveniles repatriated to and surviving on the island indicate that none of the tortoises sampled in 1994 had hatched on the island versus 3% in 2004 and 24% in 2007, which demonstrates substantial and increasing reproduction in situ once again. This recovery occurred despite the parental population having an estimated effective population size <8 due to a combination of unequal reproductive success of the breeders and nonrandom mating in captivity. These results provide guidelines for adapting breeding regimes in the parental captive population and decreasing inbreeding in the repatriated population. Using simple morphological data scored on the sampled animals, we also show that a strongly heterogeneous distribution of tortoise sizes on Española Island observed today is due to a large variance in the number of animals included in yearly repatriation events performed in the last 40 years. Our study reveals that, at least in the short run, some endangered species can recover dramatically despite a lack of genetic variation and irregular repatriation efforts. PMID:23467700

  3. Effects of Protective Fencing on Birds, Lizards, and Black-Tailed Hares in the Western Mojave Desert.

    PubMed

    BROOKS

    1999-04-01

    / 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. KEY WORDS: Birds; Fenced protection; Lepus californicus, Lizards; Mojave Desert; Off-highway vehicles; Protected area management; Sheep grazing

  4. Quantum Tunneling of the Non-stationary Kerr-Newman Black Hole via a New Type of General Tortoise Coordinate Transformation

    NASA Astrophysics Data System (ADS)

    Feng, Zhong-Wen; Deng, Juan; Li, Guo-Ping; Yang, Shu-Zheng

    2012-10-01

    In this paper, the quantum tunneling of the non-stationary Kerr-Newman black hole is investigated via Hamilton-Jacobi equation and two types of general tortoise coordinate transformations. The tunneling rates, the Hawking temperatures and radiation spectrums are derived respectively. Our result shows that the new type of general tortoise coordinate transformation is more reasonable.

  5. Military Review: Operation Desert Shield/Desert Storm

    DTIC Science & Technology

    1991-09-01

    stunrm by Lieutenant General William G. Pagonts, US Army and Major Harod E Raugh Jr., US Army OW61 6.3r -- 40 Moving an Army: Movement Control for Desert...headquarters to the controlling headquarters for three armies in one: the Army compo-~nent, the theater army nd a number d field army. Viwtory in the Desert...contingency, had just completed Central was bleak. Saddam Hussein had invaded Kuwait Command Exercise INTERNAL on 2 August, gaining control of that

  6. Detection and characterization of Mycoplasma spp. and Salmonella spp. in free-living European tortoises (Testudo hermanni, Testudo graeca, and Testudo marginata).

    PubMed

    Lecis, Roberta; Paglietti, B; Rubino, S; Are, B M; Muzzeddu, M; Berlinguer, F; Chessa, B; Pittau, M; Alberti, A

    2011-07-01

    Free-living and captive chelonians might suffer from upper respiratory tract disease (URTD), a pathology primarily caused by Mycoplasma agassizii. Wild tortoises can also be an important reservoir of Salmonella spp., which are commensal in the host reptile but are potential zoonotic agents. Between July 2009 and June 2010, we screened free-living European tortoises (spur-thighed tortoises Testudo graeca, Hermann's tortoises Testudo hermanni, marginated tortoises Testudo marginata) temporarily housed in a wildlife center in Italy. We molecularly characterized 13 Mycoplasma isolates detected in all Testudo spp. studied, and three PCR-positive animals showed typical URTD clinical signs at the time of sampling. Three Salmonella enterica serotypes (Abony, Potsdam, Granlo), already related to reptile-associated human infections, were also identified. These results highlight the potential role played by wildlife recovery centers in the spread and transmission of pathogens among wild chelonians and to humans.

  7. Keeping the desert at bay

    SciTech Connect

    El-Kassas, M.

    1981-02-01

    Man-made desert (areas that are no longer productive) has increased the world's deserts from 36.3 to 43% of the land surface. Desertification involves ecological degradation that makes the land less productive or allows an uneconomic type of vegetation, such as mesquite, to replace an economic plant. The process was first thought to be an encroachment by expanding deserts, but, except for the movement of sand dunes, desertification is now viewed as productive land that deteriorated and was added to the desert. Land is lost to agriculture by erosion, loss of nutrients, compaction, salination, urban development, and pollution. The interacting biosphere, technosphere, and social sphere form the framework of man's existence. An understanding of this framework is crucial to those offering technological assistance to developing countries. (DCK)

  8. Hawking effect and quantum nonthermal radiation of an arbitrarily accelerating charged black hole using a new tortoise coordinate transformation

    NASA Astrophysics Data System (ADS)

    Pan, Wei-Zhen; Yang, Xue-Jun; Xie, Zhi-Kun

    2011-04-01

    Using a new tortoise coordinate transformation, this paper investigates the Hawking effect from an arbitrarily accelerating charged black hole by the improved Damour—Ruffini method. After the tortoise coordinate transformation, the Klein—Gordon equation can be written as the standard form at the event horizon. Then extending the outgoing wave from outside to inside of the horizon analytically, the surface gravity and Hawking temperature can be obtained automatically. It is found that the Hawking temperatures of different points on the surface are different. The quantum nonthermal radiation characteristics of a black hole near the event horizon is also discussed by studying the Hamilton—Jacobi equation in curved spacetime and the maximum overlap of the positive and negative energy levels near the event horizon is given. There is a dimensional problem in the standard tortoise coordinate and the present results may be more reasonable.

  9. Description of a New Galapagos Giant Tortoise Species (Chelonoidis; Testudines: Testudinidae) from Cerro Fatal on Santa Cruz Island

    PubMed Central

    Chiari, Ylenia; Garrick, Ryan C.; Russello, Michael A.; Benavides, Edgar; Watkins-Colwell, Gregory J.; Glaberman, Scott; Tapia, Washington; Gibbs, James P.; Cayot, Linda J.; Caccone, Adalgisa

    2015-01-01

    The taxonomy of giant Galapagos tortoises (Chelonoidis spp.) is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumulated for multiple independent evolutionary lineages, spurring the need for taxonomic revision. On the island of Santa Cruz there is currently a single named species, C. porteri. Recent genetic and morphological studies have shown that, within this taxon, there are two evolutionarily and spatially distinct lineages on the western and eastern sectors of the island, known as the Reserva and Cerro Fatal populations, respectively. Analyses of DNA from natural populations and museum specimens, including the type specimen for C. porteri, confirm the genetic distinctiveness of these two lineages and support elevation of the Cerro Fatal tortoises to the rank of species. In this paper, we identify DNA characters that define this new species, and infer evolutionary relationships relative to other species of Galapagos tortoises. PMID:26488886

  10. Description of a New Galapagos Giant Tortoise Species (Chelonoidis; Testudines: Testudinidae) from Cerro Fatal on Santa Cruz Island.

    PubMed

    Poulakakis, Nikos; Edwards, Danielle L; Chiari, Ylenia; Garrick, Ryan C; Russello, Michael A; Benavides, Edgar; Watkins-Colwell, Gregory J; Glaberman, Scott; Tapia, Washington; Gibbs, James P; Cayot, Linda J; Caccone, Adalgisa

    2015-01-01

    The taxonomy of giant Galapagos tortoises (Chelonoidis spp.) is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumulated for multiple independent evolutionary lineages, spurring the need for taxonomic revision. On the island of Santa Cruz there is currently a single named species, C. porteri. Recent genetic and morphological studies have shown that, within this taxon, there are two evolutionarily and spatially distinct lineages on the western and eastern sectors of the island, known as the Reserva and Cerro Fatal populations, respectively. Analyses of DNA from natural populations and museum specimens, including the type specimen for C. porteri, confirm the genetic distinctiveness of these two lineages and support elevation of the Cerro Fatal tortoises to the rank of species. In this paper, we identify DNA characters that define this new species, and infer evolutionary relationships relative to other species of Galapagos tortoises.

  11. Mate desertion in the snail kite

    USGS Publications Warehouse

    Beissinger, S.R.; Snyder, N.F.R.

    1988-01-01

    Mate desertion during the breeding cycle was documented at 28 of 36 (78%) snail kite, Rostrhamus sociabilis nests in Florida between 1979 and 1983. Offspring mortality occurred at only one deserted nest, however. Parents that were deserted by their mates continued to care for their young until independence (3?5 additional weeks) and provided snails at a rate similar to that of both parents combined before desertion. Males and females deserted with nearly equal frequency, except in 1982 when more females deserted. No desertion occurred during drought years, whereas desertion occurred at nearly every nest during favourable conditions. The occurrence of mate desertion was generally related to indirect measures of snail abundance: foraging range, snail delivery rates to the young and growth rates. Small broods were deserted more frequently by females than by males and tended to be deserted earlier than large ones. After desertion, deserters had the opportunity to re-mate and nest again since breeding seasons were commonly lengthy, but whether they did so was impossible to determine conclusively in most cases. The deserted bird sometimes incurred increased energetic costs and lost breeding opportunities during periods of monoparental care.

  12. An Annual Plant Growth Proxy in the Mojave Desert Using MODIS-EVI Data

    PubMed Central

    Wallace, Cynthia S.A.; Thomas, Kathryn A.

    2008-01-01

    In the arid Mojave Desert, the phenological response of vegetation is largely dependent upon the timing and amount of rainfall, and maps of annual plant cover at any one point in time can vary widely. Our study developed relative annual plant growth models as proxies for annual plant cover using metrics that captured phenological variability in Moderate-Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) satellite images. We used landscape phenologies revealed in MODIS data together with ecological knowledge of annual plant seasonality to develop a suite of metrics to describe annual growth on a yearly basis. Each of these metrics was applied to temporally-composited MODIS-EVI images to develop a relative model of annual growth. Each model was evaluated by testing how well it predicted field estimates of annual cover collected during 2003 and 2005 at the Mojave National Preserve. The best performing metric was the spring difference metric, which compared the average of three spring MODIS-EVI composites of a given year to that of 2002, a year of record drought. The spring difference metric showed correlations with annual plant cover of R2 = 0.61 for 2005 and R2 = 0.47 for 2003. Although the correlation is moderate, we consider it supportive given the characteristics of the field data, which were collected for a different study in a localized area and are not ideal for calibration to MODIS pixels. A proxy for annual growth potential was developed from the spring difference metric of 2005 for use as an environmental data layer in desert tortoise habitat modeling. The application of the spring difference metric to other imagery years presents potential for other applications such as fuels, invasive species, and dust-emission monitoring in the Mojave Desert. PMID:27873958

  13. Habitat invasibility and dominance by alien annual plants in the western Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    1999-01-01

    Patterns of habitat invasibility and alien dominance, respectively measured as species richness and biomass of alien annual plants, were evaluated in association with four habitat factors at the Desert Tortoise Research Natural Area (DTNA) in the western Mojave Desert, USA. Habitat factors varied in levels of disturbance outside (high) and inside (low) the DTNA, and in levels of soil nutrients in washlet (high) and hummock (low) topographic positions, in Larrea-north (high), Larrea-south (medium), and interspace (low) microhabitats near creosote bushes (Larrea tridentata), and during 1995 when rainfall was 207% (high) and 1994 when rainfall was 52% (low) of the long-term average. Dominant alien plants included the annual grasses Bromus rubens, Bromus trinii, and Schismus spp., and the forb Erodium cicutarium. Species richness and dominance of alien annual plants were slightly higher where disturbance was high, and much higher where soil nutrients were high. B. rubens and B. trinii were most dominant in washlets and in the Larrea-north microhabitats during both years. These two species evolved in mesic ecosystems, and appeared to be particularly limited by soil nutrients at this site. Schismus spp. and E. cicutarium were also most dominant in washlets, but their dominance varied between interspaces in 1994 and the Larrea-south microhabitat in 1995. Monitoring to detect the invasion of new annual plants should focus on regions of high rainfall and nitrogen deposition and on washes and beneath-canopy microhabitats. The ecological range of each alien species should be evaluated separately, because their evolutionary origins may greatly affect their patterns of invasion and dominance in the Mojave Desert.

  14. An annual plant growth proxy in the Mojave Desert using MODIS-EVI data

    USGS Publications Warehouse

    Wallace, C.S.A.; Thomas, K.A.

    2008-01-01

    In the arid Mojave Desert, the phenological response of vegetation is largely dependent upon the timing and amount of rainfall, and maps of annual plant cover at any one point in time can vary widely. Our study developed relative annual plant growth models as proxies for annual plant cover using metrics that captured phenological variability in Moderate-Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) satellite images. We used landscape phenologies revealed in MODIS data together with ecological knowledge of annual plant seasonality to develop a suite of metrics to describe annual growth on a yearly basis. Each of these metrics was applied to temporally-composited MODIS-EVI images to develop a relative model of annual growth. Each model was evaluated by testing how well it predicted field estimates of annual cover collected during 2003 and 2005 at the Mojave National Preserve. The best performing metric was the spring difference metric, which compared the average of three spring MODIS-EVI composites of a given year to that of 2002, a year of record drought. The spring difference metric showed correlations with annual plant cover of R2 = 0.61 for 2005 and R 2 = 0.47 for 2003. Although the correlation is moderate, we consider it supportive given the characteristics of the field data, which were collected for a different study in a localized area and are not ideal for calibration to MODIS pixels. A proxy for annual growth potential was developed from the spring difference metric of 2005 for use as an environmental data layer in desert tortoise habitat modeling. The application of the spring difference metric to other imagery years presents potential for other applications such as fuels, invasive species, and dust-emission monitoring in the Mojave Desert.

  15. Evidence for and geomorphologic consequences of a reptilian ecosystem engineer: The burrowing cascade initiated by the Gopher Tortoise

    NASA Astrophysics Data System (ADS)

    Kinlaw, A.; Grasmueck, M.

    2012-07-01

    Physical ecosystem engineers often make major, durable physical constructs that can provide living space for other species and can structure local animal communities over evolutionary time. In Florida, a medium sized chelonian, the Gopher Tortoise (Gopherus polyphemus) will excavate extensive subterranean chambers that can endure for long periods of time. The tortoise starts a 'burrowing cascade', by first excavating a larger burrow that may extend 10 m, which is then re-engineered by Florida Mice (Podomys floridanus) and other rodents that dig smaller side-burrows and pockets. This sequence is often followed by an invertebrate, the camel cricket (Ceuthophilus labibuli) which is reported to excavate even smaller chambers. Our first aim was to quantify the zoogeomorphic impact of this burrowing cascade by measuring the amount of soil excavated in a large sample of burrows in two communities. Secondly, we hypothesized that the high biodiversity reported for these structures might be related to the quasi-fractal nature of the geometry, following the work of Frontier (1987). To visualize this underground geometry, we used high-resolution 3D Ground Penetrating Radar (GPR), which provided images and insights previously unobtainable using excavations or 2D GPR. Our images verified that the active tortoise burrow had a spiraling shape, but also showed splits in the larger burrow apparently dug by tortoises. For the first time, the smaller Florida Mouse burrows were imaged, showing side loops that exit and re-renter the tortoise burrow. This study also presents new information by making the discovery of numerous remnants of past tortoise burrows underground in the sampling grid surrounding the active burrow. Our third aim was to interpret our field results with previous ecological field studies to evaluate the strength of evidence that this species ranks as an ecosystem engineer.

  16. 75 FR 61467 - Desert Southwest Power, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... Energy Regulatory Commission Desert Southwest Power, LLC; Notice of Filing September 27, 2010. Take notice that on September 24, 2010, Desert Southwest Power, LLC (Desert Southwest) supplemented the... Commission's July 28, 2010 letter regarding Desert Southwest's petition for declaratory order...

  17. Desert and desertification in Iran

    NASA Astrophysics Data System (ADS)

    Bahrami, M.

    2009-04-01

    One of the greatest environmental concerns in Iran as in other arid and semiarid countries is the transformation of once productive, or marginally productive, land to deteriorated land and soil unable to support plants and animals. Because the land becomes barren and dry, the process is described as desertification, which occurs as a sequence of events. The area of deserts in Iran is about 340,000 Km2 (less than one fifth of its total area), of which 100,000 Km2 is being used for some cultivation, 120,000 Km2 is subjected to moving sands about 40 % of which is active sand dunes. Most of features and processes usual in world famous deserts are also observed in Iran: low precipitation, high evaporation, poor or lack of vegetation, saline and alkaline soils, low population and small and sparse oases. The deserts of Iran are generally classified in the subtropical, warm, arid and semiarid group, but the effect and presence of some geographical and geoclimatical factors such as height, vicinity to Indian Ocean and so on do some changes in climatic conditions and geographical features causing some local and regional differences in them. Geographically, two groups of deserts have been known in Iran: (1) Coastal deserts which, like a ribbon with variable width, stretch from extreme southeast to extreme southwest, at the north parts of Oman Sea and Persian Gulf. One important feature of these deserts is relatively high humidity which differentiates them from other deserts. This causes an increase in vegetation coverage and hence a decrease in eolian erosion and also a dominance of chemical weathering to that of physical. (2) internal deserts, which rest in central, eastern and southeastern plateau of the country and in independent and semi dependent depressions. This situation, which is due to the surrounding high mountains, blocks humidity entry and causes the aridity of these deserts. Wind as a dominant process in the area causes deflated features such as Reg (desert

  18. Historical DNA analysis reveals living descendants of an extinct species of Galápagos tortoise.

    PubMed

    Poulakakis, Nikos; Glaberman, Scott; Russello, Michael; Beheregaray, Luciano B; Ciofi, Claudio; Powell, Jeffrey R; Caccone, Adalgisa

    2008-10-07

    Giant tortoises, a prominent symbol of the Galápagos archipelago, illustrate the influence of geological history and natural selection on the diversification of organisms. Because of heavy human exploitation, 4 of the 15 known species (Geochelone spp.) have disappeared. Charles Darwin himself detailed the intense harvesting of one species, G. elephantopus, which once was endemic to the island of Floreana. This species was believed to have been exterminated within 15 years of Darwin's historic visit to the Galápagos in 1835. The application of modern DNA techniques to museum specimens combined with long-term study of a system creates new opportunities for identifying the living remnants of extinct taxa in the wild. Here, we use mitochondrial DNA and microsatellite data obtained from museum specimens to show that the population on Floreana was evolutionarily distinct from all other Galápagos tortoise populations. It was demonstrated that some living individuals on the nearby island of Isabela are genetically distinct from the rest of the island's inhabitants. Surprisingly, we found that these "non-native" tortoises from Isabela are of recent Floreana ancestry and closely match the genetic data provided by the museum specimens. Thus, we show that the genetic line of G. elephantopus has not been completely extinguished and still exists in an intermixed population on Isabela. With enough individuals to commence a serious captive breeding program, this finding may help reestablish a species that was thought to have gone extinct more than a century ago and illustrates the power of long-term genetic analysis and the critical role of museum specimens in conservation biology.

  19. Tortoise Coordinates and Hawking Radiation in a Dynamical Spherically Symmetric Spacetime

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Zhao, Zheng; Tian, Gui-Hua; Liu, Wen-Biao

    2009-12-01

    Hawking effect from dynamical spherical Vaidya black hole, Vaidya-Bonner black hole, and Vaidya-de Sitter black hole is investigated using the improved Damour-Ruffini method. After the new tortoise coordinate transformation in which the position r of event horizon is an undetermined function and the temperature parameter κ is an undetermined constant, the Klein-Gordon equation can be written as the standard form at the event horizon, and both r and κ can be determined automatically. Then extending the outgoing wave from outside to inside of the horizon analytically, the Hawking temperature can also be obtained automatically.

  20. Imaging diagnosis--seminoma causing liver compression in a spur-thighed tortoise (Testudo graeca).

    PubMed

    Pees, Michael; Ludewig, Eberhard; Plenz, Bastian; Schmidt, Volker

    2015-01-01

    A 13-year-old male spur-thighed tortoise (Testudo graeca) was presented with anorexia, apathy, and prolapse of penile tissue. Ultrasonography revealed a large heterogeneous mass in the coelomic cavity, and fine-needle aspiration demonstrated sperm. Magnetic resonance imaging showed a sharply defined mass originating from the left testis. Appearance and signal intensities were similar to those reported in testicular neoplasms in humans, in particular sharing similarities with seminomas. Necropsy results and histopathological findings were consistent with a seminoma. To the authors' knowledge this is the first report of the diagnosis of testicular neoplasia in a reptile using imaging techniques.

  1. Multiple congenital malformations in a dicephalic spur-thighed tortoise (Testudo graeca ibera).

    PubMed

    Palmieri, C; Selleri, P; Di Girolamo, N; Montani, A; Della Salda, L

    2013-01-01

    A 22-day-old dicephalic spur-thighed tortoise (Testudo graeca ibera) died following a history of lethargy, anorexia and absence of defecation. The two heads were anatomically similar with independent reaction to external stimuli. The carapace showed doubled first and extra second vertebral scutes. Radiography and transplastronal ultrasonography, performed when the animal was alive, revealed two symmetrical stomachs and two asynchronous hearts. These findings were confirmed by necropsy examination. Oesophagus, liver, gallbladder and trachea were also duplicated. Other malformations included pyloric valve atresia of the left stomach, focal stenosis of the transverse colon and liver hypoplasia. Dicephalism rarely occurs in Testudinidae and its pathogenesis, still unclear, is discussed.

  2. Hidden threat of tortoise ticks: high prevalence of Crimean-Congo haemorrhagic fever virus in ticks Hyalomma aegyptium in the Middle East.

    PubMed

    Široký, Pavel; Bělohlávek, Tomáš; Papoušek, Ivo; Jandzik, David; Mikulíček, Peter; Kubelová, Michaela; Zdražilová-Dubská, Lenka

    2014-03-11

    It is the first time that Crimean-Congo haemorrhagic fever virus (CCHFV), causing potentially lethal disease of humans, has been reported from the Middle East region and from the tortoise tick Hyalomma aegyptium from a tortoise host, whose epidemiological significance may have remained almost completely overlooked so far. We used RT-PCR to screen for 245 ticks collected from 38 Testudo graeca tortoise individuals. Results of our genetic screening provide unambiguous evidence of occurrence of CCHFV in this region and host, suggesting a potentially important role of H. aegyptium in CCHF epidemiology.

  3. Phytoremediation for Oily Desert Soils

    NASA Astrophysics Data System (ADS)

    Radwan, Samir

    This chapter deals with strategies for cleaning oily desert soils through rhizosphere technology. Bioremediation involves two major approaches; seeding with suitable microorganisms and fertilization with microbial growth enhancing materials. Raising suitable crops in oil-polluted desert soils fulfills both objectives. The rhizosphere of many legume and non-legume plants is richer in oil-utilizing micro-organisms than non-vegetated soils. Furthermore, these rhizospheres also harbour symbiotic and asymbiotic nitrogen-fixing bacteria, and are rich in simple organic compounds exuded by plant roots. Those exudates are excellent nutrients for oil-utilizing microorganisms. Since many rhizospheric bacteria have the combined activities of hydrocarbon-utilization and nitrogen fixation, phytoremediation provides a feasible and environmentally friendly biotechnology for cleaning oil-polluted soils, especially nitrogen-poor desert soils.

  4. 75 FR 52776 - Notice of Availability of the Draft Environmental Impact Statement for the Desert Sunlight...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-27

    ... Desert Sunlight Holdings, LLC Desert Sunlight Solar Farm Project and Possible California Desert...) has prepared a Draft Environmental Impact Statement (EIS) and Draft California Desert Conservation Area (CDCA) Plan Amendment for the Desert Sunlight Holdings, LLC Desert Sunlight Solar Farm...

  5. 77 FR 60981 - TGP Granada, LLC and Roosevelt Wind Ranch, LLC v. Public Service Company of New Mexico, Tortoise...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. EL12-42-000, EL12-42-001; EL12-43-000, EL12-43-001 TGP Granada, LLC and Roosevelt Wind Ranch, LLC v. Public Service Company of New Mexico, Tortoise Capital...

  6. Middle and Later Stone Age large mammal and tortoise remains from Die Kelders Cave 1, Western Cape Province, South Africa.

    PubMed

    Klein, R G; Cruz-Uribe, K

    2000-01-01

    Die Kelders Cave 1, South Africa, has provided more than 150,000 taxonomically identifiable mammal and tortoise bones from Middle Stone Age (MSA) and Later Stone Age (LSA) deposits. Cape dune mole-rats dominate the mammal sample, and they appear to have been accumulated mainly by people during the LSA occupation and mainly by eagle owls in the MSA. In sharp contrast to the LSA fauna, the MSA sample contains extralimital ungulates that imply relatively moist, grassy conditions. The large mean size of the MSA mole-rats also points to greater humidity, while the large size of the gray mongooses implies cooler temperatures. The sum supports luminescence and ESR dates that place the MSA occupation within the early part of the Last Glaciation (global isotope stage 4). The Die Kelders ungulate bones support those from Klasies River Mouth in suggesting that MSA people obtained dangerous terrestrial prey much less frequently than their LSA successors, probably because MSA people lacked the bow and arrow and other projectile weapons. The Die Kelders tortoise bones constrain the extent of climatic change, since their abundance indicates that warm, dry days remained common, at least seasonally. The tortoises tend to be much larger in the MSA layers than in the LSA ones, suggesting that MSA people collected tortoises less intensively, probably because MSA populations were relatively sparse.

  7. Quantifying dust emissions from desert landforms, eastern Mojave Desert, USA

    NASA Astrophysics Data System (ADS)

    Sweeney, Mark R.; McDonald, Eric V.; Etyemezian, Vicken

    2011-12-01

    The measurement of natural dust emissions from desert landforms is crucial in environmental hazard assessment and field checking the accuracy of global dust models. More than 500 individual dust measurements from eight common desert landforms in southern California were collected using the PI-SWERL (Portable In Situ Wind Erosion Lab). The largest emitters of dust are dry washes (13.787 to 0.007 mg m - 2 s - 1 ), dunes, playa margins, distal alluvial fans, and lacustrine beaches. Low emitters include salt-crusted playas (0.692 to 0.002 mg m - 2 s - 1 ), silt-clay-crusted playas, and desert pavements. High emissions are a function of saltating sand that bombards the surface, liberating dust-sized particles for entrainment. Low dust emissions are primarily a function of surface crusting, gravel armoring, and vegetation density. PI-SWERL measurements reveal that emission rates can vary by at least three orders of magnitude, reflecting local variability in soil texture and continuity of surface crusts. Shear-stress partitioning models can be applied to dust data measured by the PI-SWERL to account for large surface roughness features, such as vegetation. The results presented here give an approximation of the contributions to atmospheric dust loading by landforms in the Mojave Desert, and can potentially be used to improve atmospheric dust models.

  8. Exercise Desert Rock, Staff Memorandums. Army, Camp Desert Rock, Nevada.

    DTIC Science & Technology

    1957-01-01

    activities with the Safety Program. (2) Notifying the Exercise Safety Director of all fire@ involving government prcperty and equipment and for... Exercise Safety Director to the organization or activity conc- erned. o _ . _ . - : : , _ : ... .. ... .. . - _ . . .. . , ... .. .. ... ... . . ..7 memo...Nr 1, Exercise Desert Rocc4.WIVn’d VIII, 17 May 57 (Contd) (4) The officer in charge of the activity shall, within ten days after receiving the

  9. As the raven flies: using genetic data to infer the history of invasive common raven (Corvus corax) populations in the Mojave Desert.

    PubMed

    Fleischer, Robert C; Boarman, William I; Gonzalez, Elena G; Godinez, Alvaro; Omland, Kevin E; Young, Sarah; Helgen, Lauren; Syed, Gracia; McIntosh, Carl E

    2008-01-01

    Common raven (Corvus corax) populations in Mojave Desert regions of southern California and Nevada have increased dramatically over the past five decades. This growth has been attributed to increased human development in the region, as ravens have a commensal relationship with humans and feed extensively at landfills and on road-killed wildlife. Ravens, as a partially subsidized predator, also represent a problem for native desert wildlife, in particular threatened desert tortoises (Gopherus agassizii). However, it is unclear whether the more than 15-fold population increase is due to in situ population growth or to immigration from adjacent regions where ravens have been historically common. Ravens were sampled for genetic analysis at several local sites within five major areas: the West Mojave Desert (California), East Mojave Desert (southern Nevada), southern coastal California, northern coastal California (Bay Area), and northern Nevada (Great Basin). Analyses of mtDNA control region sequences reveal an increased frequency of raven 'Holarctic clade' haplotypes from south to north inland, with 'California clade' haplotypes nearly fixed in the California populations. There was significant structuring among regions for mtDNA, with high F(ST) values among sampling regions, especially between the Nevada and California samples. Analyses of eight microsatellite loci reveal a mostly similar pattern of regional population structure, with considerably smaller, but mostly significant, values. The greater mtDNA divergences may be due to lower female dispersal relative to males, lower N(e), or effects of high mutation rates on maximal values of F(ST). Analyses indicate recent population growth in the West Mojave Desert and a bottleneck in the northern California populations. While we cannot rule out in situ population growth as a factor, patterns of movement inferred from our data suggest that the increase in raven populations in the West Mojave Desert resulted from

  10. Distribution and habitat utilization of the gopher tortoise tick (Amblyomma tuberculatum) in Southern Mississippi

    USGS Publications Warehouse

    Ennen, J.R.; Qualls, C.P.

    2011-01-01

    The distribution of the gopher tortoise tick (Amblyomma tuberculatum) has been considered intrinsically linked to the distribution of its primary host, gopher tortoises (Gopherus polyphemus). However, the presence of G. polyphemus does not always equate to the presence of A. tuberculatum. There is a paucity of data on the ecology, habitat preferences, and distribution of A. tuberculatum. The goals of this study were to assess the distribution of A. tuberculatum in southern Mississippi and to determine which, if any, habitat parameters explain the distribution pattern of A. tuberculatum. During 2006-2007, we examined 13 G. polyphemus populations in southern Mississippi for the presence of A. tuberculatum, and we measured a suite of habitat parameters at each site. Only 23% of the G. polyphemus populations supported A. tuberculatum, suggesting a more restricted distribution than its host. The results of our multivariate analyses identified several habitat variables, e.g., depth of sand and percentage of sand in the topsoil and burrow apron, as being important in discriminating between sites with, and without, A. tuberculatum. Amblyomma tuberculatum was only found at sites with a mean sand depth of >100 cm and a mean percentage of topsoil and burrow apron sand composition >94.0 and 92.4, respectively. Thus, environmental factors, and not just its host's range, seem to influence the distribution of A. tuberculatum. ?? American Society of Parasitologists 2011.

  11. Distribution and habitat utilization of the gopher tortoise tick (Amblyomma tuberculatum) in southern Mississippi

    USGS Publications Warehouse

    Ennen, Joshua R.; Qualls, Carl P.

    2011-01-01

    The distribution of the gopher tortoise tick (Amblyomma tuberculatum) has been considered intrinsically linked to the distribution of its primary host, gopher tortoises (Gopherus polyphemus). However, the presence of G. polyphemus does not always equate to the presence of A. tuberculatum. There is a paucity of data on the ecology, habitat preferences, and distribution of A. tuberculatum. The goals of this study were to assess the distribution of A. tuberculatum in southern Mississippi and to determine which, if any, habitat parameters explain the distribution pattern of A. tuberculatum. During 2006-2007, we examined 13 G. polyphemus populations in southern Mississippi for the presence of A. tuberculatum, and we measured a suite of habitat parameters at each site. Only 23% of the G. polyphemus populations supported A. tuberculatum, suggesting a more restricted distribution than its host. The results of our multivariate analyses identified several habitat variables, e.g., depth of sand and percentage of sand in the topsoil and burrow apron, as being important in discriminating between sites with, and without, A. tuberculatum. Amblyomma tuberculatum was only found at sites with a mean sand depth of >100 cm and a mean percentage of topsoil and burrow apron sand composition >94.0 and 92.4, respectively. Thus, environmental factors, and not just its host's range, seem to influence the distribution of A. tuberculatum.

  12. Campylobacter geochelonis sp. nov. isolated from the western Hermann's tortoise (Testudo hermanni hermanni).

    PubMed

    Piccirillo, Alessandra; Niero, Giulia; Calleros, Lucía; Pérez, Ruben; Naya, Hugo; Iraola, Gregorio

    2016-09-01

    During a screening study to determine the presence of species of the genus Campylobacter in reptiles, three putative strains (RC7, RC11 and RC20T) were isolated from different individuals of the western Hermann's tortoise (Testudo hermanni hermanni). Initially, these isolates were characterized as representing Campylobacterfetus subsp. fetus by multiplex PCR and partial 16S rRNA gene sequence analysis. Further whole- genome characterization revealed considerable differences compared to other Campylobacter species. A polyphasic study was then undertaken to determine the exact taxonomic position of the isolates. The three strains were characterized by conventional phenotypic tests and whole genome sequencing. We generated robust phylogenies that showed a distinct clade containing only these strains using the 16S rRNA and atpA genes and a set of 40 universal proteins. Our phylogenetic analysis demonstrates their designation as representing a novel species and this was further confirmed using whole- genome average nucleotide identity within the genus Campylobacter (~80 %). Compared to most Campylobacter species, these strains hydrolysed hippurate, and grew well at 25 °C but not at 42 °C. Phenotypic and genetic analyses demonstrate that the three Campylobacter strains isolated from the western Hermann's tortoise represent a novel species within the genus Campylobacter, for which the name Campylobactergeochelonis sp. nov. is proposed, with RC20T (=DSM 102159T=LMG 29375T) as the type strain.

  13. Egyptian tortoise conservation: A community-based, field research program developed from a study on a captive population.

    PubMed

    Attum, Omar; Baha El Din, Mindy; Baha El Din, Sherif; Habinan, Suliman

    2007-09-01

    Local community participation and ex situ conservation has the potential to assist the recovery of the endangered Egyptian tortoise, Testudo kleinmanni. We initiated an in situ community-based conservation and research program from a captive population of T. kleinmanni. We used a captive population of the Egyptian tortoise to train a member of the local community as a research technician and used his indigenous tracking skills and knowledge of the area to collect activity and dietary data on 28 captive tortoises. We overcame problems with illiteracy by creating a data sheet based on symbols and numbers. This data sheet allowed us to use the indigenous knowledge of various people from the community, and employ them in the future. Our local community approach to data collection, in conjunction with a craft program, made the conservation of the Egyptian tortoise more rewarding to the local community by providing a more sustainable form of income than collecting animals for the pet trade. Our multidimensional approach (local community participation as research technicians, craft program, and trust building) for gaining local support eventually led to the rediscovery of wild Egyptian tortoises in North Sinai, which was significant, as this species was presumed extinct in Egypt. We have now shifted our focus to in situ conservation, using the research and local capacity building template developed from this captive population study. Our template can be used by zoos and conservation organizations with small budgets and collections of native species in natural habitats to create similar captive research programs that can be applied to in situ conservation. Zoo Biol 26:397-406, 2007. (c) 2007 Wiley-Liss, Inc.

  14. In the Green Desert: Non-formal Distance Education Project for Nomadic Women of the Gobi Desert, Mongolia. Education for All: Making It Work. Innovations Series, 12.

    ERIC Educational Resources Information Center

    Robinson, Bernadette

    With the disintegration of the former Soviet Union, Mongolia was severed from its exterior financial and technical support. The dramatic shift in socioeconomic conditions created a need for new forms of adult education. The nomadic women of the Gobi Desert were targeted as most at risk, and the Gobi Women's Project conducted a needs assessment in…

  15. Histological analysis of tissue structures of the internal organs of steppe tortoises following their exposure to spaceflight conditions while circumnavigating the moon aboard the Zond-7 automatic station

    NASA Technical Reports Server (NTRS)

    Sutulov, L. S.; Sutulov, Y. L.; Trukhina, L. V.

    1975-01-01

    Tortoises flown around the Moon on the 6-1/2 day voyage of the Zond-7 automatic space station evidently did not suffer any pathological changes to their peripheral blood picture, heart, lungs, intestines, or liver.

  16. Sterilisation of hybrid Galapagos tortoises (Geochelone nigra) for island restoration. Part 1: endoscopic oophorectomy of females under ketamine-medetomidine anaesthesia.

    PubMed

    Knafo, S E; Divers, S J; Rivera, S; Cayot, L J; Tapia-Aguilera, W; Flanagan, J

    2011-01-15

    An endoscopic sterilisation technique for use in Galapagos tortoises (Geochelone nigra) was developed as part of a conservation and ecosystem restoration project. Fifteen female giant Galapagos tortoises were anaesthetised, intubated and positioned in dorsal recumbency. A bilateral prefemoral approach was made and the ovaries were identified using a 5 mm × 33 cm rigid telescope. In the case of endoscope-assisted oophorectomy, the ovaries were exteriorised through the same incision, the vasculature was ligated and the mesovarium was transected. Two tortoises had immature ovaries that could not be exteriorised. In these animals, endoscopic oophorectomy was performed using radiosurgery. Closure of the incisions was routine. All tortoises except one recovered well from surgery. There were no reported complications six weeks and six months postoperatively, and all were successfully released on to Pinta Island in May 2010.

  17. Modeling Soil Moisture in the Mojave Desert

    USGS Publications Warehouse

    Miller, David M.; Hughson, Debra; Schmidt, Kevin M.

    2008-01-01

    The Mojave Desert is an arid region of southeastern California and parts of Nevada, Arizona, and Utah; the desert occupies more than 25,000 square miles (fig. 1). Ranging from below sea level to over 5,000 feet (1,524 m) in elevation, the Mojave Desert is considered a ?high desert.? On the west and southwest it is bounded by the Sierra Nevada, the San Gabriel, and the San Bernardino Mountains. These imposing mountains intercept moisture traveling inland from the Pacific Ocean, producing arid conditions characterized by extreme fluctuations in daily temperatures, strong seasonal winds, and an average annual precipitation of less than six inches. The Mojave Desert lies farther south and at a lower elevation than the cooler Great Basin Desert and grades southward into the even lower and hotter Sonoran Desert.

  18. Diet composition of common ravens across the urban-wildland interface of the West Mojave Desert

    USGS Publications Warehouse

    Kristan, William B.; Boarman, William I.; Crayon, John J.

    2004-01-01

    Common ravens (Corvus corax) are human-subsidized scavengers and predators in the Mojave Desert. They have increased dramatically in number and have been implicated as contributors to the decline in desert tortoise (Gopherus agassizii) populations. Known patterns of increased fledging success near human developments suggested that food was the most likely resource subsidy received by ravens. Because ravens are opportunistic foragers with a generalist diet, we predicted that the types of resource subsidy provided by different kinds of human developments should be reflected in measures of diet composition of breeding ravens. We estimated diet composition from contents of raven pellets collected at nests and related diet composition to distance of the nests from roads and point sources of resource subsidies, such as towns or landfills. Ravens that nested close to point subsidies far from major roads had the greatest incidence of trash in their diets. Ravens that nested close to roads but far from point subsidies had a low incidence of trash and a higher incidence of presumably road-killed mammals and reptiles. Ravens far from both roads and point subsidies had more plant material and arthropods, and ravens close to both roads and point subsidies had more birds and amphibians. Diet diversity was not related to distance from roads or developments. Fledging success was correlated with diet composition, such that birds with diets consistent with trash or road-kill subsidies fledged the greatest number of chicks. Our results suggest that ravens forage opportunistically on foods available near their nests, and different kinds of human developments contribute different foods. Improved management of landfills and highway fencing to reduce road-kills may help slow the growth of raven populations in the Mojave.

  19. Sympatric cattle grazing and desert bighorn sheep foraging

    USGS Publications Warehouse

    Garrison, Kyle R.; Cain, James W.; Rominger, Eric M.; Goldstein, Elise J.

    2015-01-01

    Foraging behavior affects animal fitness and is largely dictated by the resources available to an animal. Understanding factors that affect forage resources is important for conservation and management of wildlife. Cattle sympatry is proposed to limit desert bighorn population performance, but few studies have quantified the effect of cattle foraging on bighorn forage resources or foraging behavior by desert bighorn. We estimated forage biomass for desert bighorn sheep in 2 mountain ranges: the cattle-grazed Caballo Mountains and the ungrazed San Andres Mountains, New Mexico. We recorded foraging bout efficiency of adult females by recording feeding time/step while foraging, and activity budgets of 3 age-sex classes (i.e., adult males, adult females, yearlings). We also estimated forage biomass at sites where bighorn were observed foraging. We expected lower forage biomass in the cattle-grazed Caballo range than in the ungrazed San Andres range and lower biomass at cattle-accessible versus inaccessible areas within the Caballo range. We predicted bighorn would be less efficient foragers in the Caballo range. Groundcover forage biomass was low in both ranges throughout the study (Jun 2012–Nov 2013). Browse biomass, however, was 4.7 times lower in the Caballo range versus the San Andres range. Bighorn in the Caballo range exhibited greater overall daily travel time, presumably to locate areas of higher forage abundance. By selecting areas with greater forage abundance, adult females in the Caballo range exhibited foraging bout efficiency similar to their San Andres counterparts but lower overall daily browsing time. We did not find a significant reduction in forage biomass at cattle-accessible areas in the Caballo range. Only the most rugged areas in the Caballo range had abundant forage, potentially a result of intensive historical livestock use in less rugged areas. Forage conditions in the Caballo range apparently force bighorn to increase foraging effort by

  20. Exercise Desert Rock Letter Orders. Army, Camp Desert Rock, Nevada.

    DTIC Science & Technology

    1957-08-01

    WILF.iED J MSGT A19032i3 HJ;,ŕWAY, ELLafGzJN 8FC Xf,37791267 INOZ W, P. 1. PVT2 US52401808 KELLEY, JESSIE J SFC R1� EVaS, LOUIS PFC .,53073109...Ord Co (HAM) Camo Desert Rock, Nevada You will preeeed to Reynolds Funeral Vome, Sigourney, Iowa 0/a 24 AU ist 1957 for apprx fourteen (14) days to

  1. Design and analysis on the dynamics of ICPF actuated tortoise-like flexible micro-robot

    NASA Astrophysics Data System (ADS)

    Nie, Lin; Li, Desheng; Guo, Shuxiang

    2006-11-01

    In the paper, we present a novel tortoise-like flexible micro-robot with four legs which can crawl and swim underwater. These legs are actuated by ICPF (Ionic Conducting Polymer Film) which is a kind of smart film and has the characteristics of flexibility, good response and being driven by a low voltage. For improving the robot's reliability and feasibility, we establish the micro-robot's dynamic model by applying Pseudo-Rigid-Body-Dynamic-Model (PRBDM). The model is established by considering the dynamic effect of the robot, which is based on statics and kinematics. Then, the frequency analysis of a micro-robot based on PRBDM is investigated. Based on the PRBDM, the relation between the robot's structure parameters and its natural frequency is theoretically derived and a numerical computation of the robot is performed.

  2. Surfing in tortoises? Empirical signs of genetic structuring owing to range expansion.

    PubMed

    Graciá, Eva; Botella, Francisco; Anadón, José Daniel; Edelaar, Pim; Harris, D James; Giménez, Andrés

    2013-06-23

    Much of our current knowledge about the genetic dynamics in range expansions originates from models, simulations and microcosm experiments that need to be corroborated by field data. Here, we report a neutral genetic pattern that matches the predictions of the genetic surfing theory. Genetic surfing occurs when repeated founding events and genetic drift act on the wave of advance of an expanding population, promoting strong spatial structure. In the range expansion of the tortoise Testudo graeca from North Africa to southeastern Spain, we found several genetic signatures consistent with surfing: a decrease of genetic diversity with distance from the initial founder area, clinal patterns in allele frequencies, rare African alleles which have become common at distal sites in the Spanish range, and stronger spatial differentiation in the expanded range than in the original one. Our results provide support for the theory that genetic drift can be an important force in shaping the genetic structure of expanding populations.

  3. Desert Studies - A Global View

    DTIC Science & Technology

    1985-08-23

    Exploration, Dec. 6-10, 1982, Ft. Worth, TX, p. 39-40. 1983: 2 abs. published, 2 papers submitted for publication Breed, C. S., 1983, Subsurface imaging with...2-10 (in Chinese). Elachi, C., Roth, L. E., and Schaber, G. G., 1984, Spaceborne radar subsurface imaging in hyperarid regions, 1984: IEEE...are 55) km o. 18t BIBLIOGRAPHY (CITED REFERENCES) Breed, C. S., 1983, Subsurface imaging with SIR-A in the Egyptian Desert (abs.): Summaries, 17th

  4. Methane Output of Tortoises: Its Contribution to Energy Loss Related to Herbivore Body Mass

    PubMed Central

    Franz, Ragna; Soliva, Carla R.; Kreuzer, Michael; Hatt, Jean-Michel; Furrer, Samuel; Hummel, Jürgen; Clauss, Marcus

    2011-01-01

    An increase in body mass (M) is traditionally considered advantageous for herbivores in terms of digestive efficiency. However, recently increasing methane losses with increasing M were described in mammals. To test this pattern in non-mammal herbivores, we conducted feeding trails with 24 tortoises of various species (M range 0.52–180 kg) fed a diet of grass hay ad libitum and salad. Mean daily dry matter and gross energy intake measured over 30 consecutive days scaled to M0.75 (95%CI 0.64–0.87) and M0.77 (95%CI 0.66–0.88), respectively. Methane production was measured over two consecutive days in respiration chambers and scaled to M1.03 (95%CI 0.84–1.22). When expressed as energy loss per gross energy intake, methane losses scaled to 0.70 (95%CI 0.47–1.05) M0.29 (95%CI 0.14–0.45). This scaling overlaps in its confidence intervals to that calculated for nonruminant mammals 0.79 (95%CI 0.63–0.99) M0.15 (95%CI 0.09–0.20), but is lower than that for ruminants. The similarity between nonruminant mammals and tortoises suggest a common evolution of the gut fauna in ectotherms and endotherms, and that the increase in energetic losses due to methane production with increasing body mass is a general allometric principle in herbivores. These findings add evidence to the view that large body size itself does not necessarily convey a digestive advantage. PMID:21408074

  5. From release to absorption: Elucidating the effects of a desert locust pheromone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We used a glass-vial bioassay to test the contact effect of the desert locust pheromone phenylacetonitrile (PAN) on nymphs and adults after 2 hand 4 h respectively, and quantified the amount of the pheromone absorbed and released by the nymphs after 2 h and 12 h. We also monitored the knockdown effe...

  6. The age of the Taklimakan Desert.

    PubMed

    Sun, Jimin; Liu, Tungsheng

    2006-06-16

    The Taklimakan Desert is located in the foreland basin of the Tibetan Plateau. We report here the results of stratigraphic investigations of a 1626-meter-thick sequence with interbedded wind-blown silt from the southern marginal Taklimakan Desert. Because the studied section is located downwind of the desert, the eolian silt accumulation is closely linked to desert formation. Our new evidence indicates that shifting sand dunes prevailed in the Tarim Basin by at least 5.3 million years ago, as they do today. We attribute this event to late Cenozoic climatic deterioration, as well as to changes in atmospheric circulation induced by Tibetan Plateau uplift.

  7. Alternate Energy from the Desert

    NASA Astrophysics Data System (ADS)

    Malek, E.

    2003-12-01

    Due to rapid growth of the world's population and more demands for energy, and due to limited amount of fossil fuels (which provide 95 % of the world's energy needs), harnessing of alternate energy sources such as solar and wind power should be considered. In addition to the mountain passes with usually high wind, vast and flat desert areas could be good candidates for harvesting both solar and wind power. We set up a weather station in the middle of a desert, approximately 65 km east-west by 130 km north-south, located at Dugway (40\\deg 08' N, 113\\deg 27' W, 1124 m above mean sea level) in northwestern Utah, USA, in 1999. This station measured the incoming (Rsi) and outgoing (Rso) solar or shortwave radiation using two CM21 Kipp & Zonen pyranometers (one inverted), the incoming (Rli or atmospheric) and outgoing (Rlo or terrestrial) longwave radiation, using two CG1 Kipp & Zonen pyrgeometers (one inverted), and the net (Rn) radiation using a Q*7 net radiometer (Radiation Energy Balance System, REBS). We also measured the 3-m wind speed (U3) and direction (R.M. Young wind monitor) and precipitation (Campbell Sci., Inc.) and some other weather parameters. The measurements were taken every two seconds, and averaged into 20-min, continuously, throughout the year. The two-year (January 2000 - December 2001) period comparisons of global or solar radiation and windiness with two other stations in central (Hunter) and northern (Logan) Utah, indicate higher average solar radiation [Rsi,Dugway = 601 MJ / (m2-month) vs. Rsi, Hunter = 5371 MJ /(m2-month) and Rsi, Logan = 516 MJ /(m2-month)] and much higher 10-m average wind (UDugway = 478 km/d vs. UHunter = 323 km/d and ULogan = 275 km/d) throughout the period over the desert. These data reveal the possibility of simultaneously harvesting these two sources of clean energies at this vast and uniform desert area. Keywords: Desert, energy, radiation balance, solar and wind energies, windiness.

  8. Sterilisation of hybrid Galapagos tortoises (Geochelone nigra) for island restoration. Part 2: phallectomy of males under intrathecal anaesthesia with lidocaine.

    PubMed

    Rivera, S; Divers, S J; Knafo, S E; Martinez, P; Cayot, L J; Tapia-Aguilera, W; Flanagan, J

    2011-01-22

    Lidocaine intrathecal anaesthesia was used to perform phallectomies in 15 hybrid Galapagos tortoises (Geochelone nigra) in a field setting as part of a conservation and ecosystem restoration project in the Galapagos Islands. The intrathecal injection was performed in the dorsal intercoccygeal region of the tail. Once the tail and hindlimbs were relaxed and the phallus was easily exteriorised, phallectomy was performed in a routine manner. All the animals recovered well from the procedure and were walking 30 to 60 minutes after surgery. No adverse effects were noted as a result of lidocaine intrathecal anaesthesia. One of the larger animals had evidence of haemorrhage from the surgical site 48 hours postoperatively. All tortoises continued to make full recoveries and were released on to the island of Pinta in May 2010.

  9. Computed tomography imaging of a leopard tortoise (Geochelone pardalis pardalis) with confirmed pulmonary fibrosis: a case report

    PubMed Central

    2013-01-01

    An approximately 20-year-old, female Leopard tortoise (Geochelone pardalis pardalis) was presented with dypsnea, wheezing, anorexia and depression. Whole body radiographs revealed generalized diffuse unstructured ‘interstitial lung pattern’ with thickened pulmonary septae while computed tomography (CT) showed emphysematous lung parenchyma and thickened pulmonary septae bordered by irregular ground-glass opacity with smaller areas of ‘honeycombing’. These imaging findings together with histopathologic findings were compatible with chronic, extensive ‘interstitial’ pulmonary fibrosis. PMID:23618386

  10. Effects of two dietary vitamin and mineral supplements on the growth and health of Hermann's tortoise (Testudo hermanni).

    PubMed

    Hetényi, Nikoletta; Sátorhelyi, Tamás; Kovács, Szilvia; Hullár, István

    2014-01-01

    The aim of the study was to determine the long-term effects of two different vitamin and mineral supplements on the growth and health of Hermann's tortoises. Twelve one-month-old tortoises were randomly divided into two groups of six animals (group A and B). Diets were supplemented on a daily basis with two different products ("A": vit. D350 000 IU/kg, 150 g/kg Ca or "B": vit. D3, 2000 IU/kg, 148 g/kg Ca) for 12 months. Product "B" was richer in most of the vitamins. Weight and shell parameters were measured weekly. After one year animals in group B had significantly higher final body weights than those in group A (186.7 g vs. 131.6 g). The shell of the individuals in group A was firm and healthy, while all the tortoises in group B (in different levels) had weakened shells. The loss of bone tissue was not so serious to have visual signs on x-rays. High amount of vitamins (vitamin E, K, B1, 2, 6, 12, biotin) given for safety reasons and relatively low level of vitamin D3 (like in product "B") applied on a daily basis seem to be disadvantageous. The moderate metabolic bone disease that developed in group B during the experiment could be treated after the study by using the supplement "A". The authors recommend such supplements which have similar ingredients to product "A" for growing tortoises housed indoor with low or without irradiation exposure to UVB.

  11. Computed tomography imaging of a leopard tortoise (Geochelone pardalis pardalis) with confirmed pulmonary fibrosis: a case report.

    PubMed

    Lim, Chee Kin; Kirberger, Robert M; Lane, Emily P; Elliott, Dorianne L

    2013-04-23

    An approximately 20-year-old, female Leopard tortoise (Geochelone pardalis pardalis) was presented with dypsnea, wheezing, anorexia and depression. Whole body radiographs revealed generalized diffuse unstructured 'interstitial lung pattern' with thickened pulmonary septae while computed tomography (CT) showed emphysematous lung parenchyma and thickened pulmonary septae bordered by irregular ground-glass opacity with smaller areas of 'honeycombing'. These imaging findings together with histopathologic findings were compatible with chronic, extensive 'interstitial' pulmonary fibrosis.

  12. Kinship, inbreeding and fine-scale spatial structure influence gut microbiota in a hindgut-fermenting tortoise.

    PubMed

    Yuan, Michael L; Dean, Samantha H; Longo, Ana V; Rothermel, Betsie B; Tuberville, Tracey D; Zamudio, Kelly R

    2015-05-01

    Herbivorous vertebrates rely on complex communities of mutualistic gut bacteria to facilitate the digestion of celluloses and hemicelluloses. Gut microbes are often convergent based on diet and gut morphology across a phylogenetically diverse group of mammals. However, little is known about microbial communities of herbivorous hindgut-fermenting reptiles. Here, we investigate how factors at the individual level might constrain the composition of gut microbes in an obligate herbivorous reptile. Using multiplexed 16S rRNA gene sequencing, we characterized the faecal microbial community of a population of gopher tortoises (Gopherus polyphemus) and examined how age, genetic diversity, spatial structure and kinship influence differences among individuals. We recovered phylotypes associated with known cellulolytic function, including candidate phylum Termite Group 3, suggesting their importance for gopher tortoise digestion. Although host genetic structure did not explain variation in microbial composition and community structure, we found that fine-scale spatial structure, inbreeding, degree of relatedness and possibly ontogeny shaped patterns of diversity in faecal microbiomes of gopher tortoises. Our findings corroborate widespread convergence of faecal-associated microbes based on gut morphology and diet and demonstrate the role of spatial and demographic structure in driving differentiation of gut microbiota in natural populations.

  13. Genetic variation and population structure in the endangered Hermann's tortoise: the roles of geography and human-mediated processes.

    PubMed

    Perez, Melanie; Livoreil, Barbara; Mantovani, Sara; Boisselier, Marie-Catherine; Crestanello, Barbara; Abdelkrim, Jawad; Bonillo, Céline; Goutner, Vassilis; Lambourdière, Josie; Pierpaoli, Massimo; Sterijovski, Bogoljub; Tomovic, Ljiljana; Vilaça, Sibelle T; Mazzotti, Stefano; Bertorelle, Giorgio

    2014-01-01

    The Hermann's tortoise (Testudo hermanni) is an endangered land tortoise distributed in disjoint populations across Mediterranean Europe. We investigated its genetic variation by typing 1 mitochondrial locus and 9 nuclear microsatellites in approximately 300 individuals from 22 localities. Our goal was to understand the relative impact of natural and human-mediated processes in shaping the genetic structure and to identify the genetic priorities for the conservation of this species. We found that 1) all geographic areas are highly differentiated, mainly as a function of their distance but with a clear genetic discontinuity (F st values larger than 0.4) between the Eastern and the Western subspecies; 2) the contact zone between subspecies is located farthest to the west than previously believed, and it probably coincides with the delta of the largest Italian river; 3) extinction events due to climatic conditions in the Upper Palaeolithic and subsequent human-mediated translocations in the Neolithic possibly explain the unexpected similarity among Spain, Sicily, and Corsica. For conservation purposes, the large majority of genetic pools appears native although hybridization among subspecies, related to extensive 20th century trade of tortoises across Europe, is observed in Spain and some Italian samples. Most populations do not seem at immediate risk of low genetic variation, except the French population, which has very low nuclear genetic diversity (heterozygosity = 0.25) and where 50 out of 51 sampled animals shared the same mitochondrial sequence. In general, restocking and reintroduction plans should carefully consider the genetic background of the individuals.

  14. A new coccidian (Apicomplexa: Eimeriidae) from Galápagos tortoise, Chelonoidis sp. (Testudines: Testudinidae), from the Dallas Zoo.

    PubMed

    McAllister, Chris T; Duszynski, Donald W; Roberts, David T

    2014-02-01

    During January 1994, feces from a captive juvenile Galápagos tortoise, Chelonoidis sp., from the Dallas Zoo, Dallas County, Texas was examined for coccidia. The tortoise was found to harbor an eimerian which is described as new. Sporulated oocysts of Eimeria iversoni n. sp. were ovoidal with a smooth, single-layered wall (∼ 0.5-0.8) that measured (L × W) 13.5 × 10.3 μm, with a length/width (L/W) ratio of 1.3; micropyle, oocyst residuum, and polar granule(s) were all absent; 2 conical projections were present on 1 end of oocyst and measured 1.0-1.5. Sporocysts were elongate-ellipsoidal and measured 8.3 × 4.5 μm, with L/W of 1.8; a Stieda body (∼ 0.5 high) was present, but substieda and parastieda bodies were absent; a sporocyst residuum was composed of 2-5 granules in a compact mass between sporozoites; sporozoites were banana-shaped and measured 9.5 × 2.5 in situ, with an ellipsoidal posterior refractile body and a spheroidal anterior refractile body. This is only the second time an eimerian has been reported from Galápagos tortoises.

  15. On carbon sequestration in desert ecosystems

    USGS Publications Warehouse

    Schlesinger, W.H.; Belnap, J.; Marion, G.

    2009-01-01

    Recent reports of net ecosysytem production >100 g C m-2 yr-1 in deserts are incompatible with existing measurements of net primary production and carbon pools in deserts. The comparisions suggest that gas exchange measurements should be used with caution and better validation if they are expected to indicate the magnitude of carbon sink in these ecosysytems. ?? 2009 Blackwell Publishing.

  16. Magnetic Analysis Techniques Applied to Desert Varnish

    NASA Technical Reports Server (NTRS)

    Schmidgall, E. R.; Moskowitz, B. M.; Dahlberg, E. D.; Kuhlman, K. R.

    2003-01-01

    Desert varnish is a black or reddish coating commonly found on rock samples from arid regions. Typically, the coating is very thin, less than half a millimeter thick. Previous research has shown that the primary components of desert varnish are silicon oxide clay minerals (60%), manganese and iron oxides (20-30%), and trace amounts of other compounds [1]. Desert varnish is thought to originate when windborne particles containing iron and manganese oxides are deposited onto rock surfaces where manganese oxidizing bacteria concentrate the manganese and form the varnish [4,5]. If desert varnish is indeed biogenic, then the presence of desert varnish on rock surfaces could serve as a biomarker, indicating the presence of microorganisms. This idea has considerable appeal, especially for Martian exploration [6]. Magnetic analysis techniques have not been extensively applied to desert varnish. The only previous magnetic study reported that based on room temperature demagnetization experiments, there were noticeable differences in magnetic properties between a sample of desert varnish and the substrate sandstone [7]. Based upon the results of the demagnetization experiments, the authors concluded that the primary magnetic component of desert varnish was either magnetite (Fe3O4) or maghemite ( Fe2O3).

  17. Notes from the Great American Desert

    ERIC Educational Resources Information Center

    Grady, Marilyn L.; LaCost, Barbara Y.

    2005-01-01

    In the good old days, the state that is Nebraska was identified as part of the Great American Desert. In many ways, in climate and terrain, it still bears a resemblance to a desert. As a frontier or a land of pioneers, it deserves recognition. Invisibility may be one of the greatest challenges women face. One of the great flaws in the writing of…

  18. Feeding behaviour in a ‘basal’ tortoise provides insights on the transitional feeding mode at the dawn of modern land turtle evolution

    PubMed Central

    Tzankov, Nikolay; Werneburg, Ingmar; Heiss, Egon

    2015-01-01

    Almost all extant testudinids are highly associated with terrestrial habitats and the few tortoises with high affinity to aquatic environments are found within the genus Manouria. Manouria belongs to a clade which forms a sister taxon to all remaining tortoises and is suitable as a model for studying evolutionary transitions within modern turtles. We analysed the feeding behaviour of Manouria emys and due to its phylogenetic position, we hypothesise that the species might have retained some ancestral features associated with an aquatic lifestyle. We tested whether M. emys is able to feed both in aquatic and terrestrial environments. In fact, M. emys repetitively tried to reach submerged food items in water, but always failed to grasp them—no suction feeding mechanism was applied. When feeding on land, M. emys showed another peculiar behaviour; it grasped food items by its jaws—a behaviour typical for aquatic or semiaquatic turtles—and not by the tongue as generally accepted as the typical feeding mode in all tortoises studied so far. In M. emys, the hyolingual complex remained retracted during all food uptake sequences, but the food transport was entirely lingual based. The kinematical profiles significantly differed from those described for other tortoises and from those proposed from the general models on the function of the feeding systems in lower tetrapods. We conclude that the feeding behaviour of M. emys might reflect a remnant of the primordial condition expected in the aquatic ancestor of the tortoises. PMID:26339550

  19. Desert bighorn sheep lambing habitat: Parturition, nursery, and predation sites

    USGS Publications Warehouse

    Karsch, Rebekah C.; Cain, James W.; Rominger, Eric M.; Goldstein, Elise J.

    2016-01-01

    Fitness of female ungulates is determined by neonate survival and lifetime reproductive success. Therefore, adult female ungulates should adopt behaviors and habitat selection patterns that enhance survival of neonates during parturition and lactation. Parturition site location may play an important role in neonatal mortality of desert bighorn sheep (Ovis canadensis mexicana) when lambs are especially vulnerable to predation, but parturition sites are rarely documented for this species. Our objectives were to assess environmental characteristics at desert bighorn parturition, lamb nursery, and predation sites and to assess differences in habitat characteristics between parturition sites and nursery group sites, and predation sites and nursery group sites. We used vaginal implant transmitters (VITs) to identify parturition sites and capture neonates. We then compared elevation, slope, terrain ruggedness, and visibility at parturition, nursery, and lamb predation sites with paired random sites and compared characteristics of parturition sites and lamb predation sites to those of nursery sites. When compared to random sites, odds of a site being a parturition site were highest at intermediate slopes and decreased with increasing female visibility. Odds of a site being a predation site increased with decreasing visibility. When compared to nursery group sites, odds of a site being a parturition site had a quadratic relationship with elevation and slope, with odds being highest at intermediate elevations and intermediate slopes. When we compared predation sites to nursery sites, odds of a site being a predation were highest at low elevation areas with high visibility and high elevation areas with low visibility likely because of differences in hunting strategies of coyote (Canis latrans) and puma (Puma concolor). Parturition sites were lower in elevation and slope than nursery sites. Understanding selection of parturition sites by adult females and how habitat

  20. Desert Test Site Uniformity Analysis

    NASA Technical Reports Server (NTRS)

    Kerola, Dana X.; Bruegge, Carol J.

    2009-01-01

    Desert test sites such as Railroad Valley (RRV) Nevada, Egypt-1, and Libya-4 are commonly targeted to assess the on-orbit radiometric performance of sensors. Railroad Valley is used for vicarious calibration experiments, where a field-team makes ground measurements to produce accurate estimates of top-of-atmosphere (TOA) radiances. The Sahara desert test sites are not instrumented, but provide a stable target that can be used for sensor cross-comparisons, or for stability monitoring of a single sensor. These sites are of interest to NASA's Atmospheric Carbon Observation from Space (ACOS) and JAXA's Greenhouse Gas Observation SATellite (GOSAT) programs. This study assesses the utility of these three test sites to the ACOS and GOSAT calibration teams. To simulate errors in sensor-measured radiance with pointing errors, simulated data have been created using MODIS Aqua data. MODIS data are further utilized to validate the campaign data acquired from June 22 through July 5, 2009. The first GOSAT vicarious calibration experiment was conducted during this timeframe.

  1. Co-occurence of Invasive Species on Priority TES Installations

    DTIC Science & Technology

    2006-05-01

    forb O,F San Bernadino Ft. Irwin CA Desert Tortoise African Rue Peganum harmala forb O San Bernadino Ft. Irwin CA Desert Tortoise Curlyleaf Pondweed...forb O AZ Desert Tortoise African Rue Peganum harmala forb O AZ Desert Tortoise Kikuyugrass Pennisetum clandestinum grass AZ Desert...Name Form Habitat County Border County TX BCV & GCW Guineagrass Panicum maximum grass O,W TX BCV & GCW African Rue Peganum harmala forb O TX

  2. 75 FR 57761 - Desert Southwest Power, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ... Energy Regulatory Commission Desert Southwest Power, LLC; Notice of Filing September 14, 2010. Take notice that on September 10, 2010, Desert Southwest Power, LLC (Desert Southwest) filed responses to the... Commission's July 28, 2010 letter regarding Desert Southwest's petition for declaratory order...

  3. The current voltage relationship of the delayed outward current in the heart of the frog (Rana esculenta) and the tortoise (Testudo germani).

    PubMed

    de Hemptinne, A

    1978-11-30

    Steady state and non steady state I-V relationships of the resting membrane and delayed rectifying membrane were analysed by applying trapezoid voltage clamp pulses on atrial fibres isolated from the frog and the tortoise. The fibres were disposed in a perfusion chamber for double sucrose gap. In both types of preparation, a component of delayed rectification current was identified which was activated following a comparable time course. The amplitude of the delayed rectification current, when expressed either as normalized to the calculated membrane capacity or to the initial background current, is significantly larger in the frog than in the tortoise. Full activation of the delayed rectifying system can be demonstrated in the tortoise, while in the frog this process is presumably complicated by simultaneous accumulation of K ions in the extracellular region. The difference in magnitude of the delayed outward current has no influence on the duration of action potential which is recorded over the sucrose gap.

  4. Infiltration Through Desert Pavements, Mojave Desert, CA, USA

    NASA Astrophysics Data System (ADS)

    Young, M. H.; McDonald, E. V.; Caldwell, T. C.; Benner, S. G.

    2003-04-01

    Desert pavements consist of a surface layer of closely packed gravel that overlies thin, gravel-poor vesicular A (Av) soil horizon. Pavements are prominent features in arid and semi-arid environments and can be found on a variety of landforms of significantly diverse ages ranging from Holocene to Tertiary. Well-developed Av profiles form distinct and highly structured prismatic peds. These fine-grained, structured soils can exhibit drastically reduced infiltration rates, rendering some localized areas nearly impermeable and greatly impacting soil development, plant and biota diversity, and groundwater recharge. We sought to study how desert pavement development can impact the hydraulic conductivity characteristics in localized areas (order of 10s of cm). Field sites were chosen at the Mojave Natural Preserve, near Kelso Dunes, CA, USA, which has been the location of considerable prior research by the second author. The sites vary by parent material, clay and silt content, surface age, and variable degree of surface clast cover. Transects were chosen that traversed pavement surfaces of variable development (well developed to poorly developed). Hydraulic conductivity was determined with a tension infiltrometer conducted at different tensions and initial water contents (to better estimate the potential for preferential flow). Sites with dry initial conditions were first analyzed at zero tensions to promote inter-ped flow. After allowing soil peds to hydrate and expand, the tests were run again at a range of soil tensions to promote matrix flow. Differences in saturated conductivities (measured and fitted) were attributed to preferential flow around desiccated peds. Soil texture and structure were measured and described, respectively, allowing for the correlation of conductivity functions to soil surface age and physical characteristics.

  5. Thermal and water relations of desert beetles

    NASA Astrophysics Data System (ADS)

    Cloudsley-Thompson, J.

    2001-11-01

    The physical problems that living organisms have to contend with in hot deserts are primarily extremes of temperature, low humidity, shortage or absence of free water, and the environmental factors that accentuate these - such as strong winds, sand-storms, lack of shade, rocky and impenetrable soils. Climatic factors are particularly important to smaller animals such as arthropods on account of their relatively enormous surface to volume ratios. Nevertheless, beetles (especially Tenebrionidae and, to a lesser extent, Chrysomelidae) are among the most successful animals of the desert, and are often the only ones to be seen abroad during the day. Similar physical problems are experienced by insects in all terrestrial biomes, but they are much enhanced in the desert. Although climatic extremes are often avoided by burrowing habits coupled with circadian and seasonal activity rhythms, as well as reproductive phenology, several species of desert beetle are nevertheless able to withstand thermal extremes that would rapidly cause the death of most other arthropods including insects. The reactions of desert beetles to heat are largely behavioural whilst their responses to water shortage are primarily physiological. The effects of coloration are not discussed. In addition to markedly low rates of transpiration, desert beetles can also withstand a considerable reduction in the water content of their tissues. The study of desert beetles is important because it illustrates many of the solutions evolved by arthropods to the problems engendered, in an extreme form, by life in all terrestrial environments.

  6. Thermal and water relations of desert beetles.

    PubMed

    Cloudsley-Thompson, J L

    2001-11-01

    The physical problems that living organisms have to contend with in hot deserts are primarily extremes of temperature, low humidity, shortage or absence of free water, and the environmental factors that accentuate these--such as strong winds, sand-storms, lack of shade, rocky and impenetrable soils. Climatic factors are particularly important to smaller animals such as arthropods on account of their relatively enormous surface to volume ratios. Nevertheless, beetles (especially Tenebrionidae and, to a lesser extent, Chrysomelidae) are among the most successful animals of the desert, and are often the only ones to be seen abroad during the day. Similar physical problems are experienced by insects in all terrestrial biomes, but they are much enhanced in the desert. Although climatic extremes are often avoided by burrowing habits coupled with circadian and seasonal activity rhythms, as well as reproductive phenology, several species of desert beetle are nevertheless able to withstand thermal extremes that would rapidly cause the death of most other arthropods including insects. The reactions of desert beetles to heat are largely behavioural whilst their responses to water shortage are primarily physiological. The effects of coloration are not discussed. In addition to markedly low rates of transpiration, desert beetles can also withstand a considerable reduction in the water content of their tissues. The study of desert beetles is important because it illustrates many of the solutions evolved by arthropods to the problems engendered, in an extreme form, by life in all terrestrial environments.

  7. 76 FR 50493 - Notice of Availability of the Record of Decision for the Desert Sunlight Holdings, LLC, Desert...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-15

    ... Bureau of Land Management Notice of Availability of the Record of Decision for the Desert Sunlight Holdings, LLC, Desert Sunlight Solar Farm (DSSF) and California Desert Conservation Area Plan Amendment... Amendment to the California Desert Conservation Area (CDCA) Plan, the applicable Resource Management...

  8. Swing characteristics on tail of tortoise-like flexible micro-robot

    NASA Astrophysics Data System (ADS)

    Nie, Lin; Zhang, Xinglan; Nie, Rong; Li, Desheng; Guo, Shuxiang

    2007-07-01

    Dynamic effects are very important in improving the design and study of the micro-robot. In the paper, our preliminary work in using ICPF to develop a novel tortoise-like flexible micro-robot with four legs and one tail is reported, which can crawl and swim underwater. ICPF is the abbreviation of Ionic Conducting Polymer gel Film which is a kind of smart film and can give large and fast bending displacement in the presence of a low applied voltage in wet condition. For controlling and analyzing easily the robot, we establish the micro-robot's tail dynamic model by applying Pseudo-Rigid-Body-Dynamic-Model (PRBDM). The model is established by considering the dynamic effect of the robot's tail, which is based on statics and kinematics. Then, the frequency analysis of a micro-robot based on PRBDM is investigated. Based on the PRBDM, the relation between the robot's tail angle displacement and the electrical voltage's frequency ω is theoretically derived and the simulation result for the tail's angle displacement is performed.

  9. Molecular detection of Rickettsia bellii in Amblyomma rotundatum from imported red-footed tortoise (Chelonoides carbonaria).

    PubMed

    Erster, Oran; Roth, Asael; Avni, Zvi; King, Rony; Shkap, Varda

    2015-06-01

    Introduction of exotic ticks and pathogens through international animal trade (farm animals and pets) is a serious threat to public health and local fauna. Rapid and correct identification of potential threats is an important step on the way to conduct an efficient control of imported pests. In this report we describe the molecular identification of the neotropic tick Amblyomma rotundatum intercepted from red-footed tortoise (Chelonoides carbonaria), imported to Israel from Florida, USA. Molecular analysis of the ticks conducted upon their identification, revealed that they were infected with Rickettsia bellii. Following their collection, the ticks were examined morphologically and five molecular markers were used to determine their taxonomic identity: cytochrome c oxidase subunit 1 (COX1), cytochrome b (CytB), 12S rRNA, 16S rRNA and internal transcribed sequence 2 (ITS-2). Molecular analysis indicated that all of the collected ticks were Amblyomma rotundatum. Using rickettsial gltA (citrate synthase) gene in real-time PCR analysis we found that approximately 25% of the intercepted ticks (8 of 33) were infected with Rickettsia bellii. It is concluded that accurate and timely identification of imported exotic ticks prevented their introduction to Israel, and that use of molecular tools may further improve the response to such potential threats.

  10. Switchable reflector in the Panamanian tortoise beetle Charidotella egregia (Chrysomelidae: Cassidinae)

    NASA Astrophysics Data System (ADS)

    Vigneron, Jean Pol; Pasteels, Jacques M.; Windsor, Donald M.; Vértesy, Zofia; Rassart, Marie; Seldrum, Thomas; Dumont, Jacques; Deparis, Olivier; Lousse, Virginie; Biró, László P.; Ertz, Damien; Welch, Victoria

    2007-09-01

    The tortoise beetle Charidotella egregia is able to modify the structural color of its cuticle reversibly, when disturbed by stressful external events. After field observations, measurements of the optical properties in the two main stable color states and scanning electron microscope and transmission electron microscope investigations, a physical mechanism is proposed to explain the color switching of this insect. It is shown that the gold coloration displayed by animals at rest arises from a chirped multilayer reflector maintained in a perfect coherent state by the presence of humidity in the porous patches within each layer, while the red color displayed by disturbed animals results from the destruction of this reflector by the expulsion of the liquid from the porous patches, turning the multilayer into a translucent slab that leaves an unobstructed view of the deeper-lying, pigmented red substrate. This mechanism not only explains the change of hue but also the change of scattering mode from specular to diffuse. Quantitative modeling is developed in support of this analysis.

  11. Hyperplastic stomatitis and esophagitis in a tortoise (Testudo graeca) associated with an adenovirus infection.

    PubMed

    Garcia-Morante, Beatriz; Pénzes, Judit J; Costa, Taiana; Martorell, Jaime; Martínez, Jorge

    2016-09-01

    A 2-year-old female, spur-thighed tortoise (Testudo graeca) was presented with poor body condition (1/5) and weakness. Fecal analysis revealed large numbers of oxyurid-like eggs, and radiographs were compatible with gastrointestinal obstruction. Despite supportive medical treatment, the animal died. At gross examination, an intestinal obstruction was confirmed. Histopathology revealed severe hyperplastic esophagitis and stomatitis with marked epithelial cytomegaly and enormous basophilic intranuclear inclusion bodies. Electron microscopy examination revealed a large number of 60-80 nm, nonenveloped, icosahedral virions arranged in crystalline arrays within nuclear inclusions of esophageal epithelial cells, morphologically compatible with adenovirus-like particles. PCR for virus identification was performed with DNA extracted from formalin-fixed, paraffin-embedded tissues. A nested, consensus pan-adenovirus PCR and sequencing analysis showed a novel adenovirus. According to phylogenetic calculations, it clustered to genus Atadenovirus in contrast with all other chelonian adenoviruses described to date. The present report details the pathologic findings associated with an adenovirus infection restricted to the upper digestive tract.

  12. The origin of the glucose dependent increase in the potential difference across the tortoise small intestine

    PubMed Central

    Wright, E. M.

    1966-01-01

    1. Experiments were carried out to investigate the origin of the glucose dependent increase in the potential difference (p.d.) across the isolated intestinal mucosa of the tortoise. 2. In addition to glucose, galactose, α-methyl glucoside, 3-0-methyl glucopyranose and sucrose also increased the transepithelial potential difference. There was no increase with either fructose or mannose. 3. The use of micro-electrodes demonstrated that the change in the p.d. due to the presence of glucose was wholly accounted for by the increase in the p.d. across the serosal face of the epithelial cells. 4. Diffusion potentials were produced across the isolated mucosa by varying the ionic composition of either the mucosal or serosal fluids. However, there was no reduction of the glucose dependent increase in the p.d. when the ionic concentration gradients across the serosal face of the cell were reversed. 5. These results suggest that the increase in the p.d. associated with the active transfer of sugars across the small intestine was due to the presence of an electrogenic ion pump at the serosal face of the epithelial cell. PMID:16992234

  13. Genetic analysis of a successful repatriation programme: giant Galápagos tortoises.

    PubMed

    Milinkovitch, Michel C; Monteyne, Daniel; Gibbs, James P; Fritts, Thomas H; Tapia, Washington; Snell, Howard L; Tiedemann, Ralph; Caccone, Adalgisa; Powell, Jeffrey R

    2004-02-22

    As natural populations of endangered species dwindle to precarious levels, remaining members are sometimes brought into captivity, allowed to breed and their offspring returned to the natural habitat. One goal of such repatriation programmes is to retain as much of the genetic variation of the species as possible. A taxon of giant Galápagos tortoises on the island of Española has been the subject of a captive breeding-repatriation programme for 33 years. Core breeders, consisting of 12 females and three males, have produced more than 1200 offspring that have been released on Española where in situ reproduction has recently been observed. Using microsatellite DNA markers, we have determined the maternity and paternity of 132 repatriated offspring. Contributions of the breeders are highly skewed. This has led to a further loss of genetic variation that is detrimental to the long-term survival of the population. Modifications to the breeding programme could alleviate this problem.

  14. Phylogeographic history and gene flow among giant Galápagos tortoises on southern Isabela Island.

    PubMed

    Ciofi, Claudio; Wilson, Gregory A; Beheregaray, Luciano B; Marquez, Cruz; Gibbs, James P; Tapia, Washington; Snell, Howard L; Caccone, Adalgisa; Powell, Jeffrey R

    2006-03-01

    Volcanic islands represent excellent models with which to study the effect of vicariance on colonization and dispersal, particularly when the evolution of genetic diversity mirrors the sequence of geological events that led to island formation. Phylogeographic inference, however, can be particularly challenging for recent dispersal events within islands, where the antagonistic effects of land bridge formation and vicariance can affect movements of organisms with limited dispersal ability. We investigated levels of genetic divergence and recovered signatures of dispersal events for 631 Galápagos giant tortoises across the volcanoes of Sierra Negra and Cerro Azul on the island of Isabela. These volcanoes are among the most recent formations in the Galápagos (<0.7 million years), and previous studies based on genetic and morphological data could not recover a consistent pattern of lineage sorting. We integrated nested clade analysis of mitochondrial DNA control region sequences, to infer historical patterns of colonization, and a novel Bayesian multilocus genotyping method for recovering evidence of recent migration across volcanoes using eleven microsatellite loci. These genetic studies illuminate taxonomic distinctions as well as provide guidance to possible repatriation programs aimed at countering the rapid population declines of these spectacular animals.

  15. Microphytic crusts: 'topsoil' of the desert

    USGS Publications Warehouse

    Belnap, Jayne

    1990-01-01

    Deserts throughout the world are the home of microphytic, or cryptogamic, crusts. These crusts are dominated by cyanobacteria, previously called blue-green algae, and also include lichens, mosses, green algae, microfungi and bacteria. They are critical components of desert ecosystems, significantly modifying the surfaces on which they occur. In the cold deserts of the Colorado Plateau (including parts of Utah, Arizona, Colorado, and New Mexico), these crusts are extraordinarily well-developed, and may represent 70-80% of the living ground cover.

  16. A New General Tortoise Coordinate Transformation and Quantum Tunneling Effect of the Non-Stationary Higher Dimensional Vaidya-de Sitter Black Hole

    NASA Astrophysics Data System (ADS)

    Feng, Zhong-wen; Li, Guo-ping; Zhang, Yan; Zu, Xiao-tao

    2015-02-01

    In this paper, we combine the Hamilton-Jacobi equation with a new general tortoise coordinate transformation to study quantum tunneling of scalar particles and fermions from the non-stationary higher dimensional Vaidya-de Sitter black hole. The results show that Hamilton-Jacobi equation is a semi-classical foundation equation which can easily derived from the particles' dynamic equations, it can helps us understand the origin of Hawking radiation. Besides, based on the dimensional analysis, we believed that the new general tortoise coordinate transformation is more reasonable than old ones.

  17. Desert Dust and Monsoon Rain

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kim, Kyu-Myong

    2014-01-01

    For centuries, inhabitants of the Indian subcontinent have know that heavy dust events brought on by strong winds occur frequently in the pre-monsoon season, before the onset of heavy rain. Yet scientists have never seriously considered the possibility that natural dust can affect monsoon rainfall. Up to now, most studies of the impacts of aerosols on Indian monsoon rainfall have focused on anthropogenic aerosols in the context of climate change. However, a few recent studies have show that aerosols from antropogenic and natural sources over the Indian subcontinent may affect the transition from break to active monsoon phases on short timescales of days to weeks. Writing in Nature Geoscience, Vinoj and colleagues describe how they have shown that desert dust aerosols over the Arabian Sea and West Asia can strenghten the summer monsoon over the Indial subcontinent in a matter of days.

  18. Desert Dust Satellite Retrieval Intercomparison

    NASA Technical Reports Server (NTRS)

    Carboni, E.; Thomas, G. E.; Sayer, A. M.; Siddans, R.; Poulsen, C. A.; Grainger, R. G.; Ahn, C.; Antoine, D.; Bevan, S.; Braak, R.; Brindley, H.; DeSouza-Mchado, S.; Deuze, J. L.; Diner, D.; Ducos, F.; Grey, W.; Hsu, C.; Kalashnikova, O. V.; Kahn, R.; North, P. R. J.; Salustro, C.; Smith, A.; Tanre, D.; Torres, O.; Veihelmann, B.

    2012-01-01

    This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD) during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify and understand the differences between current algorithms, and hence improve future retrieval algorithms. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR), polarisation measurements (POLDER), single-view approaches using solar wavelengths (OMI, MODIS), and the thermal infrared spectral region (SEVIRI, AIRS). Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as as20 sumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, at least as significant as these differences are sampling issues related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset.

  19. Desert potholes: Ephemeral aquatic microsystems

    USGS Publications Warehouse

    Chan, M.A.; Moser, K.; Davis, J.M.; Southam, G.; Hughes, K.; Graham, T.

    2005-01-01

    An enigma of the Colorado Plateau high desert is the "pothole", which ranges from shallow ephemeral puddles to deeply carved pools. The existence of prokaryotic to eukaryotic organisms within these pools is largely controlled by the presence of collected rainwater. Multivariate statistical analysis of physical and chemical limnologic data variables measured from potholes indicates spatial and temporal variations, particularly in water depth, manganese, iron, nitrate and sulfate concentrations and salinity. Variation in water depth and salinity are likely related to the amount of time since the last precipitation, whereas the other variables may be related to redox potential. The spatial and temporal variations in water chemistry affect the distribution of organisms, which must adapt to daily and seasonal extremes of fluctuating temperature (0-60 ??C), pH changes of as much as 5 units over 12 days, and desiccation. For example, many species become dormant when potholes dry, in order to endure intense heat, UV radiation, desiccation and freezing, only to flourish again upon rehydration. But the pothole organisms also have a profound impact on the potholes. Through photosynthesis and respiration, pothole organisms affect redox potential, and indirectly alter the water chemistry. Laboratory examination of dried biofilm from the potholes revealed that within 2 weeks of hydration, the surface of the desiccated, black biofilm became green from cyanobacterial growth, which supported significant growth in heterotrophic bacterial populations. This complex biofilm is persumably responsible for dissolving the cement between the sandstone grains, allowing the potholes to enlarge, and for sealing the potholes, enabling them to retain water longer than the surrounding sandstone. Despite the remarkable ability of life in potholes to persist, desert potholes may be extremely sensitive to anthropogenic effects. The unique limnology and ecology of Utah potholes holds great scientific

  20. Giant tortoises are not so slow: rapid diversification and biogeographic consensus in the Galápagos.

    PubMed

    Beheregaray, Luciano B; Gibbs, James P; Havill, Nathan; Fritts, Thomas H; Powell, Jeffrey R; Caccone, Adalgisa

    2004-04-27

    Isolated oceanic archipelagos have played a major role in the development of evolutionary theory by offering a unique setting for studying spatial and temporal patterns of biological diversification. However, the evolutionary events that cause associations between genetic variation and geography in archipelago radiations are largely unknown. This finding is especially true in the Galápagos Islands, where molecular studies have revealed conflicting biogeographic patterns. Here, we elucidate the history of diversification of giant Galápagos tortoises by using mtDNA sequences from 802 individuals representing all known extant populations. We test biogeographic predictions based on geological history and assess the roles of volcano emergence and island formation in driving evolutionary diversification. Patterns of colonization and lineage sorting appear highly consistent with the chronological formation of the archipelago. Populations from older islands are composed exclusively of endemic haplotypes that define divergent monophyletic clades. Younger populations, although currently differentiated, exhibit patterns of colonization, demographic variation and genetic interchange shaped by recent volcanism. Colonization probably occurs shortly after a volcano emerges through range expansion from older volcanoes. Volcanism can also create temporal shifts from historical to recurrent events, such as promoting gene flow by creating land bridges between isolated volcanoes. The association of spatial and temporal patterns of genetic variation with geophysical aspects of the environment can best be attributed to the limited dispersal and migration of tortoises following an oceanographic current. The endangered giant Galápagos tortoises represent a rapid allopatric radiation and further exemplify evolutionary processes in one of the world's greatest natural laboratories of evolution.

  1. Sampling and handling of desert soils

    NASA Technical Reports Server (NTRS)

    Blank, G. B.; Cameron, R. E.

    1969-01-01

    Report on sampling and handling desert soils includes sections on selection, characterization, and photography of area, site, and soil, sterilization of sampling equipment and containers, and soil sample collection, transport, storage, and dispersal.

  2. Desert R.A.T.S. 2011

    NASA Video Gallery

    Desert Research And Technology Studies (D-R.A.T.S) kicks off an exciting new year of field testing. The crew is back in action, testing communication scenarios for near-Earth asteroids, and two new...

  3. Giant viruses of the Kutch Desert.

    PubMed

    Kerepesi, Csaba; Grolmusz, Vince

    2016-03-01

    The Kutch Desert (Great Rann of Kutch, Gujarat, India) is a unique ecosystem: in the larger part of the year it is a hot, salty desert that is flooded regularly in the Indian monsoon season. In the dry season, the crystallized salt deposits form the "white desert" in large regions. The first metagenomic analysis of the soil samples of Kutch was published in 2013, and the data were deposited in the NCBI Sequence Read Archive. At the same time, the sequences were analyzed phylogenetically for prokaryotes, especially for bacteria. In the present work, we identified DNA sequences of recently discovered giant viruses in the soil samples from the Kutch Desert. Since most giant viruses have been discovered in biofilms in industrial cooling towers, ocean water, and freshwater ponds, we were surprised to find their DNA sequences in soil samples from a seasonally very hot and arid, salty environment.

  4. 2011 Desert RATS Sights and Sounds

    NASA Video Gallery

    Watch scenes from the 2011 Desert Research and Technology Studies (RATS) analog field test, as NASA scientists and engineers drive the Space Exploration Vehicle, assemble equipment in the Habitat D...

  5. The use of classical and operant conditioning in training Aldabra tortoises (Geochelone gigantea), for venipuncture and other, husbandry issues.

    PubMed

    Weiss, Emily; Wilson, Sandra

    2003-01-01

    A variety of nonhuman animals in zoo and research settings have been the subjects of classical and operant conditioning techniques. Much of the published work has focused on mammals, husbandry training, and veterinary issues. However, several zoos are training reptiles and birds for similar procedures, but there has been little of this work published. Using positive reinforcement techniques enabled the training of 2 male and 2 female Aldabra tortoises (Geochelone gigantea) to approach a target, hold steady on target, and stretch and hold for venipuncture. This article discusses training techniques, venipuncture sight, and future training.

  6. Hawking Radiation and Entropy of a Dynamic Dilaton-Maxwell Black Hole with a New Tortoise Coordinate Transformation

    NASA Astrophysics Data System (ADS)

    Lan, Xiao-Gang

    2013-05-01

    By introducing a new tortoise coordinate transformation, we apply Damour-Ruffini-Sannan method to study the Hawking radiation of massive scalar particles in a dynamic Dilaton-Maxwell black hole. We find that Hawking radiation spectrum shows still the blackbody one, while the Hawking temperature is significantly changed. Additionally, by adopting the thin film method, we calculate the entropy of a dynamic Dilaton-Maxwell black hole. The result indicates that the entropy for such a black hole is still in proportional to the area of its event horizon.

  7. Hawking Radiation of Dirac Particles from a General Dynamical Spherically Symmetrical Black Hole Using a New Tortoise Coordinate Transformation

    NASA Astrophysics Data System (ADS)

    Liang, Jun; Zhang, Fang-Hui; Zhang, Wei; Zhang, Jing

    2014-01-01

    By utilizing the improved Damour-Ruffini method with a new tortoise transformation, we study the Hawking radiation of Dirac particles from a general dynamical spherically symmetric black hole. In the improved Damour-Ruffini method, the position of the event horizon of the black hole is an undetermined function, and the temperature parameter κ is an undetermined constant. By requiring the Dirac equation to be the standard wave equation near the event horizon of the black hole, κ can be determined automatically. Therefore, the Hawking temperature can be obtained. The result is consistent with that of the Hawking radiation of scalar particles.

  8. A new species of Haemoproteus from a tortoise (Testudo graeca) in Turkey, with remarks on molecular phylogenetic and morphological analysis.

    PubMed

    Orkun, Ömer; Güven, Esin

    2013-02-01

    Haemoproteus anatolicum n. sp. was identified in the tortoise Testudo graeca. The new species is described based on the morphology of its blood stages and a segment of the mitochondrial cytochrome b gene, which can be used for molecular identification and diagnosis. Chelonian haemoproteids recorded in the past were defined solely on the basis of their morphological characteristics. The chelonian haemoproteid we describe as a new species has a close genetic relationship to lizard haemoproteids, i.e., Haemoproteus ptyodactylii and Haemoproteus kopki. The new species description provides significant new information for little-known chelonian haemoproteids.

  9. Late Quaternary history of the Atacama Desert

    USGS Publications Warehouse

    Latorre, Claudio; Betancourt, Julio L.; Rech, Jason A.; Quade, Jay; Holmgren, Camille; Placzek, Christa; Maldonado, Antonio; Vuille, Mathias; Rylander, Kate A.; Smith, Mike; Hesse, Paul

    2005-01-01

    Of the major subtropical deserts found in the Southern Hemisphere, the Atacama Desert is the driest. Throughout the Quaternary, the most pervasive climatic influence on the desert has been millennial-scale changes in the frequency and seasonality of the scant rainfall, and associated shifts in plant and animal distributions with elevation along the eastern margin of the desert. Over the past six years, we have mapped modern vegetation gradients and developed a number of palaeoenvironmental records, including vegetation histories from fossil rodent middens, groundwater levels from wetland (spring) deposits, and lake levels from shoreline evidence, along a 1200-kilometre transect (16–26°S) in the Atacama Desert. A strength of this palaeoclimate transect has been the ability to apply the same methodologies across broad elevational, latitudinal, climatic, vegetation and hydrological gradients. We are using this transect to reconstruct the histories of key components of the South American tropical (summer) and extratropical (winter) rainfall belts, precisely at those elevations where average annual rainfall wanes to zero. The focus has been on the transition from sparse, shrubby vegetation (known as the prepuna) into absolute desert, an expansive hyperarid terrain that extends from just above the coastal fog zone (approximately 800 metres) to more than 3500 metres in the most arid sectors in the southern Atacama.

  10. Cyanotoxins in desert environments may present a risk to human health.

    PubMed

    Metcalf, J S; Richer, R; Cox, P A; Codd, G A

    2012-04-01

    There have been few studies concerning cyanotoxins in desert environments, compared with the multitude of studies of cyanotoxins in aquatic environments. However, cyanobacteria are important primary producers in desert environments, where after seasonal rains they can grow rapidly both stabilising and fertilising arid habitats. Samples of cyanobacteria from wadis - dry, ephemeral river beds - and sabkha - supertidal salt flats - in Qatar were analysed for the presence of microcystins, nodularin, anatoxin-a, cylindrospermopsin and anatoxin-a(S). Microcystins were detected by HPLC-PDA and ELISA at concentrations between 1.5 and 53.7ngg(-1) dry wt of crust. PCR products for the mycD gene for microcystin biosynthesis were detected after amplification of DNA from desert crust samples at two out of three sample sites. The presence of anatoxin-a(S) was also indicated by acetylcholine esterase inhibition assay. As a function of area of desert crust, microcystin concentrations were between 3 and 56μgm(-2). Based on the concentration of microcystins detected in crust, with reference to the published inhalation NOAEL and LOAEL values via nasal spray inhalation of purified microcystin-LR in aqueous solution, and the amount of dust potentially inhaled by a person from these dried crusts, the dose of microcystins could exceed a calculated TDI value of 1-2ngkg(-1)day(-1) for an average adult. The presence of microcystins, and potentially of anatoxin-a(S), in desert crusts has important implications for human health. Further studies are required to monitor desert dust storms for the presence of cyanotoxins. An understanding of the risks of inhaling particles containing cyanotoxins is also warranted.

  11. Internal and External Adaptation in Army Families: Lessons from Operations Desert Shield and Desert Storm

    ERIC Educational Resources Information Center

    Pittman, Joe F.; Kerpelman, Jennifer L.; McFadyen, Jennifer M.

    2004-01-01

    This study examined 1,064 Army families reunited after a member's deployment for Operation Desert Shield and Operation Desert Storm. Postdeployment outcomes were conceptualized in terms of the "fit" between the family and the demands of Army life, especially the stress of deployment. A structural model was used to test the hypothesized effects of…

  12. HIGH FOLIAR NITROGEN IN DESERT SHRUBS: AN IMPORTANT ECOSYSTEM TRAIT OR DEFECTIVE DESERT DOCTRINE?

    EPA Science Inventory

    Nitrogen concentrations in green and senesced leaves of perennial desert shrubs were compiled from a worldwide literature search to test the validity of the doctrine that desert shrubs produce foliage and leaf litter much richer in nitrogen than that in the foliage of plants from...

  13. Developmental plasticity of cutaneous water loss and lipid composition in stratum corneum of desert and mesic nestling house sparrows

    PubMed Central

    Muñoz-Garcia, Agustí; Williams, Joseph B.

    2008-01-01

    Intercellular lipids of the stratum corneum (SC), the outer layer of the epidermis, form a barrier to water vapor diffusion through the skin. Previously, we measured cutaneous water loss (CWL) and lipid composition of the SC of adult house sparrows from two populations, one living in the deserts of Saudi Arabia and another living in mesic Ohio. Adult desert house sparrows had a lower CWL, a lower proportion of free fatty acids, and a higher proportion of ceramides and cerebrosides in the SC compared with mesic sparrows. In this study, we investigated developmental plasticity of CWL and lipid composition of the SC in desert and mesic nestling house sparrows reared in low and high humidity and compared our results with previous work on adults. We measured CWL of nestlings and analyzed the lipid composition of the SC using thin-layer chromatography. We showed that nestling house sparrows from both localities had higher CWL than adults in their natural environment, a result of major modifications of the lipid composition of the SC. The expression of plasticity in CWL seems to be a response to opposed selection pressures, thermoregulation and water conservation, at different life stages, on which regulation of CWL plays a crucial role. Desert nestlings showed a greater degree of plasticity in CWL and lipid composition of the SC than did mesic nestlings, a finding consistent with the idea that organisms exposed to more environmental stress ought to be more plastic than individuals living in more benign environments. PMID:18838693

  14. Is preference a predictor of enrichment efficacy in Galapagos tortoises (Chelonoidis nigra)?

    PubMed

    Mehrkam, Lindsay R; Dorey, Nicole R

    2014-01-01

    It is widely acknowledged that environmental enrichment plays an important role in promoting the welfare of captive animals. However, a topic of debate is whether an animal's preference for an enrichment strategy is any indicator of its efficacy. In addition, relatively few studies have evaluated environmental enrichment strategies for non-mammalian species. In the present study, we compared the results of an observational evaluation of enrichment efficacy with the results of a paired-stimulus preference assessment for three Galapagos tortoises. In the observational study, object enrichment (boomer balls and a free-flowing sprinkler) and keeper interactions (shell scrubbing and neck rubbing) were evaluated systematically for their effects on locomotion, species-typical behavior, aggressive and non-aggressive conspecific interactions, and enclosure. Preference assessments were subsequently conducted in which subjects could choose the enrichment strategy to be implemented. All subjects preferred keeper interactions consistently over object enrichment. Our results suggest that enrichment preference was a variable predictor of efficacy across enrichment species-typical behavior, activity levels, enclosure use, and aggressive and non-aggressive conspecific interactions strategies. Preference predicted efficacy for promoting species-typical behavior (1/3 subjects), activity levels (2/3 subjects), and enclosure use (2/3 subjects), but not conspecific interactions (0/3 subjects). The results suggest that preference may be an efficient predictor of enrichment efficacy when daily observational evaluations are not practical; however, the predictive utility of preference assessments may depend on the behavioral goal of the enrichment strategy. We discuss the need for future research examining the relationship between preference and enrichment efficacy-as well as other potential indicators of enrichment effectiveness-in captive animals.

  15. Differences in helminth infections between captive and wild spur-thighed tortoises Testudo graeca in southern Spain: a potential risk of reintroductions of this species.

    PubMed

    Chávarri, Malva; Berriatua, Eduardo; Giménez, Andrés; Gracia, Eva; Martínez-Carrasco, Carlos; Ortiz, Juana M; de Ybáñez, Rocío Ruiz

    2012-07-06

    Although the spur-thighed tortoise, Testudo graeca, is one of the most widely distributed species of tortoises, its natural populations are threatened through its whole range. Particularly at south-eastern Spain, the species is mainly threatened by habitat destruction and over-collection, given that this chelonian has been traditionally considered an appreciate pet. As south-eastern Spanish wildlife recovery centers shelter hundreds of captive animals mainly coming from illegal trade or captive-bred, there is a strong debate about what to do with these animals: maintaining them in captivity all along their lives or reintroducing them to wildlife. It is well known that the reintroduction of captive animals supposes a risk for the wild population due to the uncertainty of their genetic origin and to the possible spread of infectious diseases. However, despite the increasing evidence that infectious agents are a potential health hazard for wildlife, little is known about the risk that introduced parasites could suppose for the wild populations of spur-thighed tortoise. The present study investigates for the first time the presence of helminth eggs and worms in faeces from 107 wild and captive individuals collected from mid-March to mid-June 2010, and relates the findings to different environmental and host variables. Sixteen oxyurid species and the ascarid Angusticaecum holopterum were identified. This last nematode and the oxyurid species Tachygonetria palearticus and T. seurati had not been reported in Spanish wild T. graeca previously. The prevalence of oxyurid eggs and worms were 94% and 70%, respectively; while, ascarid eggs and worms were found in 26% and 5% of tortoises, respectively. Ascarid infections affected mostly captive animals and were associated to caparace deformities and symptoms of upper respiratory tract disease (p<0.05). Oxyurid infections were not associated to negative health traits and prevalence increased with age. In free-living tortoises

  16. A comparison of artificial incubation and natural incubation hatching success of gopher tortoise (Gopherus polyphemus) eggs in southern Mississippi

    USGS Publications Warehouse

    Noel, Krista M.; Qualls, Carl P.; Ennen, Joshua R.

    2012-01-01

    Recent studies have found that Gopher Tortoise, Gopherus polyphemus, populations in southern Mississippi exhibit low recruitment, due in part to very low hatching success of their eggs. We sought to determine if the cause(s) of this low hatching success was related to egg quality (intrinsic factors), unsuitability of the nest environment (extrinsic factors), or a combination of the two. In 2003, hatching success was monitored simultaneously for eggs from the same clutches that were incubated in the laboratory and left to incubate in nests. A subset of randomly chosen eggs from each clutch was incubated in the laboratory under physical conditions that were known to be conducive to successful hatching to estimate the proportion of eggs that were capable of hatching in a controlled setting. Hatching success in the laboratory was compared with that of eggs incubated in natural nests to estimate the proportion of eggs that failed to hatch presumably from extrinsic factors. Laboratory hatching success was 58.8%, suggesting that roughly 40% of the eggs were intrinsically incapable of hatching even when incubated under controlled conditions. Hatching success in natural nests, 16.7%, was significantly lower than hatching success in the laboratory, suggesting that approximately 42.1% of eggs were capable of hatching but failed to hatch due to some extrinsic aspect(s) of the nest environment. Thus, the low hatching success of Gopher Tortoise eggs in southern Mississippi appears to be attributable to a combination of intrinsic (egg quality) and extrinsic (nest environment) factors.

  17. Sex-specific ecophysiological responses to environmental fluctuations of free-ranging Hermann's tortoises: implication for conservation

    PubMed Central

    Sibeaux, Adélaïde; Michel, Catherine Louise; Bonnet, Xavier; Caron, Sébastien; Fournière, Kévin; Gagno, Stephane; Ballouard, Jean-Marie

    2016-01-01

    Physiological parameters provide indicators to evaluate how organisms respond to conservation actions. For example, individuals translocated during reinforcement programmes may not adapt to their novel host environment and may exhibit elevated chronic levels of stress hormones and/or decreasing body condition. Conversely, successful conservation actions should be associated with a lack of detrimental physiological perturbation. However, physiological references fluctuate over time and are influenced by various factors (e.g. sex, age, reproductive status). It is therefore necessary to determine the range of natural variations of the selected physiological metrics to establish useful baselines. This study focuses on endangered free-ranging Hermann's tortoises (Testudo hermanni hermanni), where conservation actions have been preconized to prevent extinction of French mainland populations. The influence of sex and of environmental factors (site, year and season) on eight physiological parameters (e.g. body condition, corticosterone concentrations) was assessed in 82 individuals from two populations living in different habitats. Daily displacements were monitored by radio-tracking. Most parameters varied between years and seasons and exhibited contrasting sex patterns but with no or limited effect of site. By combining behavioural and physiological traits, this study provides sex-specific seasonal baselines that can be used to monitor the health status of Hermann's tortoises facing environmental threats (e.g. habitat changes) or during conservation actions (e.g. translocation). These results might also assist in selection of the appropriate season for translocation. PMID:27933166

  18. Desert dust hazards: A global review

    NASA Astrophysics Data System (ADS)

    Middleton, N. J.

    2017-02-01

    Dust storms originate in many of the world's drylands and frequently present hazards to human society, both within the drylands themselves but also outside drylands due to long-range transport of aeolian sediments. Major sources of desert dust include the Sahara, the Middle East, central and eastern Asia, and parts of Australia, but dust-raising occurs all across the global drylands and, on occasion, beyond. Dust storms occur throughout the year and they vary in frequency and intensity over a number of timescales. Long-range transport of desert dust typically takes place along seasonal transport paths. Desert dust hazards are here reviewed according to the three phases of the wind erosion system: where dust is entrained, during the transport phase, and on deposition. This paper presents a synthesis of these hazards. It draws on empirical examples in physical geography, medical geology and geomorphology to discuss case studies from all over the world and in various fields. These include accelerated soil erosion in agricultural zones - where dust storms represent a severe form of accelerated soil erosion - the health effects of air pollution caused by desert aerosols via their physical, chemical and biological properties, transport accidents caused by poor visibility during desert dust events, and impacts on electricity generation and distribution. Given the importance of desert dust as a hazard to human societies, it is surprising to note that there have been relatively few attempts to assess their impact in economic terms. Existing studies in this regard are also reviewed, but the wide range of impacts discussed in this paper indicates that desert dust storms deserve more attention in this respect.

  19. Effects of Sand Dune Stabilization on the Spatial Pattern of Artemisia ordosica Population in Mu Us Desert, Northwest China

    PubMed Central

    Zhang, Jiachen; Zhang, Yuqing; Fan, Dongqing; Qin, Shugao; Jia, Xin; Wu, Bin; Chen, Dong; Gao, Hao; Zhu, Linfeng

    2015-01-01

    Vegetation patterns are strongly influenced by sand mobility in desert ecosystems. However, little is known about the spatial patterns of Artemisia ordosica, a dominant shrub in the Mu Us desert of Northwest China, in relation to sand fixation. The aim of this study was to investigate and contrast the effects of sand dune stabilization on the population and spatial distribution of this desert shrub. Spatial autocorrelation, semi-variance analysis, and point-pattern analysis were used jointly in this study to investigate the spatial patterns of A. ordosica populations on dunes in Yanchi County of Ningxia, China. The results showed that the spatial autocorrelation and spatial heterogeneity declined gradually, and the distance between the clustered individuals shortened following sand dune fixation. Seedlings were more aggregated than adults in all stage of dune stabilization, and both were more aggregated on shifting sand dunes separately. Spatial associations of the seedlings with the adults were mostly positive at distances of 0–5 m in shifting sand dunes, and the spatial association changed from positive to neutral in semi-fixed sand dunes. The seedlings were spaced in an almost random pattern around the adults, and their distances from the adults did not seem to affect their locations in semi-fixed sand dunes. Furthermore, spatial associations of the seedlings with the adults were negative in the fixed sand dune. These findings demonstrate that sand stabilization is an important factor affecting the spatial patterns of A. ordosica populations in the Mu Us desert. These findings suggest that, strong association between individuals may be the mechanism to explain the spatial pattern formation at preliminary stage of dune fixation. Sand dune stabilization can change the spatial pattern of shrub population by weakening the spatial association between native shrub individuals, which may affect the development direction of desert shrubs. PMID:26102584

  20. Effects of Sand Dune Stabilization on the Spatial Pattern of Artemisia ordosica Population in Mu Us Desert, Northwest China.

    PubMed

    Zhang, Jiachen; Zhang, Yuqing; Fan, Dongqing; Qin, Shugao; Jia, Xin; Wu, Bin; Chen, Dong; Gao, Hao; Zhu, Linfeng

    2015-01-01

    Vegetation patterns are strongly influenced by sand mobility in desert ecosystems. However, little is known about the spatial patterns of Artemisia ordosica, a dominant shrub in the Mu Us desert of Northwest China, in relation to sand fixation. The aim of this study was to investigate and contrast the effects of sand dune stabilization on the population and spatial distribution of this desert shrub. Spatial autocorrelation, semi-variance analysis, and point-pattern analysis were used jointly in this study to investigate the spatial patterns of A. ordosica populations on dunes in Yanchi County of Ningxia, China. The results showed that the spatial autocorrelation and spatial heterogeneity declined gradually, and the distance between the clustered individuals shortened following sand dune fixation. Seedlings were more aggregated than adults in all stage of dune stabilization, and both were more aggregated on shifting sand dunes separately. Spatial associations of the seedlings with the adults were mostly positive at distances of 0-5 m in shifting sand dunes, and the spatial association changed from positive to neutral in semi-fixed sand dunes. The seedlings were spaced in an almost random pattern around the adults, and their distances from the adults did not seem to affect their locations in semi-fixed sand dunes. Furthermore, spatial associations of the seedlings with the adults were negative in the fixed sand dune. These findings demonstrate that sand stabilization is an important factor affecting the spatial patterns of A. ordosica populations in the Mu Us desert. These findings suggest that, strong association between individuals may be the mechanism to explain the spatial pattern formation at preliminary stage of dune fixation. Sand dune stabilization can change the spatial pattern of shrub population by weakening the spatial association between native shrub individuals, which may affect the development direction of desert shrubs.

  1. Desert Amplification in a Warming Climate

    PubMed Central

    Zhou, Liming

    2016-01-01

    Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950–2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor. PMID:27538725

  2. Desert Amplification in a Warming Climate

    NASA Astrophysics Data System (ADS)

    Zhou, Liming

    2016-08-01

    Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950–2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor.

  3. Desert Amplification in a Warming Climate.

    PubMed

    Zhou, Liming

    2016-08-19

    Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950-2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor.

  4. Desert basins of the Southwest

    USGS Publications Warehouse

    Leake, Stanley A.; Konieczki, Alice D.; Rees, Julie A.H.

    2000-01-01

    Ground water is among the Nation’s most important natural resources. It provides drinking water to urban and rural communities, supports irrigation and industry, sustains the flow of streams and rivers, and maintains riparian and wetland ecosystems. In many areas of the Nation, the future sustainability of ground-water resources is at risk from overuse and contamination. Because ground-water systems typically respond slowly to human actions, a long-term perspective is needed to manage this valuable resource. This publication is one in a series of fact sheets that describe ground-water-resource issues across the United States, as well as some of the activities of the U.S. Geological Survey that provide information to help others develop, manage, and protect ground-water resources in a sustainable manner. Ground-water resources in the Southwest are among the most overused in the United States. Natural recharge to aquifers is low and pumping in many areas has resulted in lowering of water tables. The consequences of large-scale removal of water from storage are becoming increasingly evident. These consequences include land subsidence; loss of springs, streams, wetlands and associated habitat; and degradation of water quality. Water managers are now seeking better ways of managing ground-water resources while looking for supplemental sources of water. This fact sheet reviews basic information on ground water in the desert basins of the Southwest. Also described are some activities of the U.S. Geological Survey (USGS) that are providing scientific information for sustainable management of ground-water resources in the Southwest. Ground-water sustainability is defined as developing and using ground water in a way that can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences.

  5. Establishing food site vectors in desert ants.

    PubMed

    Bolek, Siegfried; Wittlinger, Matthias; Wolf, Harald

    2012-02-15

    When returning to the site of a successful previous forage, where does one search for the goodies? Should one rely on experience from the previous homebound journey, or should one consider the outbound journey as well, or even exclusively? Desert ants are particularly well suited for pursuing this question because of their primary reliance on path integration in open and featureless desert habitats. Path integration has been studied particularly with regard to homing after lengthy foraging trips. The ants also use path integration to return to plentiful feeding sites, but what is memorised for revisiting the feeder remains controversial. Here, we demonstrate that desert ants consider, and indeed linearly average, both outbound and inbound travel for their return to a familiar feeder. This may be interpreted as a strategy to reduce navigation errors.

  6. The Punitive Paradox: Desert and the Compulsion to Punish.

    ERIC Educational Resources Information Center

    Clear, Todd R.

    1996-01-01

    Explores the concept of a "just deserts" justice paradox in which carrying out a deserved penalty breaches the values that undergird the theory of just deserts. Examines whether it might ever be proper, from a desert perspective, to choose not to impose a deserved punishment. (KW)

  7. An Economic View of Food Deserts in the United States

    ERIC Educational Resources Information Center

    Bitler, Marianne; Haider, Steven J.

    2011-01-01

    Considerable policy and academic attention has been focused on the topic of food deserts. We consider this topic from an economic perspective. First, we consider how the components of a standard economic analysis apply to the study of food deserts. Second, using this economic lens, we revisit the empirical literature on food deserts to assess the…

  8. Desert Dust Properties, Modelling, and Monitoring

    NASA Technical Reports Server (NTRS)

    Kaskaoutis, Dimitris G.; Kahn, Ralph A.; Gupta, Pawan; Jayaraman, Achuthan; Bartzokas, Aristides

    2013-01-01

    This paper is just the three-page introduction to a Special Issue of Advances in Meteorology focusing on desert dust. It provides a paragraph each on 13 accepted papers, most relating to the used of satellite data to assess attributes or distribution of airborne desert dust. As guest Associate Editors of this issue, we organized the papers into a systematic whole, beginning with large-scale transport and seasonal behavior, then to regional dust transport, transport history, and climate impacts, first in the Mediterranean region, then India and central Asia, and finally focusing on transport model assessment and the use of lidar as a technique to constrain dust spatial-temporal distribution.

  9. Carrion insects of the Egyptian western desert.

    PubMed

    Hegazi, E M; Shaaban, M A; Sabry, E

    1991-09-01

    A general survey was made on the zoosaprophagous insects and their associates in a natural ecosystem in the Egyptian western desert (80 km west of Alexandria, 12 km from the Mediterranean Sea shore). Two types of traps were used, one for flying insects and the other for soil-burrowing insects. Two types of decaying media were used as baits: the common freshwater fish (Tilapia zilii Gerv.) and the desert snail (Eremina desertorum). More than 30 insect species were trapped. The following orders and families were represented: Diptera (Calliphoridae, Sarcophagidae, Muscidae); Coleoptera (Histeridae, Scarabaeidae, Dermestidae, Tenebrionidae); Hymenoptera (Chalcididae, Pteromalidae, Eulophidae, Formicidae). Monthly totals of numbers trapped in each of these groups are presented.

  10. A mathematical model on the optimal timing of offspring desertion.

    PubMed

    Seno, Hiromi; Endo, Hiromi

    2007-06-07

    We consider the offspring desertion as the optimal strategy for the deserter parent, analyzing a mathematical model for its expected reproductive success. It is shown that the optimality of the offspring desertion significantly depends on the offsprings' birth timing in the mating season, and on the other ecological parameters characterizing the innate nature of considered animals. Especially, the desertion is less likely to occur for the offsprings born in the later period of mating season. It is also implied that the offspring desertion after a partially biparental care would be observable only with a specific condition.

  11. IMP-GMP 5'-nucleotidase in reptiles: occurrence in a turtle, a tortoise and three species of snakes.

    PubMed

    Itoh, Roichi; Kimura, Kayoko

    2003-08-01

    IMP-hydrolyzing activity, which is reactive with goose anti-pig lung IMP-GMP 5'-nucleotidase (c-N-II: EC.3.1.3.5) serum, was detected in extracts from liver, heart, kidney, spleen, stomach, skeletal muscle and lung from several species of reptiles: The values found in liver (U/mg protein) of one animal were: 4.5 for an ammono-ureotelic turtle (Trionyx sinensis japonicus); 3.7 for an ureo-uricotelic tortoise (Testudo elegans); 13-23 for three species of uricotelic snakes: Elaphe quadrivirgata, Elaphe conspicillata and Elaphe climacophora. These findings suggest that in the liver of snakes, c-N-II may participate in the production of uric acid as an end product of amino acid metabolism.

  12. Desert Culture Area. Native American Curriculum Series.

    ERIC Educational Resources Information Center

    Ross, Cathy; Fernandes, Roger

    One in a series of Native American instructional materials, this booklet introduces elementary students to the history and culture of the Navajo, Pueblo, and other Indian tribes of the southwest desert. Written in simple language, the booklet provides background information, activities, legends, and illustrations. Topics include the climate of the…

  13. Microflora in soils of desert regions

    NASA Technical Reports Server (NTRS)

    Cameron, R. E.

    1970-01-01

    Desert soil samples, collected using aseptic techniques, are low in organic matter and cation exchange capacity. Aerobic and microaerophilic bacteria are most abundant, next are algae and molds. Chemical and physical properties are determined by standard procedures, including the Kjeldahl method and the use of Munsell soil color charts.

  14. Reclaiming freshwater sustainability in the Cadillac Desert

    USGS Publications Warehouse

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H.W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

  15. Modelling emergent patterns of dynamic desert ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In many desert ecosystems vegetation is both patchy and dynamic: vegetated areas are interspersed with patches of bare ground, and both the positioning and the species composition of the vegetated areas exhibit change through time. These characteristics lead to the emergence of multi-scale patterns ...

  16. Metagenomes from the Saline Desert of Kutch

    PubMed Central

    Pandit, A. S.; Joshi, M. N.; Bhargava, P.; Ayachit, G. N.; Shaikh, I. M.; Saiyed, Z. M.; Saxena, A. K.

    2014-01-01

    We provide the first report on the metagenomic approach for unveiling the microbial diversity in the saline desert of Kutch. High-throughput metagenomic sequencing of environmental DNA isolated from soil collected from seven locations in Kutch was performed on an Ion Torrent platform. PMID:24831151

  17. Antioxidant Activity of Sonoran Desert Bee Pollen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bee products have been consumed by mankind since antiquity and their health benefits are becoming more apparent. Bee pollen (pollen collected by honey bees) was collected in the high intensity ultraviolet (UV) Sonoran desert and was analyzed by the anti-2,2-diphenyl-1-picryhydrazyl (DPPH) assay and...

  18. Desert Research and Technology Studies 2008 Report

    NASA Technical Reports Server (NTRS)

    Romig, Barbara; Kosmo, Joseph; Gernhardt, Michael; Abercromby, Andrew

    2009-01-01

    During the last two weeks of October 2008, the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Advanced Extravehicular Activity (AEVA) team led the field test portion of the 2008 Desert Research and Technology Studies (D-RATS) near Flagstaff, AZ. The Desert RATS field test activity is the year-long culmination of various individual science and advanced engineering discipline areas technology and operations development efforts into a coordinated field test demonstration under representative (analog) planetary surface terrain conditions. The 2008 Desert RATS was the eleventh RATS field test and was the most focused and successful test to date with participants from six NASA field centers, three research organizations, one university, and one other government agency. The main test objective was to collect Unpressurized Rover (UPR) and Lunar Electric Rover (LER) engineering performance and human factors metrics while under extended periods of representative mission-based scenario test operations involving long drive distances, night-time driving, Extravehicular Activity (EVA) operations, and overnight campover periods. The test was extremely successful with all teams meeting the primary test objective. This paper summarizes Desert RATS 2008 test hardware, detailed test objectives, test operations, and test results.

  19. Reclaiming freshwater sustainability in the Cadillac Desert

    PubMed Central

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H. W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%. PMID:21149727

  20. Extrafloral nectar fuels ant life in deserts

    PubMed Central

    Aranda-Rickert, Adriana; Diez, Patricia; Marazzi, Brigitte

    2014-01-01

    Interactions mediated by extrafloral nectary (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal desert of northwestern Argentina, we surveyed the richness and phenology of EFN plants and their associated ants and examined the patterns in ant–plant interaction networks. We found that 25 ant species and 11 EFN-bearing plant species were linked together through 96 pairs of associations. Plants bearing EFNs were abundant, representing ca. 19 % of the species encountered in transects and 24 % of the plant cover. Most ant species sampled (ca. 77 %) fed on EF nectar. Interactions showed a marked seasonal pattern: EFN secretion was directly related to plant phenology and correlated with the time of highest ant ground activity. Our results reveal that EFN-mediated interactions are ecologically relevant components of deserts, and that EFN-bearing plants are crucial for the survival of desert ant communities. PMID:25381258

  1. An Ecosystem Services Framework for Desert Landscapes

    EPA Science Inventory

    Governments, tribal leaders and citizens of the deserts in North America are facing unprecedented pressures from population growth and climate change. The dominant environmental and economic issue is to ensure that people have access to clean water and sanitation while vital ecos...

  2. Endolithic microbial life in hot and cold deserts

    NASA Technical Reports Server (NTRS)

    Friedmann, E. I.

    1980-01-01

    Endolithic microorganisms (those living inside rocks) occur in hot and cold deserts and exist under extreme environmental conditions. These conditions are discussed on a comparative basis. Quantitative estimates of biomass are comparable in hot and cold deserts. Despite the obvious differences between the hot and cold desert environment, survival strategies show some common features. These endolithic organisms are able to 'switch' rapidly their metabolic activities on and off in response to changes in the environment. Conditions in hot deserts impose a more severe environmental stress on the organisms than in the cold Antarctic desert. This is reflected in the composition of the microbial flora which in hot desert rocks consist entirely of prokaryotic microorganisms, while under cold desert conditions eukaryotes predominate.

  3. Wood decay in desert riverine environments

    USGS Publications Warehouse

    Andersen, Douglas; Stricker, Craig A.; Nelson, S. Mark

    2016-01-01

    Floodplain forests and the woody debris they produce are major components of riverine ecosystems in many arid and semiarid regions (drylands). We monitored breakdown and nitrogen dynamics in wood and bark from a native riparian tree, Fremont cottonwood (Populus deltoides subsp. wislizeni), along four North American desert streams. We placed locally-obtained, fresh, coarse material [disks or cylinders (∼500–2000 cm3)] along two cold-desert and two warm-desert rivers in the Colorado River Basin. Material was placed in both floodplain and aquatic environments, and left in situ for up to 12 years. We tested the hypothesis that breakdown would be fastest in relatively warm and moist aerobic environments by comparing the time required for 50% loss of initial ash-free dry matter (T50) calculated using exponential decay models incorporating a lag term. In cold-desert sites (Green and Yampa rivers, Colorado), disks of wood with bark attached exposed for up to 12 years in locations rarely inundated lost mass at a slower rate (T50 = 34 yr) than in locations inundated during most spring floods (T50 = 12 yr). At the latter locations, bark alone loss mass at a rate initially similar to whole disks (T50 = 13 yr), but which subsequently slowed. In warm-desert sites monitored for 3 years, cylinders of wood with bark removed lost mass very slowly (T50 = 60 yr) at a location never inundated (Bill Williams River, Arizona), whereas decay rate varied among aquatic locations (T50 = 20 yr in Bill Williams River; T50 = 3 yr in Las Vegas Wash, an effluent-dominated stream warmed by treated wastewater inflows). Invertebrates had a minor role in wood breakdown except at in-stream locations in Las Vegas Wash. The presence and form of change in nitrogen content during exposure varied among riverine environments. Our results suggest woody debris breakdown in desert riverine ecosystems is primarily a microbial process with rates determined by landscape position

  4. Naturally rare versus newly rare: demographic inferences on two timescales inform conservation of Galápagos giant tortoises.

    PubMed

    Garrick, Ryan C; Kajdacsi, Brittney; Russello, Michael A; Benavides, Edgar; Hyseni, Chaz; Gibbs, James P; Tapia, Washington; Caccone, Adalgisa

    2015-02-01

    Long-term population history can influence the genetic effects of recent bottlenecks. Therefore, for threatened or endangered species, an understanding of the past is relevant when formulating conservation strategies. Levels of variation at neutral markers have been useful for estimating local effective population sizes (N e ) and inferring whether population sizes increased or decreased over time. Furthermore, analyses of genotypic, allelic frequency, and phylogenetic information can potentially be used to separate historical from recent demographic changes. For 15 populations of Galápagos giant tortoises (Chelonoidis sp.), we used 12 microsatellite loci and DNA sequences from the mitochondrial control region and a nuclear intron, to reconstruct demographic history on shallow (past ∽100 generations, ∽2500 years) and deep (pre-Holocene, >10 thousand years ago) timescales. At the deep timescale, three populations showed strong signals of growth, but with different magnitudes and timing, indicating different underlying causes. Furthermore, estimated historical N e of populations across the archipelago showed no correlation with island age or size, underscoring the complexity of predicting demographic history a priori. At the shallow timescale, all populations carried some signature of a genetic bottleneck, and for 12 populations, point estimates of contemporary N e were very small (i.e., < 50). On the basis of the comparison of these genetic estimates with published census size data, N e generally represented ∽0.16 of the census size. However, the variance in this ratio across populations was considerable. Overall, our data suggest that idiosyncratic and geographically localized forces shaped the demographic history of tortoise populations. Furthermore, from a conservation perspective, the separation of demographic events occurring on shallow versus deep timescales permits the identification of naturally rare versus newly rare populations; this distinction

  5. Naturally rare versus newly rare: demographic inferences on two timescales inform conservation of Galápagos giant tortoises

    PubMed Central

    Garrick, Ryan C; Kajdacsi, Brittney; Russello, Michael A; Benavides, Edgar; Hyseni, Chaz; Gibbs, James P; Tapia, Washington; Caccone, Adalgisa

    2015-01-01

    Long-term population history can influence the genetic effects of recent bottlenecks. Therefore, for threatened or endangered species, an understanding of the past is relevant when formulating conservation strategies. Levels of variation at neutral markers have been useful for estimating local effective population sizes (Ne) and inferring whether population sizes increased or decreased over time. Furthermore, analyses of genotypic, allelic frequency, and phylogenetic information can potentially be used to separate historical from recent demographic changes. For 15 populations of Galápagos giant tortoises (Chelonoidis sp.), we used 12 microsatellite loci and DNA sequences from the mitochondrial control region and a nuclear intron, to reconstruct demographic history on shallow (past ∽100 generations, ∽2500 years) and deep (pre-Holocene, >10 thousand years ago) timescales. At the deep timescale, three populations showed strong signals of growth, but with different magnitudes and timing, indicating different underlying causes. Furthermore, estimated historical Ne of populations across the archipelago showed no correlation with island age or size, underscoring the complexity of predicting demographic history a priori. At the shallow timescale, all populations carried some signature of a genetic bottleneck, and for 12 populations, point estimates of contemporary Ne were very small (i.e., < 50). On the basis of the comparison of these genetic estimates with published census size data, Ne generally represented ∽0.16 of the census size. However, the variance in this ratio across populations was considerable. Overall, our data suggest that idiosyncratic and geographically localized forces shaped the demographic history of tortoise populations. Furthermore, from a conservation perspective, the separation of demographic events occurring on shallow versus deep timescales permits the identification of naturally rare versus newly rare populations; this distinction should

  6. High dietary intake of prebiotic inulin-type fructans in the prehistoric Chihuahuan Desert.

    PubMed

    Leach, Jeff D; Sobolik, Kristin D

    2010-06-01

    Archaeological evidence from dry cave deposits in the northern Chihuahuan Desert reveal intensive utilisation of desert plants that store prebiotic inulin-type fructans as the primary carbohydrate. In this semi-arid region limited rainfall and poor soil conditions prevented the adoption of agriculture and thus provides a unique glimpse into a pure hunter-forager economy spanning over 10 000 years. Ancient cooking features, stable carbon isotope analysis of human skeletons, and well-preserved coprolites and macrobotanical remains reveal a plant-based diet that included a dietary intake of about 135 g prebiotic inulin-type fructans per d by the average adult male hunter-forager. These data reveal that man is well adapted to daily intakes of prebiotics well above those currently consumed in the modern diet.

  7. Steroid levels and reproductive cycle of the Galápagos tortoise, Geochelone nigra, living under seminatural conditions on Santa Cruz Island (Galápagos).

    PubMed

    Schramm, B G; Casares, M; Lance, V A

    1999-04-01

    The Galápagos Islands are home to 11 subspecies of large terrestrial tortoises (Geochelone nigra). All Galápagos tortoises are considered endangered and approximately 12,000 animals still exist. Until now, the reproductive cycle of the Galápagos tortoise has been studied only in captive animals, and no data from free-ranging tortoises have been available. During a one-year period, blood samples were collected from male and female G. nigra living under seminatural conditions on Santa Cruz Island, Galápagos. Plasma steroid hormones were measured by radioimmunoassays (RIAs). In males, plasma testosterone and corticosterone increased a few months before the onset of the mating season. Peak levels were observed while most copulations occurred and environmental temperatures were highest. Both testosterone and corticosterone showed low levels during the cold and dry nesting season and high levels during the hot and rainy mating season. In females, testosterone and corticosterone also rose during the hot and rainy mating season. Both hormones peaked during the second half of the mating season and decreased during the cooler dry season. Female estradiol levels increased at the onset of the mating season, reaching the highest level at the peak of the mating season, which coincided with the highest annual temperatures measured. Estradiol slowly decreased within the next months and rapidly dropped at the onset of the nesting season when temperatures decreased. Progesterone levels were high close to the time of ovulation and showed clearly elevated levels at the beginning of the nesting season after some females had laid their first clutch. Progesterone decreased during the nesting season, when ambient temperatures began to decrease, and reached minimal levels in the postbreeding period shortly before the onset of the next mating season. There were significant annual variations in plasma testosterone in both males and females. Plasma corticosterone was generally higher in

  8. The Rearing and Biology of the Desert Beetle, Microdera punctipennis, Under Laboratory Conditions

    PubMed Central

    Wang, Yan; Liu, Xiaoning; Zhao, Jia; Rexili, Kelaimu; Ma, Ji

    2011-01-01

    Microdera punctipennis Kasz (Coleoptera: Tenebrionidae) is a unique species that lives in the desert region of Central Asia and has adopted a nocturnal habit to survive the desert environment. Female adults are larger in size than male adults. The female/male ratio was 1.04:1. A rearing method using reused plastic bottles was used. The rearing conditions were 30 ± 0.5°C, 30 ± 6% relative humidity (RH), and 16:8 L:D photoperiod. Cabbage was provided as food. Cannibalism was avoided by rearing one larva in a bottle. A complete life cycle was obtained under these conditions. The viability of eggs, larvae, prepupae, pupae, and teneral adults was 93.54%, 83.71%, 84.76%, 87.64%, and 93.59%, respectively. Embryogenesis took 7.35 days on average. The larval duration in each instar was 2.25 days. The mean duration of the larvae, prepupae, pupae, and teneral adult was 49.27, 7.05, 9.95, and 10.12 days, respectively. The coloration of each developmental stage gradually changed from creamy white to light brownish or black. Females commenced oviposition when their body color became black. On average, each female produced 568 eggs. PMID:21529250

  9. Seedling establishment in a masting desert shrub parallels the pattern for forest trees

    NASA Astrophysics Data System (ADS)

    Meyer, Susan E.; Pendleton, Burton K.

    2015-05-01

    The masting phenomenon along with its accompanying suite of seedling adaptive traits has been well studied in forest trees but has rarely been examined in desert shrubs. Blackbrush (Coleogyne ramosissima) is a regionally dominant North American desert shrub whose seeds are produced in mast events and scatter-hoarded by rodents. We followed the fate of seedlings in intact stands vs. small-scale disturbances at four contrasting sites for nine growing seasons following emergence after a mast year. The primary cause of first-year mortality was post-emergence cache excavation and seedling predation, with contrasting impacts at sites with different heteromyid rodent seed predators. Long-term establishment patterns were strongly affected by rodent activity in the weeks following emergence. Survivorship curves generally showed decreased mortality risk with age but differed among sites even after the first year. There were no detectable effects of inter-annual precipitation variability or site climatic differences on survival. Intraspecific competition from conspecific adults had strong impacts on survival and growth, both of which were higher on small-scale disturbances, but similar in openings and under shrub crowns in intact stands. This suggests that adult plants preempted soil resources in the interspaces. Aside from effects on seedling predation, there was little evidence for facilitation or interference beneath adult plant crowns. Plants in intact stands were still small and clearly juvenile after nine years, showing that blackbrush forms cohorts of suppressed plants similar to the seedling banks of closed forests. Seedling banks function in the absence of a persistent seed bank in replacement after adult plant death (gap formation), which is temporally uncoupled from masting and associated recruitment events. This study demonstrates that the seedling establishment syndrome associated with masting has evolved in desert shrublands as well as in forests.

  10. Blood delta-ALAD, lead and cadmium concentrations in spur-thighed tortoises (Testudo graeca) from Southeastern Spain and Northern Africa.

    PubMed

    Martínez-López, E; Sousa, A R; María-Mojica, P; Gómez-Ramírez, P; Guilhermino, L; García-Fernández, A J

    2010-04-01

    Mediterranean spur-thighed tortoise (Testudo graeca) is actually included in the IUCN as vulnerable species. Its main European population is located in southeastern Spain. Although a great deal of information has been acquired on the internal medicine and survey and even parasitological fauna on these animals, there are no references about contaminants levels in this species. The objectives of this study were to compare the levels of two metals (cadmium and lead) in the blood of spur-thighed tortoises from two different populations, one from Southeastern of Spain (n = 22) and the other from North of Africa (n = 39), kept in captivity at the Santa Faz Recuperation Centre (Alicante, Spain) and to investigate the relationship between their blood levels of lead and their blood delta-aminolevulinic acid dehydratase (delta-ALAD) activity. Blood lead and cadmium concentrations were higher in tortoises from African than in those from Spain. Moreover, a negative and significant correlation (P < 0.05) was found between delta-ALAD activity and blood lead levels, indicating the suitability of this enzyme as biomarker for lead in this species.

  11. Geometeorological data collected by the USGS Desert Winds Project at Desert Wells, Sonoran Desert, central-west Arizona, 1981 - 1996

    USGS Publications Warehouse

    Helm, Paula J.; Breed, Carol S.; Tigges, Richard; Creighton, Shawn

    1998-01-01

    The data in this report were obtained by instruments deployed on a GOES-satellite data collection station operated by the U.S. Geological Survey Desert Winds Project at Desert Wells (latitude 33° 42' 08" N, longitude 113° 48' 40" W), La Paz County, west-central Arizona. The elevation is 344 m (1,130 ft). From January 9, 1981 through May 31, 1995 the station recorded eight parameters: wind direction, wind speed, peak gust, air temperature, precipitation, humidity, barometric pressure, and soil temperature. On June 1, 1995, the station was upgraded by adding a SENSIT sand-flux sensor, which records grain impacts concurrently with wind speed and wind direction measurements. Included with the data is descriptive text on the geology, soils, climate, vegetation, and land use at the site, as well as text on data format, date retrieval software and instructions, and metadata

  12. Snow, the Great River, and the Desert

    NASA Astrophysics Data System (ADS)

    Rango, A.

    2005-12-01

    While many major rivers around the world originate from alpine snowpacks in mountain regions, some experience the extreme contrast of flowing through harsh desert environments downriver. One such stream is the Rio Grande which rises in the San Juan and the Sangre de Christo mountains of southern Colorado and northern New Mexico. Eventually, the snow fed Rio Grande flows through North America's largest desert, the Chihuahuan Desert in New Mexico, Texas, and Mexico, and simultaneously becomes part of the border between the United States and Mexico. As is often true, urban areas develop along the river corridors rather than in more inaccessible mountain regions. This demographic preference tends to isolate the vast majority of population in the Rio Grande, who are dependent on water for their livelihoods, from the mountain snowpacks where the flow is generated. Ironically then, snow is seldom viewed as the source of the much needed water flowing through the desert by the majority of the basin's population. In arid regions of the western U.S., water demand far exceeds the water supply, and water use is apportioned under the doctrine of prior appropriation with the oldest right getting the first use of water. The increasing population in urban areas does not usually have a right to use the water flowing through the desert unless water rights have been purchased by municipalities from the major category of water user in these basins, namely, irrigated agriculture. In the entire Rio Grande basin, irrigation makes up 80% of the consumptive use of water. Additionally, basin compacts and international treaties apportion water between states and countries. Because these formal agreements were based on above average runoff years, there is little flexibility in changing the use of water, particularly in dry to normal runoff years. Most of the older water rights in the Rio Grande, especially the upper basin, are supplied by snowmelt. This leaves the lower basin to depend upon

  13. Deriving Polarization Properties of Desert-Reflected Solar Spectra with PARASOL Data

    NASA Technical Reports Server (NTRS)

    Sun, Wenbo; Baize, Rosemary R.; Lukashin, Constantine

    2015-01-01

    Reflected solar radiation from desert is strongly polarized by sand particles. To date, there is no reliable desert surface reflection model to calculate desert reflection matrix. In this study, the PARASOL data are used to retrieve physical properties of desert. These physical properties are then used in the ADRTM to calculate polarization of desert-reflected light for the whole solar spectra.

  14. 76 FR 21402 - Notice of Availability of the Final Environmental Impact Statement for the Desert Sunlight...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-15

    ... Desert Sunlight Holdings, LLC, Desert Sunlight Solar Farm and Proposed California Desert Conservation... Impact Statement (EIS) for the Desert Sunlight Solar Farm (DSSF) project and by this notice is announcing.../st/en/fo/palmsprings/Solar_Projects/Desert_Sunlight.html . All protests must be in writing and...

  15. 43 CFR 2524.6 - Desert-land entryman may proceed independently of Government irrigation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Desert-land entryman may proceed... (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.6 Desert-land... that a desert-land entryman who owns a water right and reclaims the land embraced in his entry...

  16. 43 CFR 2524.6 - Desert-land entryman may proceed independently of Government irrigation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Desert-land entryman may proceed... (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.6 Desert-land... that a desert-land entryman who owns a water right and reclaims the land embraced in his entry...

  17. 43 CFR 2524.6 - Desert-land entryman may proceed independently of Government irrigation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Desert-land entryman may proceed... (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.6 Desert-land... that a desert-land entryman who owns a water right and reclaims the land embraced in his entry...

  18. 43 CFR 2524.6 - Desert-land entryman may proceed independently of Government irrigation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Desert-land entryman may proceed... (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.6 Desert-land... that a desert-land entryman who owns a water right and reclaims the land embraced in his entry...

  19. Al Eskan disease: Desert Storm pneumonitis.

    PubMed

    Korényi-Both, A L; Korényi-Both, A L; Molnár, A C; Fidelus-Gort, R

    1992-09-01

    The authors observed an acute desert-related disease when the mixture of the fine Saudi sand dust and pigeon droppings triggered a hyperergic lung condition. It was further aggravated by various kinds of organic pathogenic components contributing to an opportunistic infection of the lung. These all lead to the recognition of a new clinicopathological entity, Desert Storm pneumonitis or Al Eskan disease. For the first time, the Saudi sand dust's elemental composition was studied by ultrastructural and microanalytical means. The authors concluded that, contrary to previous beliefs, sand particles less than 1 microns (0.1 microns to 0.25 microns) in diameter are present in substantial quantities in the Saudi sand and are pathogenic, causing hyperergia. Pathogenesis of the sand dust, induced hyperergia, and its immunopathologic background are highlighted.

  20. High performance robotic traverse of desert terrain.

    SciTech Connect

    Whittaker, William

    2004-09-01

    This report presents tentative innovations to enable unmanned vehicle guidance for a class of off-road traverse at sustained speeds greater than 30 miles per hour. Analyses and field trials suggest that even greater navigation speeds might be achieved. The performance calls for innovation in mapping, perception, planning and inertial-referenced stabilization of components, hosted aboard capable locomotion. The innovations are motivated by the challenge of autonomous ground vehicle traverse of 250 miles of desert terrain in less than 10 hours, averaging 30 miles per hour. GPS coverage is assumed to be available with localized blackouts. Terrain and vegetation are assumed to be akin to that of the Mojave Desert. This terrain is interlaced with networks of unimproved roads and trails, which are a key to achieving the high performance mapping, planning and navigation that is presented here.

  1. Desert wetlands in the geologic record

    USGS Publications Warehouse

    Pigati, Jeff S.; Rech, Jason A.; Quade, Jay; Bright, Jordon; Edwards, L.; Springer, A.

    2014-01-01

    Desert wetlands support flora and fauna in a variety of hydrologic settings, including seeps, springs, marshes, wet meadows, ponds, and spring pools. Over time, eolian, alluvial, and fluvial sediments become trapped in these settings by a combination of wet ground conditions and dense plant cover. The result is a unique combination of clastic sediments, chemical precipitates, and organic matter that is preserved in the geologic record as ground-water discharge (GWD) deposits. GWD deposits contain information on the timing and magnitude of past changes in water-table levels and, therefore, are a potential source of paleohydrologic and paleoclimatic information. In addition, they can be important archeological and paleontological archives because desert wetlands provide reliable sources of fresh water, and thus act as focal points for human and faunal activities, in some of the world's harshest and driest lands. Here, we review some of the physical, sedimentological, and geochemical characteristics common to GWD deposits, and provide a contextual framework that researchers can use to identify and interpret geologic deposits associated with desert wetlands. We discuss several lines of evidence used to differentiate GWD deposits from lake deposits (they are commonly confused), and examine how various types of microbiota and depositional facies aid in reconstructing past environmental and hydrologic conditions. We also review how late Quaternary GWD deposits are dated, as well as methods used to investigate desert wetlands deeper in geologic time. We end by evaluating the strengths and limitations of hydrologic and climatic records derived from GWD deposits, and suggest several avenues of potential future research to further develop and utilize these unique and complex systems.

  2. Desert wetlands in the geologic record

    NASA Astrophysics Data System (ADS)

    Pigati, Jeffrey S.; Rech, Jason A.; Quade, Jay; Bright, Jordon

    2014-05-01

    Desert wetlands support flora and fauna in a variety of hydrologic settings, including seeps, springs, marshes, wet meadows, ponds, and spring pools. Over time, eolian, alluvial, and fluvial sediments become trapped in these settings by a combination of wet ground conditions and dense plant cover. The result is a unique combination of clastic sediments, chemical precipitates, and organic matter that is preserved in the geologic record as ground-water discharge (GWD) deposits. GWD deposits contain information on the timing and magnitude of past changes in water-table levels and, therefore, are a potential source of paleohydrologic and paleoclimatic information. In addition, they can be important archeological and paleontological archives because desert wetlands provide reliable sources of fresh water, and thus act as focal points for human and faunal activities, in some of the world's harshest and driest lands. Here, we review some of the physical, sedimentological, and geochemical characteristics common to GWD deposits, and provide a contextual framework that researchers can use to identify and interpret geologic deposits associated with desert wetlands. We discuss several lines of evidence used to differentiate GWD deposits from lake deposits (they are commonly confused), and examine how various types of microbiota and depositional facies aid in reconstructing past environmental and hydrologic conditions. We also review how late Quaternary GWD deposits are dated, as well as methods used to investigate desert wetlands deeper in geologic time. We end by evaluating the strengths and limitations of hydrologic and climatic records derived from GWD deposits, and suggest several avenues of potential future research to further develop and utilize these unique and complex systems.

  3. Operation Desert Sweep: The Restoration of Kuwait

    DTIC Science & Technology

    1992-08-01

    of ordnance and other contaminations. A CMS proprietary software system called Minefield and Ordnance Recovery System (MORS) was used to collate...Operation Desert Sweep The Restoration of Kuwait Author: Fred Dibella VP Planning and Coordination CMS , Inc. 4904 Eisenhower Boulevard Tampa...NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) CMS , Inc,4904

  4. Integrated Desert Terrain Forecasting for Military Operations

    DTIC Science & Technology

    2013-02-15

    of methods including Terrestrial In-Situ Cosmogenic Nuclides (TCN), luminescence dating , and radiocarbon dating . Furthermore, because much soil...REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 15-02-2013 13. SUPPLEMENTARY NOTES The views, opinions and/or findings contained in this report are...775-673-7302 3. DATES COVERED (From - To) 1-Jul-2003 Standard Form 298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 - 30-Jun-2012 Integrated Desert

  5. Optical and Image Transmission through Desert Atmospheres

    DTIC Science & Technology

    1994-01-25

    McDonald, Principal Investigator and Professor of Electrical Engineering Graduate Students: Carlos Becera" Jesus Carbajal Gonzalo Romero * Carmen ...C McDonald, G. Romero , C. Ortiz, J. Carbajal. "Measurement of the aerosol component of the modulation transfer function in the desert atmospheres... Romero * Completed B.S.E.E. Completed M.S.E.E. 41 BIBLIOGRAPHY 1. N. S. Kopika, "Overview of imaging through the atmo- sphere," In proceedings of SPIE

  6. Water capture by a desert beetle.

    PubMed

    Parker, A R; Lawrence, C R

    2001-11-01

    Some beetles in the Namib Desert collect drinking water from fog-laden wind on their backs. We show here that these large droplets form by virtue of the insect's bumpy surface, which consists of alternating hydrophobic, wax-coated and hydrophilic, non-waxy regions. The design of this fog-collecting structure can be reproduced cheaply on a commercial scale and may find application in water-trapping tent and building coverings, for example, or in water condensers and engines.

  7. Consumption of atmospheric methane by desert soils

    USGS Publications Warehouse

    Striegl, R.G.; McConnaughey, T.A.; Thorstenson, D.C.; Weeks, E.P.; Woodward, J.C.

    1992-01-01

    ATMOSPHERIC concentrations of methane, a greenhouse gas, are increasing at a rate of about 1% yr-1 (refs 1-4). Oxidation by methylotrophic bacteria in soil is the largest terrestrial sink for atmospheric CH4, and is estimated to consume about 30?? 1012 g CH4 yr-1 (refs 4-6). Spatial and temporal variability in the rate of soil CH4 consumption are incompletely understood6-19, as are the apparent inhibitory12,13,18 or enhancing20 effects of changes in land use. Dry deserts, which constitute 20% of total land surface, are not currently included in global soil uptake estimates. Here we describe measurements of the rate of uptake of atmospheric CH4 by undisturbed desert soils. We observed rates as great as 4.38 mg CH4 m-2 day-1; 50% of the measured rates were between 0.24 and 0.92 mg CH4 m2 d-1. Uptake of CH4 by desert soil is enhanced by rainfall after an initial soil-drainage period - opposite to the response of temperate forest soils12. Methane is consumed to a depth of about 2 m, allowing for deep removal of atmospheric CH4 if near-surface conditions are unfavourable for consumption. On the basis of an annual average CH4 consumption rate of 0.66 mg CH4 m-2 d-1, we estimate that the global CH4 sink term needs to be increased by about 7 ?? 1012 g yr-1 to account for the contribution of desert soils.

  8. Anthropocene changes in desert area: Sensitivity to climate model predictions

    NASA Astrophysics Data System (ADS)

    Mahowald, Natalie M.

    2007-09-01

    Changes in desert area due to humans have important implications from a local, regional to global level. Here I focus on the latter in order to better understand estimated changes in desert dust aerosols and the associated iron deposition into oceans. Using 17 model simulations from the World Climate Research Programme's Coupled Model Intercomparison Project phase 3 multi-model dataset and the BIOME4 equilibrium vegetation model, I estimate changes in desert dust source areas due to climate change and carbon dioxide fertilization. If I assume no carbon dioxide fertilization, the mean of the model predictions is that desert areas expand from the 1880s to the 2080s, due to increased aridity. If I allow for carbon dioxide fertilization, the desert areas become smaller. Thus better understanding carbon dioxide fertilization is important for predicting desert response to climate. There is substantial spread in the model simulation predictions for regional and global averages.

  9. The Palm Desert renewable [hydrogen] transportation system

    SciTech Connect

    Chamberlin, C.E.; Lehman, P.

    1998-08-01

    This paper describes the Schatz Energy Research Center (SERC) progress on the Palm Desert Renewable Hydrogen Transportation System Project for the period June 1997 through May 1998. The project began in March 1996. The goal of the Palm Desert Project is to develop a clean and sustainable transportation system for a community. The project demonstrates the practical utility of hydrogen as a transportation fuel and the proton exchange membrane (PEM) fuel cell as a vehicle power system. The project includes designing and building 4 fuel cell powered vehicles, a solar hydrogen generating and refueling station, and a fuel cell vehicle diagnostic center. Over this last year, SERC has built a fuel cell powered neighborhood electric vehicle and delivered it to the City of Palm Desert. The design of the hydrogen refueling station is near completion and it is anticipated that construction will be complete in the fall of 1998. The vehicles are currently being refueled at a temporary refueling station. The diagnostic center is being designed and maintenance procedures as well as computer diagnostic programs for the fuel cell vehicles are being developed. City employees are driving the vehicles daily and monitoring data are being collected. The drivers are pleased with the performance of the vehicles.

  10. Wind modeling of Chihuahuan Desert dust outbreaks

    NASA Astrophysics Data System (ADS)

    Rivera Rivera, Nancy I.; Gill, Thomas E.; Gebhart, Kristi A.; Hand, Jennifer L.; Bleiweiss, Max P.; Fitzgerald, Rosa M.

    The Chihuahuan Desert region of North America is a significant source of mineral aerosols in the Western Hemisphere, and Chihuahuan Desert dust storms frequently impact the Paso del Norte (El Paso, USA/Ciudad Juarez, Mexico) metropolitan area. A statistical analysis of HYSPLIT back trajectory residence times evaluated airflow into El Paso on all days and on days with synoptic (non-convective) dust events in 2001-2005. The incremental probability—a measure of the areas most likely to have been traversed by air masses arriving at El Paso during dusty days—was only strongly positively associated with the region west-southwest of the city, a zone of known dust source areas. Focused case studies were made of major dust events on 15 April and 15 December 2003. Trajectories approached the surface and MM5 (NCAR/Penn State Mesoscale Model) wind speeds increased at locations consistent with dust sources observed in satellite imagery on those dates. Back trajectory and model analyses suggested that surface cyclones adjacent to the Chihuahuan Desert were associated with the extreme dust events, consistent with previous studies of dust storms in the Southern High Plains to the northeast. The recognition of these meteorological patterns serves as a forecast aid for prediction of dust events likely to impact the Paso del Norte.

  11. Adsorption of dyes on Sahara desert sand.

    PubMed

    Varlikli, Canan; Bekiari, Vlasoula; Kus, Mahmut; Boduroglu, Numan; Oner, Ilker; Lianos, Panagiotis; Lyberatos, Gerasimos; Icli, Siddik

    2009-10-15

    Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SEM and FTIR techniques. It was found that water-soluble kyanite, which is detected in natural sand, is the dominant factor affecting adsorbance of cationic dyes. The sand adsorbs over 75% of cationic dyes but less than 21% for anionic ones. Among the dyes studied, Methylene Blue (MB) demonstrated the strongest affinity for Sahara desert sand (Q(e)=11.98 mg/g, for initial dye solution concentration 3.5 x 10(-5)mol/L). The effects of initial dye concentration, the amount of the adsorbent, the temperature and the pH of the solution on adsorption capacity were tested by using Methylene Blue as model dye. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of Methylene Blue on Sahara desert sand followed pseudo-second order kinetics. Gibbs free energy, enthalpy change and entropy change were calculated and found -6411 J/mol, -30360 J/mol and -76.58 J/mol K, respectively. These values indicate that the adsorption is an exothermic process and has a spontaneous nature at low temperatures.

  12. Operation Desert Shield/Storm after Action Report

    DTIC Science & Technology

    1992-05-01

    ARI Research Note 92-34 Operation Desert Shield /Storm After Action Report AD- A25 1 212 Plans, Programs, and Operations Office James A. Bynum, Chief...DATES COVERED 1992, May Final Report Aug 1990 - Mar 1991 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Operation Desert Shield /Storm After Action Report n/a 6...chronicles ARI’s response to the challenges of Operation Desert Shield /Storm, and reports on the programs brought forward to assist our own and allied

  13. An experimental analysis of granivory in desert ecosystems

    SciTech Connect

    Davidson, D.W.

    1988-01-01

    In our studies of desert granivore ecology, we have outlined the network of interaction pathways linking granivore and resource species in a Chihuahuan Desert Ecosystem. Here, a major fraction of the primary productivity takes the form of the seeds of annual plants. These seeds support two major resident taxa of desert granivores, ants and rodents. Population responses to removal of various taxa of granivores or seasonal classes of resource species are described.

  14. Aerosol direct radiative forcing in desert and semi-desert regions of northwestern China

    NASA Astrophysics Data System (ADS)

    Xin, Jinyuan; Gong, Chongshui; Wang, Shigong; Wang, Yuesi

    2016-05-01

    The optical properties of dust aerosols were measured using narrow-band data from a portable sun photometer at four desert and semi-desert stations in northwestern China from 2004 to 2007. Ground-based and satellite observations indicated absorbing dust aerosol loading over the region surrounded by eight large-scale deserts. Radiation forcing was identified by using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model. The ranges of annual mean aerosol optical depth (AOD), Angström exponents, and single-scattering albedo (SSA) were from 0.25 to 0.35, from - 0.73 to 1.18, and from 0.77 to 0.86, respectively. The ranges of annual mean aerosol direct radiative forcing values at the top of the atmosphere (TOA), mid-atmosphere, and on the surface were from 3.9 to 12.0, from 50.0 to 53.1, and from - 39.1 to - 48.1 W/m2, respectively. The aerosols' optical properties and radiative characteristics showed strong seasonal variations in both the desert and semi-desert regions. Strong winds and relatively low humidity will lead dust aerosols in the atmosphere to an increase, which played greatly affected these optical properties during spring and winter in northwestern China. Based on long-term observations and retrieved data, aerosol direct radiative forcing was confirmed to heat the atmosphere (50-53 W/m2) and cool the surface (- 39 to - 48 W/m2) above the analyzed desert. Radiative forcing in the atmosphere in spring and winter was 18 to 21 W/m2 higher than other two seasons. Based on the dust sources around the sites, the greater the AOD, the more negative the forcing. The annual averaged heating rates for aerosols close to the ground (1 km) were approximately 0.80-0.85 K/day.

  15. 77 FR 47536 - Revisions to the California State Implementation Plan, Mojave Desert, Northern Sierra, Sacramento...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-09

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Mojave Desert, Northern... to the Mojave Desert Air Quality Management District (MDAQMD), Northern Sierra ] Air Quality... Desert Air Quality Management District. (1) Rule 1116, ``Automotive Refinishing Operations,'' amended...

  16. Nationwide desert highway assessment: a case study in China.

    PubMed

    Mao, Xuesong; Wang, Fuchun; Wang, Binggang

    2011-07-01

    The natural environment affects the construction of desert highways. Conversely, highway construction affects the natural environment and puts the ecological environment at a disadvantage. To satisfy the variety and hierarchy of desert highway construction and discover the spatio-temporal distribution of the natural environment and its effect on highway construction engineering, an assessment of the natural regional divisions of desert highways in China is carried out for the first time. Based on the general principles and method for the natural region division, the principles, method and index system for desert highway assessment is put forward by combining the desert highway construction features and the azonal differentiation law. The index system combines the dominant indicator and four auxiliary indicators. The dominant indicator is defined by the desert's comprehensive state index and the auxiliary indicators include the sand dune height, the blown sand strength, the vegetation coverage ratio and the annual average temperature difference. First the region is divided according to the dominant indicator. Then the region boundaries are amended according to the four auxiliary indicators. Finally the natural region division map for desert highway assessment is presented. The Chinese desert highways can be divided into three sections: the east medium effect region, the middle medium-severe effect region, and the west slight-medium effect region. The natural region division map effectively paves the way for the route planning, design, construction, maintenance and ongoing management of desert highways, and further helps environmental protection.

  17. Origin of desert loess from some experimental observations

    NASA Technical Reports Server (NTRS)

    Whalley, W. B.; Smith, B. J.; Marshall, J. R.

    1982-01-01

    The aeolian attrition of angular quartz grains previously produced by weathering in deserts has been simulated, yielding abrasion products which show that both coarse and fine silt sizes are produced by this process. These results suggest that desert aeolian processes can produce loess, and it is speculated that while much of this material from many deserts has been deposited in the sea, the Chinese loess could have been produced in the Gobi desert. The finest of the particles produced by such attrition may serve as a source of silica for silcrete formation.

  18. Atmospheric transport of mold spores in clouds of desert dust.

    PubMed

    Shinn, Eugene A; Griffin, Dale W; Seba, Douglas B

    2003-08-01

    Fungal spores can be transported globally in clouds of desert dust. Many species of fungi (commonly known as molds) and bacteria--including some that are human pathogens--have characteristics suited to long-range atmospheric transport. Dust from the African desert can affect air quality in Africa, Europe, the Middle East, and the Americas. Asian desert dust can affect air quality in Asia, the Arctic, North America, and Europe. Atmospheric exposure to mold-carrying desert dust may affect human health directly through allergic induction of respiratory stress. In addition, mold spores within these dust clouds may seed downwind ecosystems in both outdoor and indoor environments.

  19. Atmospheric transport of mold spores in clouds of desert dust

    USGS Publications Warehouse

    Shinn, E.A.; Griffin, Dale W.; Seba, D.B.

    2003-01-01

    Fungal spores can be transported globally in clouds of desert dust. Many species of fungi (commonly known as molds) and bacteria--including some that are human pathogens--have characteristics suited to long-range atmospheric transport. Dust from the African desert can affect air quality in Africa, Europe, the Middle East, and the Americas. Asian desert dust can affect air quality in Asia, the Arctic, North America, and Europe. Atmospheric exposure to mold-carrying desert dust may affect human health directly through allergic induction of respiratory stress. In addition, mold spores within these dust clouds may seed downwind ecosystems in both outdoor and indoor environments.

  20. America's Atomic Army: The Historical Archaeology of Camp Desert Rock

    SciTech Connect

    Susan R. Edwards

    2007-11-02

    Established in 1951, Camp Desert Rock served as the training ground for America's 'Atomic Army'. For the next six years, U.S. ground troops traveled to the Nevada desert to participate in military maneuvers during atmospheric atomic weapons testing. Nearly 60,000 soldiers received physical and psychological training in atomic warfare. Abandoned when atmospheric testing ended, Camp Desert Rock was dismantled and its buildings moved to other locations. Today, the camp appears as a sterile expanse of desert marked by rock-lined tent platforms, concrete foundations, and trash scatters. Although visually unimposing, the site is rich with the history of America's nuclear testing program.

  1. The provenance of Taklamakan desert sand

    NASA Astrophysics Data System (ADS)

    Rittner, Martin; Vermeesch, Pieter; Carter, Andrew; Bird, Anna; Stevens, Thomas; Garzanti, Eduardo; Andò, Sergio; Vezzoli, Giovanni; Dutt, Ripul; Xu, Zhiwei; Lu, Huayu

    2016-03-01

    Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run

  2. The Use of Water During the Crew 144, Mars Desert Research Station, Utah Desert

    NASA Astrophysics Data System (ADS)

    De Morais Mendonca Teles, Antonio

    2016-07-01

    Well. from November 29th to December 14th, 2014, the author conducted astrobiological and geological surveys, as analog astronaut member of the international Crew 144, at the site of the Mars Society's Mars Desert Research Station, located at a remote location in the Utah desert, United States. The use of water for drinking, bathing, cleaning, etc., in the crew was a major issue for consideration for a human expedition to the planet Mars in the future. The author would like to tell about the factors of the rationalized use of water.

  3. How hazardous is the Sahara Desert crossing for migratory birds? Indications from satellite tracking of raptors.

    PubMed

    Strandberg, Roine; Klaassen, Raymond H G; Hake, Mikael; Alerstam, Thomas

    2010-06-23

    We investigated the risk associated with crossing the Sahara Desert for migrating birds by evaluating more than 90 journeys across this desert by four species of raptors (osprey Pandion haliaetus, honey buzzard Pernis apivorus, marsh harrier Circus aeruginosus and Eurasian hobby Falco subbuteo) recorded by satellite telemetry. Forty per cent of the crossings included events of aberrant behaviours, such as abrupt course changes, slow travel speeds, interruptions, aborted crossings followed by retreats from the desert and failed crossings due to death, indicating difficulties for the migrants. The mortality during the Sahara crossing was 31 per cent per crossing attempt for juveniles (first autumn migration), compared with only 2 per cent for adults (autumn and spring combined). Mortality associated with the Sahara passage made up a substantial fraction (up to about half for juveniles) of the total annual mortality, demonstrating that this passage has a profound influence on survival and fitness of migrants. Aberrant behaviours resulted in late arrival at the breeding grounds and an increased probability of breeding failure (carry-over effects). This study also demonstrates that satellite tracking can be a powerful method to reveal when and where birds are exposed to enhanced risk and mortality during their annual cycles.

  4. Ecological constraints on breeding system evolution: the influence of habitat on brood desertion in Kentish plover.

    PubMed

    Kosztolányi, András; Székely, Tamas; Cuthill, Innes C; Yilmaz, K Tuluhan; Berberoglu, Süha

    2006-01-01

    1. One of the fundamental insights of behavioural ecology is that resources influence breeding systems. For instance, when food resources are plenty, one parent is able to care for the young on its own, so that the other parent can desert and became polygamous. We investigated this hypothesis in the context of classical polyandry when females may have several mates within a single breeding season, and parental duties are carried out largely by the male. 2. We studied a precocial wader, the Kentish plover Charadrius alexandrinus, that exhibits variable brood care such that the chicks may be raised by both parents, only by the female or, more often, only by the male. The timing of female desertion varies: some females desert their brood at hatching of the eggs and lay a clutch for a new mate, whereas other females stay with their brood until the chicks fledge. Kentish plovers are excellent organisms with which to study breeding system evolution, as some of their close relatives exhibit classical polyandry (Eurasian dotterel Eudromias morinellus, mountain plover Charadrius montanus), whereas others are polygynous (northern lapwing Vanellus vanellus). 3. Kentish plovers raised their broods in two habitats in our study site in southern Turkey: saltmarsh and lakeshore. Food intake was higher on the lakeshore than in the saltmarsh as judged from feeding behaviour of chicks and adults. As the season proceeded and the saltmarsh dried out, the broods moved toward the lakeshore. 4. As the density of plovers increased on lakeshore, the parents spent more time defending their young, and female parents stayed with their brood longer on the lakeshore. 5. We conclude that the influence of food abundance on breeding systems is more complex than currently anticipated. Abundant food resources appear to have profound implications on spatial distribution of broods, and the social interactions between broods constrain female desertion and polyandry.

  5. Extensional collapse along the Sevier Desert reflection, northern Sevier Desert basin, western United States

    NASA Astrophysics Data System (ADS)

    Coogan, James C.; Decelles, Peter G.

    1996-10-01

    Newly released and previously published seismic reflection data from the northern Sevier Desert basin provide a complete seismic transect between the tilted western margin of the basin and the eastern breakaway zone. When tied to well and surface age data, the transect delineates a continuum of extensional fault and basin fill geometries that developed between late Oligocene and Pleistocene time across the basin. A minimum of 18 km of top-to-the-west normal displacement is estimated across the Sevier Desert from only the most conspicuous growth geometries and offsets across listric normal faults that sole downward into the Sevier Desert reflection (SDR). The SDR clearly marks a normal fault zone beneath the entire basin, where stratal truncations are imaged for 50% of the 39 km length of the reflection east of the Cricket Mountains block. Restoration of extensional displacement along this entire 39 km fault length is necessary to reconstruct the pre-Oligocene configuration and erosion level of Sevier thrust sheets across the Sevier Desert area. The SDR normal fault zone underlies the former topographic crest of the Sevier orogenic belt, where it accommodated extensional collapse after cessation of regional contractile tectonism.

  6. Characterization of Morphology, Volatile Profiles, and Molecular Markers in Edible Desert Truffles from the Negev Desert.

    PubMed

    Kamle, Madhu; Bar, Einat; Lewinsohn, Dalia; Shavit, Elinoar; Roth-Bejerano, Nurit; Kagan-Zur, Varda; Barak, Ze'ev; Guy, Ofer; Zaady, Eli; Lewinsohn, Efraim; Sitrit, Yaron

    2017-03-28

    Desert truffles are mycorrhizal, hypogeous fungi considered a delicacy. On the basis of morphological characters, we identified three desert truffle species that grow in the same habitat in the Negev desert. These include Picoa lefebvrei (Pat.), Tirmania nivea (Desf.) Trappe, and Terfezia boudieri (Chatain), all associated with Helianthemum sessiliflorum. Their taxonomy was confirmed by PCR-RFLP. The main volatiles of fruit bodies of T. boudieri and T. nivea were 1-octen-3-ol and hexanal; however, volatiles of the latter species further included branched-chain amino acid derivatives such as 2-methylbutanal and 3-methylbutanal, phenylalanine derivatives such as benzaldehyde and benzenacetaldehyde, and methionine derivatives such as methional and dimethyl disulfide. The least aromatic truffle, P. lefebvrei, contained low levels of 1-octen-3-ol as the main volatile. Axenic mycelia cultures of T. boudieri displayed a simpler volatile profile compared to its fruit bodies. This work highlights differences in the volatile profiles of desert truffles and could hence be of interest for selecting and cultivating genotypes with the most likable aroma.

  7. Plasma corticosterone of city and desert Curve-billed Thrashers, Toxostoma curvirostre, in response to stress-related peptide administration.

    PubMed

    Fokidis, H Bobby; Deviche, Pierre

    2011-05-01

    We compared the activity and responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis of an urban (Phoenix, Arizona) and desert population of a male songbird species (Curve-billed Thrasher, Toxostoma curvirostre), by measuring plasma corticosterone in response to acute administration of corticotropin-releasing factor, arginine vasotocin, or adrenocorticotropin hormone. Urban adult male thrashers showed greater responsiveness than desert birds to an injection of arginine vasotocin or adrenocorticotropin hormone, suggesting a population difference in pituitary and adrenal gland sensitivity. Plasma corticosterone in response to corticotropin-releasing factor injection did, however, not differ between populations. The differential corticosterone response to arginine vasotocin and corticotropin-releasing factor may reflect effects of chronic stress or habituation, which are known to favor arginine vasotocin over corticotropin-releasing factor sensitivity. Efficacy of HPA negative feedback by glucocorticoids was determined by measuring plasma corticosterone in response to acute administration of the synthetic glucocorticoid dexamethasone. This administration decreased plasma corticosterone similarly in urban and desert thrashers, suggesting that the negative feedback of glucocorticoids on the HPA axis in the two populations was equally effective. The higher sensitivity of urban than desert thrashers to adrenocorticotropin hormone and arginine vasotocin may result from up-regulation of the HPA axis in urban birds. This up-regulation may in turn make it easier for city birds to cope with urban environment-associated stressors.

  8. The tortoise or the hare? Impacts of within-host dynamics on transmission success of arthropod-borne viruses

    PubMed Central

    Althouse, Benjamin M.; Hanley, Kathryn A.

    2015-01-01

    Arthropod-borne viruses (arboviruses) are maintained in a cycle of alternating transmission between vertebrate hosts and arthropod vectors. Arboviruses possess RNA genomes capable of rapid diversification and adaptation, and the between-host trade-offs inherent to host alternation impose well-documented constraints on arbovirus evolution. Here, we investigate the less well-studied within-host trade-offs that shape arbovirus replication dynamics and transmission. Arboviruses generally establish lifelong infection in vectors but transient infection of variable magnitude (i.e. peak virus concentration) and duration in vertebrate hosts. In the majority of experimental infections of vertebrate hosts, both the magnitude and duration of arbovirus replication depended upon the dose of virus administered, with increasing dose resulting in greater magnitude but shorter duration of viraemia. This pattern suggests that the vertebrate immune response imposes a trade-off between the height and breadth of the virus replication curve. To investigate the impact of this trade-off on transmission, we used a simple modelling approach to contrast the effect of ‘tortoise’ (low magnitude, long duration viraemia) and ‘hare’ (high magnitude, short duration viraemia) arbovirus replication strategies on transmission. This model revealed that, counter to previous theory, arboviruses that adopt a tortoise strategy have higher rates of persistence in both host and vector populations. PMID:26150665

  9. Extreme difference in rate of mitochondrial and nuclear DNA evolution in a large ectotherm, Galápagos tortoises.

    PubMed

    Caccone, Adalgisa; Gentile, Gabriele; Burns, Catherine E; Sezzi, Erminia; Bergman, Windsong; Ruelle, Morgan; Saltonstall, Kristin; Powell, Jeffrey R

    2004-05-01

    We sequenced approximately 4.5 kb of mtDNA from 161 individuals representing 11 named taxa of giant Galápagos tortoises (Geochelone nigra) and about 4 kb of non-coding nuclear DNA from fewer individuals of these same 11 taxa. In comparing mtDNA and nucDNA divergences, only silent substitutions (introns, ITS, mtDNA control region, and synonymous substitutions in coding sequences) were considered. mtDNA divergence was about 30 times greater than that for nucDNA. This rate discrepancy for mtDNA and nucDNA is the greatest yet documented and is particularly surprising for large ectothermic animals that are thought to have relatively low rates of mtDNA evolution. This observation may be due to the somewhat unusual reproductive biology and biogeographic history of these organisms. The implication is that the ratio of effective population size of nucDNA/mtDNA is much greater than the usually assumed four. The nearly neutral theory of molecular evolution predicts this would lead to a greater difference between rates of evolution.

  10. Species Boundaries and Host Range of Tortoise Mites (Uropodoidea) Phoretic on Bark Beetles (Scolytinae), Using Morphometric and Molecular Markers

    PubMed Central

    Knee, Wayne; Beaulieu, Frédéric; Skevington, Jeffrey H.; Kelso, Scott; Cognato, Anthony I.; Forbes, Mark R.

    2012-01-01

    Understanding the ecology and evolutionary history of symbionts and their hosts requires accurate taxonomic knowledge, including clear species boundaries and phylogenies. Tortoise mites (Mesostigmata: Uropodoidea) are among the most diverse arthropod associates of bark beetles (Curculionidae: Scolytinae), but their taxonomy and host associations are largely unstudied. We tested the hypotheses that (1) morphologically defined species are supported by molecular data, and that (2) bark beetle uropodoids with a broad host range comprise cryptic species. To do so, we assessed the species boundaries of uropodoid mites collected from 51 host species, across 11 countries and 103 sites, using morphometric data as well as partial cytochrome oxidase I (COI) and nuclear large subunit ribosomal DNA (28S). Overall, morphologically defined species were confirmed by molecular datasets, with a few exceptions. Twenty-nine of the 36 uropodoid species (Trichouropoda, Nenteria and Uroobovella) collected in this study had narrow host ranges, while seven species had putative broad host ranges. In all but one species, U. orri, our data supported the existence of these host generalists, which contrasts with the typical finding that widespread generalists are actually complexes of cryptic specialists. PMID:23071768

  11. Oropharyngeal morphology in the basal tortoise Manouria emys emys with comments on form and function of the testudinid tongue.

    PubMed

    Heiss, Egon; Natchev, Nikolay; Schwaha, Thomas; Salaberger, Dietmar; Lemell, Patrick; Beisser, Christian; Weisgram, Josef

    2011-10-01

    In tetrapods, the ability to ingest food on land is based on certain morphological features of the oropharynx in general and the feeding apparatus in particular. Recent paleoecological studies imply that terrestrial feeding has evolved secondarily in turtles, so they had to meet the morphological oropharyngeal requirements independently to other amniotes. This study is designed to improve our limited knowledge about the oropharyngeal morphology of tortoises by analyzing in detail the oropharynx in Manouria emys emys. Special emphasis is placed on the form and function of the tongue. Even if Manouria is considered a basal member of the only terrestrial turtle clade and was hypothesized to have retained some features reflecting an aquatic ancestry, Manouria shows oropharyngeal characteristics found in more derived testudinids. Accordingly, the oropharyngeal cavity in Manouria is richly structured and the glands are large and complexly organized. The tongue is large and fleshy and bears numerous slender papillae lacking lingual muscles. The hyolingual skeleton is mainly cartilaginous, and the enlarged anterior elements support the tongue and provide insertion sides for the well-developed lingual muscles, which show striking differences to other reptiles. We conclude that the oropharyngeal design in Manouria differs clearly from semiaquatic and aquatic turtles, as well as from other reptilian sauropsids.

  12. Physiological conjunction of allelochemicals and desert plants.

    PubMed

    Yosef Friedjung, Avital; Choudhary, Sikander Pal; Dudai, Nativ; Rachmilevitch, Shimon

    2013-01-01

    Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from two different sources (cultivar cuttings and wild seeds) were studied in their natural habitats. Growth rate, relative water content, osmotic potential, photochemical efficiency, volatile composition and vital factors of allelopathy were analyzed at regular intervals along four seasons with winter showing optimum soil water content and summer showing water deficit conditions. A comprehensive analysis of the volatile composition of the leaves, ambient air and soil in the biological niche of the plants under study was carried out to determine the effects of soil water conditions and sample plants on the surrounding flora. Significant morpho-physiological changes were observed across the seasons and along different soil water content. Metabolic analysis showed that water deficit was the key for driving selective metabolomic shifts. A. judaica showed the least metabolic shifts, while A. sieberi showed the highest shifts. All the species exhibited high allelopathic effects; A. judaica displayed relatively higher growth-inhibition effects, while O. dayi showed comparatively higher germination-inhibition effects in germination assays. The current study may help in understanding plant behavior, mechanisms underlying secondary-metabolite production in water deficit conditions and metabolite-physiological interrelationship with allelopathy in desert plants, and can help cull economic benefits from the produced volatiles.

  13. The Palm Desert Renewable Hydrogen Transportation System

    SciTech Connect

    Lehman, P.

    1996-10-01

    The present paper describes, for purposes of the Department of Energy (DoE) Hydrogen Program Review, Schatz Energy Research Center (SERC) progress on the Palm Desert Renewable Hydrogen Transportation System Project for the period January through June 1996. This period represents the first six months of the three year project. The estimated cost over three years is $3.9M, $1.859M of which is funded by the DoE ($600 k for fiscal year 1996). The goal of the Palm Desert Project is to develop a clean and sustainable transportation system for a community. The project will demonstrate the practical utility of hydrogen as a transportation fuel and proton exchange membrane (PEM) fuel cells as vehicle power plants. This transportation system will be developed in the City of Palm Desert in southern California and will include a fleet of 8 fuel cell powered vehicles, solar and wind powered hydrogen generating facilities, a consumer-ready refueling station, and a service infrastructure. The system holds the promise of a clean environment and an energy supply that is predictable, domestic, safe, and abundant. During, the first part of 1996 SERC has nearly completed building a fuel cell powered personal utility vehicle, which features an upgraded safety and computer system; they have designed and built a test bench that is able to mimic golf cart loads and test fuel cell system auxiliary components; they have begun the design of the solar hydrogen generating station; they have worked with Sandia National Laboratory on an advanced metal hydride storage system; they have increased the power density of the SERC fuel cell by as much as 50%; and they have reached out to the rest of the world with a new fact sheet, world wide web pages, a press release, video footage for a television program. and instruction within the community.

  14. 7 CFR 925.304 - California Desert Grape Regulation 6.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false California Desert Grape Regulation 6. 925.304 Section 925.304 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... GROWN IN A DESIGNATED AREA OF SOUTHEASTERN CALIFORNIA Assessment Rates § 925.304 California Desert...

  15. 7 CFR 925.304 - California Desert Grape Regulation 6.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false California Desert Grape Regulation 6. 925.304 Section 925.304 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... GROWN IN A DESIGNATED AREA OF SOUTHEASTERN CALIFORNIA Assessment Rates § 925.304 California Desert...

  16. Food Deserts and Overweight Schoolchildren: Evidence from Pennsylvania

    ERIC Educational Resources Information Center

    Schafft, Kai A.; Jensen, Eric B.; Hinrichs, C. Clare

    2009-01-01

    The concept of the "food desert", an area with limited access to retail food stores, has increasingly been used within social scientific and public health research to explore the dimensions of spatial inequality and community well-being. While research has demonstrated that food deserts are frequently characterized by higher levels of…

  17. 7 CFR 925.304 - California Desert Grape Regulation 6.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false California Desert Grape Regulation 6. 925.304 Section 925.304 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... GROWN IN A DESIGNATED AREA OF SOUTHEASTERN CALIFORNIA Assessment Rates § 925.304 California Desert...

  18. 7 CFR 925.304 - California Desert Grape Regulation 6.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false California Desert Grape Regulation 6. 925.304 Section 925.304 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... GROWN IN A DESIGNATED AREA OF SOUTHEASTERN CALIFORNIA Assessment Rates § 925.304 California Desert...

  19. 7 CFR 925.304 - California Desert Grape Regulation 6.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false California Desert Grape Regulation 6. 925.304 Section 925.304 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... GROWN IN A DESIGNATED AREA OF SOUTHEASTERN CALIFORNIA Assessment Rates § 925.304 California Desert...

  20. Mauna Iki and the Kaju Desert: Kilauea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.

    1974-01-01

    The Ka'u Desert lies southwest of Kilauea Volcano. The region contains some of the most interesting and best preserved volcanic features found in the islands. The structural setting and synopsis of recent volcanic activity on the Ka'u Desert are discussed here, and a field guide to Mauna Iki is provided.