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Sample records for gaviota cangrejera larus

  1. Monitoring organic contaminants in eggs of glaucous and glaucous-winged gulls (Larus hyperboreus and Larus glaucescens) from Alaska.

    PubMed

    Vander Pol, Stacy S; Becker, Paul R; Ellisor, Michael B; Moors, Amanda J; Pugh, Rebecca S; Roseneau, David G

    2009-03-01

    Gull eggs have been used to monitor contaminants in many parts of the world. The Seabird Tissue Archival and Monitoring Project (STAMP) is a long-term program designed to track trends in pollutants in northern marine environments using seabird eggs. Glaucous and glaucous-winged gull (Larus hyperboreus and Larus glaucescens) eggs collected in 2005 from seven Alaskan colonies were analyzed for organic contaminants. Concentrations ranged from below detection limits to 322 ng g(-1) wet mass in one egg for 4,4'-DDE and differed among the samples collected in the Gulf of Alaska and Bering and Chukchi Seas. Chick growth and survival rates may be affected by the contaminant levels found in the eggs, but the eggs should be safe for human consumption if they are eaten in small quantities. STAMP plans to continue collecting and banking gull eggs for future real-time and retrospective analyses. PMID:19110348

  2. High-Resolution Chirp and Mini-Sparker Seismic-Reflection Data From the Southern California Continental Shelf - Gaviota to Mugu Canyon

    USGS Publications Warehouse

    Sliter, Ray W.; Triezenberg, Peter J.; Hart, Patrick E.; Draut, Amy E.; Normark, William R.; Conrad, James E.

    2008-01-01

    The U.S. Geological Survey (USGS) collected high-resolution shallow seismic-reflection data in September, 2007, and June-July, 2008, from the continental shelf offshore of southern California between Gaviota and Mugu Canyon, in support of the California's State Waters Mapping Program. Data were acquired using SIG 2mille mini-sparker and Edgetech chirp 512 instruments aboard the R/V Zephyr (Sept. 2007) and R/V Parke Snavely (June-July 2008). The survey area spanned approximately 120 km of coastline, and included shore-perpendicular transects spaced 1.0-1.5 km apart that extended offshore to at least the 3-mile limit of State waters, in water depths ranging from 10 m near shore to 300 m near the offshore extent of Mugu and Hueneme submarine canyons. Subbottom acoustic penetration spanned tens to several hundred meters, variable by location. This report includes maps of the surveyed transects, linked to Google Earth software, as well as digital data files showing images of each transect in SEG-Y, JPEG, and TIFF formats. The images of sediment deposits, tectonic structure, and natural-gas seeps collected during this study provide geologic information that is essential to coastal zone and resource management at Federal, State and local levels, as well as to future research on the sedimentary, tectonic, and climatic record of southern California.

  3. Complete mitochondrial genome of Relict Gull, Larus relictus (Charadriiformes: Laridae).

    PubMed

    Yang, Chao; Wang, Qing-Xiong; Huang, Yuan; Xiao, Hong

    2016-01-01

    The complete mitochondrial genome sequence of Larus relictus was 16,586-bp long, containing 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and a control region. Most PCGs begin with the typical ATN start codon with the exception of COI and ND5 genes, which use GTG as the initiation codon. Stop codons AGG, TAG, TAA and AGA are present in the PCGs; exceptions are COIII and ND4, which possess incomplete termination codons (T), and ND3, in which one extra C nucleotide is found. Secondary structure prediction of the 22 tRNA genes revealed the absence of the DHU arm in tRNA(Ser)((AGN)). Seven conserved sequence box elements, as well as the origin of H-strand replication (OH) and bidirectional light- and heavy-strand transcription promoters (LSP/HSP), are found in control region. PMID:24621217

  4. Introduction of the air cushion vehicle 'Larus' to the North American market

    NASA Astrophysics Data System (ADS)

    Makinen, E.; Wainwright, J.

    The 'Larus' ACV, which currently operates as a ferry in the Northern Baltic with a payload of 25 tonnes and 46 passengers, will be refurbished for operations in the Canadian Arctic. These modifications will encompass the incorporation of an Arctic-grade rubber skirt, additional fire and thermal insulation, more heating and washrooms for passenger compartments, a fire extinghuishing system, a second radar unit, and satellite navigation. A development history and performance evaluation of the Larus are given.

  5. Reduced oxygen diffusion across the shell of Gray gull (Larus modestus) eggs.

    PubMed

    Monge, C C; Ostojic, H; Aguilar, R; Cifuentes, V

    2000-01-01

    Gray gulls, Larus modestus, nest 1500 m above sea level in northern Chile's Atacama Desert, one of the driest in the world. Their eggshell gas permeability, one third of that found in other Larus species, is an adaptation that reduces water loss, but at the expense of oxygen diffusion into the air cell with resultant hypoxia and reduced metabolic rate. This contrasts with characteristics found in birds nesting at very high altitudes where oxygen diffusion across the egg shell is maximized at the expense of water conservation. The oxygen consumption (MO2) of Larus modestus is 66% that of Larus argentatus; the oxygen conductance (GO2) is equivalent to 48% of that obtained in 5 other bird species. The oxygen partial pressure (PAO2) in the air chamber of Larus modestus (84 Torr) is lower than that of 10 other bird species whose average (PAO2) is 106 Torr. The CO2 partial pressure (PACO2) in the air chamber of Larus modestus is 68 Torr, a higher value than that found in 9 other bird species whose average (PACO2) is 39 Torr. PMID:15696681

  6. Genetic affinities within the herring gull Larus argentatus assemblage revealed by AFLP genotyping.

    PubMed

    de Knijff P; Denkers, F; van Swelm, N D; Kuiper, M

    2001-01-01

    To date, the taxonomic status of circumpolar breeding populations of the Herring Gull Larus argentatus, the Lesser Black-backed Gull Larus fuscus, and the closely related Yellow-legged Gull Larus cachinnans has been based on differences or similarities in phenotype, morphology, and feeding and premating behavior. To shed some new light on the many taxonomic uncertainties surrounding these taxa, we describe the results of a large DNA study based on comparing the distribution of 209 biallelic markers among 109 gulls, representing 11 gull taxa of the Herring Gull assemblage and the Common Gull Larus canus. A detailed phylogenetic analysis failed to show clustering of individuals into groups representing either geographic origin or phenotype. Alternatively, birds were grouped into taxa defined on the basis of phenotype and geographic origin or phenotype alone. Genetic analyses revealed significantly different genetic distances between all pairs of taxa. However, based on these genetic distances, again no consistent phylogenetic tree could be constructed. Analysis of molecular variance indicated that about 77% of the total genetic variability among these gulls could be explained by within-taxon differences. Only 23% of the total genetic variability was due to genetic differences between taxa, irrespective of their species or subspecies status. Although this seems to challenge the current taxonomic treatment of the herring gull assemblage, our results are too premature and too incomplete to recommend a drastic change. PMID:11139298

  7. [Hematologic and hematochemical characteristics of the herring gull (Larus argentatus) and the buzzard (Buteo buteo)].

    PubMed

    Bini, P P; Floris, B; Nuvole, P; Pau, S; Zedda, M T

    1989-09-01

    Some hematological and hematochemical parameters in eight herring gulls (Larus argentatus) and in six buzzards (Buteo buteo) were checked. The buzzards were fed with ovine meat exclusively, while the herring gulls were fed with fish and ovine meat. Considerable differences between the two species were noted, particularly as far as the hematological and lipidic parameters are concerned. These differences are probably related to the aquatic life of the herring gull. PMID:2627341

  8. Contaminant levels in Herring (Larus argentatus) and Great Black-backed Gull (Larus marinus) eggs from colonies in the New York harbor complex between 2012 and 2013

    PubMed Central

    Elbin, Susan

    2014-01-01

    Birds living in coastal areas are exposed to severe storms and tidal flooding during the nesting season, but also to contaminants that move up the food chain from the water column and sediment to their prey items. We examine metals in Herring Gull (Larus argentatus) and Great Black-backed Gull (Larus marinus) eggs collected from the New York/New Jersey harbor estuary in 2012 and in 2013 to determine if there were significant yearly differences in metal levels. We test the null hypothesis that there were no significant yearly differences in metal levels. We investigate whether there were consistent differences in metals from 2012 to 2013 that might suggest a storm-related effect because Superstorm Sandy landed in New Jersey in October 2012 with high winds and extensive flooding, and view this research as exploratory. Except for arsenic, there were significant inter-year variations in the mean levels for all colonies combined for Herring Gull, and for lead, mercury and selenium for Great Black-backed Gulls. All metal levels in 2013 were less than in 2012, except for lead. These differences were present for individual colonies as well. Metal levels varied significantly among islands for Herring Gulls in both years (except for cadmium in 2013). No one colony had the highest levels of all metals for Herring Gulls. A long term data set on mercury levels in Herring Gulls indicated that the differences between 2012 and 2013 were greater than usual. Several different factors could account for these differences, and these are discussed. PMID:25471353

  9. Vigilance and feeding behaviour in large feeding flocks of laughing gulls, Larus atricilla, on Delaware Bay

    NASA Astrophysics Data System (ADS)

    Burger, Joanna; Gochfeld, Michael

    1991-02-01

    Laughing gulls ( Larus atricilla) forage on horseshoe crab ( Limulus polyphemus) eggs during May in Delaware Bay each year. They feed in dense flocks, and foraging rates vary with vigilance, bird density, number of steps and location in the flock, whereas time devoted to vigilance is explained by number of steps, density, location and feeding rates. The time devoted to vigilance decreases with increasing density, increasing foraging rates and decreasing aggression. Birds foraging on the edge of flocks take fewer pecks and more steps, and devote more time to vigilance than those in the intermediate or central parts of a flock.

  10. Finding of pentastomes of genus Reighardia (Pentastomida) in the Belcher's gull (Larus belcheri).

    PubMed

    Naupay, Asucena I; Cribillero, Nelly G; Lopez-Urbina, Maria T; Gonzalez, Armando E; Gomez-Puerta, Luis A

    2016-06-01

    This report describes the finding of Reighardia sp. (Pentastomida) infecting the air sac of two Belcher's gulls (Larus belcheri) found dead on the beaches of Pucusana, a district in southern Lima, Peru. Three pentastomes were collected from two Belcher's gulls. Then, they were morphologically and molecular analyzed. Molecular characterization of the parasite was achieved by amplifying a fragment of the small subunit ribosomal RNA gene (SSU rRNA). Based on both morphological and molecular data the pentastomes were identified as pentastomes of the genus Reighardia. This is the first report showing that the Belcher's gull is a new natural definitive host for this pentastome. PMID:26892103

  11. Chiral organochlorine contaminants in blood and eggs of glaucous gulls (Larus hyperboreus) from the Norwegian Arctic.

    PubMed

    Ross, Matthew S; Verreault, Jonathan; Letcher, Robert J; Gabrielsen, Geir W; Wong, Charles S

    2008-10-01

    Glaucous gulls (Larus hyperboreus) and their eggs from Svalbard (Norwegian Arctic) have been used as biomonitors of contaminants in the marine environment. In this study, the enantiomer fractions (EFs) of chiral chlordanes and atropisomeric polychlorinated biphenyl (PCB) congeners were determined in the blood plasma of adult male and female glaucous gulls from three breeding colonies in Svalbard. Plasma EFs were similar in magnitude and direction to EFs previously reported in glaucous gulls from other arctic food webs, suggesting overall similarities in the biochemical processes influencing the EFs of bioaccumulated organochlorine (OC) contaminants within the food webs at those locations. Additionally, EFs in yolk of eggs collected concurrently from within the same nesting colonies varied with location, laying date, and OC concentrations, and may be influenced by changes in the local feeding ecology between those colonies. No differences were found between the EFs for any analyte in female gulls compared to those found in egg yolk, indicating that processes involved in the maternal transfer of chlordanes and PCBs to eggs do not modulate the stereochemical ratio between enantiomers. Therefore, the use of eggs as a valuable and noninvasive means of OC biomonitoring may also extend to enantiomer compositions in glaucous gulls, and perhaps also in other seabird species from arctic regions. PMID:18939544

  12. Heavy metal concentrations in Black-tailed Gull (Larus crassirostris) chicks, Korea.

    PubMed

    Kim, Jungsoo; Oh, Jon-Min

    2014-10-01

    The objectives of this study were to quantify concentrations of heavy metals in livers and stomach contents of Black-tailed Gull (Larus crassirostris) chicks from two islands in Korea. Iron and manganese concentrations were significantly higher in chick livers at Hongdo Island compared to Rando Islnad. In contrast, zinc, copper and cadmium concentrations were significantly higher at Rando Island than Hongdo Island. On Hongdo Island, Black-tailed Gull chicks at a lighthouse site had higher lead concentrations in livers and stomach contents than at a nearby reference site and stomach contents of Black-tailed Gull chicks had significantly higher lead concentrations than regurgitated diets. In Hongdo Island, manganese, lead and cadmium concentrations were significantly correlated between livers and stomach contents. Essential elements such as iron, zinc, manganese and copper concentrations from the present study were within the range reported for other seabird species including gulls. Livers of four individual gull chicks (13.3%) were at a level considered lead exposed (6-30 μg g(-1) dry weight), but cadmium concentrations in all specimens were within the background level (<3 μg g(-1) dry weight) for wild birds. Elevated lead concentrations on lighthouse site may be attributed to ingestion of paint chips and these concentrations may negatively affect chick behavior, growth and survival. PMID:25048929

  13. An outbreak of type C botulism in Herring Gulls (Larus argentatus) in Southeastern Sweden

    USGS Publications Warehouse

    Neimanis, A.; Gavier-Widen, D.; Leighton, F.; Bollinger, T.; Rocke, T.; Morner, T.

    2007-01-01

    From 2000 to 2004, over 10,000 seabirds, primarily Herring Gulls (Larus argentatus), died from an undetermined cause in the Blekinge archipelago in southeastern Sweden. In June 2004, 24 affected Herring Gulls were examined clinically, killed humanely, and 23 were examined by necropsy. Seven and 10 unaffected Herring Gulls collected from a local landfill site and from Iceland, respectively, served as controls. All affected birds showed similar neurologic signs, ranging from mild incoordination and weakness to severe flaccid paralysis of legs and wings, but generally were alert and responsive. All affected gulls were in normal nutritional condition, but were dehydrated and had empty stomachs. No gross or microscopic lesions, and no bacterial or viral pathogens were identified. Type C botulinum toxin was detected in the sera of 11 of 16 (69%) affected gulls by mouse inoculation. Type C botulism was the proximate cause of disease in 2004. Sera from 31% of birds tested from outbreaks in 2000 to 2003 also had detectable type C botulinum toxin by mouse inoculation. No large-scale botulism outbreak has been documented previously in this area. The source of toxin, initiating conditions, and thus, the ultimate cause of this outbreak are not known. This epidemic might signal environmental change in the Baltic Sea. ?? Wildlife Disease Association 2007.

  14. Effects of organochlorine contaminants on thyroid hormone levels in Arctic breeding glaucous gulls, Larus hyperboreus.

    PubMed Central

    Verreault, Jonathan; Skaare, Janneche Utne; Jenssen, Bjørn Munro; Gabrielsen, Geir Wing

    2004-01-01

    Studies on glaucous gulls (Larus hyperboreus) breeding in the Barents Sea have reported that high blood levels of halogenated organic contaminants in this species might cause reproductive, behavioral, and developmental stress. However, potential endocrine system modulation caused by contaminant exposure has yet not been reported in this Arctic apical predator. In this present study we aimed to investigate whether the current levels of a selection of organochlorines (OCs) were associated with altered circulating levels of thyroid hormones (THs) in free-ranging adult glaucous gulls breeding at Bear Island in the Barents Sea. Blood concentrations of 14 polychlorinated biphenyls, hexachlorobenzene (HCB), oxychlordane, and p,p' -dichlorodiphenyldichloroethylene (p,p' -DDE) were quantified, in addition to free and total thyroxine (T4) and triiodothyronine (T3), in plasma of 66 glaucous gulls in the spring of 2001. Negative correlations were found between plasma levels of T4 and T4:T3 ratio, and blood levels of OCs in male glaucous gulls. Despite their relatively low contribution to the total OC fraction, HCB and oxychlordane were the most prominent compounds in terms of their negative effect on the variation of the T4:T3 ratio. Moreover, lower T4 levels and T4:T3 ratios were measured in glaucous gulls breeding in a colony exposed to high levels of OCs, compared with a less exposed colony. Levels of T3 were elevated in the high-OC-exposed colony. This may indicate that the glaucous gull is susceptible to changes to TH homeostasis mediated by exposure to halogenated organic contaminants. PMID:15064156

  15. Trace element contamination in nestling black-tailed gulls (Larus crassirostris) in Korea.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2015-05-01

    At Hongdo Island, Gyeongsangnam-do, Korea, a breeding site of black-tailed gull (Larus crassirostris), we collected nestlings from two locations: a "reference" site (n = 10) with no known source of lead contamination and "lighthouse" site (n = 10) with suspected lead contamination from leaded paint. Iron concentrations in the kidney and bone, manganese in the muscle, copper in the bone, lead in the muscle and bone, and cadmium in the liver, muscle, and bone at the reference site were significantly higher than at the lighthouse. Manganese concentrations in the liver and kidney, and lead in the kidney were significantly greater at the lighthouse than at the reference site. Iron, zinc, manganese, copper, lead and cadmium concentrations had tissue-specific accumulation at both sites. Lead concentrations in 10 % of livers and in 80 % of kidneys at the lighthouse, and in 20 % of livers from the reference were within a range considered toxic (>6.00 μg/g dw in the liver and kidney). Lead concentrations in 50 % of black-tailed gull nestlings at the reference and 80 % nestlings at the lighthouse were greater in livers than in bones, which is suggestive of acute lead exposure. For cadmium, all liver and kidney concentrations from two sites were at a level considered background in birds. Cadmium concentrations of every sample were higher in kidneys than in livers, suggestive of chronic cadmium exposure. Lead concentrations in gull nestlings in the present study were relatively higher than other gull species worldwide, but cadmium concentrations were relatively lower. PMID:25763522

  16. Hybridization among Arctic white-headed gulls (Larus spp.) obscures the genetic legacy of the Pleistocene

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; Chesser, R. Terry; Bell, Douglas A.; Dove, Carla J.

    2012-01-01

    We studied the influence of glacial oscillations on the genetic structure of seven species of white-headed gull that breed at high latitudes (Larus argentatus, L. canus, L. glaucescens, L. glaucoides, L. hyperboreus, L. schistisagus, and L. thayeri). We evaluated localities hypothesized as ice-free areas or glacial refugia in other Arctic vertebrates using molecular data from 11 microsatellite loci, mitochondrial DNA (mtDNA) control region, and six nuclear introns for 32 populations across the Holarctic. Moderate levels of genetic structure were observed for microsatellites (FST= 0.129), introns (ΦST= 0.185), and mtDNA control region (ΦST= 0.461), with among-group variation maximized when populations were grouped based on subspecific classification. Two haplotype and at least two allele groups were observed across all loci. However, no haplotype/allele group was composed solely of individuals of a single species, a pattern consistent with recent divergence. Furthermore, northernmost populations were not well differentiated and among-group variation was maximized when L. argentatus and L. hyberboreus populations were grouped by locality rather than species, indicating recent hybridization. Four populations are located in putative Pleistocene glacial refugia and had larger t estimates than the other 28 populations. However, we were unable to substantiate these putative refugia using coalescent theory, as all populations had genetic signatures of stability based on mtDNA. The extent of haplotype and allele sharing among Arctic white-headed gull species is noteworthy. Studies of other Arctic taxa have generally revealed species-specific clusters as well as genetic structure within species, usually correlated with geography. Aspects of white-headed gull behavioral biology, such as colonization ability and propensity to hybridize, as well as their recent evolutionary history, have likely played a large role in the limited genetic structure observed.

  17. Impact of egg harvesting on breeding success of black-headed gulls, Larus ridibundus

    NASA Astrophysics Data System (ADS)

    Wood, Philippa J.; Hudson, Malcolm D.; Doncaster, C. Patrick

    2009-01-01

    Gull colonies world-wide have been harvested for their eggs for centuries with minimal knowledge of the impacts on breeding. Although most Laridae can replace lost eggs, they have comparatively high energetic demands for egg production. In this paper we assess the impacts of a licensed egg harvest on the breeding success of black-headed gulls Larus ridibundus, which nest colonially in an EU Special Protection Area in Hampshire, southern England. We compared egg volume, hatching and chick survival from harvested and un-harvested nests in central and fringe positions within colonies of various sizes, including colonies with no harvesting activity. Eggs from various laying stages were collected from harvested and un-harvested colonies of similar pre-harvest intrinsic quality, for comparison of their volumes, yolk-to-albumen ratios and eggshell thickness. Egg volume and the yolk-to-albumen ratio depended on laying time and location, with the largest eggs laid during the peak period by birds breeding in central positions on large colonies. Eggs produced by these peak layers also had the largest yolk-to-albumen ratios. Harvested sites were characterised by reductions in egg volume, yolk-to-albumen ratio and eggshell thickness, which translated to poorer hatching success and chick survival. Harvested sites also had a higher proportion of abnormal eggs, particularly taking the forms of small yolkless eggs and unpigmented eggs. The reduced breeding success on harvested colonies is likely to be linked to depletion of the female's endogenous reserves which can also reduce future survival and breeding propensity.

  18. Description of Maritrema formicae sp. nov. (Digenea, Microphallidae) parasitic in the kelp gull, Larus dominicanus, from the Patagonian coast, Argentina.

    PubMed

    Diaz, Julia I; Gilardoni, Carmen; Cremonte, Florencia

    2012-06-01

    Maritrema formicae sp. nov. is described from the Patagonian coast, Argentina, based on adults obtained from the kelp gull, Larus dominicanus. The new species fits with the "eroliae complex" and can be distinguished from other related species mainly in shape and size of body, shape, size, and pattern of distribution of cirrus spines, uterus extension, number and size of eggs, vitellarium in a complete ring in all specimens, and its Neotropical distribution. The new species is sympatric with another species of the genus, Maritrema madrynense, which was recorded in the same host and locality. PMID:22807050

  19. Nesting biology of laughing gulls Larus atricilla in relation to agricultural chemicals in south Texas USA 1978-1981

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Prouty, R.M.

    1983-01-01

    Various aspects of the breeding biology of Laughing Gulls (Larus atricilla) have been studied extensively in Florida (Dinsmore and Schreiber 1974, Schreiber et al. 1979, Schreiber and Schreiber 1980), New Jersey (Bongiorno 1970, Burger and Beer 1976, Burger 1976, Montevecchi 1978), and Massachusetts (Noble and Wurm 1943), but little is known of their yearly fledging success in Texas or elsewhere. The Laughing Gull is a common colonial nester along most of the Texas coast, second only to the Cattle Egret (Bubulcus ibis) in breeding abundance; however, the Laughing Gull may be threatened in Texas because of suspected declines at certain traditional nesting locales (Blacklock et al. 1979). Since Laughing Gulls often nest in proximity to agricultural and industrial areas, we were concerned that environmental pollutants might be adversely affecting productivity. In 1978-1981 we conducted studies along the south Texas coast to learn more about the nesting ecology of Laughing Gulls and to evaluate the effects of environmental contaminants on reproduction.

  20. Organochlorine contaminants in the muscle, liver and brain of seabirds (Larus) from the coastal area of the Southern Baltic.

    PubMed

    Falkowska, Lucyna; Reindl, Andrzej R; Grajewska, Agnieszka; Lewandowska, Anita U

    2016-11-01

    The presence of persistent organic pollutants in the environment manifests itself most strongly in the marine trophic chain, where the highest link is comprised of seabirds. At the same time, seabirds are excellent indicators of contamination in their habitat. The present study concentrates on toxic substances: polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFs) and chlorinated organic pesticides (OCPs) accumulated in the livers, pectoral muscles and brains of dead gulls collected along the Polish coast of the Baltic Sea in the years 2010-12. The highest toxic equivalence was determined in the livers of Larus argentatus (TEQ(birds TEF)-28.3pgg(-1) ww) and Larus marinus (TEQ(birds TEF)-29.9pgg(-1) ww.). However, the toxic equivalence of muscles was lower and amounted to 3.9pgg(-1) ww. and 7.8pgg(-1) ww. respectively for the two species. The lowest toxic equivalence was found in the brains of birds, where only one, the most toxic, 2,3,7,8 TCDD congener was found (TEQ(birds TEF) 0.87pgg(-1) ww). The highest concentration of chloroorganic pesticides was determined in the brains of the birds (total OCP 167.8pgg(-1) ww.), lower concentrations were found in the livers (total OCP 92.1pgg(-1) ww.) and muscles (total OCP 43.1pgg(-1) ww.). With regard to pesticides, the highest proportion in the total OCP content was constituted by DDT and its isomers (liver 81%, muscles 77% and brain 55%). High concentrations of the studied pollutants in the livers of gulls found dead on the coast of the Southern Baltic could have been effected by levels of contamination in the birds' last meals, which resulted in a seven-fold increase of the liver's toxic equivalence and a two-fold increase in OCP concentration in relation to muscles. PMID:27414257

  1. Cytochrome P4501A induction and DNA adduct formation in glaucous gulls (Larus hyperboreus), fed with environmentally contaminated gull eggs.

    PubMed

    Østby, Lene; Gabrielsen, Geir Wing; Krøkje, Ase

    2005-11-01

    This study indicates that complex mixtures of pollutants found in the Arctic marine environment have genotoxic effects in glaucous gulls (Larus hyperboreus). DNA adducts were quantified, by the (32)P-postlabeling technique, in liver samples from gulls fed with hen eggs (controls) and from gulls fed with environmentally contaminated gull eggs (exposed). All birds were grown and fed under laboratory conditions. Hepatic homologues to mammalian cytochrome P4501A (CYP1A) proteins were also determined by Western blotting. DNA adducts were detected in all but one liver sample, but the exposed birds had a significantly increased level of DNA adducts relative to that of the controls. There was no clear significant correlation between the DNA adduct level and the level of organochlorine compounds (OCs) in blood. The level of CYP1A protein was significantly higher in the liver of exposed male gulls than in the liver of control males and positively correlated, with significance, to the level of OC compounds measured in blood. There was no significant correlation between the level of DNA adducts and the CYP1A protein content. PMID:16216630

  2. Effect of reduced food intake on toxicokinetics of halogenated organic contaminants in herring gull (Larus argentatus) chicks.

    PubMed

    Routti, Heli; Helgason, Lisa Bjørnsdatter; Arukwe, Augustine; Wolkers, Hans; Heimstad, Eldbjørg Sofie; Harju, Mikael; Berg, Vidar; Gabrielsen, Geir Wing

    2013-01-01

    The aim of the present study was to investigate how contaminant exposure and reduced food intake affect tissue distribution and biotransformation of halogenated organic contaminants (HOCs) in Arctic seabirds using herring gull (Larus argentatus) as a model species. Herring gull chicks were exposed for 44 d to cod liver oil containing a typical mixture of contaminants. Following exposure, food intake was reduced for a one-week period in a subgroup of the chicks. Polyclorinated biphenyls, organochlorine pesticides, and brominated flame retardants, as well as a wide range of hydroxy, methyl sulfone, and methoxy compounds were measured in liver, brain, and plasma samples. Additionally, phase I biotransformation enzyme activities and phase I and II messenger ribonucleic acid (mRNA) expression were investigated in the liver, brain, or both. Both contaminant exposure and reduced food intake had an increasing effect on the concentrations of HOCs and their metabolites. The HOC exposure and reduced food intake also led to increased 7-ethoxyresorufin-O-deethylation (EROD) activity, whereas mRNA expression of the biotransformation enzymes increased only following the reduced food intake. Tissue distribution of HOCs and their metabolites was not affected by either contaminant exposure or reduced food intake. In conclusion, the results indicate that biotransformation capacity and formation of HOC metabolites increase during reduced food intake. This finding supports the hypothesis that reduced food intake increases the susceptibility of Arctic animals to the effects of lipophilic HOCs. PMID:23060285

  3. Diets of nesting laughing gulls (Larus atricilla) at the Virginia Coast Reserve: observations from stable isotope analysis

    USGS Publications Warehouse

    Knoff, A.J.; Macko, S.A.; Erwin, R.M.

    2001-01-01

    Food web studies often ignore details of temporal, spatial, and intrapopulation dietary variation in top-level consumers. In this study, intrapopulation dietary variation of a dominant carnivore, the Laughing Gull (Larus atricilla), was examined using carbon, nitrogen, and sulfur isotope analysis of gull tissues as well as their prey (fish, invertebrates, and insects) from the Virginia Coast Reserve estuarine system. As earlier traditional diet studies found evidence of individual dietary specialization within gull populations, this study used stable isotope analysis to assess specialization in a coastal Laughing Gull population. Specifically, blood, muscle, and feather isotope values indicated significant intrapopulation dietary specialization. Some gulls relied more heavily on estuarine prey (mean blood δ13C = -17.5, δ15N = 12.6, and δ34S = 9.3), whereas others appeared to consume more foods of marine origin (mean blood δ13C = -19.4, δ15N = 14.8, and δ34S = 10.4). It is important to account for such dietary variability when assessing trophic linkages in dynamic estuarine systems.

  4. Individual and population-level sex-dependent lateralization in yellow-legged gull (Larus michahellis) chicks.

    PubMed

    Romano, Maria; Parolini, Marco; Caprioli, Manuela; Spiezio, Caterina; Rubolini, Diego; Saino, Nicola

    2015-06-01

    Behavioral lateralization at the population level is widespread across vertebrates, with considerable variation among species. However, evidence for individual-level and sex-dependent lateralization is sparse and inconsistent in fish, reptiles and birds. In addition, covariation of lateralization with position in the laying sequence, which is expected because the concentration of maternal egg hormones varies with laying order, has never been investigated. We analyzed lateralization of yellow-legged gull (Larus michahellis) chicks in reverting from supine to prone posture ('RTP' response) and in pecking at a dummy parental bill to solicit food provisioning ('begging' response). Chicks were lateralized both at the population and at the individual level in the RTP response and at the individual level in begging. Lateralization in the RTP was sex-dependent, as females showed a leftward preference. Lateralization in either motor task was not correlated within individuals. Lateralization did not differ among families, suggesting little additive genetic variation. Lateral preference in begging response varied according to laying order and matched variation in egg androgens concentration. Our study confirms previous findings on population-level lateralization and adds to the scant information on individual-level and heritable variation in lateralization in birds. Moreover, it hints at epigenetic components in lateralization depending on maternal effects. PMID:25818662

  5. Variation in Immune Parameters and Disease Prevalence among Lesser Black-Backed Gulls (Larus fuscus sp.) with Different Migratory Strategies

    PubMed Central

    Arriero, Elena; Müller, Inge; Juvaste, Risto; Martínez, Francisco Javier; Bertolero, Albert

    2015-01-01

    The ability to control infections is a key trait for migrants that must be balanced against other costly features of the migratory life. In this study we explored the links between migration and disease ecology by examining natural variation in parasite exposure and immunity in several populations of Lesser Black-backed Gulls (Larus fuscus) with different migratory strategies. We found higher activity of natural antibodies in long distance migrants from the nominate subspecies L.f.fuscus. Circulating levels of IgY showed large variation at the population level, while immune parameters associated with antimicrobial activity showed extensive variation at the individual level irrespective of population or migratory strategy. Pathogen prevalence showed large geographical variation. However, the seroprevalence of one of the gull-specific subtypes of avian influenza (H16) was associated to the migratory strategy, with lower prevalence among the long-distance migrants, suggesting that migration may play a role in disease dynamics of certain pathogens at the population level. PMID:25679797

  6. Diets of nesting laughing gulls (Larus atricilla) at the Virginia Coast Reserve: observations from stable isotope analysis.

    PubMed

    Knoff, A J; Macko, S A; Erwin, R M

    2001-01-01

    Food web studies often ignore details of temporal, spatial, and intrapopulation dietary variation in top-level consumers. In this study, intrapopulation dietary variation of a dominant carnivore, the Laughing Gull (Larus atricilla), was examined using carbon, nitrogen, and sulfur isotope analysis of gull tissues as well as their prey (fish, invertebrates, and insects) from the Virginia Coast Reserve estuarine system. As earlier traditional diet studies found evidence of individual dietary specialization within gull populations, this study used stable isotope analysis to assess specialization in a coastal Laughing Gull population. Specifically, blood, muscle, and feather isotope values indicated significant intrapopulation dietary specialization. Some gulls relied more heavily on estuarine prey (mean blood delta13C = -17.5, delta15N = 12.6, and delta34S = 9.3), whereas others appeared to consume more foods of marine origin (mean blood delta13C = -19.4, delta15N = 14.8, and delta34S = 10.4). It is important to account for such dietary variability when assessing trophic linkages in dynamic estuarine systems. PMID:11558657

  7. Structural characteristics of the Relict Gull (Larus relictus) mitochondrial DNA control region and its comparison to other Laridae.

    PubMed

    Yang, Chao; Lian, Ting; Wang, Qing-Xiong; Huang, Yuan; Xiao, Hong

    2016-07-01

    The structure of the mitochondrial DNA control region in the Relict Gull (Larus relictus) was predicted and compared with data from the National Center for Biotechnology Information (NCBI) on five other gulls. The results showed that the control regions of the six gulls comprise three domains. Sequences of CSB-1-like (domain I) and CSB-1 (domain III) in L. relictus have the highest similarity with those in the other five gulls. The insertion fragments are located in downstream domain I of L. ridibundus, L. brunnicephalus, and L. saundersi. Seven conserved sequence boxes (additional box, F-box, E-box, D-box, C-box, bird-similarity-box, and B-box) are located in domain II in all six gulls. It is suggested that the CSB-2/3 sequence, the origin of H-strand replication, and bidirectional light- and heavy-strand transcription promoters in domain III of L. relictus have some distinguishing features to those of other gulls. Some repeat units are contained in the 3' end of the control region in the five gulls; however, no repeat units are found in the sequence CAAACAACAAA in L. relictus. The distribution of nucleotide diversity analysis will provide the useful information on the selected DNA fragment within the control region for genetic analyses among gulls. PMID:26016878

  8. Maternal condition, yolk androgens and offspring performance: a supplemental feeding experiment in the lesser black-backed gull (Larus fuscus).

    PubMed Central

    Verboven, Nanette; Monaghan, Pat; Evans, Darren M; Schwabl, Hubert; Evans, Neil; Whitelaw, Christine; Nager, Ruedi G

    2003-01-01

    It has been proposed that the maternal androgens in avian egg yolk enhance offspring fitness by accelerating growth and improving competitive ability. Because egg quality is strongly influenced by maternal condition, we predicted that females in good condition would produce high-quality eggs with relatively high androgen content. We experimentally enhanced maternal condition by supplementary feeding lesser black-backed gulls (Larus fuscus) during egg formation and compared the concentrations of androstenedione (A4), 5alpha-dihydrotestosterone (DHT) and testosterone (T) in their eggs with those in eggs laid by control females. We also measured circulating levels of T in females immediately after laying. Egg androgens could affect offspring performance directly through chick development and/or indirectly through changes in the competitive ability of a chick relative to its siblings. To avoid confounding these two routes, and to separate effects operating through the egg itself with those operating through experimental changes in parental chick rearing capacity, we fostered eggs from both maternal treatment groups singly into the nests of unmanipulated parents. Contrary to expectation, mothers with experimentally enhanced body condition laid eggs with lower levels of androgens, while exhibiting higher circulating T concentrations post-laying. Despite these lower levels of egg androgen, offspring hatched from eggs laid by mothers in good condition did not show reduced growth or survival when reared in the absence of sibling competition. Our results demonstrate that yolk androgen concentrations vary with the body condition of the female at the time of egg formation and that females in good condition reduced the yolk androgen content of their eggs without altering offspring performance. PMID:14613608

  9. Gene expression, glutathione status and indicators of hepatic oxidative stress in laughing gull (Larus atricilla) hatchlings exposed to methylmercury

    USGS Publications Warehouse

    Jenko, Kathryn; Karouna-Renier, Natalie K.; Hoffman, David J.

    2012-01-01

    Despite extensive studies of methylmercury (MeHg) toxicity in birds, molecular effects on birds are poorly characterized. To improve our understanding of toxicity pathways and identify novel indicators of avian exposure to Hg, the authors investigated genomic changes, glutathione status, and oxidative status indicators in liver from laughing gull (Larus atricilla) hatchlings that were exposed in ovo to MeHg (0.05–1.6 µg/g). Genes involved in the transsulfuration pathway, iron transport and storage, thyroid-hormone related processes, and cellular respiration were identified by suppression subtractive hybridization as differentially expressed. Quantitative polymerase chain reaction (qPCR) identified statistically significant effects of Hg on cytochrome C oxidase subunits I and II, transferrin, and methionine adenosyltransferase RNA expression. Glutathione-S-transferase activity and protein-bound sulfhydryl levels decreased, whereas glucose-6-phosphate dehydrogenase activity increased dose-dependently. Total sulfhydryl concentrations were significantly lower at 0.4 µg/g Hg than in controls. T ogether, these endpoints provided some evidence of compensatory effects, but little indication of oxidative damage at the tested doses, and suggest that sequestration of Hg through various pathways may be important for minimizing toxicity in laughing gulls. This is the first study to describe the genomic response of an avian species to Hg. Laughing gulls are among the less sensitive avian species with regard to Hg toxicity, and their ability to prevent hepatic oxidative stress may be important for surviving levels of MeHg exposures at which other species succumb.

  10. Egg production in a coastal seabird, the glaucous-winged gull (Larus glaucescens), declines during the last century.

    PubMed

    Blight, Louise K

    2011-01-01

    Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens), a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y(-1) from 1902 (108 y), equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008-2010) 7 d later than in previous studies (1959-1986). This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50-100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas. PMID:21789207

  11. Egg Production in a Coastal Seabird, the Glaucous-Winged Gull (Larus glaucescens), Declines during the Last Century

    PubMed Central

    Blight, Louise K.

    2011-01-01

    Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens), a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y−1 from 1902 (108 y), equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008–2010) 7 d later than in previous studies (1959–1986). This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50–100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas. PMID

  12. New organochlorine contaminants and metabolites in plasma and eggs of glaucous gulls (Larus hyperboreus) from the Norwegian Arctic.

    PubMed

    Verreault, Jonathan; Letcher, Robert J; Muir, Derek C G; Chu, Shaogang; Gebbink, Wouter A; Gabrielsen, Geir W

    2005-10-01

    The present study investigated new or lesser-studied and legacy organochlorine (OC) contaminants and metabolites in plasma and eggs of glaucous gulls (Larus hyperboreus) collected from major breeding colonies on Bear Island in the Norwegian Arctic. Hexachlorobutadiene was below the method limit of detection (< 0.07 ng/g lipid wt) in all samples. The sum (sum) of 20 chlorobornane congener concentrations ranged between 294 and 986 ng/g lipid weight and 104 and 1,121 ng/g lipid weight in plasma and eggs, respectively, whereas those of sum 20polychlorinated naphthalene ranged between 1.34 and 126 ng/g lipid weight in plasma and 1.82 and 162 ng/g lipid weight in eggs. Bis(4-chlorophenyl) sulfone concentrations ranged between 5.24 and 143 ng/ g lipid weight plasma, which is the first report of this contaminant in arctic biota north of Sweden. Based on 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs), partial dioxin-like toxicity varied between 3.04 and 20.8 ng TEQ/g lipid weight in plasma and 0.94 and 46.5 ng TEQ/g lipid weight in eggs, and largely was due to concentrations of non-ortho polychlorinated biphenyls (PCBs), with a very minor contribution from mono-ortho PCBs and polychlorinated naphthalenes. The major aryl sulfone metabolite in plasma was an unidentified hexachlorinated MeSO2-PCB congener (range: 13.5-551 ng/g lipid wt), whereas the pentachlorinated congeners 3'- and 4'-MeSO2-CB101 (range: 4.49-38.1 ng/g lipid wt) dominated in eggs. The predominant halogenated phenolic compound (HPC) in plasma was consistently the PCB metabolite 4-OH-CB187 (range: 0.29-17.5 ng/g wet wt), whereas in eggs, detectable HPCs were at very low and transient concentrations. As part of a complex profile of contaminant exposure, these chemical classes and metabolites may be contributing factors to enhance physiological stress in breeding glaucous gulls. PMID:16268150

  13. Mercury and other metals in eggs and feathers of glaucous-winged gulls (Larus glaucescens) in the Aleutians

    PubMed Central

    Gochfeld, Michael; Jeitner, Christian; Burke, Sean; Volz, Conrad D.; Snigaroff, Ronald; Snigaroff, Daniel; Shukla, Tara; Shukla, Sheila

    2014-01-01

    Levels of mercury and other contaminants should be lower in birds nesting on isolated oceanic islands and at high latitudes without any local or regional sources of contamination, compared to more urban and industrialized temperate regions. We examined concentrations of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in the eggs, and the feathers of fledgling and adult glaucous-winged gulls (Larus glaucescens) nesting in breeding colonies on Adak, Amchitka, and Kiska Islands in the Aleutian Chain of Alaska in the Bering Sea/North Pacific. We tested the following null hypotheses: 1) There were no differences in metal levels among eggs and feathers of adult and fledgling glaucous-winged gulls, 2) There were no differences in metal levels among gulls nesting near the three underground nuclear test sites (Long Shot 1965, Milrow 1969, Cannikin 1971) on Amchitka, 3) There were no differences in metal levels among the three islands, and 4) There were no gender-related differences in metal levels. All four null hypotheses were rejected at the 0.05 level, although there were few differences among the three test sites on Amchitka. Eggs had the lowest levels of cadmium, lead, and mercury, and the feathers of adults had the lowest levels of selenium. Comparing only adults and fledglings, adults had higher levels of cadmium, chromium, lead and mercury, and fledglings had higher levels of arsenic, manganese and selenium. There were few consistent interisland differences, although levels were generally lower for eggs and feathers from gulls on Amchitka compared to the other islands. Arsenic was higher in both adult feathers and eggs from Amchitka compared to Adak, and chromium and lead were higher in adult feathers and eggs from Adak compared to Amchitka. Mercury and arsenic, and chromium and manganese levels were significantly correlated in the feathers of both adult and fledgling gulls. The feathers of males had significantly higher levels of chromium and

  14. Transmission of H5N1 high pathogenicity avian influenza virus to Herring gulls (Larus argentatus) through intranasal inoculation of virus and ingestion of virus-infected chicken meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to evaluate the susceptibility of herring gulls (Larus argentatus) to H5N1 highly pathogenic avian influenza (HPAI) virus under natural routes of infection, we exposed gulls to two Asian lineage H5N1 HPAI viruses (A/whooper swan/Mongolia/244/05 and A/duck meat/Anyang/AVL-1/01) via intranasa...

  15. A transactional analysis of changes in parent and chick behaviour prior to separation of Herring Gulls (Larus Argentatus): A three-term contingency model.

    PubMed

    Reed, Phil

    2015-09-01

    The effect of the passage of time on parent-offspring behaviour of urban Herring Gulls (Larus Argentatus) was studied and analysed using a three-term contingency model. A behavioural sequence was initiated by the arrival of a parental adult gull, which would lead to feeding in the chick. However, with the passage of time, and approach of the separation period, this pattern changed. Chicks' begging became more intense, and parent gulls more often withheld food. However, the chicks' begging became directed at a wider range of adults over the observation period. These activities are placed within a three-term contingency model, which may have implications for understanding some behavioural processes involved in parent-offspring separation. PMID:26003136

  16. Maternal Antibody Transmission in Relation to Mother Fluctuating Asymmetry in a Long-Lived Colonial Seabird: The Yellow-Legged Gull Larus michahellis

    PubMed Central

    Hammouda, Abdessalem; Selmi, Slaheddine; Pearce-Duvet, Jessica; Chokri, Mohamed Ali; Arnal, Audrey; Gauthier-Clerc, Michel; Boulinier, Thierry

    2012-01-01

    Female birds transfer antibodies to their offspring via the egg yolk, thus possibly providing passive immunity against infectious diseases to which hatchlings may be exposed, thereby affecting their fitness. It is nonetheless unclear whether the amount of maternal antibodies transmitted into egg yolks varies with female quality and egg laying order. In this paper, we investigated the transfer of maternal antibodies against type A influenza viruses (anti-AIV antibodies) by a long-lived colonial seabird, the yellow-legged gull (Larus michahellis), in relation to fluctuating asymmetry in females, i.e. the random deviation from perfect symmetry in bilaterally symmetric morphological and anatomical traits. In particular, we tested whether females with greater asymmetry transmitted fewer antibodies to their eggs, and whether within-clutch variation in yolk antibodies varied according to the maternal level of fluctuating asymmetry. We found that asymmetric females were in worse physical condition, produced fewer antibodies, and transmitted lower amounts of antibodies to their eggs. We also found that, within a given clutch, yolk antibody level decreased with egg laying order, but this laying order effect was more pronounced in clutches laid by the more asymmetric females. Overall, our results support the hypothesis that maternal quality interacts with egg laying order in determining the amount of maternal antibodies transmitted to the yolks. They also highlight the usefulness of fluctuating asymmetry as a sensitive indicator of female quality and immunocompetence in birds. PMID:22590497

  17. Developmental toxicity of PFOS and PFOA in great cormorant (Phalacrocorax carbo sinensis), herring gull (Larus argentatus) and chicken (Gallus gallus domesticus).

    PubMed

    Nordén, Marcus; Berger, Urs; Engwall, Magnus

    2016-06-01

    Perfluoroalkyl acids (PFAAs) are found globally in environmental samples and have been studied in various species. In this study, we compare the sensitivity of three avian species to the toxic effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). Eggs of great cormorant (Phalacrocorax carbo sinensis), herring gull (Larus argentatus) and the domestic White Leghorn chicken (Gallus gallus domesticus) were exposed in ovo by injection into the air sac. Effects on embryo survival were observed following exposure to PFOS and PFOA in chicken and herring gull. Chicken was found to be the most sensitive species with 50 % reduced embryo survival at 8.5 μg/g egg for PFOS and 2.5 μg/g egg for PFOA. Cormorant was shown to be the least sensitive species. The difference in sensitivity between chicken and herring gull was a factor of 2.7 for PFOS and 3.5 for PFOA. Between chicken and great cormorant, the sensitivity difference was 2.6 for PFOS and 8.2 for PFOA. Effects on embryo survival were seen at egg injection doses of PFOS close to levels found in environmental samples from wild birds, indicating that PFOS could be having effects in highly exposed populations of birds. This study also shows that there are differences in species sensitivity to PFOS and PFOA that should be taken into consideration in avian wildlife risk assessment. PMID:26895726

  18. Foraging movements of Audouin’s gull (Larus audouinii) in the Ebro Delta, NW Mediterranean: A preliminary satellite-tracking study

    NASA Astrophysics Data System (ADS)

    Christel, Isadora; Navarro, Joan; del Castillo, Marcos; Cama, Albert; Ferrer, Xavier

    2012-01-01

    A knowledge of the foraging strategies of marine predators is essential to understand the intrinsic factors controlling their distribution, abundance and their ecological function within the marine ecosystem. Here, we investigated for the first time the foraging movements and activity patterns of Audouin's gull Larus audouinii by using satellite-tracking data from eight breeding adults in the main colony of the species worldwide (Ebro Delta, NW Mediterranean). Tagged gulls foraged in the marine area close to the breeding colony (62% of foraging locations) and in the terrestrial area of the Ebro Delta (mainly rice fields; 38% of foraging locations). The foraging activity patterns changed significantly throughout the day; lower from dusk through the first half of the night (19-1 h; 32% of active locations) and higher during the rest of the day (1-19 h; 75.5 ± 4.3% of active locations). These results confirm the foraging plasticity of this seabird and, based on previous information about the dietary habits of this species, we hypothesize how its time-dependent activity patterns and habitat use could be associated with variations in the availability of marine food resources (e.g. diel vertical migrations of pelagic fish) and the exploitation of terrestrial resources (e.g. American crayfish Procambarus clarkii).

  19. Effect of rapid modulation of circulating plasma testosterone concentration on begging, aggressive behavior and competition for food in black-headed gull (Larus ridibundus) chicks.

    PubMed

    Boncoraglio, Giuseppe; Groothuis, Ton G G

    2013-08-01

    Sibling competition mediated by begging behavior is extremely common in avian species and recent studies have highlighted the role of endogenous testosterone in regulating such phenomenon. However, current literature depicts an inconsistent pattern in altricial vs. semi-precocial species, with stimulating versus inhibitory effects of the hormone respectively. This is possibly due to a difference in the methodology of hormone treatment (short-term moderate dose versus a long-term stronger elevation, respectively) between the studies performed so far. In this study, we induced short-term moderate peaks in plasma testosterone levels, as applied in altricial bird species, and assessed the effects of our manipulation on begging, competitive and aggressive behavior in black-headed gull (Larus ridibundus) chicks, a semi-precocial species. Our results suggest that, unlike in altricial songbirds, temporary increase of plasma testosterone concentration suppresses begging and enhances aggressiveness towards intruders. However, it also increases aggression and the chances of getting priority while scrambling with nest mates to gain access to food. Thus, the inconsistencies in the hormonal control of begging behavior observed between altricial vs. semi-precocial birds seem real and perhaps related to species differences in complexity of the display and the nature of competition. These may be elucidated by future comparative studies. PMID:23962563

  20. The influence of predation by herring gulls Larus argentatus and oystercatchers Haematopus ostralegus on a newly established mussel Mytilus edulis bed in autumn and winter

    NASA Astrophysics Data System (ADS)

    Hilgerloh, G.; Herlyn, M.; Michaelis, H.

    1997-08-01

    Predation by herring gulls Larus argentatus and oystercatchers Haematopus ostralegus was evaluated on a newly established mussel Mytilus edulis bed on tidal flats of the German Wadden Sea. The mussel bed covered an area of 2 ha and showed a decrease in biomass of 40% in the most densely covered parts from August to January. Synchronously, the extent of the mussel bed was reduced, resulting in a decrease of average biomass of 98% over the whole mussel bed. From the beginning of August 1994 to mid January 1995, the average size of mussels increased from 10.7 to 20.3 mm. The P/B-ratio was 0.68 in August and 0.18 between September and November. Herring gulls and oystercatchers were the most important mussel predators. On average, 266 herring gulls and 63 oystercatchers were present on the mussel bed during one low tide; 34% of the herring gulls and 78% of the oystercatchers were observed to be feeding. Herring gulls fed at a rate of 4.2 mussels per minute and oystercatchers at a rate of 1.3 mussels per minute. While herring gulls took the most common mussel sizes (mean: 20 mm), oystercatchers searched for the largest mussels available (mean: 25 mm). Herring gulls consumed 13 mussels/m2 (0.3g AFDW) during one day and oystercatchers 1.7 mussels/m2 (0.1 g AFDW). Predation by birds was compensated by 33% of the production. The proportion removed by bird predation amounted to 10% of abundance and to 16% of biomass (including production). Oystercatchers were responsible for 1% of the reduction in abundance and for 3% of biomass. Removal was highest in the most common size classes of mussels, mainly caused by herring gulls. However, the highest proportion of mussels was eaten in the largest size classes, mainly by oystercatchers. *** DIRECT SUPPORT *** A03B6035 00004

  1. Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina.

    PubMed

    Marón, Carina F; Beltramino, Lucas; Di Martino, Matías; Chirife, Andrea; Seger, Jon; Uhart, Marcela; Sironi, Mariano; Rowntree, Victoria J

    2015-01-01

    At least 626 southern right whale (Eubalaena australis) calves died at the Península Valdés calving ground, Argentina, between 2003 and 2014. Intense gull harassment may have contributed to these deaths. In the 1970s, Kelp Gulls (Larus dominicanus) began feeding on skin and blubber pecked from the backs of living right whales at Valdés. The frequency of gull attacks has increased dramatically over the last three decades and mother-calf pairs are the primary targets. Pairs attacked by gulls spend less time nursing, resting and playing than pairs not under attack. In successive attacks, gulls open new lesions on the whales' backs or enlarge preexisting ones. Increased wounding could potentially lead to dehydration, impaired thermoregulation, and energy loss to wound healing. The presence, number and total area of gull-inflicted lesions were assessed using aerial survey photographs of living mother-calf pairs in 1974-2011 (n = 2680) and stranding photographs of dead calves (n = 192) in 2003-2011. The percentage of living mothers and calves with gull lesions increased from an average of 2% in the 1970s to 99% in the 2000s. In the 1980s and 1990s, mothers and calves had roughly equal numbers of lesions (one to five), but by the 2000s, calves had more lesions (nine or more) covering a greater area of their backs compared to their mothers. Living mother-calf pairs and dead calves in Golfo Nuevo had more lesions than those in Golfo San José in the 2000s. The number and area of lesions increased with calf age during the calving season. Intensified Kelp Gull harassment at Península Valdés could be compromising calf health and thereby contributing to the high average rate of calf mortality observed in recent years, but it cannot explain the large year-to-year variance in calf deaths since 2000. PMID:26488493

  2. Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina

    PubMed Central

    Marón, Carina F.; Beltramino, Lucas; Di Martino, Matías; Chirife, Andrea; Seger, Jon; Uhart, Marcela; Sironi, Mariano; Rowntree, Victoria J.

    2015-01-01

    At least 626 southern right whale (Eubalaena australis) calves died at the Península Valdés calving ground, Argentina, between 2003 and 2014. Intense gull harassment may have contributed to these deaths. In the 1970s, Kelp Gulls (Larus dominicanus) began feeding on skin and blubber pecked from the backs of living right whales at Valdés. The frequency of gull attacks has increased dramatically over the last three decades and mother-calf pairs are the primary targets. Pairs attacked by gulls spend less time nursing, resting and playing than pairs not under attack. In successive attacks, gulls open new lesions on the whales’ backs or enlarge preexisting ones. Increased wounding could potentially lead to dehydration, impaired thermoregulation, and energy loss to wound healing. The presence, number and total area of gull-inflicted lesions were assessed using aerial survey photographs of living mother-calf pairs in 1974–2011 (n = 2680) and stranding photographs of dead calves (n = 192) in 2003–2011. The percentage of living mothers and calves with gull lesions increased from an average of 2% in the 1970s to 99% in the 2000s. In the 1980s and 1990s, mothers and calves had roughly equal numbers of lesions (one to five), but by the 2000s, calves had more lesions (nine or more) covering a greater area of their backs compared to their mothers. Living mother-calf pairs and dead calves in Golfo Nuevo had more lesions than those in Golfo San José in the 2000s. The number and area of lesions increased with calf age during the calving season. Intensified Kelp Gull harassment at Península Valdés could be compromising calf health and thereby contributing to the high average rate of calf mortality observed in recent years, but it cannot explain the large year-to-year variance in calf deaths since 2000. PMID:26488493

  3. [A comparative analysis of the helminth fauna of kittiwake Rissa tridactyla (Linnaeus, 1758) and glaucous gull Larus hyperboreus Gunnerus, 1767 from different parts of the Barents Sea].

    PubMed

    Kuklin, V V; Galaktionov, K V; Galkin, A K; Marasaev, S F

    2005-01-01

    The article is based on the results of helminthological observations made on kittiwake Rissa tridactyla and glaucous gull Larus hyperboreus in 1991-2001 in different areas of the Barents Sea (Eastern Murman coast, Franz Josef Land, Novaya Zemlya, Spitzbergen). 18 helminth species (2 trematodes, 11 cestodes, 4 nematodes, and 2 acanthocephalans) were recorded in the kittiwakes and 19 (3 trematodes, 9 cestodes, 5 nematodes and 2 acanthocephalans) species were recorded in the glaucous gulls. Trematodes were absent in the birds collected at the Franz Josef Land and the northern island of Novaya Zemlya. 3 trematode species, namely Gymnophallus sp. (somateria?), Microphallus sp. 1 (M. pseudopygmaeus), and Cryptocotyle lingua were found in the glaucous gulls of western Spitzbergen. It was supposed that the life cycles of these parasites can be completed there. On the other hand, coastal ecosystems of Arctic archipelagoes turn out to be favourable for the transmission of some cestodes. This is closely connected with the regional traits in the marine bird diet, namely the increase of the amphipod (intermediate hosts of hymenolepidids and some dilepidids) and polar cod (supposed second intermediate host for some tetrabothriids) portion in Arctic. As a result, cestodes are the base of the helminth fauna of kittiwakes and glaucous gulls of the Barents Sea, by their species richness, prevalence and abundance. Nematodes and acanthocephalans were represented by a few species with low infection intensity. The main ecological factors affected the regional difference in the species richness and abundance of the helminths parasitising kittiwakes and glaucous gulls in the Barents Sea are proposed. Those are regional climatic features and regional traits in the behaviour and food priorities of birds, and also the distribution of the helminths intermediate hosts, invertebrates and fishes. The phenomenon of host specificity lowering with respect to the definitive host was recorded in some

  4. Field Metabolic Rate Is Dependent on Time-Activity Budget in Ring-Billed Gulls (Larus delawarensis) Breeding in an Anthropogenic Environment.

    PubMed

    Marteinson, Sarah C; Giroux, Jean-François; Hélie, Jean-François; Gentes, Marie-Line; Verreault, Jonathan

    2015-01-01

    Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR). However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of activity (measured by detailed time-activity budgets) and a series of extrinsic and intrinsic factors on FMR of the omnivorous ring-billed gull (Larus delawarensis). The experiment was conducted during the incubation period when both members of the pair alternate between attending the nest-site and leaving the colony to forage in aquatic and anthropogenic environments (city, agricultural). FMR was determined using the doubly labeled water method. Time-activity budgets were extrapolated from spatio-temporal data (2-5 days) obtained from bird-borne GPS data loggers. Gulls had low FMRs compared to those predicted by allometric equations based on recorded FMRs from several seabird species. Gulls proportioned their time mainly to nest-site attendance (71% of total tracking time), which reduced FMR/g body mass, and was the best variable explaining energy expenditure. The next best variable was the duration of foraging trips, which increased FMR/g; FMR/g was also elevated by the proportion of time spent foraging or flying (17% and 8% of tracking time respectively). Most environmental variables measured did not impact FMR/g, however, the percent of time birds were subjected to temperatures below their lower critical temperature increased FMR. Time-activity budgets varied between the sexes, and with temperature and capture date suggesting that these variables indirectly affected FMR/g. The gulls foraged preferentially in anthropogenic-related habitats, which may have contributed to their low FMR/g due to the high availability of protein- and lipid-rich foods. This study demonstrates that activities were the best predictors of FMR/g in

  5. Field Metabolic Rate Is Dependent on Time-Activity Budget in Ring-Billed Gulls (Larus delawarensis) Breeding in an Anthropogenic Environment

    PubMed Central

    Marteinson, Sarah C.; Giroux, Jean-François; Hélie, Jean-François; Gentes, Marie-Line; Verreault, Jonathan

    2015-01-01

    Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR). However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of activity (measured by detailed time-activity budgets) and a series of extrinsic and intrinsic factors on FMR of the omnivorous ring-billed gull (Larus delawarensis). The experiment was conducted during the incubation period when both members of the pair alternate between attending the nest-site and leaving the colony to forage in aquatic and anthropogenic environments (city, agricultural). FMR was determined using the doubly labeled water method. Time-activity budgets were extrapolated from spatio-temporal data (2-5 days) obtained from bird-borne GPS data loggers. Gulls had low FMRs compared to those predicted by allometric equations based on recorded FMRs from several seabird species. Gulls proportioned their time mainly to nest-site attendance (71% of total tracking time), which reduced FMR/g body mass, and was the best variable explaining energy expenditure. The next best variable was the duration of foraging trips, which increased FMR/g; FMR/g was also elevated by the proportion of time spent foraging or flying (17% and 8% of tracking time respectively). Most environmental variables measured did not impact FMR/g, however, the percent of time birds were subjected to temperatures below their lower critical temperature increased FMR. Time-activity budgets varied between the sexes, and with temperature and capture date suggesting that these variables indirectly affected FMR/g. The gulls foraged preferentially in anthropogenic-related habitats, which may have contributed to their low FMR/g due to the high availability of protein- and lipid-rich foods. This study demonstrates that activities were the best predictors of FMR/g in

  6. Temporal and geographic variation of organochlorine residues in eggs of the common snapping turtle (Chelydra serpentina serpentina) (1981-1991) and comparisons to trends in the herring gull (Larus argentatus) in the Great Lakes basin in Ontario, Canada.

    PubMed

    Bishop, C A; Ng, P; Norstrom, R J; Brooks, R J; Pettit, K E

    1996-11-01

    Common snapping turtle (Chelydra serpentina serpentina) eggs from five sites within the Great Lakes basin, and from a reference site in north-central Ontario were collected during 1981-1991 and analyzed for four organochlorine pesticides, polychlorinated biphenyls (PCBs) including six non-ortho PCBs, polychlorinated dibenzodioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). The pattern of geographic variation was consistent over time in eggs with Cootes Paradise/ Hamilton Harbour and Lynde Creek eggs on Lake Ontario containing the highest concentrations and most PCDD and PCDF congeners among all sites. Eggs from Cranberry Marsh on Lake Ontario contained organochlorine concentrations similar to those from Big Creek Marsh and Rondeau Provincial Park on Lake Erie except PCDDs and PCDFs which occurred at higher concentrations and more congeners were detectable in Cranberry Marsh eggs. Concentrations of most contaminants in turtle eggs from Algonquin Park, the reference site, have significantly decreased in the past decade. Dieldrin concentrations, however, increased in Algonquin Park eggs from 1981 to 1989. Significant decreases in concentrations of hexachlorobenzene, mirex and PCBs occurred between turtle eggs collected in 1981/84 and 1989 at Big Creek Marsh and Rondeau Provincial Park, whereas there was no significant change in concentrations of p,p'-DDE and dieldrin. In Lake Ontario eggs, concentrations of PCBs, p,p'-DDE and dieldrin increased significantly between 1984 and 1991. Differences were also found in patterns of temporal variation in contamination between herring gulls (Larus argentatus) and snapping turtles which were attributed to differences in diet. Elevated and continued contamination in turtle eggs from Lake. Ontario is probably due to a combination of local sources of chemicals and consumption of large migratory fish that spawn in wetlands inhabited by these turtles. PMID:8975824

  7. Influence of trophic ecology on the accumulation of dioxins and furans (PCDD/Fs), non-ortho polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in Mediterranean gulls (Larus michahellis and L. audouinii): A three-isotope approach.

    PubMed

    Roscales, Jose L; Vicente, Alba; Muñoz-Arnanz, Juan; Morales, Laura; Abad, Esteban; Aguirre, Jose I; Jiménez, Begoña

    2016-05-01

    The impact of pollution caused by severe anthropogenic pressure in the Mediterranean Sea, an important biodiversity hotspot, requires continuous research efforts. Sources of highly toxic chemicals such as Persistent Organic Pollutants (POPs) are misunderstood in representative Mediterranean species, which limits our capability to establish proper conservation strategies. In the present study, eggs of Audouin's and yellow-legged gulls (Larus audouinii and L. michahellis) were used to investigate the trophic sources, as measured by δ(13)C, δ(15)N, and δ(34)S, of legacy POPs, in particular, polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and non-ortho polychlorinated biphenyls (no-PCBs), as well as recently-regulated POPs, e.g., polybrominated diphenyl ethers (PBDEs). Special attention was paid to the usefulness of rarely-explored δ(34)S ratios in explaining POP exposure in wildlife, and δ(34)S was the isotopic ratio that best explained POP variations among gulls in most cases, thus demonstrating its usefulness for understanding POP exposure in wildlife. Significant relationships between stable isotope signatures and POP concentrations revealed increasing levels of no-PCBs and low halogenated PCDD/Fs and PBDEs in Mediterranean gulls as the consumption of marine resources increases. In contrast, highly chlorinated and brominated congeners appeared to preferentially accumulate in gulls feeding primarily on refuse from dump sites and terrestrial food webs. The use of suitable dietary tracers in the study of POPs in yellow-legged gulls revealed the importance of dump sites as a source of POPs in Mediterranean seabirds, which has not previously been reported. In contrast, the preferential accumulation through marine food webs of low chlorinated PCCD/Fs and no-PCBs, which show the highest toxic equivalents factors (TEFs), led to a significantly greater toxicological concern in Audouin's as compared to yellow-legged gulls. Audouin's gull exposure to POPs appears

  8. Comparison of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers in bald eagle (Haliaeetus leucocephalus), and comparison with common eider (Somateria mollissima), glaucous-winged gull (Larus glaucescens), pigeon guillemot (Cepphus columba), and tufted puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska

    PubMed Central

    Burger, Joanna; Gochfeld, Michael

    2014-01-01

    There is an abundance of field data for levels of metals from a range of places, but relatively few from the North Pacific Ocean and Bering Sea. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from common eiders (Somateria mollissima), glaucous-winged gulls (Larus glaucescens), pigeon guillemots (Cepphus columba), tufted puffins (Fratercula cirrhata) and bald eagles (Haliaeetus leucocephalus) from the Aleutian Chain of Alaska. Our primary objective was to test the hypothesis that there are no trophic levels relationships for arsenic, cadmium, chromium, lead, manganese, mercury and selenium among these five species of birds breeding in the marine environment of the Aleutians. There were significant interspecific differences in all metal levels. As predicted bald eagles had the highest levels of arsenic, chromium, lead, and manganese, but puffins had the highest levels of selenium, and pigeon guillemot had higher levels of mercury than eagles (although the differences were not significant). Common eiders, at the lowest trophic level had the lowest levels of some metals (chromium, mercury and selenium). However, eiders had higher levels than all other species (except eagles) for arsenic, cadmium, lead, and manganese. Levels of lead were higher in breast than in wing feathers of bald eagles. Except for lead, there were no significant differences in metal levels in feathers of bald eagles nesting on Adak and Amchitka Island; lead was higher on Adak than Amchitka. Eagle chicks tended to have lower levels of manganese than older eagles. PMID:18521716

  9. Comparison of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers in bald eagle (Haliaeetus leucocephalus), and comparison with common eider (Somateria mollissima), glaucous-winged gull (Larus glaucescens), pigeon guillemot (Cepphus columba), and tufted puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska.

    PubMed

    Burger, Joanna; Gochfeld, Michael

    2009-05-01

    There is an abundance of field data for levels of metals from a range of places, but relatively few from the North Pacific Ocean and Bering Sea. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from common eiders (Somateria mollissima), glaucous-winged gulls (Larus glaucescens), pigeon guillemots (Cepphus columba), tufted puffins (Fratercula cirrhata) and bald eagles (Haliaeetus leucocephalus) from the Aleutian Chain of Alaska. Our primary objective was to test the hypothesis that there are no trophic levels relationships for arsenic, cadmium, chromium, lead, manganese, mercury and selenium among these five species of birds breeding in the marine environment of the Aleutians. There were significant interspecific differences in all metal levels. As predicted bald eagles had the highest levels of arsenic, chromium, lead, and manganese, but puffins had the highest levels of selenium, and pigeon guillemot had higher levels of mercury than eagles (although the differences were not significant). Common eiders, at the lowest trophic level had the lowest levels of some metals (chromium, mercury and selenium). However, eiders had higher levels than all other species (except eagles) for arsenic, cadmium, lead, and manganese. Levels of lead were higher in breast than in wing feathers of bald eagles. Except for lead, there were no significant differences in metal levels in feathers of bald eagles nesting on Adak and Amchitka Island; lead was higher on Adak than Amchitka. Eagle chicks tended to have lower levels of manganese than older eagles. PMID:18521716

  10. Changes in food web structure affect rate of PCB decline in herring gull (Larus argentatus) eggs

    SciTech Connect

    Hebert, C.E.; Hobson, K.A.; Shutt, J.L.

    2000-05-01

    Biological monitors provide important information regarding temporal trends in levels of persistent organic pollutants. Correct interpretation of these trends is critical if one is to accurately assess his progress in eliminating these contaminants from the environment. In the Laurentian Great Lakes, polychlorinated biphenyl concentrations in herring gull eggs declined during the 1970s and early 1980s. By the mid-1980s, further declines were not as obvious. An exception to this trend was observed in eggs from Lake Erie. On that lake, egg PCB concentrations continued to decline rapidly during the 1980s/1990s. Evidence from stable isotope analysis indicated that temporal changes in the composition of the herring gull diet occurred on Lake Erie. In the eastern basin, declines in fish availability may have forced the gulls to incorporate a greater proportion of terrestrial food into their diets. Decreases in the proportion of fish in the gull diet would have resulted in reduced PCB exposure. This may be partially responsible for the continuing rapid rate of decline in egg PCB concentrations. This decline should be interpreted with caution. These trends may not be indicative of lake-wide declines in PCB bioavailability but only reflect changes in dietary exposure brought about by alterations in food web structure.

  11. Modelling terrestrial and marine foraging habitats in breeding Audouin's gulls Larus audouinii: timing matters.

    PubMed

    Bécares, Juan; García-Tarrasón, Manuel; Villero, Dani; Bateman, Santiago; Jover, Lluís; García-Matarranz, Víctor; Sanpera, Carolina; Arcos, José Manuel

    2015-01-01

    Although the breeding ecology of Audouin's gull has been widely studied, its spatial distribution patterns have received little attention. We assessed the foraging movements of 36 GPS-tracked adult Audouin's gulls breeding at the Ebro Delta (NW Mediterranean), coinciding with the incubation period (May 2011). This also coincided with a trawling moratorium northwards from the colony. We modelled the distribution of the gulls by combining these tracking data with environmental variables (including fishing activities from Vessel Monitoring System, VMS), using Maxent. The modelling range included both marine and terrestrial areas. Models were produced separately for every 2h time interval across the day, and for 2 fishing activity scenarios (workdays vs. weekends), allowing to assess the spatio-temporal distribution patterns of the gulls and the degree of association with fisheries. During workdays, gull distribution at sea fully matched with fishing activities, both trawling (daylight) and purse-seining (nightime). Gulls tended to avoid the area under trawling moratorium, confirming the high influence of fisheries on the distribution patterns of this species. On weekends, gulls made lesser use of the sea and tended to increase the use of rice fields. Overall, Audouin's gull activity was more intense during dailight hours, although birds also showed nocturnal activity, on both workdays and weekends. Nocturnal patterns at sea were more disperse during the latter, probably because these gulls are able to capture small pelagic fish at night in natural conditions, but tend to congregate around purse-seiners (which would enhance their foraging efficiency) in workdays. These results provide important insight for the management of this species. This is of particular relevance under the current scenario of European fisheries policies, since new regulations are aimed at eliminating discards, and this would likely influence Audouin's gull populations. PMID:25875597

  12. Relationships of metals between feathers and diets of black-tailed gull (Larus crassirostris) chicks.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2014-03-01

    In birds, metal contaminants in feathers are influenced by prey concentrations and environmental quality. In Black-tailed Gull chicks, Cd, Pb and Cu concentrations were strongly correlated between feathers and stomach contents. Between feathers and livers, Pb, Zn and Fe concentrations were significantly correlated. Cd concentrations were within the range of other seabirds and within the background level for bird feathers (<2 μg/g dw). At the lighthouse, eight chicks exceeded the background for Pb level in feathers (>4 μg/g dw). Elevated Pb concentrations might be attributed to ingestion of paint-based chips and natural (soil and rocks) sources. There is evidence that the analyzed birds suffered from acute toxicity, including high levels of pecking from conspecifics and increased mortality from elevated Pb levels. It seems likely that these birds might experience negative health effects from this increased Pb exposure. As a result, Black-tailed Gull chick feathers are a very useful monitoring tool for assessing Cd, Pb and Cu contamination. Essential elements such as Fe, Zn, Mn and Cu were all within the acceptable range of normal concentrations for seabird species including gulls and may be maintained by normal homeostatic mechanisms. PMID:24414165

  13. Molecular Detection of Campylobacter spp. in California Gull (Larus californicus) Excreta

    EPA Science Inventory

    We examined the prevalence, quantity, and diversity of Campylobacter species in the excreta of 159 California gull samples using PCR and qPCR based detection assays. While Campylobacter prevalence and abundance was relatively high in the gull excreta examined, molecular data ind...

  14. Insects, vegetation, and the control of laughing gulls (Larus atricilla) at Kennedy International Airport, New York

    USGS Publications Warehouse

    Buckley, P.A.; McCarthy, M.

    1994-01-01

    1. In response to a purported 'bird-strike problem' at J.F. Kennedy International Airport in New York City, we examined short (5 cm) and long (45 cm) grass heights as gull deterrents, in a randomized-block experiment. 2. Vegetative cover, numbers of adult insects and of larval beetles (suspected on-airport food of the gulls) were sampled in the six-block, 36-plot study area, as well as gut contents of adult and downy young gulls in the immediately adjacent colony in the Jamaica Bay Wildlife Refuge. 3. We found that (i) Oriental beetle larvae were the most numerous and concentrated in one experimental block; (ii) beetle larvae numbers were uncorrelated with grass height; (iii) adult beetles were also uncorrelated with grass height; (iv) laughing gulls were distributed across blocks irrespective of percentage cover; (v) within blocks, laughing gulls were selecting short grass and avoiding long grass plots; (vi) laughing gull numbers were positively associated with numbers of Oriental beetle larvae; (vii) adult laughing gulls on the airport were eating lower-nutrition food of terrestrial origin (74-83% adult beetles, mostly Oriental plus green June and ground beetles); (viii) on the other hand, gull chicks in the adjacent breeding colony were being fed more easily digested, higher-protein food of marine origin (86-88% fishes, crustacea and molluscs); (ix) laughing gulls on the airport were taking their adult beetles only in short-grass plots, ignoring large numbers in adjacent long grass; (x) during the summer, on-airport gulls shifted from performing largely maintenance activities on pavement to feeding actively for beetles on newly mown short grass, the change coinciding with adult beetle emergence; (xi) standing water on the airport attracted significantly more gulls than dry areas all summer long. 4. We recommend a series of ecologically compatible, but aggressive habitat management actions for controlling laughing gulls on Kennedy Airport by rendering the airport unattractive to them, notably by implementing an airport-wide programme of long-grass encouragement, draining standing water and improving runoff in water-collecting areas, and controlling beetles. 5. We conclude by outlining the necessity for airport-wide bird, vegetation and habitat management programmes fully integrated into airport operation and planning activities.

  15. Modelling Terrestrial and Marine Foraging Habitats in Breeding Audouin's Gulls Larus audouinii: Timing Matters

    PubMed Central

    Bécares, Juan; García-Tarrasón, Manuel; Villero, Dani; Bateman, Santiago; Jover, Lluís; García-Matarranz, Víctor; Sanpera, Carolina; Arcos, José Manuel

    2015-01-01

    Although the breeding ecology of Audouin’s gull has been widely studied, its spatial distribution patterns have received little attention. We assessed the foraging movements of 36 GPS-tracked adult Audouin’s gulls breeding at the Ebro Delta (NW Mediterranean), coinciding with the incubation period (May 2011). This also coincided with a trawling moratorium northwards from the colony. We modelled the distribution of the gulls by combining these tracking data with environmental variables (including fishing activities from Vessel Monitoring System, VMS), using Maxent. The modelling range included both marine and terrestrial areas. Models were produced separately for every 2h time interval across the day, and for 2 fishing activity scenarios (workdays vs. weekends), allowing to assess the spatio-temporal distribution patterns of the gulls and the degree of association with fisheries. During workdays, gull distribution at sea fully matched with fishing activities, both trawling (daylight) and purse-seining (nightime). Gulls tended to avoid the area under trawling moratorium, confirming the high influence of fisheries on the distribution patterns of this species. On weekends, gulls made lesser use of the sea and tended to increase the use of rice fields. Overall, Audouin’s gull activity was more intense during dailight hours, although birds also showed nocturnal activity, on both workdays and weekends. Nocturnal patterns at sea were more disperse during the latter, probably because these gulls are able to capture small pelagic fish at night in natural conditions, but tend to congregate around purse-seiners (which would enhance their foraging efficiency) in workdays. These results provide important insight for the management of this species. This is of particular relevance under the current scenario of European fisheries policies, since new regulations are aimed at eliminating discards, and this would likely influence Audouin’s gull populations. PMID:25875597

  16. Recurrent hybridization and recent origin obscure phylogenetic relationships within the 'white-headed' gull (Larus sp.) complex.

    PubMed

    Sonsthagen, Sarah A; Wilson, Robert E; Chesser, R Terry; Pons, Jean-Marc; Crochet, Pierre-Andre; Driskell, Amy; Dove, Carla

    2016-10-01

    Species complexes that have undergone recent radiations are often characterized by extensive allele sharing due to recent ancestry and (or) introgressive hybridization. This can result in discordant evolutionary histories of genes and heterogeneous genomes, making delineating species limits difficult. Here we examine the phylogenetic relationships among a complex group of birds, the white-headed gulls (Aves: Laridae), which offer a unique window into the speciation process due to their recent evolutionary history and propensity to hybridize. Relationships were examined among 17 species (61 populations) using a multilocus approach, including mitochondrial and nuclear intron DNA sequences and microsatellite genotype information. Analyses of microsatellite and intron data resulted in some species-based groupings, although most species were not represented by a single cluster. Considerable allele and haplotype sharing among white-headed gull species was observed; no locus contained a species-specific clade. Despite this, our multilocus approach provided better resolution among some species than previous studies. Interestingly, most clades appear to correspond to geographic locality: our BEAST analysis recovered strong support for a northern European/Icelandic clade, a southern European/Russian clade, and a western North American/canus clade, with weak evidence for a high latitude clade spanning North America and northwestern Europe. This geographical structuring is concordant with behavioral observations of pervasive hybridization in areas of secondary contact. The extent of allele and haplotype sharing indicates that ecological and sexual selection are likely not strong enough to complete reproductive isolation within several species in the white-headed gull complex. This suggests that just a few genes are driving the speciation process. PMID:27369453

  17. Molecular characterization of antibiotic resistance in enterococci recovered from seagulls (Larus cachinnans) representing an environmental health problem.

    PubMed

    Radhouani, Hajer; Igrejas, Gilberto; Pinto, Luís; Gonçalves, Alexandre; Coelho, Céline; Rodrigues, Jorge; Poeta, Patrícia

    2011-08-01

    Antimicrobial resistance and the mechanisms implicated were studied in 54 enterococci recovered from 57 seagull fecal samples. Almost 78% of the recovered enterococci showed resistance against one or more antibiotics and these isolates were identified to the species level. E. faecium was the most prevalent species (52.4%). High percentages of erythromycin and tetracycline resistances were found among our isolates (95.2%), and lower percentages were identified to other antibiotics. Most of the tetracycline-resistant strains carried the tet(M) and/or tet(L) genes. Genes associated with Tn916/Tn1545 and/or Tn5397 transposons were detected in 45% of tetracycline-resistant isolates. The erm(B) gene was detected in 65% of erythromycin-resistant isolates. The vat(D) and vat(E) genes were present in 5.9% and 11.8% of quinupristin/dalfopristin-resistant isolates, respectively. The ant(6)-Ia gene was identified in 57.1% of streptomycin-resistant isolates. All nine kanamycin-resistant isolates carried the aph(3)'-IIIa gene. The cat(A) gene was found in two chloramphenicol-resistant isolates. Seagulls should be considered a risk species for spreading in the environment antimicrobial resistant enterococci and can serve as a sentinel for antibiotic pressure from the surrounding farm and urban setting. PMID:21674073

  18. Levels of DDT and PCB's in different stages of life cycle of the arctic tern Sterna paradisaea and the herring gull Larus argentatus

    SciTech Connect

    Lemmetyinen, R.; Rantamaki, P.; Karlin, A.

    1982-01-01

    ..sigma..DDT and PCB levels were analyzed in samples of arctic terns and herring gulls collected in the archipelago of southwestern Finland. Special attention was paid to the levels at various stages of the life cycle and in different sexes. The levels were nearly ten times higher in the herring gull. The highest loads were found in adult birds and in newly hatched chicks but the levels were much lower (only 7-12 % in the herring gull) in chicks just before fledgling. The levels in young gulls remained low until the end of August at least. Therefore it is plausible that the high levels found in adult gulls are a consequence of their wintering in the southern Baltic. The levels of ..sigma..DDT and PCB residues were significantly lower in female arctic terns than in male terns. Differences between the sexes were small in the herring gull. Thus it is possible that the female of the arctic tern is able to release pollutants, especially PCB residues, more effectively into eggs than the female of the herring gull. The biochemical mechanisms involved are not clear but a possible explanation may be different lipoprotein structures in the eggs of the species.

  19. Constraints on nest site selection: a comparison of predator and flood avoidance in four species of marsh-nesting birds (genera: Catoptrophorus, Larus, Rallus, and Sterna).

    PubMed

    Storey, A E; Montevecchi, W A; Andrews, H F; Sims, N

    1988-03-01

    Nest site characteristics associated with flood and predator avoidance were compared for four nonpasserine species of marsh-nesting birds: clapper rails, willets, laughing gulls, and common terns. Species with short nests, willets and terns, minimized flood damage by nesting on higher ground than did gulls and rails that build tall nests. Species with dispersed, cryptic nests had taller surrounding grass than did open-nesting colonial species. Total nest height was similar for species with tall nests and for terns whose short nests were elevated by placement on mats of dead Spartina grass. Willets had lower nest heights than the other species, probably because the inverse relation between grass height and ground height in the salt marsh makes it difficult for willets to find sites with high enough ground for flood avoidance while still retaining high enough grass for nest crypticity. Ground height for common terns and grass height for gulls and rails appear to be cues used in nest site selection. Nests of each species in which these characteristics were maximized were more successful in a major tidal flood. Laughing gulls and clapper rails appear to be more specialized salt marsh nesters than the other two species. PMID:3365941

  20. Lesser black-backed gulls (Larus fuscus) consuming swimming crabs: An important link in the food web of the southern North Sea

    NASA Astrophysics Data System (ADS)

    Schwemmer, Henriette; Schwemmer, Philipp; Ehrich, Siegfried; Garthe, Stefan

    2013-03-01

    Swimming crabs (Liocarcinus spp.) are one of the most common brachyuran species in the North Sea, and their abundance has substantially increased over the last century. Seabirds such as lesser black-backed gulls (LBBG) commonly feed mainly on higher-trophic-level organisms such as fish. However, intensive use of swimming crabs by LBBGs in the eastern North Sea has been noted over several years. Our investigation of this aspect of the food web by examining food remains from breeding LBBGs showed that swimming crabs accounted for more than half of the nutrition of LBBGs. Gulls selected larger individuals than expected, based on sizes of free-living swimming crabs. A long-term data set (2002-2006) shows that gulls took swimming crabs mainly in the early morning and late evening, suggesting that they might migrate vertically in the water column. Moreover, it shows that although swimming crabs occurred at considerable distances from the shore, LBBGs took this prey item exclusively from near the shore where it was most abundant. This suggests the existence of a possible energy threshold above which gulls experience a net energy loss, if they have to travel too far from their colony, where the abundance of swimming crabs is lower and the energy intake might thus not compensate for the long-distance flights. Swimming-crab abundance did not appear to be the primary factor influencing overall gull distribution. A simple bioenergetic model showed that the 22,000 individual LBBGs in the most important breeding colony in the south-eastern North Sea consumed approximately 35 million swimming crabs annually (i.e. 1590 swimming crabs per individual gull) during the breeding period. However, considering the high numbers of swimming crabs in the south-eastern North Sea (demonstrated by bottom-trawl surveys in 2005 and 2007) LBBGs are unlikely to exert top-down control on this prey. Conversely, a bottom-up effect is more likely, potentially enabling further increases in LBBG populations through increases in their most important prey item in the south-eastern North Sea.

  1. GEOGRAPHIC VARIATION IN BLOOD PLASMA PROTEIN CONCENTRATIONS IN YOUNG HERRING GULLS (LARUS ARGENTATUS) AND CASPIAN TERNS (STERNA CASPIA) FROM THE GREAT LAKES AND LAKE WINNIPEG. (R825216)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  2. Pattern of mercury accumulation in different tissues of migratory and resident birds: Western reef heron (Egretta gularis) and Siberian gull (Larus heuglini) in Hara International Wetland-Persian Gulf.

    PubMed

    Majidi, Yousef; Bahramifar, Nader; Ghasempouri, Seyed Mahmoud

    2015-01-01

    The Hara Mangrove Forest of the Persian Gulf is undergoing increasing pollution from industrial, municipal, and petroleum sources; however, little research in ecotoxicology has been carried out in this ecosystem. In the present study, mercury distribution and accumulation were investigated in muscle, liver, kidney, and feather of the resident Western reef heron (n = 15) and the migratory Siberian gull (n = 15). We also evaluated the relation between Hg concentrations, sex, and age (juvenile vs. adult). Results showed that the highest concentrations of Hg were recorded in the feather (35 ± 0.14-3.0 ± 0.27 mg kg(-1) dw) and at 3.7-, 1.6-, and 1.3-fold in muscle, kidney, and liver, respectively. Concentrations of mercury in tissues of migratory birds were two times higher than in resident birds; geographical differences and feeding habits were used to explain these variations. We found a weak relationship between Hg concentrations in feathers and internal tissues (r ≤ 0.50); conversely, liver presented strong positive correlations with other soft tissues, especially kidney (p > 0.05; r = 0.82). Results showed that sex and age have no significant effects on T-Hg accumulation in these birds (p > 0.05; r < -0.01). Based on these findings, Hg concentrations were low in both species. Therefore, Hg contamination of this aquatic ecosystem is not a threat. Accordingly, we recommend the use of the Western reef heron as a bioindicator of mercury pollution in this region. PMID:25492705

  3. Phosphorus in seagull colonies and the effect on the habitats. The case of yellow-legged gulls (Larus michahellis) in the Atlantic Islands National Park (Galicia-NW Spain).

    PubMed

    Otero, X L; Tejada, O; Martín-Pastor, M; De La Peña, S; Ferreira, T O; Pérez-Alberti, A

    2015-11-01

    During the period 1980-2000, the yellow-legged gull population underwent exponential growth due to an increase in the availability of anthropogenic food resources. The aim of this study was to highlight the effect of the gull colonies on the P soil cycle and the associated effects on coastal ecosystems. Samples of soil, water and faecal material were collected in a colony of yellow-legged gulls (Cíes Islands) and in a control area. Four sampling plots were installed in the study areas, and samples were collected in summer and winter in 1997 and 2011. Sample analysis included soil characterization and determination of the total P content (TP), bioavailable-P and fractionated-P forms in the soils and faecal material. The (31)P NMR technique was also used to determine organic P forms. Clear differences between the gull colony soils and the control soil were observed. The TP was 3 times higher in the gull colony soil, and the bioavailable P was 30 times higher than in the control soil. The P forms present at highest concentrations in the faecal material (P-apatite, P-residual and P-humic acid) were also present at high concentrations in the colony soil. The absence of any seasonal or annual differences in P concentration indicates that the P has remained stable in the soil over time, regardless of the changes in the gull population density. The degree of P saturation indicated that soils are saturated with P due to the low concentration of Fe/Al-hydroxides, which is consistent with a high P concentration in the run-off from the colonies. The P output from the colony soils to coastal waters may cause eutrophication of a nearby lagoon and the disappearance of a Zostera marina seagrass meadow. Similarly, the enrichment of P concentration in dune system of Muxieiro may induce irreversible changes in the plant communities. PMID:26081740

  4. 75 FR 65646 - Endangered and Threatened Wildlife and Plants; Permit, Santa Barbara County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-26

    ... FR 22041). The Gaviota Tarplant was listed as endangered on March 20, 2000 (65 FR 14888) and has been... take of the federally endangered El Segundo Blue Butterfly incidental to otherwise lawful activities that would result in the loss of Coast Buckwheat, which serves as butterfly habitat. We invite...

  5. 20 CFR Appendix A to Subpart F of... - U.S. Seaports

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., GA St. Mary, GA Cocoa, FL Fernandina Beach, FL Fort Lauderdale, FL Fort Pierce, FL Jacksonville, FL Miami, FL Palm Beach, FL Port Canaveral, FL Port Everglades, FL Riviera, FL Aguadilla, PR Ceiba, PR... Carpinteria, CA Crockett, CA El Segundo, CA Eureka, CA Estero Bay, CA Gaviota, CA Huntington Beach, CA...

  6. 20 CFR Appendix A to Subpart F of... - U.S. Seaports

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., GA St. Mary, GA Cocoa, FL Fernandina Beach, FL Fort Lauderdale, FL Fort Pierce, FL Jacksonville, FL Miami, FL Palm Beach, FL Port Canaveral, FL Port Everglades, FL Riviera, FL Aguadilla, PR Ceiba, PR... Carpinteria, CA Crockett, CA El Segundo, CA Eureka, CA Estero Bay, CA Gaviota, CA Huntington Beach, CA...

  7. Distribution of seabirds in the northern Gulf of Mexico in relation to mesoscale features: Initial observations

    USGS Publications Warehouse

    Ribic, C.A.; Davis, R.; Hess, N.; Peake, D.

    1997-01-01

    The presence of seabirds was related to offshore surface eddies and the freshwater plume of the Mississippi River in the northern Gulf of Mexico during autumn, winter, spring, and summer 1992-1993. Skuas (Stercorarius spp.) were the most common bird seen in autumn, whereas skuas and gulls (Larus spp.) were the most common in winter. Few birds were seen in the spring, and terns (Sterna spp.) were the most common birds seen in late summer. During summer, terns were associated with the freshwater plume of the Mississippi River. In the winter, herring (Larus argentatus) and laughing gulls (L. artricilla) were associated with areas with steep thermoclines, while pomarine skuas (Stercorarius pomarinus) were found in areas of low productivity. Herring and laughing gulls in the winter, all birds in the spring, and terns in the summer were more common outside eddies. Only pomarine skuas in the winter were seen more commonly inside warm-core eddies.

  8. Avian wildlife reservoir of Campylobacter fetus subsp. jejuni, Yersinia spp., and Salmonella spp. in Norway.

    PubMed

    Kapperud, G; Rosef, O

    1983-02-01

    Cloacal swabs from 540 wild-living birds were cultured for Campylobacter fetus subsp. jejuni, Yersinia spp., and Salmonella spp. The carrier rates detected were as follows: C. fetus subsp. jejuni, 28.4%; Yersinia spp., 1.2%; and Salmonella spp., 0.8%. All birds were apparently healthy when captured. C. fetus subsp. jejuni was isolated from 11 of the 40 bird species examined. Among birds inhabiting the city of Oslo, the highest isolation rate was found in crows (Corvus corone cornix) (89.8%), followed by gulls (Larus spp.) (50.0%) and domestic pigeons (Columba livia domesticus) (4.2%). The gulls and crows scavenge on refuse dumps. High carrier rates were also detected among the following birds from nonurban, coastal areas: puffin (Fratercula arctica) (51.3%), common tern (Sterna hirundo) (5.6%), common gull (Larus canus) (18.9%), black-headed gull (Larus ridibundus) (13.2%), and herring gull (Larus argentatus) (4.2%). The list of species harboring C. fetus subsp. jejuni also includes the Ural owl (Strix uralensis), goldeneye (Bucephala clangula), and reed bunting (Emberiza schoeniclus). The following five Yersinia strains were isolated: Y. kristensenii (two strains), Y. intermedia (two strains), and "Yersinia X2" (one strain). Four strains belonging to the genus Salmonella were isolated from three different species of gulls. These isolates were identified as S. typhimurium, S. indiana, and S. djugu. The results indicate that campylobacters are a normal component of the intestinal flora in several bird species, whereas Salmonella and Yersinia carriers are more sporadic. PMID:6338824

  9. Avian cholera causes marine bird mortality in the Bering Sea of Alaska

    USGS Publications Warehouse

    Bodenstein, Barbara L.; Kimberlee Beckmen; Gay Sheffield; Kathy Kuletz; Van Hemert, Caroline R.; Berlowski-Zier, Brenda M.; Shearn-Bochsler, Valerie I.

    2015-01-01

    The first known avian cholera outbreak among wild birds in Alaska occurred during November 2013. Liver, intestinal, and splenic necrosis consistent with avian cholera was noted, and Pasteurella multocida serotype 1 was isolated from liver and lung or spleen in Crested Auklets (Aethia cristatella), Thick-billed Murres (Uria lomvia), Common Eider (Somateria mollissima), Northern Fulmars (Fulmarus glacialis), and Glaucous-winged Gulls (Larus glaucescens).

  10. Seabird bycatch in Alaska demersal longline fishery trials: a demographic summary

    USGS Publications Warehouse

    Phillips, Elizabeth M.; Nevins, HannahRose M.; Hatch, Scott A.; Ramey, Andy M.; Miller, Melissa A.; Harvey, James T.

    2010-01-01

    The seasonal and spatial demographics are summarized for seabirds killed incidentally during gear modification trials for a demersal longline fishery in the Bering Sea. We examined 417 carcasses, including Northern Fulmar Fulmarus glacialis (n = 205), Glaucous-winged Gull Larus glaucescens (n = 103), Short-tailed Shearwater Puffinus tenuirostris (n = 48), Glaucous Gull Larus hyperboreus (n = 23), Slaty-backed Gull Larus schistisagus (n = 4), Black-legged Kittiwake Rissa tridactyla (n = 1), Laysan Albatross Diomedea immutabilis (n = 1), and unidentified gull species Larus spp. (n = 32). There was a significant male bias in the sex ratio of fulmars but not of gulls or shearwaters. For the top three species killed, the age composition of resident species was dominated numerically by adults (Northern Fulmar—86%; Glaucous-winged Gull—63%), whereas migrant species were primarily immature birds (Short-tailed Shearwater—71%). The majority of migratory Short-tailed Shearwaters (88%) were caught in July and August, whereas 70% of resident fulmars and gulls were caught in October and November. Age-class frequencies did not differ by month of capture, indicating that adult mortality is substantial. Eighty percent of the fulmars caught during July and August were within 200 km of two colonies in the Bering Sea, whereas only 7% of fulmars were caught in the same area during September to November. This is one of the first demographic summaries of seabird bycatch in Alaska longline fisheries. Additional studies of the species, age and sex of seabirds subject to fisheries-related mortality will provide data necessary to evaluate population-level impacts.

  11. Observations of a live Glaucous-winged Gull chick in an active Bald Eagle nest

    USGS Publications Warehouse

    Anthony, R.G.; Faris, J.T.

    2003-01-01

    We report an apparent nonlethal predation attempt on and subsequent adoption of a Glaucous-winged Gull (Larus glaucescens) chick by a pair of Bald Eagles (Haliaeetus leucocephalus) in the Aleutian Archipelago, Alaska. To the best of our knowledge, this is the first report of a live Glaucous-winged Gull chick in a Bald Eagle nest. We describe our observations of this occurrence and offer explanations on how it may have occurred.

  12. Species differences in total mercury concentration in gulls from the Gulf of Gdansk (Southern Baltic).

    PubMed

    Szumiło-Pilarska, Emilia; Grajewska, Agnieszka; Falkowska, Lucyna; Hajdrych, Julia; Meissner, Włodzimierz; Frączek, Tomasz; Bełdowska, Magdalena; Bzoma, Szymon

    2016-01-01

    Aquatic birds occupy a high position in the trophic pyramid of the Baltic Sea. This means that they accumulate the greatest amount of harmful substances, including mercury, in their bodies. This element penetrates into their systems mainly via the alimentary canal. The amount of mercury absorbed from food depends on how badly the environment is polluted with this metal. The aim of this study was to discover the concentrations of total mercury (HgT) in the contour feathers, muscles, brain, lungs, liver, kidneys, heart and blood of four gull species Herring Gull (Larus argentatus), Common Gull (Larus canus), Black-headed Gull (Larus ridibundus) and Great Black-backed Gull (Larus marinus) and organic mercury (Hgorg) in the liver and brain of Herring Gull. The most important characteristic of the results obtained for the studied gulls was the statistically significant differences between the four species, probably resulting from their different diets-confirmed by stable-isotopes analysis (δ(15)N and δ(13)C). A logarithmic dependence was found between HgT in the blood and HgT in the brain of the Herring Gull. The authors suggest that among gulls burdened with the greatest mercury load, it is possible that the brain is protected by higher Hg accumulation in the muscles. The percentage share of Hgorg in the brain and liver of the Herring Gull depended on the concentration of HgT in these tissues and was always higher in the brain. In none of the cases, did the mercury levels assayed in the internal gulls' tissues exceed values associated with adverse health effects. PMID:26653750

  13. An Evaluation of Techniques to Control Problem Bird Species on Landfill Sites

    NASA Astrophysics Data System (ADS)

    Cook, Aonghais; Rushton, Steven; Allan, John; Baxter, Andrew

    2008-06-01

    Birds feeding on landfill sites cause problems in terms of nuisance to neighbors, flight safety, a threat to public health, and affecting the day to day site operation. A number of control measures exist to deter problem species; however, research into their effectiveness across sites and for multiple species has been limited. We use a modeling approach in order to assess the effectiveness of nine techniques — pyrotechnics, hand-held distress calls, static distress calls, blank ammunition, a combination of blank and lethal use of ammunition, the use of falcons, the use of hawks, wailers and helium-filled bird-scaring kites — at deterring three commonly recorded species — the Black-headed Gull ( Larus ridibundus), the Herring Gull ( Larus argentatus) and the Lesser Black-backed Gull ( Larus fuscus) — from six landfill sites across the United Kingdom. The use of distress calls, falconry, and combinations of lethal and nonlethal use of ammunition were the most effective techniques for initially deterring birds from these sites. However, when habituation is considered, there is a clear difference between techniques such as falconry, which have a lethal aspect and may act to reinforce the deterrence, and the use of techniques such as distress calls, which do not. However there are problems related to legislation and public perception when lethal techniques are used.

  14. An evaluation of techniques to control problem bird species on landfill sites.

    PubMed

    Cook, Aonghais; Rushton, Steven; Allan, John; Baxter, Andrew

    2008-06-01

    Birds feeding on landfill sites cause problems in terms of nuisance to neighbors, flight safety, a threat to public health, and affecting the day to day site operation. A number of control measures exist to deter problem species; however, research into their effectiveness across sites and for multiple species has been limited. We use a modeling approach in order to assess the effectiveness of nine techniques--pyrotechnics, hand-held distress calls, static distress calls, blank ammunition, a combination of blank and lethal use of ammunition, the use of falcons, the use of hawks, wailers and helium-filled bird-scaring kites --at deterring three commonly recorded species--the Black-headed Gull (Larus ridibundus), the Herring Gull (Larus argentatus) and the Lesser Black-backed Gull (Larus fuscus)--from six landfill sites across the United Kingdom. The use of distress calls, falconry, and combinations of lethal and nonlethal use of ammunition were the most effective techniques for initially deterring birds from these sites. However, when habituation is considered, there is a clear difference between techniques such as falconry, which have a lethal aspect and may act to reinforce the deterrence, and the use of techniques such as distress calls, which do not. However there are problems related to legislation and public perception when lethal techniques are used. PMID:18256779

  15. Antimicrobial Resistance in Wildlife: Implications for Public Health.

    PubMed

    Carroll, D; Wang, J; Fanning, S; McMahon, B J

    2015-11-01

    The emergence and spread of antimicrobial-resistant (AMR) bacteria in natural environments is a major concern with serious implications for human and animal health. The aim of this study was to determine the prevalence of AMR Escherichia coli (E. coli) in wild birds and mammalian species. Thirty faecal samples were collected from each of the following wildlife species: herring gulls (Larus argentatus), black-headed gulls (Larus ridibundus), lesser black-back gulls (Larus fuscus), hybrid deer species (Cervus elaphus x Cervus nippon) and twenty-six from starlings (Sturnus vulgaris). A total of 115 E. coli isolates were isolated from 81 of 146 samples. Confirmed E. coli isolates were tested for their susceptibility to seven antimicrobial agents by disc diffusion. In total, 5.4% (8/146) of samples exhibited multidrug-resistant phenotypes. The phylogenetic group and AMR-encoding genes of all multidrug resistance isolates were determined by PCR. Tetracycline-, ampicillin- and streptomycin-resistant isolates were the most common resistant phenotypes. The following genes were identified in E. coli: bla(TEM), strA, tet(A) and tet(B). Plasmids were identified in all samples that exhibited multidrug-resistant phenotypes. This study indicates that wild birds and mammals may function as important host reservoirs and potential vectors for the spread of resistant bacteria and genetic determinants of AMR. PMID:25639901

  16. Cruise summary for P-1-02-SC: acoustic imaging of natural oil and gas seeps and measurement of dissolved methane concentration in coastal waters near Pt. Conception, California

    USGS Publications Warehouse

    Lorenson, T.D.; Dougherty, Jennifer A.; Ussler, William, III; Paull, Charles K.

    2003-01-01

    Water-column acoustic anomalies and methane concentrations were documented in coastal waters surrounding Pt. Conception, California, in March 2002. The purpose of this survey, supported by the Minerals Management Service, was to locate active oil and gas seeps in the area as a background for further studies to determine hydrocarbon flux, mainly oil, into the environment. Objectives in reaching this goal are to (1) document the locations and geochemically fingerprint natural seeps within the offshore southern Santa Maria Basin; (2) geochemically fingerprint coastal tar residues and potential sources, both onshore and offshore, in this region; (3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; (4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; (5) attempt to predict transport pathways of oil from seep sources to the coastline and; (6) interpret the petroleum system history for the natural seeps. This survey, addressing objective 1, focused on the area from offshore Surf Beach to the north and Gaviota to the south in water depths ranging from 20 to 500m. In addition, nine stations were sampled outside this area to provide a regional context. Water-column methane concentrations were measured in water samples collected from the R/V Point Sur with Niskin bottles from various depths. A total of 724 water samples from 94 stations were collected.

  17. Morphological Variation on Isolated Populations of Praocis (Praocis) spinolai

    PubMed Central

    Benítez, Hugo A.; Pizarro-Araya, Jaime; Bravi, Raffaella; Sanzana, María-José; Alfaro, Fermín M.

    2014-01-01

    In this study, the morphological variations of four geographically isolated populations of Praocis (Praocis) spinolai Gay & Solier (Coleoptera: Tenebrionidae) in the transitional coastal desert, Chile, were studied. The study was conducted in the coastal area of Punta de Choros and Los Choros-Archipelago, which includes three islands: Choros, Damas, and Gaviota. 113 specimens of the species P. (P.) spinolai belonging to the four locations sampled were collected analyzed with geometric morphometrics techniques to explore the pattern of shape variation on the different isolated environments. The principal component analysis revealed a well-defined pattern of variation between the populations analyzed. Moreover, differences between populations emerged also from the canonical variation analysis and were confirmed by the Procrustes ANOVA. All analyses performed confirmed the existence of a pattern of variation, due to the isolation of the populations and to environmental effects. The islands are subject to more arid pressures than the continent, where there is a more stable environment and the presence of coastal wetlands and the coastal range of mountains act together and enable fog condensation. This study indicates the existence of a clear pattern of variation, which indicates an evolutionary trend among the population examined. PMID:25373158

  18. Distribution of Ground-Nesting Marine Birds Along Shorelines in Glacier Bay, Southeastern Alaska: An Assessment Related to Potential Disturbance by Back-Country Users

    USGS Publications Warehouse

    Arimitsu, M.L.; Piatt, J.F.; Romano, Marc D.

    2007-01-01

    With the exception of a few large colonies, the distribution of ground-nesting marine birds in Glacier Bay National Park in southeastern Alaska is largely unknown. As visitor use increases in back-country areas of the park, there is growing concern over the potential impact of human activities on breeding birds. During the 2003i??05 breeding seasons, the shoreline of Glacier Bay was surveyed to locate ground-nesting marine birds and their nesting areas, including wildlife closures and historical sites for egg collection by Alaska Native peoples. The nesting distribution of four common ground-nesting marine bird species was determined: Arctic Tern (Sterna paradisaea), Black Oystercatcher (Haematopus bachmani), Mew Gull (Larus canus), and Glaucous-winged Gull (Larus glaucescens). Observations of less abundant species also were recorded, including Herring Gull (Larus argentatus), Red-throated Loon (Gavia stellata), Canada Goose (Branta canadensis), Willow Ptarmigan (Lagopus lagopus), Semipalmated Plover (Charadrius semipalmatus), Spotted Sandpiper (Actitis macularia), Least Sandpiper (Calidris minutilla), Parasitic Jaeger (Stercorarius parasiticus), and Aleutian Tern (Sterna aleutica). Nesting distribution for Arctic Terns was largely restricted to the upper arms of the bay and a few treeless islets in the lower bay, whereas Black Oystercatchers were more widely distributed along shorelines in the park. Mew Gulls nested throughout the upper bay in Geikie Inlet and in Fingers and Berg Bays, and most Glaucous-winged Gull nests were found at wildlife closures in the central and lower bays. Several areas were identified where human disturbance could affect breeding birds. This study comprises the first bay-wide survey for the breeding distribution of ground-nesting marine birds in Glacier Bay National Park, providing a minimum estimate of their numbers and distribution within the park. This information can be used to assess future human disturbance and track natural

  19. Habitat Suitability Index Models: Laughing Gull

    USGS Publications Warehouse

    Zale, Alexander V.; Mulholland, Rosemarie

    1985-01-01

    A review and synthesis of existing information were used to develop a habitat model for laughing gull (Larus atricilla). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimally suitable habitat) for areas along the Gulf of Mexico coast. Habitat suitability indices are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for application of the model and techniques for measuring model variables are described.

  20. Retraction of a longevity record for a 36-year-old herring gull

    USGS Publications Warehouse

    Jonkel, G.M.; Pettingill, O.S., Jr.

    1974-01-01

    Full text: The longevity record for a 36-year-old Herring Gull, Larus argentatus (Pettingill 1967, Auk 84: 123), is erroneous. Herring Gull with band number A-676871, the basis of the record, was found dead on 20 June 1966 on the shore of Little Traverse Bay near Petoskey, Michigan, and reported to the Bird Banding Laboratory. The laboratory then mistakenly advised Pettingill that this gull was banded by him on 29 June 1930 on coastal Maine. He actually banded Herring Gull number A-676871 as a young bird on one of the Beaver Islands in Lake Michigan on 8 July 1948. The gull was thus 18 instead of 36 years old.

  1. Waterbird mortality from botulism type E in Lake Michigan (USA, Canada): an update

    USGS Publications Warehouse

    Brand, Christopher J.; Duncan, Ruth M.; Garrow, S.P.; Olson, D.; Schumann, L.E.

    1983-01-01

    Three outbreaks of botulism type E occurring in waterbirds on Lake Michigan since autumn 1976 are discussed. Natural ingestion of food containing type E toxin by Ring-billed Gulls (Larus delawarensis) and the presence of type E toxin in the blood from moribund gulls were demonstrated. Concurrent presence of type C and type E botulinal toxins was found in a die-off of Common Loons (Gavia immer). In combination with previous reported outbreaks, these incidents suggest that this disease is geographically widespread in Lake Michigan, and that environmental conditions conducive to type E botulinal toxin production and consumption occur in both summer and autumn.

  2. Identification and characterization of a novel adenovirus in the cloacal bursa of gulls

    SciTech Connect

    Bodewes, R.; Bildt, M.W.G. van de; Schapendonk, C.M.E.; Leeuwen, M. van; Boheemen, S. van; Jong, A.A.W. de; Osterhaus, A.D.M.E.; Smits, S.L.; Kuiken, T.

    2013-05-25

    Several viruses of the family of Adenoviridae are associated with disease in birds. Here we report the detection of a novel adenovirus in the cloacal bursa of herring gulls (Larus argentatus) and lesser black-backed gulls (Larus fuscus) that were found dead in the Netherlands in 2001. Histopathological analysis of the cloacal bursa revealed cytomegaly and karyomegaly with basophilic intranuclear inclusions typical for adenovirus infection. The presence of an adenovirus was confirmed by electron microscopy. By random PCR in combination with deep sequencing, sequences were detected that had the best hit with known adenoviruses. Phylogenetic analysis of complete coding sequences of the hexon, penton and polymerase genes indicates that this novel virus, tentatively named Gull adenovirus, belongs to the genus Aviadenovirus. The present study demonstrates that birds of the Laridae family are infected by family-specific adenoviruses that differ from known adenoviruses in other bird species. - Highlights: ► Lesions typical for adenovirus infection detected in cloacal bursa of dead gulls. ► Confirmation of adenovirus infection by electron microscopy and deep sequencing. ► Sequence analysis indicates that it is a novel adenovirus in the genus Aviadenovirus. ► The novel (Gull) adenovirus was detected in multiple organs of two species of gulls.

  3. Environmental pollutants in endangered vs. increasing subspecies of the lesser black-backed gull on the Norwegian Coast.

    PubMed

    Bustnes, Jan Ove; Helberg, Morten; Strann, Karl-Birger; Skaare, Janneche Utne

    2006-12-01

    Organochlorine (OC) residues were measured in eggs and blood of different subspecies of the lesser black-backed gull, Larus fuscus, on the Norwegian coast: a) increasing L. f. intermedius in the North Sea; b) endangered L. f. fuscus near the Arctic Circle; c) L. f. fuscus and greyish-mantled gulls, with a L. f. intermedius appearance, in the Barents Sea region. The dominating OCs in lesser black-backed gulls were polychlorinated biphenyls (PCB) and p,p'-dichlorodiphenyldichloroethylene (DDE). DDE and beta-hexachlorocyclohexane (beta-HCH) residues were higher in L. f. fuscus compared to L. f. intermedius and greyish-mantled birds in the Barents Sea region. In the latter area, blood residues of PCB and DDE in lesser black-backed gulls were as high as in great black-backed gulls, Larus marinus, while in the other regions they were lower. The higher DDE residues in endangered L. f. fuscus compared to increasing L. f. intermedius and greyish-mantled birds, which are invading northern Norway, suggest that OCs may have played a role in the population decline of L. f. fuscus, possibly in combination with nutrient stress. PMID:16564607

  4. Environmental and biological monitoring of persistent organic pollutants in waterbirds by non-invasive versus invasive sampling.

    PubMed

    Kocagöz, Rasih; Onmuş, Ortaç; Onat, İlgen; Çağdaş, Beste; Sıkı, Mehmet; Orhan, Hilmi

    2014-10-15

    Three main groups of persistent organic pollutants (POPs); namely organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs) were quantified in water and sediment samples, as well as in various invasive and non-invasive samples from waterbirds in the Büyük Menderes River (BMR). Liver and muscle tissues, blood, and preen gland oil samples of yellow-legged gull (Larus michahellis) and Euroasian coot (Fulica atra) were collected both from the origin (Işıklı Lake) and the estuary (Söke) of the river, blood and preen gland oil samples of grey heron (Ardea cinerea) and pelican (Pelecanus crispus) were collected from the estuary only. In addition, non-hatched eggs from several above species and Mediterranean gull (Larus melanocephalus), in either station were collected. In all samples, POP contamination was measured and the potential usefulness of those invasive and non-invasive sampling for biomonitoring was evaluated. Activities of antioxidant enzymes were measured as potential indicators of POP exposure and of changes in the cellular defence. Venous blood proved to be a promising biomonitor for the concentrations in liver and muscle, especially for PCBs. Activities of antioxidant enzymes were correlated with the liver concentrations of several OCP congeners. The measured egg DDE concentrations were below the established threshold concentrations for the risk of hatch and reproductive success. PMID:24503014

  5. Persistent organic pollutant and mercury concentrations in eggs of ground-nesting marine birds in the Canadian high Arctic.

    PubMed

    Peck, Liam E; Gilchrist, H Grant; Mallory, Conor D; Braune, Birgit M; Mallory, Mark L

    2016-06-15

    We collected eggs of eight marine bird species from several colony sites in the Canadian high Arctic located at approximately 76°N and analyzed them for concentrations of legacy persistent organic pollutants (POPs) and mercury. We provide the first report on concentrations of POPs in eggs of three Arctic species (Thayer's gull Larus thayeri, Sabine's gull Xema sabini, Ross's Gull Rhodostethia rosea), and we found significant differences in each of the POP profiles among the five species with sufficient data for statistical comparisons (Thayer's gull, black guillemot Cepphus grylle, Sabine's gull, Arctic tern Sterna paradisaea and common eider Somateria mollissima borealis). The Ross's Gull had unexpectedly high POP concentrations relative to the other species examined, although this was based on a single egg, while glaucous gull Larus hyperboreus eggs from our sampling location had very low POPs. Sabine's gulls had the lowest Hg of the eggs studied, consistent with their low trophic position, but concentrations of their legacy POPs were higher than expected. We also noted that total hexachlorocyclohexanes were higher than reported elsewhere in the circumpolar Arctic in three species. PMID:26971212

  6. Dioxins and dl-PCBs in gull eggs from Spanish Natural Parks (2010-2013).

    PubMed

    Morales, Laura; Gene'rosa Martrat, Ma; Parera, Jordi; Bertolero, Albert; Ábalos, Manuela; Santos, Francisco Javier; Lacorte, Silvia; Abad, Esteban

    2016-04-15

    The aim of this study was to evaluate the presence and distribution of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and biphenyls (PCBs), concretely those so-called as dioxin-like PCBs, in yellow-legged gull eggs (Larus michahellis) collected from five Natural Parks (some of them National Parks) in Spain during the period 2010-2013. PCDD/Fs and dl-PCBs were detected in all the samples. Due to the proximity to important urban and industrial areas higher concentrations were determined in colonies located in the Northern Mediterranean coast than those found in the Southern Mediterranean or Atlantic colonies where a softer anthropogenic impact occurs. Mean ∑PCDD/F concentrations ranged from 49 to 223pg/g lipid weight (lw) and ∑dl-PCB concentrations varied from 146 to 911ng/g lw. In the Natural Park of the Ebro Delta (Northern Mediterranean coast) two gull species share habitat: yellow-legged and Audouin gull (Larus audouinii). Eggs from both species were collected and PCDD/F and dl-PCB levels compared. The species that feeds exclusively on pelagic fish (L. audouinii) had significantly higher PCDD/F and dl-PCB levels than the scavenger L. michahellis, pointing out the diet-dependent differences in the accumulation of persistent organic pollutants between similar cohabitant breeding species. Finally, mean TEQ values were in general below those considered as critical for toxicological effects in birds. PMID:26808402

  7. Avian Bornaviruses in North American Gulls.

    PubMed

    Guo, Jianhua; Tizard, Ian; Baroch, John; Shivaprasad, H L; Payne, Susan L

    2015-07-01

    Avian bornaviruses, recently described members of the family Bornaviridae, have been isolated from captive parrots and passerines as well as wild waterfowl in which they may cause lethal neurologic disease. We report detection of avian bornavirus RNA in the brains of apparently healthy gulls. We tested 439 gull brain samples from 18 states, primarily in the northeastern US, using a reverse-transcriptase PCR assay with primers designed to detect a conserved region of the bornavirus M gene. Nine birds yielded a PCR product of appropriate size. Sequencing of PCR products indicated that the virus was closely related to aquatic bird bornavirus 1 (ABBV-1). Viral RNA was detected in Herring Gulls (Larus argentatus), Ring-billed Gulls (Larus delawarensis), and Laughing Gulls (Leucophaeus atricilla). Eight of the nine positive birds came from the New York/New Jersey area. One positive Herring Gull came from New Hampshire. Histopathologic examination of one well-preserved brain from a Herring Gull from Union County New Jersey, showed a lymphocytic encephalitis similar to that observed in bornavirus-infected parrots and geese. Bornavirus N protein was confirmed in two Herring Gull brains by immunohistochemistry. Thus ABBV-1 can infect gulls and cause encephalitic brain lesions similar to those observed in other birds. PMID:25973630

  8. Dioxins, furans and AHH-active PCB congeners in eggs of two gull species from the western Mediterranean.

    PubMed

    Pastor, D; Ruiz, X; Barceló, D; Albaigés, J

    1995-09-01

    Polychlorinated biphenyls, dibenzodioxins and dibenzofurans were analysed in eggs of a protected gull species, the Audouin's Gull (Larus audouinii) and compared to those of the Yellow-legged Gull (Larus cachinnans), both breeding in the Western Mediterranean (Ebro Delta and Medes Islands, respectively). Differences in concentrations as well as in congener profiles reflected differences in both habitat and diet of the two species. Levels of AHH-active PCB congeners were lower in Yellow-legged Gull (0.4-1.6 micrograms/g d.w) than in Audouin's Gull eggs (1.2-33.9 micrograms/g d.w.). These concentrations, expressed in international toxic equivalence factors (i-TEQ/g d.w.), were on average 24 times higher in the Audouin's gull. I-TEQ levels due to dioxins were also higher in this species by a factor of ca. 7. I-TEQ levels related to PCBs resulted 90-230 times higher than those of dioxins and furans. Thus, AHH-inducing PCBs might represent even higher toxicological hazards than dioxins and furans to some populations of seabirds. The necessity of assessing the impact of these compounds in rare and protected species is pointed out. PMID:8528648

  9. Lead and cadmium in wild birds in southeastern Spain

    SciTech Connect

    Garcia-Fernandez, A.J.; Sanchez-Garcia, J.A.; Luna, A.; Jimenez-Montalban, P.

    1995-12-01

    The main purpose of this study was to monitor exposure to lead and cadmium in wild birds in Murcia, a southeastern region of Spain on the Mediterranean coast. This region lies on one of the African-European flyways. Samples of liver, kidney, brain, bone, and whole blood from several species of wild birds were obtained during 1993. The authors found a clear relationship between cadmium and lead concentrations in birds and their feedings habits. Vultures (Gyps fulvus) had the highest concentrations of lead (mean 40 {micro}g/dl in blood), and seagulls (Larus argentatus and Larus ridibundus) the highest concentrations of cadmium (mean 4.43 {micro}g/g in kidney). Insectivores had high concentrations of both metals, and diurnal and nocturnal raptors showed the lowest tissue concentrations. The findings that tissue and blood concentrations were generally not elevated suggests environmental (rather than acute) exposure. Birds from more industrialized areas of the region studied here had higher concentrations of both lead and cadmium.

  10. Tracing waterbird exposure to total mercury and selenium: a case study at the solar saltworks of Thyna (sfax, Tunisia).

    PubMed

    Ramírez, Francisco; Abdennadher, Aida; Sanpera, Carola; Jover, Lluís; Hobson, Keith A; Wassenaar, Leonard I

    2011-06-15

    Saltworks have emerged as important alternative/complementary feeding habitats for avifauna. However, the consequences of such habitat shifts in terms of changes in exposure to contaminants are poorly understood. We evaluated the exposure of the waterbird community breeding at the saltworks of Thyna (Tunisia) to total Hg (THg) and Se according to their differential use of saltworks dietary resources, as revealed by δ¹³C and δ¹⁵N values in their eggs (included species [n] -sorted according to increasing reliance on saltworks resources: Yellow-legged Gull Larus michahellis [12], Common Tern Sterna hirundo [12], Slender-billed Gull Larus genei [15], Little Egret Egretta garzetta [20], and Pied Avocet Recurvirostra avosetta [22]). Concentrations of THg and Se were under the threshold points for deleterious effects. Egg THg concentrations significantly decreased as the dietary contribution of saltworks resources increased (mean: 3.23, 1.66, 0.76, 0.4, and 0.27 μg/g dw, respectively). Conversely, egg Se concentrations did not vary according to foraging habitats (2.49, 2.96, 2.61, 3.27, and 1.5 μg/g dw, respectively). Tracing waterbird exposure to THg and Se at saltworks was feasible through the use stable isotopic assays of eggs. Birds using saltworks are not exposed to higher concentrations of THg and Se than in adjacent marine habitats. PMID:21663312

  11. Natural Offshore Oil Seepage and Related Tarball Accumulation on the California Coastline - Santa Barbara Channel and the Southern Santa Maria Basin: Source Identification and Inventory

    USGS Publications Warehouse

    Lorenson, T.D.; Hostettler, Frances D.; Rosenbauer, Robert J.; Peters, Kenneth E.; Dougherty, Jennifer A.; Kvenvolden, Keith A.; Gutmacher, Christina E.; Wong, Florence L.; Normark, William R.

    2009-01-01

    Oil spillage from natural sources is very common in the waters of southern California. Active oil extraction and shipping is occurring concurrently within the region and it is of great interest to resource managers to be able to distinguish between natural seepage and anthropogenic oil spillage. The major goal of this study was to establish the geologic setting, sources, and ultimate dispersal of natural oil seeps in the offshore southern Santa Maria Basin and Santa Barbara Basins. Our surveys focused on likely areas of hydrocarbon seepage that are known to occur between Point Arguello and Ventura, California. Our approach was to 1) document the locations and geochemically fingerprint natural seep oils or tar; 2) geochemically fingerprint coastal tar residues and potential tar sources in this region, both onshore and offshore; 3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; 4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; and 5) interpret the petroleum system history for the natural seeps. To document the location of sub-sea oil seeps, we first looked into previous studies within and near our survey area. We measured the concentration of methane gas in the water column in areas of reported seepage and found numerous gas plumes and measured high concentrations of methane in the water column. The result of this work showed that the seeps were widely distributed between Point Conception east to the vicinity of Coal Oil Point, and that they by in large occur within the 3-mile limit of California State waters. Subsequent cruises used sidescan and high resolution seismic to map the seafloor, from just south of Point Arguello, east to near Gaviota, California. The results of the methane survey guided the exploration of the area west of Point Conception east to Gaviota using a combination of seismic instruments. The

  12. Root and shoot parts of strawberry: factories for production of functional human pro-insulin.

    PubMed

    Tavizi, Ashkan; Javaran, Mokhtar Jalali; Moieni, Ahmad; Mohammadi-Dehcheshmeh, Manijeh; Mohebodini, Mehdi; Ebrahimie, Esmaeil

    2015-05-01

    Diabetes, a disease caused by excessive blood sugar, is caused by the lack of insulin. For commercial production, insulin is made in bacteria or yeast by protein recombinant technology. The focus of this research is evaluating another resource and producing of recombinant insulin protein in as strawberry as this plant has high potential in production of pharmaceutical proteins. Strawberry is a suitable bioreactor for production of recombinant proteins especially edible vaccines. In this research, human pro-insulin gene was cloned in pCAMBIA1304 vector under CaMV35S promoter and NOS terminator. Agrobacterium tumefaciens LBA4404, AGL1, EHA105, EHA101, C58, C58 (pGV2260) and C58 (pGV3101) strains were used for transformation of pro-insulin gene into strawberry cv. Camarosa, Selva, Sarian Hybrid, Pajaro, Paros, Gaviota, Alpine. Additionally, Agrobacterium rhizogenes K599, R1000, A4 and MSU440 strains were utilized for gene transformation into hairy roots. PCR analysis indicated the presence of transformed human pro-insulin gene in the strawberry and hairy roots. Also, its transcription was confirmed using RT-PCR. Furthermore, the analysis of plants, fruits and hairy roots at the level of proteins using dot blot, ELISA, SDS-PAGE and ECL tests re-confirmed the expression of this protein in the transgenic plants as well as hairy roots. Protein purification of human pro-insulin from transgenic tissues was performed using affinity chromatography. Finally, the bioassay of recombinant pro-insulin was performed. The analysis of second generations of transgenic plants (T1) at DNA and protein levels was also performed as a complementary experiment. This study opens a new avenue in molecular farming of human pro-insulin through its mass production in roots and shoots of strawberry. PMID:25403333

  13. Contrasting clonal structure among Pocillopora (Scleractinia) communities at two environmentally distinct sites in the Gulf of California

    NASA Astrophysics Data System (ADS)

    Pinzón, J. H.; Reyes-Bonilla, H.; Baums, I. B.; LaJeunesse, T. C.

    2012-09-01

    The contributions of sexual versus asexual reproduction are thought to play an important role in the abundance and ecological success of corals, especially in marginal habitats. Pocillopora corals are distributed throughout the Indo-Pacific and dominate shallow hard-bottom communities in the eastern Pacific where broad seasonal fluctuations in temperature and water turbidity create suboptimal conditions for reef community development. Previous work had revealed three genetic clades in the eastern Pacific that show little correspondence with colony morphology; the broad distribution of type 1 extends into the subtropical southern Gulf of California. Here we examine genetic and clonal structure of two type 1 communities separated by 10 km with microsatellite data. Samples were collected randomly in six 10 m radius circular plots (20 colonies per plot, 3 plots per site). Sites differed in their relative clonality because clonemates (ramets) from a single clone (genet) dominated a large portion (90.9 m long) of the protected leeward side of Gaviota Island (Number of genets/Number of samples = 0.35; observed Genotypic diversity/expected Genotypic diversity = 0.087), while an exposed community at the entrance to La Paz Bay, Punta Galeras, exhibited high genotypic diversity ( N g / N = 0.85; G o / G e = 0.714). Gene flow was unrestricted between sites indicating these communities comprised a single population. The relative proportion of asexual colonies found between community aggregations of Pocillopora in the Gulf of California differed significantly and suggests factors at local, not regional, scales affect these patterns. The possibility that heterogeneity in clonal structure is common throughout the eastern Pacific and across the west Indo-Pacific requires further study. Finally, since morphological variation in Pocillopora has been underappreciated and is in need of taxonomic revision, the use of a consistent field-sampling protocol and high-resolution makers will

  14. Morphology, acoustic characteristics, and Late Quaternary growth of conception Fan, Santa Barbara basin, California

    SciTech Connect

    Kraemer, S.M.C.

    1986-04-01

    A radial borderland-basin fan in the western half of the Santa Barbara basin, the Conception Fan, shows characteristics of a debris slope. More than 3000 mi of closely spaced (3.5 kHz) high-resolution profiles, 270 gravity cores, and 8 borings were used to map channel and fan morphology, and channel, levee, and lobe acoustic facies. Two major unconformities are recognized on the seismic profiles. The upper unconformity represents the 10-k.y.B.P. horizon. The lower unconformity is the erosional surface of the late Wisconsinan lowstand of sea level, 18-26 k.y.B.P. Eustasy and tectonism produced two pulses of deposition, each from a different point source, during the Flandrian transgression. Prior to the late Pleistocene, the Conception Fan was fed by one major canyon/channel system, above the western part of the fan. During the late Pleistocene, two small submarine canyons were cut into the slope 7 mi east. Four major channels, smaller than the western channel system, were incised into the fan surface, indicating the eustatic decrease in sediment input. The fault-controlled western canyon (Sacate) fed all but the eastern channel. Faulting and slumping on the slope cut the eastern canyon (Gaviota) and formed the eastern channel. Numerous slope gullies influenced eastern canyon and channel development. Holocene currents rounding Point Conception have winnowed fine sediments in the western channel region, resulting in hummocky topography and the scoured appearance of the channel. Hemipelagic deposition dominates the lower-middle and lower fan of the eastern part of the fan. The western part of the fan seems to be receiving slope-like deposits over the relict fan surface.

  15. Dynamic growth of slip surfaces in catastrophic landslides

    PubMed Central

    Germanovich, Leonid N.; Kim, Sihyun; Puzrin, Alexander M.

    2016-01-01

    This work considers a landslide caused by the shear band that emerges along the potential slip (rupture) surface. The material above the band slides downwards, causing the band to grow along the slope. This growth may first be stable (progressive), but eventually becomes dynamic (catastrophic). The landslide body acquires a finite velocity before it separates from the substrata. The corresponding initial-boundary value problem for a dynamic shear band is formulated within the framework of Palmer & Rice's (Proc. R. Soc. Lond. A 332, 527–548. (doi:10.1098/rspa.1973.0040)) approach, which is generalized to the dynamic case. We obtain the exact, closed-form solution for the band velocity and slip rate. This solution assesses when the slope fails owing to a limiting condition near the propagating tip of the shear band. Our results are applicable to both submarine and subaerial landslides of this type. It appears that neglecting dynamic (inertia) effects can lead to a significant underestimation of the slide size, and that the volumes of catastrophic slides can exceed the volumes of progressive slides by nearly a factor of 2. As examples, we consider the Gaviota and Humboldt slides offshore of California, and discuss landslides in normally consolidated sediments and sensitive clays. In particular, it is conceivable that Humboldt slide is unfinished and may still displace a large volume of sediments, which could generate a considerable tsunami. We show that in the case of submarine slides, the effect of water resistance on the shear band dynamics may frequently be limited during the slope failure stage. For a varying slope angle, we formulate a condition of slide cessation. PMID:26997904

  16. At-sea distribution and abundance of seabirds off southern California: A 20-year comparison

    USGS Publications Warehouse

    Mason, J.W.; McChesney, G.J.; McIver, W.R.; Carter, H.R.; Takekawa, J.Y.; Golightly, R.T.; Ackerman, J.T.; Orthmeyer, D.L.; Perry, W.M.; Yee, J.L.; Pierson, M.O.; McCrary, M.D.

    2007-01-01

    We conducted aerial at-sea and coastal surveys to examine the distribution and abundance of seabirds off southern California, from Cambria, California, to the Mexican border. From May 1999-January 2002, we flew 102 d, covered >54,640 km of transect lines, and conducted nine complete surveys of southern California in January, May, and September. We identified 54 species comprising 12 families and counted >135,000 individuals. Seabird densities were greater along island and mainland coastlines than at sea and were usually greatest in January surveys. Densities were greatest at sea near the northern Channel Islands in January and north of Point Conception in May, and lowest in the southwestern portion of the Southern California Bight in all survey months. On coastal transects, seabird densities were greatest along central and southern portions of the mainland coastline from Point Arguello to Mexico. We estimated that 981,000 ?? 144,000 (x?? ?? SE) seabirds occurred in the study area in January, 862,000 ?? 95,000 in May, and 762,000 ?? 72,000 in September. California Gulls (Larus californicus), Western Grebes (Aechmophorus occidentalis), and Cassin's Auklets (Ptychoramphus aleuticus) were most abundant in January surveys at sea, whereas Sooty and Short-tailed shearwaters (Puffinus griseus and P. tenuirostris), phalaropes (Phalaropus spp.), and Western Gulls (Larus. occidentalis) were most abundant in May and September surveys. On coastal transects, California Gulls, Western Grebes, Western Gulls, and Surf Scoters (Melanitta perspicillata) were most abundant in January; Western Grebes, Western Gulls, Surf Scoters, and Brown Pelicans (Pelecanus occidentalis) were most abundant in May; and Sooty Shearwaters, Short-tailed Shearwaters, Western Gulls, Western Grebes, Brown Pelicans, and Heermann's Gulls (Larus heermanni) were most abundant in September. Compared to historical seabird densities collected in the same area two decades ago (1975-1978 and 1980-1983), abundance

  17. Mixed-function oxidase activity in seabirds and its relationship to oil pollution.

    PubMed

    Peakall, D B; Jeffrey, D A; Boersma, D

    1987-01-01

    1. The hepatic activity of epoxide hydrolase, aldrin epoxidase, aminopyrine N-demethylase, 7-ethoxyresorufin O-deethylase, benzo(a)pyrene 3-hydroxylase and UDP glucuronyl transferase was determined in adult herring gulls (Larus argentatus) at various stages of the breeding season. 2. MFO activity was measured for adult Leach's storm-petrels (Oceanodroma leucorhoa), guillemot (Uria aalge) and Atlantic puffins (Fratercula arctica). For most assays the values were highest for the puffin. 3. MFO activity in both nestling and adult Atlantic puffins was determined. The degree of induction caused by a single internal dose of Prudhoe Bay crude oil in adult puffins and that caused by multiple internal doses in nestling puffins was measured. PMID:2890477

  18. Levels and temporal trends (1983-2003) of persistent organic pollutants (POPs) and mercury (Hg) in seabird eggs from Northern Norway.

    PubMed

    Helgason, Lisa B; Barrett, Rob; Lie, Elisabeth; Polder, Anuschka; Skaare, Janneche U; Gabrielsen, Geir W

    2008-09-01

    The main objective of this study was to investigate possible temporal trends of persistent organic pollutants (POPs) and mercury in eggs of herring gulls (Larus argentatus), black-legged kittiwakes (Rissa tridactyla), common guillemots (Uria aalge) and Atlantic puffins (Fratercula arctica) in Northern Norway. Eggs were collected in 1983, 1993 and 2003. Egg concentrations of POPs (PCB congeners IUPAC numbers: CB-28, 74, 66, 101, 99, 110, 149, 118, 153, 105, 141, 138, 187, 128, 156, 157, 180, 170, 194, 206, HCB, alpha-HCH, beta-HCH, gamma-HCH, oxychlordane, trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT) and mercury were quantified. Generally, POP levels decreased between 1983 and 2003 in all species. No significant temporal trend in mercury levels was found between 1983 and 2003. PMID:18262696

  19. Levels and temporal trends (1983-2003) of polybrominated diphenyl ethers and hexabromocyclododecanes in seabird eggs from north Norway.

    PubMed

    Helgason, Lisa B; Polder, Anuschka; Føreid, Siri; Baek, Kine; Lie, Elisabeth; Gabrielsen, Geir W; Barrett, Robert T; Skaare, Janneche U

    2009-05-01

    The present study assessed temporal trends (1983-2003) of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in eggs of herring gulls (Larus argentatus), Atlantic puffins (Fratercula arctica), and black-legged kittiwakes (Rissa tridactyla) in North Norway. Generally, PBDE concentrations increased between 1983 and 1993 and then leveled out, although species-specific trends were reported. Levels of alpha-HBCD increased in all species throughout the 20-year period. Levels of nona-BDEs and BDE 209 ranged from nondetectable to parts per billion. Nevertheless, highly variable procedural blanks were reported for the nona-BDEs and BDE 209, which clearly illustrates the importance of including blanks repeatedly during determination of these compounds. PMID:19102583

  20. Contaminant levels in colonial waterbirds from Green Bay and Lake Michigan, 1975-80

    USGS Publications Warehouse

    Heinz, G.H.; Erdman, T.C.; Haseltine, S.D.; Stafford, C.

    1985-01-01

    Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polychlorinated styrenes (PCSs), and mercury were measured in the eggs of 10 species of colonial waterbirds nesting in areas aroung Green Bay or Lake Michigan from 1975 to 1980. Residues also were measured in the carcasses and brains of black-crowned night-herons (Nycticorax nycticorax). The highest residues were of PCBs, DDE, mercury, and dieldrin; for some species, levels of these chemicals possibly were high enough to have caused reproductive effects. Other organochlorine pesticides were found at low levels. Only trace amounts of PCSs and PBBs were found. Eggs of herring gulls (Larus argentatus) collected in 1977 from an island in Lake Michigan contained an average of 100 ppm PCBs and 33 ppm DDE; this was the most- contaminated species. Cattle egrets (Bubulcus ibis), the only bird that is not a fish eater, contained only small quantities of DDE and mercury.

  1. Effects of PCBs on liver ultrastructure and monooxygenase activities in Japanese quail

    SciTech Connect

    Stouvenakers, N.; Kremers, P.

    1996-05-01

    The effect of environmental pollutants such as PCBs and DDT on avian species is well documented. It is proven that chronic high level PCB intoxication perturbs calcium metabolism in birds, affecting eggshell thickness. PCBs have an impact on the liver. which accumulates high levels of toxicants. These induce drug-metabolizing enzyme activities in quail (Coturnix coturnix), herring gull (larus argentatus), and partridge (Prdix perdix). As these enzymes can degrade endogeneous molecules such as steroids, xenobiotics like PCBs can severely hinder birds` reproductive performance. PCBs induce damage such as regression of the testes, decreased sperm concentration, and altered embryonic development resulting in death or malformation of chicks. More ever, ultrastructural alterations linked with induction of these enzymes have been observed in the livers of PCB-contaminated chickens and ducks. This study examines the effects of Aroclor 1254 on liver morphology and glycogen content in quail, and related morphological modification to liver monoxygenase activities. 26 refs., 6 figs., 1 tab.

  2. Infectious bursal disease virus antibodies in eider ducks and Herring Gulls

    USGS Publications Warehouse

    Hollmen, T.; Franson, J.C.; Docherty, D.E.; Kilpi, Mikael; Hario, Martti; Creekmore, L.H.; Petersen, M.R.

    2000-01-01

    We measured antibodies to infectious bursal disease virus (IBDV) in blood of nesting Common Eider (Somateria mollissima) females and immature Herring Gulls (Larus argentatus) in the Baltic Sea, and in blood of Spectacled Eider (Somateria fischeri) females nesting in a remote area of western Alaska. Positive (??? 1:16) IBDV titers occurred in 75% of the eiders and 45% of the Herring Gull chicks. In eiders, the prevalence of positive titers differed among locations. We found no evidence that IBDV exposure impaired the immune function of Herring Gull chicks, based on their response to inoculation of sheep red blood cells. We suggest that eider ducks and Herring Gulls have been exposed to IBDV, even in locations where contact with poultry is unlikely. The presence of this virus in wild bird populations is of concern because it causes mortality of up to 30% in susceptible poultry.

  3. Behaviorally Induced Camouflage: A New Mechanism of Avian Egg Protection.

    PubMed

    Mayani-Parás, Fernando; Kilner, Rebecca M; Stoddard, Mary Caswell; Rodríguez, Cristina; Drummond, Hugh

    2015-10-01

    When animals potentially occupy diverse microhabitats, how can camouflage be achieved? Here we combine descriptive and experimental methods to uncover a novel form of phenotypic plasticity in the camouflage of bird eggs that may be present in other avian taxa. Soil from the bare substrate adheres to the blue-footed booby's (Sula nebouxii's) pale eggs, which parents manipulate both under and on top of their webs. Analysis of digital images confirmed that dirtiness increases progressively during the first 16 days of the incubation period, making eggs more similar to the nest substrate. Observations of 3,668 single-egg clutches showed that the probability of egg loss declines progressively over the same time frame and then remains low for the rest of the 41-day incubation period. An experiment showed that when chicken eggs are soiled and exposed in artificial booby nests, they are less likely to be taken by Heermann's gulls (Larus heermanni) than clean eggs. PMID:26655580

  4. Vaccinia recombinant virus expressing the rabies virus glycoprotein: safety and efficacy trials in Canadian wildlife.

    PubMed Central

    Artois, M; Charlton, K M; Tolson, N D; Casey, G A; Knowles, M K; Campbell, J B

    1990-01-01

    Twenty-six meadow voles (Microtus pennsylvanicus), ten woodchucks (Marmota monax), thirteen grey squirrels (Sciurus carolinensis), thirteen ring-billed gulls (Larus delawarensis), six red-tailed hawks (Buteo jamaicensis) and eight great horned owls (Bubo virginianus) received vaccinia virus recombinant expressing the rabies virus glycoprotein (V-RG) by direct instillation into the oral cavity. Each of ten coyotes (Canis latrans) received the virus in two vaccine-laden baits. Several voles and most of the gulls died from diseases unrelated to vaccination during the observation period, but all other animals remained healthy and survived. These deaths from causes other than vaccination and the absence of any lesions suggestive of vaccinia infection indicate that it is unlikely that any animal suffered or died as a result of V-RG administration. In addition several animals showed an unexpected high level of rabies neutralizing antibodies. PMID:2249183

  5. Preliminary assessment of contaminants in the sediment and organisms of the Swartkops Estuary, South Africa.

    PubMed

    Nel, L; Strydom, N A; Bouwman, H

    2015-12-30

    Urban estuaries are susceptible to metal and organic pollution, yet most remain understudied in South Africa with respect to the presence, concentrations and distribution of contaminants. Metal and organic chemical concentrations were assessed in sediment and organisms from different trophic levels in the lower reaches of the Swartkops Estuary. Species sampled included Upogebia africana (Malacostraca: Upogebiidae), Gilchristella aestuaria (Clupeidae), Psammogobius knysnaensis (Gobiidae), Mugil cephalus (Mugilidae), Lichia amia (Carangidae), Argyrosomus japonicus (Sciaenidae), Pomadasys commersonnii (Haemulidae) and Larus dominicanus (Avis: Laridae). This study is one of the most comprehensive studies to date assessing pollution levels in a food web in estuaries in South Africa. Due to biomagnification, higher concentrations of Arsenic, Lead, Mercury and Cadmium were found in the juveniles stages of popular angling fishes. High concentrations of Cadmium and Arsenic were recorded in the liver of L. amia, A. japonicus and P. commersonnii which exceed international quality food guidelines. Eggs from the gull, L. dominicanus, showed detectable concentrations of PCBs. PMID:26593278

  6. Mutagenicity studies on herring gulls from different locations on the Great Lakes. I. Sister chromatid exchange rates in herring-gull embryos.

    PubMed

    Ellenton, J A; McPherson, M F

    1983-01-01

    Unincubated herring-gull (Larus argentatus) eggs were collected from five colonies on the Great Lakes Basin and from one relatively pollutant-clean colony on the Atlantic coast. Eggs were incubated at 38 degrees C with 55% relative humidity, and sister chromatid exchange (SCE) levels were measured in 7-d embryos. For all of the colonies, the average SCE/chromosome frequency ranged from 0.069 to 0.101; however, no significant differences were found. Organochlorine analysis was carried out on egg homogenates for each colony, to determine the levels of several contaminants. There were no relationships found between any of the contaminant levels and the SCE frequencies. The study indicates that either the contaminants present in the herring-gull eggs are not having any genetic effects on the embryos or, alternatively, that there may be genetic damage that measurement of SCEs in the 7-d embryo is unable to detect. PMID:6655738

  7. Mercury concentrations in feathers of marine birds in Arctic Canada.

    PubMed

    Mallory, Mark L; Braune, Birgit M; Provencher, Jennifer F; Callaghan, D Benjamin; Gilchrist, H Grant; Edmonds, Samuel T; Allard, Karel; O'Driscoll, Nelson J

    2015-09-15

    Mercury (Hg) concentrations are a concern in the Canadian Arctic, because they are relatively high compared to background levels and to similar species farther south, and are increasing in many wildlife species. Among marine birds breeding in the Canadian Arctic, Hg concentrations have been monitored regularly in eggs and intermittently in livers, but feathers have generally not been used as an indicator of Hg exposure or burden. We examined Hg concentrations in six marine bird species in the Canadian Arctic. Ivory gull Pagophila eburnea, feather Hg was exceptionally high, while glaucous gull Larus hyperboreus feather Hg was unexpectedly low, and ratios of feather THg to egg THg varied across species. The proportion of total Hg that was comprised of methyl Hg in ivory gull feathers was lower than in other species, and may be related to photo-demethylation or keratin breakdown in semi-opaque feather tissue. PMID:26130527

  8. Sleeping gulls monitor the vigilance behaviour of their neighbours

    PubMed Central

    Beauchamp, Guy

    2008-01-01

    Individuals in groups are often thought to scan their surroundings for threats independently of one another. Models, however, suggest that foragers should monitor the vigilance level of their neighbours to prevent cheating, and to gather information about incipient predation risk. Evidence for monitoring of vigilance is scant. Here, I examined changes in vigilance levels in sleeping gulls (Larus sp.) surrounded by neighbours in various states of alertness. Controlling for group size and neighbour density, gulls interrupted sleep more often to scan their surroundings, and were therefore more vigilant, when their neighbours were alert rather than sleeping or preening. The results provide evidence for copying of vigilance within groups of birds, suggesting a complex flow of information about predation risk in groups. PMID:18940772

  9. Weathered oil: effect on hatchability of heron and gull eggs

    SciTech Connect

    Macko, S.A.; King, S.M.

    1980-08-01

    Contact with weathered oil seems more likely for waterbirds than contact with fresh oil; however, the effects of weathered oil on embryo survival have only partially been explored. Results of one study showed that 20 ..mu..L of 4 week-old crude oil applied to the eggshell surface caused a significant decrease in embryo survival of mallard (Anas platyrhynchos) eggs. In that study, oil was weathered under laboratory conditions using fresh water. To our knowledge, there have been no tests to determine the effects on egg hatchability of oil naturally weathered in marine habitats. The present study assesses the effects of external applications of naturally weathered crude oil on embryo survival of Louisiana heron (Hydranassa tricolor) and laughing gull (Larus atricilla) eggs.

  10. Analysis and visualization of animal movement

    PubMed Central

    Shamoun-Baranes, Judy; van Loon, E. Emiel; Purves, Ross S.; Speckmann, Bettina; Weiskopf, Daniel; Camphuysen, C. J.

    2012-01-01

    The interdisciplinary workshop ‘Analysis and Visualization of Moving Objects’ was held at the Lorentz Centre in Leiden, The Netherlands, from 27 June to 1 July 2011. It brought together international specialists from ecology, computer science and geographical information science actively involved in the exploration, visualization and analysis of moving objects, such as marine reptiles, mammals, birds, storms, ships, cars and pedestrians. The aim was to share expertise, methodologies, data and common questions between different fields, and to work towards making significant advances in movement research. A data challenge based on GPS tracking of lesser black-backed gulls (Larus fuscus) was used to stimulate initial discussions, cross-fertilization between research groups and to serve as an initial focus for activities during the workshop. PMID:21865243

  11. Vaccinia recombinant virus expressing the rabies virus glycoprotein: safety and efficacy trials in Canadian wildlife.

    PubMed

    Artois, M; Charlton, K M; Tolson, N D; Casey, G A; Knowles, M K; Campbell, J B

    1990-10-01

    Twenty-six meadow voles (Microtus pennsylvanicus), ten woodchucks (Marmota monax), thirteen grey squirrels (Sciurus carolinensis), thirteen ring-billed gulls (Larus delawarensis), six red-tailed hawks (Buteo jamaicensis) and eight great horned owls (Bubo virginianus) received vaccinia virus recombinant expressing the rabies virus glycoprotein (V-RG) by direct instillation into the oral cavity. Each of ten coyotes (Canis latrans) received the virus in two vaccine-laden baits. Several voles and most of the gulls died from diseases unrelated to vaccination during the observation period, but all other animals remained healthy and survived. These deaths from causes other than vaccination and the absence of any lesions suggestive of vaccinia infection indicate that it is unlikely that any animal suffered or died as a result of V-RG administration. In addition several animals showed an unexpected high level of rabies neutralizing antibodies. PMID:2249183

  12. Changes in prevalence and intensity of infection of Profilicollis altmani (Perry, 1942) cystacanth (Acanthocephala) parasitizing the mole crab Emerita analoga (Stimpson, 1857): an El Niño cascade effect?

    NASA Astrophysics Data System (ADS)

    Oliva, Marcelo E.; Barrios, Irene; Thatje, Sven; Laudien, Jürgen

    2008-03-01

    Prevalence and intensity changes in cystacanths of the acanthocephalan Profilicollis altmani parasitizing the mole crab Emerita analoga under El Niño (EN) and non-El Niño (non-EN) conditions are analyzed. Both, mean intensity and prevalence of infection by P. altmani differ significantly for the whole size range and for each size class of 10 mm intervals (except prevalence for size classes exceeding 18 mm carapace length) between EN (1998) and non-EN (2002) years, without observed size distribution differences in the intermediate host E. analoga under either condition. Significant difference in infestation rates of the intermediate host E. analoga is discussed as being an EN cascade effect on predators such as sea birds (i.e., Larus spp. and Calidris sp.), acting as definitive hosts of P. altmani, and which are known to decrease significantly in abundance during EN.

  13. Uptake of /sup 226/Ra by established vegetation and black cutworm larvae, Agrotis ipsilon (class Insecta: order Lepidoptera), on U mill tailings at Elliot Lake, Canada

    SciTech Connect

    Clulow, F.V.; Dave, N.K.; Lim, T.P.; Cloutier, N.R.

    1988-07-01

    Radium-226 levels in samples from an inactive U tailings site at Elliot Lake, Ontario, Canada, were: 9140 +/- 500 mBq g-1 dry weight in the substrate; 62 +/- 1 mBq g-1 dry weight in rye, Secale cereale, and less than 3.7 mBq g-1 dry weight in oats, Avena sativa, the dominant species established by revegetation of the tailings; and 117 +/- 7 mBq g-1 dry weight in washed and unwashed black cutworm larvae. Concentration ratios were: vegetation to tailings 0.001-0.007; black cutworms to vegetation 3.6 and black cutworms to tailings 0.01. The values are considered too low to be considered a hazard to herring gulls, Larus argentatus, which occasionally feed on cutworms.

  14. Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: associations with basal metabolism and circulating thyroid hormones.

    PubMed

    Verreault, Jonathan; Bech, Claus; Letcher, Robert J; Ropstad, Erik; Dahl, Ellen; Gabrielsen, Geir W

    2007-01-01

    Exposure to organohalogens in endotherms has been suggested to impose chemically induced stress by affecting functions related to maintenance energy requirements. Effects on basal metabolic rate (BMR) have been suggested to be, in part, mediated through interactions with the thyroid hormones (THs). We investigated the relationships between plasma concentrations of major organochlorines, PBDEs, hydroxylated (OH)- and methoxylated (MeO)-PBDEs and OH-PCBs, circulating TH levels and BMR in breeding glaucous gulls (Larus hyperboreus) from the Norwegian Arctic. Negative associations were found between BMR and concentrations of sigma PCB, Sigma DDT and particularly Sigma chlordane, which combined made up 91% of the total contaminant burden. Levels of THs (thyroxine and triiodothyronine) were not associated significantly with variation of BMR or concentrations of any of the compounds determined. The present study suggests that BMR may be altered in glaucous gulls exposed to high loadings of persistent contaminants in the Norwegian Arctic environment. PMID:16713050

  15. Nesting biology of laughing gulls in relation to agricultural chemicals in south Texas, 1978-81

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Prouty, R.M.

    1983-01-01

    Laughing Gulls (Larus atricilla) were studied along the south Texas coast during 1978-1981 to determine productivity and to evaluate the effects of environmental pollutants on reproduction. The average clutch-size was 2.6, ranging from 2.3-2.8. Sixty-six percent of the eggs hatched and 82% of the pairs hatched at least one egg. Productivity (fledglings/total nests) averaged 1.0 fledgling per nest. DDE and other organochlorine residues were low in eggs (usually <3 ppm wet weight) and were not suspected of causing reproductive problems. However, organophosphate pesticides sprayed on crops near the study areas reduced productivity by as much as 33% during 3 of 4 years, implying that certain of these chemicals may pose serious threats to the population.

  16. Prevalence of Cryptosporidium species in wildlife populations within a watershed landscape in southeastern New York State.

    PubMed

    Ziegler, Peter E; Wade, Susan E; Schaaf, Stephanie L; Stern, David A; Nadareski, Christopher A; Mohammed, Hussni O

    2007-06-20

    A cross-sectional study was conducted to determine the prevalence of Cryptosporidium in wildlife in the New York City (NYC) Watershed in southeastern New York State. A total of 6227 fecal samples were collected and evaluated from 5892 mammals (38 species), 263 birds (14 species), 2 reptiles (2 species), 8 amphibians (4 species), and 62 fish (15 species). Cryptosporidium was detected in 30 species. Of the species found positive for Cryptosporidium, 16 represented new records for this parasite-Alosa pseudoharengus, Larus delawarensis, Blarina brevicauda, Sorex cinereus, Parascalops breweri, Myotis lucifugus, Peromyscus maniculatus, Microtus pennsylvanicus, Clethrionomys gapperi, Tamiasciurus hudsonicus, Marmota monax, Erethizon dorsatum, Canis latrans, Mustela erminea, Mustela vison, and Lynx rufus. Factors such as age, sex, season, and land use were evaluated to determine if there was any association with infection by this parasite. Animals were more likely to be positive for Cryptosporidium during spring and in agricultural land use. PMID:17466459

  17. Effectiveness of data dependence analysis

    SciTech Connect

    Maydan, D.E.; Hennessy, J.L.; Lam, M.S.

    1995-02-01

    Data dependence testing is the basic step in detecting loop level parallelism in numerical programs. The problem is undecidable in the general case. Therefore, work has been concentrated on a simplified problems, affine memory disambiguation. In this simpler domain, array references and loops bounds are assumed to be linear integer functions of loop variables. Dataflow information is ignored. For this domain, we have shown that in practice the problem can be solved accurately and efficiently. This paper studies empirically the effectiveness of this domain restriction, however many real references are affine and flow insensitive. We use Larus`s llpp system to find all the data dependences dynamically. We compare these to the results given by our affine memory disambiguation system. This system is exact for all the cases we see in practice. We show that while the affine approximation is reasonable, memory disambiguation is not a sufficient approximation for data dependence analysis. We propose extensions to improve the analysis.

  18. Balancing predation and egg harvest in a colonial seabird: A simulation model

    USGS Publications Warehouse

    Zador, S.G.; Piatt, J.F.; Punt, A.E.

    2006-01-01

    We developed an individual-based model to study the effects of different regimes of harvesting eggs and natural predation on reproductive success in a colony of the glaucous-winged gull (Larus glaucescens) in Glacier Bay National Park, Alaska. The model incorporates the sequence of egg laying, relaying, and incubation to hatching for individual nests and calculates hatching success, incubation length, and the total number of eggs laid (as a result of re-nesting and relaying) in all nests in the colony. Stochasticity is incorporated in the distribution of nest lay dates, predation rates, and nests attacked during predation and harvest events. We estimated parameter values by fitting the model to data collected at a small colony during 1999 and 2000 using maximum likelihood. We then simulated harvests and analyzed model predictions. Model outputs indicate that harvesting early, and at one time, provides a predictable take of eggs with the least impact to gulls.

  19. Stable isotope analysis of temporal variation in the diets of pre-fledged Laughing Gulls

    USGS Publications Warehouse

    Knoff, A.J.; Macko, S.A.; Erwin, R.M.; Brown, K.M.

    2002-01-01

    The *13C, *15N, and *34S stable isotopic values of feathers from pre-fledged Laughing Gulls (Larus atricilla) in coastal Virginia and Jamaica Bay, New York were used to examine dietary variation during the nestling period. The tip portions of the feathers were used to indicate diet during the initiation of primary feather growth, whereas the base portions indicated diet during the period immediately prior to fledging. The results indicate that diets of the nestlings in Virginia moved to a higher trophic level during the period prior to fledging, however the New York nestlings did not appear to undergo any appreciable dietary change during this period. Overall, nestlings from both colonies consumed proportionately more foods of marine origin than freshwater or terrestrial. Therefore, the results do not support those of earlier studies that suggested that partially developed salt glands in young gulls might restrict the diet to more terrestrial or freshwater prey in the early stages of nestling growth.

  20. Simulations of seabird damage and recovery from oilspills in the northern Gulf of Alaska.

    USGS Publications Warehouse

    Samuels, W.B.; Lanfear, K.J.

    1982-01-01

    If an oilspill contacts a colony of glaucous-winged gulls Larus hyperboreus, reducing the population by 50%, the population is expected to recover to its pre-spill level in c.20 yr. For common murres Uria aalge, this same situation yields a recovery time of c.70 yr. Assuming that oil is found in the study area, and based on the expected number of oilspills to occur and contact these colonies during the lease lifetime, and assuming that each oilspill contact causes a fractional population loss of 0.95, the probability of reducing the population to some fraction of its initial level was calculated. For gulls, only a 10% change of population reduction to less than one-half the pre-spill level was calculated for the lease lifetime. For murres, only a 4% change of similar reduction was calculated.-from Authors

  1. Effects of egg oiling on larid productivity and population dynamics

    USGS Publications Warehouse

    Lewis, S.J.; Malecki, R.A.

    1984-01-01

    In this study, oil was applied to naturally incubated great black-backed gull (Larus marinus) and herring gull (L. argentatus) eggs, and its effects on reproductive success were assessed. Embryo survival was inversely proportional to the quantity of petroleum applied to eggshell surfaces. Dose responses, however, were dependent on embryonic age at the time of treatment. Eggs of either species, treated with 10-20 mu l of No. 2 fuel oil 4-8 days after laying, experienced significant reductions in hatching success. Embryos oiled past the midpoint of the 28-day incubation period were insensitive to as much as 100 mu l of petroleum. Fuel oil weathered outdoors for several weeks was as toxic as fresh oil to larid embryos. Only under severe conditions (e.g., large doses of petroleum contaminating young embryos) could egg oiling have a significant impact upon populations of the herring gull and species with similar life-history characteristics.

  2. California gull chicks raised near colony edges have elevated stress levels

    USGS Publications Warehouse

    Herring, Garth; Ackerman, Joshua T.

    2011-01-01

    Coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. Birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. We used fecal corticosterone metabolites in California gull chicks (Larus californicus) to examine whether colony size or location within the colony influenced a chick's physiological condition. We found that chicks being raised near colony edges had higher fecal corticosterone metabolite concentrations than chicks raised near colony centers, but that colony size (ranging from 150 to 11,554 nests) had no influence on fecal corticosterone levels. Fecal corticosterone metabolite concentrations also increased with chick age. Our results suggest that similarly aged California gull chicks raised near colony edges may be more physiologically stressed, as indicated by corticosterone metabolites, than chicks raised near colony centers.

  3. Effects of introducing foxes and raccoons on herring gull colonies

    USGS Publications Warehouse

    Kadlec, J.A.

    1971-01-01

    Red foxes (Vulpes fulva) and raccoons (Procyon lotor) released at colonies of herring gulls (Larus argentatus) on islands off the Massachusetts coast effectively eliminated the production of young gulls. Annual predator introductions for 2-4 years caused major reductions in colony size and occasionally total abandonment of the island as a colony site. Observations of the experimental islands for 2 years after cessation of predator introductions showed slow repopulation of the islands and lower breeding success than on control islands. The size of the regional population was reduced largely because of the movements of gulls off the experimental islands. The introduced predators are, in most cases, difficult to maintain on the islands; this restricts their utility in population management.

  4. Regional, temporal, and species patterns of mercury in Alaskan seabird eggs: mercury sources and cycling or food web effects?

    PubMed

    Day, Rusty D; Roseneau, David G; Vander Pol, Stacy S; Hobson, Keith A; Donard, Olivier F X; Pugh, Rebecca S; Moors, Amanda J; Becker, Paul R

    2012-07-01

    Mercury concentration ([Hg]), δ(15)N, and δ(13)C values were measured in eggs from common murres (Uria aalge), thick-billed murres (U. lomvia), glaucous gulls (Larus hyperboreus), and glaucous-winged gulls (L. glaucescens) collected in Alaska from 1999 to 2005. [Hg] was normalized to a common trophic level using egg δ(15)N values and published Hg trophic magnification factors. Egg [Hg] was higher in murres from Gulf of Alaska, Cook Inlet, and Norton Sound regions compared to Bering Sea and Bering Strait regions, independent of trophic level. We believe the Yukon River outflow and terrestrial Hg sources on the southern Seward Peninsula are responsible for the elevated [Hg] in Norton Sound eggs. Normalizing for trophic level generally diminished or eliminated differences in [Hg] among taxa, but temporal variability was unrelated to trophic level. Normalizing murre egg [Hg] by trophic level improves the confidence in regional comparisons of Hg sources and biogeochemical cycling in Alaska. PMID:22522226

  5. Organochlorine compounds and their metabolites in seven Icelandic seabird species - a comparative study.

    PubMed

    Jörundsdóttir, Hrönn; Löfstrand, Karin; Svavarsson, Jörundur; Bignert, Anders; Bergman, Ake

    2010-05-01

    The present study is designed to assess the occurrence of a few organochlorine contaminants and their metabolites in eggs of different marine bird species in Iceland, a country located in the sub-Arctic of the North-Western Atlantic. Previous investigations from e.g. Sweden and The Netherlands have shown some obvious differences in contaminant concentrations, including e.g. hydroxylated polychlorinated biphenyl metabolites (OH-PCBs) in guillemot (Uria aalge) and other bird species. Eggs from seven marine bird species, Arctic tern (Sterna paradisaea), common eider (Somateria mollissima), guillemot, fulmar (Fulmarus glacialis), great black-backed gull (Larus marinus), lesser black-backed gull (Larus fuscus), and great skua (Stercorarius skua), that all breed in Iceland, were collected and analyzed for several persistent organic compounds and their metabolites. The contaminant levels varied between the species investigated. The highest concentrations were found in eggs from the great skua (18 and 23 microg/g l.w. of CB-153 and 4,4'-DDE, respectively). The concentration difference was generally 2 orders of magnitude higher in great skua for all organochlorine compounds analyzed with the exception of HCB. HCB did not vary as much between the seven species (ranging from 34 to 710 ng/g l.w). OH-PCB and MeSO(2)-PCB metabolites congener concentrations and patterns showed differences in metabolic capacity between bird species. Guillemot and great skua seem to distinguish themselves most from other species i.e. with the absence of 4-OH-CB187 and low relative levels of 4-OH-CB146 in guillemot and the low abundance of OH-PCBs in great skua. PMID:20356092

  6. An evaluation of marine bird population trends following the Exxon Valdez oil spill, Prince William Sound, Alaska.

    PubMed

    Lance, B K; Irons, D B; Kendall, S J; McDonald, L L

    2001-04-01

    We examined post-spill trends (1989-1998) of marine bird populations in Prince William Sound (PWS) following the Exxon Valdez oil spill (EVOS) to evaluate recovery of injured taxa. Two criteria were employed. First, we examined population trends of injured taxa only in the oiled area of PWS using regression models. Second, we examined population trends of injured taxa in the oiled area relative to the unoiled area using homogeneity of the slopes tests. We considered a population recovering if there was a positive trend using either criteria. We considered a population not recovering if there was no trend using either criteria or a negative trend in the oiled area. A significant negative trend in the oiled area relative to the unoiled area was considered a continuing and increasing effect. Most taxa for which injury was previously demonstrated were not recovering and some taxa showed evidence of increasing effects nine years after the oil spill. Four taxa (loons Gavia spp, Harlequin Duck Histrionicus histrionicus, Bufflehead Bucephala spp, and North-western Crow Corvus caurinus) showed weak to very weak evidence of recovery. None of these taxa showed positive trends in both winter and summer. Nine taxa (grebes Podiceps spp, cormorants Phalacrocorax spp, Black Oystercatcher Haematopus bachmani, Mew Gull Larus canus, Glaucous-winged Gull Larus glaucescens, terns Sterna spp, murres Uria spp, Pigeon Guillemot Cepphus columba, and murrelets Brachyramphus spp) showed no evidence of recovery during summer or winter. Four taxa (scoters Melanitta spp, mergansers Mergus spp, goldeneyes Bucephala spp, and Black-legged Kittiwaka Rissa tridactyla) showed evidence of continuing, increasing effects. We showed evidence of slow recovery, lack of recovery, and divergent population trends in many taxa which utilize shoreline and nearshore habitats where oil is likely to persist. Potential lingering spill effects and natural variability appear to be acting in concert in delaying

  7. Contaminant effects on Great Lakes' fish-eating birds: a population perspective

    USGS Publications Warehouse

    Heinz, G.H.

    1998-01-01

    Preventing environmental contaminants from reducing wildlife populations is the greatest concern in wildlife toxicology. In the Great Lakes, environmental contaminants have a history of reducing populations of many species of fish-eating birds. Endocrine effects may have contributed to declines in fish-eating bird populations, but the overriding harm was caused by DDE-induced eggshell thinning. Toxic effects may still be occurring today, but apparently they are not of a sufficient magnitude to depress populations of most fish-eating birds. Once DDE levels in the Great Lakes declined, eggshells of birds began to get thicker and reproductive success improved. Populations of double-crested cormorants (Phalacrocorax auritus) and ring-billed gulls (Larus delawarensis) have increased dramatically since the bans on DDT and other organochlorine pesticides. Bald eagles (Haliaeetus leucocephalus) are still not reproducing at a normal rate along the shores of the Great Lakes, but success is much improved compared to earlier records when eggshell thinning was worse. Other species, such as herring gulls (Larus argentatus) and black-crowned night-herons (Nycticorax nycticorax), seem to be having improved reproductive success, but data on Great Lakes'-wide population changes are incomplete. Reproductive success of common terns (Sterna hirundo), Caspian terns (Sterna caspia), and Forster's terns (Sterna forsteri) seems to have improved in recent years, but, again, data on population changes are not very complete, and these birds face many habitat related problems as well as contaminant problems. Although contaminants are still producing toxic effects, and these effects may include endocrine disfunction, fish-eating birds in the Great Lakes seem to be largely weathering these effects, at least as far as populations are concerned. A lack of obvious contaminant effects on populations of fish-eating birds in the Great Lakes, however, should not be equated with a lack of any harm to

  8. Nest survival is influenced by parental behaviour and heterospecifics in a mixed-species colony

    USGS Publications Warehouse

    Brussee, Brianne E.; Coates, Peter S.; Hothem, Roger L.; Howe, Kristy; Casazza, Michael L.; Eadie, John M.

    2016-01-01

    Studies of avian nest success often focus on examining influences of variation in environmental and seasonal factors. However, in-depth evaluations can also incorporate variation in individual incubation behaviour to further advance our understanding of avian reproductive ecology. We examined these relationships in colonially nesting Black-crowned Night-Herons Nycticorax nycticorax using intensive video-monitoring methods to quantify incubation behaviours. We modelled nest survival as a function of both extrinsic factors and incubation behaviours over a 3-year period (2010–12) on Alcatraz Island, USA. Model-averaged parameter estimates indicated that nest survival increased as a function of greater incubation constancy (% of time spent incubating eggs within a 24-h period), and average daily precipitation throughout the nesting stage. Common Ravens Corvus corax are the only known nest predator of Night-Herons on Alcatraz Island, as on many other coastal Pacific islands. We also investigated the effects of heterospecific nesting of California Gulls Larus californicus and Western Gulls Larus occidentalis in a mixed-species colony with Night-Herons, based on nesting proximity data collected over a 2-year period (2011–12). This second analysis indicated that, in addition to incubation behaviours, nesting heterospecifics are an important factor for explaining variation in Night-Heron nest survival. However, contrary to our original expectation, we found that Night-Herons experienced increased nest survival with increasing distance from gull colony boundaries. These results may apply to other areas with multiple colonial nesting species and similar predator communities and climatic patterns.

  9. Hemosporidian blood parasites in seabirds—a comparative genetic study of species from Antarctic to tropical habitats

    PubMed Central

    Martínez, Javier; Hennicke, Janos; Ludynia, Katrin; Gladbach, Anja; Masello, Juan F.; Riou, Samuel; Merino, Santiago

    2010-01-01

    Whereas some bird species are heavily affected by blood parasites in the wild, others reportedly are not. Seabirds, in particular, are often free from blood parasites, even in the presence of potential vectors. By means of polymerase chain reaction, we amplified a DNA fragment from the cytochrome b gene to detect parasites of the genera Plasmodium, Leucocytozoon, and Haemoproteus in 14 seabird species, ranging from Antarctica to the tropical Indian Ocean. We did not detect parasites in 11 of these species, including one Antarctic, four subantarctic, two temperate, and four tropical species. On the other hand, two subantarctic species, thin-billed prions Pachyptila belcheri and dolphin gulls Larus scoresbii, were found infected. One of 28 thin-billed prions had a Plasmodium infection whose DNA sequence was identical to lineage P22 of Plasmodium relictum, and one of 20 dolphin gulls was infected with a Haemoproteus lineage which appears phylogenetically clustered with parasites species isolated from passeriform birds such as Haemoproteus lanii, Haemoproteus magnus, Haemoproteus fringillae, Haemoproteus sylvae, Haemoproteus payevskyi, and Haemoproteus belopolskyi. In addition, we found a high parasite prevalence in a single tropical species, the Christmas Island frigatebird Fregata andrewsi, where 56% of sampled adults were infected with Haemoproteus. The latter formed a monophyletic group that includes a Haemoproteus line from Eastern Asian black-tailed gulls Larus crassirostris. Our results are in agreement with those showing that (a) seabirds are poor in hemosporidians and (b) latitude could be a determining factor to predict the presence of hemosporidians in birds. However, further studies should explore the relative importance of extrinsic and intrinsic factors on parasite prevalence, in particular using phylogenetically controlled comparative analyses, systematic sampling and screening of vectors, and within-species comparisons. PMID:20652673

  10. METAL LEVELS IN EGGS OF WATERBIRDS IN THE NEW YORK HARBOR (USA): TROPHIC RELATIONSHIPS AND POSSIBLE RISK TO HUMAN CONSUMERS

    PubMed Central

    Burger, Joanna; Elbin, Susan

    2015-01-01

    Health professionals are interested in evaluating the risks that heavy metals pose to eco-receptors and humans. The objective of this study was to examine levels of mercury (Hg), lead (Pb), cadmium (Cd), and other contaminants in waterbirds nesting in the New York harbor in 2012 to determine (1) whether there were species and locational differences, and (2) whether consumption of eggs posed a health risk to predators or humans. For arsenic (As), Pb, Hg, and selenium (Se), species contributed more to variations in levels than location; for Cd and chromium (Cr), location was more significant. Mean metal levels differed among species for all metals, except Cd. Highest levels were As (great black-backed gulls, Larus marinus), Cr (great egret, Ardea alba), Pb (Canada goose, Branta canadensis), and Hg and Se (black-crowned night heron, Nycticorax nycticorax). There were significant locational differences only for herring gulls (Larus argentatus); significant differences were found for all metals. Levels of Hg and Pb may be sufficiently high in eggs of some species to produce adverse effects in predators that eat them. The proportion of samples above 0.3 ppm Hg (U.S. Environmental Protection Agency [EPA] freshwater criteria for freshwater fish), the contaminant of health concern, ranged from 0% (Canada goose, great egret), to 14 and 27% in gulls, to 50% (black-crowned night heron). Some herring gull, great black-backed gull, and black-crowned night heron eggs had 0.5 ppm or higher Hg. Thus, human consumption of eggs may pose a risk to fetuses and young children. PMID:25424617

  11. Hemosporidian blood parasites in seabirds—a comparative genetic study of species from Antarctic to tropical habitats

    NASA Astrophysics Data System (ADS)

    Quillfeldt, Petra; Martínez, Javier; Hennicke, Janos; Ludynia, Katrin; Gladbach, Anja; Masello, Juan F.; Riou, Samuel; Merino, Santiago

    2010-09-01

    Whereas some bird species are heavily affected by blood parasites in the wild, others reportedly are not. Seabirds, in particular, are often free from blood parasites, even in the presence of potential vectors. By means of polymerase chain reaction, we amplified a DNA fragment from the cytochrome b gene to detect parasites of the genera Plasmodium, Leucocytozoon, and Haemoproteus in 14 seabird species, ranging from Antarctica to the tropical Indian Ocean. We did not detect parasites in 11 of these species, including one Antarctic, four subantarctic, two temperate, and four tropical species. On the other hand, two subantarctic species, thin-billed prions Pachyptila belcheri and dolphin gulls Larus scoresbii, were found infected. One of 28 thin-billed prions had a Plasmodium infection whose DNA sequence was identical to lineage P22 of Plasmodium relictum, and one of 20 dolphin gulls was infected with a Haemoproteus lineage which appears phylogenetically clustered with parasites species isolated from passeriform birds such as Haemoproteus lanii, Haemoproteus magnus, Haemoproteus fringillae, Haemoproteus sylvae, Haemoproteus payevskyi, and Haemoproteus belopolskyi. In addition, we found a high parasite prevalence in a single tropical species, the Christmas Island frigatebird Fregata andrewsi, where 56% of sampled adults were infected with Haemoproteus. The latter formed a monophyletic group that includes a Haemoproteus line from Eastern Asian black-tailed gulls Larus crassirostris. Our results are in agreement with those showing that (a) seabirds are poor in hemosporidians and (b) latitude could be a determining factor to predict the presence of hemosporidians in birds. However, further studies should explore the relative importance of extrinsic and intrinsic factors on parasite prevalence, in particular using phylogenetically controlled comparative analyses, systematic sampling and screening of vectors, and within-species comparisons.

  12. Circulation of a Meaban-Like Virus in Yellow-Legged Gulls and Seabird Ticks in the Western Mediterranean Basin

    PubMed Central

    Cerdà-Cuéllar, Marta; Lecollinet, Sylvie; Pearce-Duvet, Jessica; Busquets, Núria; García-Bocanegra, Ignacio; Pagès, Nonito; Vittecoq, Marion; Hammouda, Abdessalem; Samraoui, Boudjéma; Garnier, Romain; Ramos, Raül; Selmi, Slaheddine; González-Solís, Jacob; Jourdain, Elsa; Boulinier, Thierry

    2014-01-01

    In recent years, a number of zoonotic flaviviruses have emerged worldwide, and wild birds serve as their major reservoirs. Epidemiological surveys of bird populations at various geographical scales can clarify key aspects of the eco-epidemiology of these viruses. In this study, we aimed at exploring the presence of flaviviruses in the western Mediterranean by sampling breeding populations of the yellow-legged gull (Larus michahellis), a widely distributed, anthropophilic, and abundant seabird species. For 3 years, we sampled eggs from 19 breeding colonies in Spain, France, Algeria, and Tunisia. First, ELISAs were used to determine if the eggs contained antibodies against flaviviruses. Second, neutralization assays were used to identify the specific flaviviruses present. Finally, for colonies in which ELISA-positive eggs had been found, chick serum samples and potential vectors, culicid mosquitoes and soft ticks (Ornithodoros maritimus), were collected and analyzed using serology and PCR, respectively. The prevalence of flavivirus-specific antibodies in eggs was highly spatially heterogeneous. In northeastern Spain, on the Medes Islands and in the nearby village of L'Escala, 56% of eggs had antibodies against the flavivirus envelope protein, but were negative for neutralizing antibodies against three common flaviviruses: West Nile, Usutu, and tick-borne encephalitis viruses. Furthermore, little evidence of past flavivirus exposure was obtained for the other colonies. A subset of the Ornithodoros ticks from Medes screened for flaviviral RNA tested positive for a virus whose NS5 gene was 95% similar to that of Meaban virus, a flavivirus previously isolated from ticks of Larus argentatus in western France. All ELISA-positive samples subsequently tested positive for Meaban virus neutralizing antibodies. This study shows that gulls in the western Mediterranean Basin are exposed to a tick-borne Meaban-like virus, which underscores the need of exploring the spatial and

  13. Bounded hybrid superiority in an avian hybrid zone: effects of mate, diet, and habitat choice.

    PubMed

    Good, T P; Ellis, J C; Annett, C A; Pierotti, R

    2000-10-01

    There has been considerable debate in the study of hybrid zones as to whether hybrids may be superior to parental types within the area of contact (bounded hybrid superiority). In birds, naturally occurring hybridization is relatively common, and hybridization within this group always involves mate choice. If hybrids are superior, females choosing heterospecific mates should be expected to show higher fitness under the conditions prevalent in the hybrid zone. Hybrid superiority under these circumstances would reduce reinforcement and thereby help to maintain the hybrid zone. To examine this issue, we studied reproductive performances of hybrids and parental species of gulls (Larus occidentalis and Larus glaucescens) at two colonies within a linear hybrid zone along the west coast of the United States. This hybrid zone contains predominantly gulls of intermediate phenotype. Previous studies indicated that hybrids were superior to one or both parental types, but provided no data on possible mechanisms that underlie this hybrid superiority. Using a hybrid index designed specifically for these species, we identified to phenotype more than 300 individuals associated with nests, including both individual males and females within 73 pairs in the central portion of the hybrid zone and 74 pairs in the northern portion of the hybrid zone. There was little evidence of assortative mating, and what little there was resulted solely because of pairings within intergrades. In the central hybrid zone, females paired with hybrid males produced larger clutches and hatched and fledged more chicks compared with females paired to western gull males. This was a result of heavy predation on eggs in sand habitat, where male western gulls established territories. In contrast, many hybrid males established territories in vegetated cover that was less vulnerable to predation. In the northern part of the hybrid zone, clutch size did not differ among pair categories, however, there were

  14. A Comparitive Analysis of the Influence of Weather on the Flight Altitudes of Birds.

    NASA Astrophysics Data System (ADS)

    Shamoun-Baranes, Judy; van Loon, Emiel; van Gasteren, Hans; van Belle, Jelmer; Bouten, Willem; Buurma, Luit

    2006-01-01

    Birds pose a serious risk to flight safety worldwide. A Bird Avoidance Model (BAM) is being developed in the Netherlands to reduce the risk of bird aircraft collisions. In order to develop a temporally and spatially dynamic model of bird densities, data are needed on the flight-altitude distribution of birds and how this is influenced by weather. This study focuses on the dynamics of flight altitudes of several species of birds during local flights over land in relation to meteorological conditions.We measured flight altitudes of several species in the southeastern Netherlands using tracking radar during spring and summer 2000. Representatives of different flight strategy groups included four species: a soaring species (buzzard ), an obligatory aerial forager (swift Apus apus), a flapping and gliding species (blackheaded gull Larus+ridibundus&search_kingdom=every&search_span=exactly_for&categories=All&source=html&search_credRating=All" TARGET='itis_window'>Larus ridibundus), and a flapping species (starling Sturnus vulgaris).Maximum flight altitudes varied among species, during the day and among days. Weather significantly influenced the flight altitudes of all species studied. Factors such as temperature, relative humidity, atmospheric instability, cloud cover, and sea level pressure were related to flight altitudes. Different combinations of factors explained 40% 70% of the variance in maximum flight altitudes. Weather affected flight

  15. Relationships between environmental organochlorine contaminant residues, plasma corticosterone concentrations, and intermediary metabolic enzyme activities in Great Lakes herring gull embryos.

    PubMed Central

    Lorenzen, A; Moon, T W; Kennedy, S W; Glen, G A

    1999-01-01

    Experiments were conducted to survey and detect differences in plasma corticosterone concentrations and intermediary metabolic enzyme activities in herring gull (Larus argentatus) embryos environmentally exposed to organochlorine contaminants in ovo. Unincubated fertile herring gull eggs were collected from an Atlantic coast control site and various Great Lakes sites in 1997 and artificially incubated in the laboratory. Liver and/or kidney tissues from approximately half of the late-stage embryos were analyzed for the activities of various intermediary metabolic enzymes known to be regulated, at least in part, by corticosteroids. Basal plasma corticosterone concentrations were determined for the remaining embryos. Yolk sacs were collected from each embryo and a subset was analyzed for organochlorine contaminants. Regression analysis of individual yolk sac organochlorine residue concentrations, or 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs), with individual basal plasma corticosterone concentrations indicated statistically significant inverse relationships for polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs), total polychlorinated biphenyls (PCBs), non-ortho PCBs, and TEQs. Similarly, inverse relationships were observed for the activities of two intermediary metabolic enzymes (phosphoenolpyruvate carboxykinase and malic enzyme) when regressed against PCDDs/PCDFs. Overall, these data suggest that current levels of organochlorine contamination may be affecting the hypothalamo-pituitary-adrenal axis and associated intermediary metabolic pathways in environmentally exposed herring gull embryos in the Great Lakes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:10064546

  16. Differential Annual Movement Patterns in a Migratory Species: Effects of Experience and Sexual Maturation

    PubMed Central

    Jorge, Paulo E.; Sowter, David; Marques, Paulo A. M.

    2011-01-01

    Some animals migrate long distances to exploit important seasonal food resources in the northern regions of the northern hemisphere, whilst avoiding winter starvation. Changes in the individual's age and navigational skills are likely to affect migration, which in turn influences the geographic distribution of individuals. Processes such as sexual maturation and navigational abilities are affected by age, and age is thus a key factor in understanding migration patterns and differences in distribution ranges. In the present study, we investigated the effects of age on the geographic distribution of a population of Lesser Black-backed Gulls Larus fuscus throughout its annual cycle, by analyzing a dataset of 19,096 records from 10,000 color-ringed gulls. In contrast to previous assumptions, the results showed that gulls were geographically segregated by age throughout the entire annual cycle, rather than showing a geographic age-related cline only in the wintering areas. This asymmetric distribution results from a reduction in the annual range of sexually mature gulls, and the differential distribution of mature and immature individuals (mature birds remained in more northern areas, compared to immature birds, throughout the annual cycle). Furthermore, although immature gulls travelled longer distances than adults, they initiated their fall migration with short movements, in contrast to adults that migrated using longer movements. The effects identified in this study explain the non-homogenous distribution of populations throughout the annual cycle, with wide implications for the development of effective human health policies and/or wildlife management strategies. PMID:21799853

  17. Polychlorinated biphenyl (PCB) congener concentrations in seabirds found dead in mortality incidents around the British coast.

    PubMed

    Malcolm, H M; Osborn, D; Wright, J; Wienburg, C L; Sparks, T H

    2003-07-01

    Livers from 121 birds killed in mortality incidents in U.K. coastal waters between 1991 and 1996 were analyzed for 16 PCB congeners (IUPAC numbers 8, 18, 28, 31, 52, 77, 101, 118, 126, 128, 138, 149, 153, 169, 170, and 180). Species analyzed were guillemot (Uria aalge), shag (Phalacrocorax arisotelis), kittiwake (Rissa tridactyla), puffin (Fratercula arctica), razorbill (Alca torda), fulmar (Fulmarus glacialis), gannet (Sula bassana), and herring gull (Larus argentatus). This is the first report of PCBs in U.K. seabird tissues to be presented since 1983. Mean concentrations of total PCBs ranged from 0.47 to 15.8 mg/kg WW, similar to concentrations reported for North Sea birds during the 1970s and 1980s and lower than those reported for the same species in the Irish Sea during the late 1960s and early 1970s. The congeners generally present in the highest concentrations were (in decreasing order) 153, 138, 180, 118, and 170. Despite the birds having similar diets, both inter- and intraspecies differences in PCB congener profile were found. In guillemots from several sites on the east coast, the dominant congener was 138, compared to guillemots from the south coast, which had the more typical congener pattern found in seabirds. Some of the differences in total PCB values could be due to different causes of death, with a subsequent effect on body lipid levels. PMID:12948183

  18. [Serological monitoring of arbovirus infections in the estuary of the Kuban River (the 2006-2007 data)].

    PubMed

    L'vov, D K; Shchelkanov, M Iu; Kolobukhina, L V; L'vov, D N; Galkina, I V; Aristova, V A; Morozova, T N; Proshina, E S; Kulikov, A G; Kogdenko, N V; Andronova, O V; Pronin, N I; Shevkoplias, V N; Fontanetskiĭ, A S; Vlasov, N A; Nepoklonov, E A

    2008-01-01

    Solid-phase enzyme immunoassay, neutralization test, and the hemagglutination-inhibition test were used to study the sera from human beings (152 samples), agricultural animals (n = 77), hares (n = 3), and wild birds (n = 69), collected in 2006-2007 in the Kuban River estuary (Temryuk District, Krasnodar Territory). There were specific antibodies against viruses of West Nile (WH), tick-borne encephalitis (TBE) (Flaviviridae, Flavivirus), Sindbis (Togaviridae, Alphavirus), the antigenic complex of California, Batai (Bunyaviridae, Orthobunyavirus), Dhori (Orthomyxoviridae, Thogotovirus). The findings suggest the presence of arboviruses from 6 transmitting mosquitoes and ticks in the study area and human infection by the viruses of the antigenic complex of California (20-47%), Batai (3-15%), West Nile (3-12%), Dhori (2%). The index agricultural animals (horses, cattle) were observed to have specific antibodies to the viruses of WN (8-15%), TBE (0-2%), Sindbis (2-9%), the antigenic complex of California (27-54%). Out of the representatives of the wild fauna, virus-neutralizing antibodies to Sindbis virus were found in European hares (Lepus europaeus), California complex virus in gulls (Larus argentatus) and terns (Sterna hirundo), WN and Sindbis viruses in herons (Ardea purpurea), and WN and California complex viruses in bald-coots (Fulica atra). PMID:18756814

  19. Poplar Island Environmental Restoration Project: Challenges in waterbird restoration on an island in Chesapeake Bay

    USGS Publications Warehouse

    Erwin, R.M.; Miller, J.; Reese, J.G.

    2007-01-01

    At 460 hectares, the Paul Sarbanes Environmental Restoration Project at Poplar Island, Talbot County, Maryland, represents the largest 'beneficial use' dredged material project of the U. S. Army Corps of Engineers (a cooperative project with Maryland Port Administration). Begun in 1998, the 15-year restoration project will ultimately consist of roughly 220 ha of uplands and 220 ha of tidal wetland habitats, with limited areas of dike roads, perimeter riprap, and unvegetated mudflats. Wetland restoration began in one small section (or 'cell') in 2002, but not all cells will be filled with dredged material until at least 2013. As a major objective of the restoration, six species of waterbirds were identified as 'priority species' for Chesapeake Bay: American black duck (Anas rubripes), snowy egret (Egretta thula), cattle egret (Bubulcus ibis), osprey (Pandion haliaetus), common tern (Sterna hirundo), and least tern (S. antillarum). Monitoring of nesting activities of these species from 2002 to 2005 indicated that all species except black ducks colonized the site rapidly. More than 800 pairs of common terns nested in 2003 to 2004. Because of predation by red fox (Vulpes vulpes) and great horned owl (Bubo virginianus), reproductive success was very low for the terns. Trapping was effective in removing the foxes, and other controls have been applied to opportunistic nesting species including herring gulls (Larus argentatus) and Canada geese (Branta canadensis). An effective public education program on the island has helped address concerns about animal control.

  20. Mercury levels in Great Lakes herring gull eggs, 1972--1992

    SciTech Connect

    Weseloh, D.V.; Koster, M.D.; Ryckman, D.P.; Struger, J.

    1995-12-31

    Since 1971, the herring gull (Larus argentatus) has been used as a sentinel species for monitoring the levels of persistent contaminants in the Great Lakes ecosystem. In this study, 21 herring gull colonies in the Great Lakes and connecting channels were sampled for years 1972--1976, 1981--1983, 1985 and 1992. For each year, 10 eggs (usually) were collected from each colony site and analyzed for total mercury (ppm, wet weight). Results indicated that eggs from Lake Ontario displayed the highest mercury levels, mean = 0.28 (s.d. = 0.08) to 0.73 (0.23). Lake Erie typically displayed the lowest egg mercury levels, 0.18 (0.08) to 0.24 (0.11). Overall, mercury levels ranged from 0.12 (0.02) in 1985 to 0.88 (0.23) in 1982 for Channel-Shelter Island (Lake Huron) and Pigeon Island (Lake Ontario), respectively. Generally, all colony sites showed peak mercury levels in 1982. A significant decline in egg mercury levels was observed in six colony sites between 1972 and 1992 and in three colony sites between 1981 and 1992. The mean herring gull egg mercury levels observed in the early and mid 1970s and in 1982 for some colony sites were within the range found which potentially reduces hatchability in other fish-eating bird species.

  1. Shell thinning and pesticide residues in Texas aquatic bird eggs, 1970

    USGS Publications Warehouse

    King, K.A.; Flickinger, Edward L.; Hildebrand, H.H.

    1978-01-01

    Significant decreases in eggshell thickness were found in 15 of 22 species of aquatic birds in Texas in 1970. Shell thickness reductions of 9 to 15 percent were found in white pelicans (Pelecanus erythrorhynchos), brown pelicans (P .occidentalis), and great blue herons (Ardea herodias). DDT family compounds were found in all eggs, and mean residues ranged from 0.4 ppm in white ibis (Eudocimus albus) to 23.2 ppm in great egrets (Casmerodius albus). GDDT residues were negatively correlated with shell thickness in five species; PCBs were negatively correlated in two. Residues in marine birds were generally lower and more uniform than levels in birds feeding in fresh and brackish water. DDT and dieldrin residues were higher in eggs from colonies near agricultural areas where these insecticides were heavily used; higher PCB residues were consistently associated with urban and industrial areas. Populations of five species have declined and deserve continued study: brown pelican, reddish egret (Dichromanassa rufescens), white-faced ibis (Plegadis chihi), laughing gull (Larus atricilla), and Forster's tern (Sterna forsteri). Population trends of four other species were undetermined and should be followed closely in future years.

  2. Adrenocortical function of Arctic-breeding glaucous gulls in relation to persistent organic pollutants.

    PubMed

    Verboven, Nanette; Verreault, Jonathan; Letcher, Robert J; Gabrielsen, Geir W; Evans, Neil P

    2010-03-01

    Unpredictable changes in the environment stimulate the avian hypothalamo-pituitary-adrenal axis to produce corticosterone, which induces behavioural and metabolic changes that enhance survival in the face of adverse environmental conditions. In addition to profound environmental perturbations, such as severe weather conditions and unpredictable food shortages, many Arctic-breeding birds are also confronted with chronic exposure to persistent organic pollutants (POPs), some of which are known to disrupt endocrine processes. This study investigated the adrenocortical function of a top predator in the Arctic marine environment, the glaucous gull (Larus hyperboreus). High concentrations of organochlorines, brominated flame retardants and metabolically-derived products in blood plasma of incubating glaucous gulls were associated with high baseline corticosterone concentrations in both sexes and a reduced stress response in males. Contaminant-related changes in corticosterone concentration occurred over and above differences in body condition and seasonal variation. Chronically high corticosterone concentrations and/or a compromised adrenocortical response to stress can have negative effects on the health of an individual. The results of the present study suggest that exposure to POPs may increase the vulnerability of glaucous gulls to environmental stressors and thus could potentially compromise their ability to adapt to the rapidly changing environmental conditions associated with climate change that are currently seen in the Arctic. PMID:19932109

  3. Parasitic fauna of a yellow-legged gull colony in the island of Escombreras (South-eastern Mediterranean) in close proximity to a landfill site: potential effects on cohabiting species.

    PubMed

    Parejo, Sandra Hervías; Martínez-Carrasco, Carlos; Diaz, Julia I; Chitimia, Lidia; Ortiz, Juana; Mayo, Elvira; Ybáñez, Rocío Ruiz de

    2015-06-01

    We identified the ectoparasites and helminth fauna of yellow-legged gulls (Larus michahellis michahellis), breeding near to a solid waste landfill, and compared infection levels with those of other yellow-legged gull colonies. Moreover, we analysed correlations between parasites and sex and body condition of yellow-legged gulls, co-infections and the helminth community structure in order to propose the role of this species as reservoir of certain parasites. We also discuss the potential transmission of parasites between the yellow-legged gull and the endangered Audouin's gull, because interactions between these two species, such as kleptoparasitism and predation, occur frequently around colonies. The following species were recorded: Ornithodorus capensis (Arthropoda); Cosmocephalus obvelatus, Paracuaria adunca, Eucoleus contortus, Tetrameres skrjabini and Contracaecum sp. (Nematoda); Tetrabothrius cylindraceus (Cestoda); Acanthotrema armata, Cardiocephaloides longicollis and Ornithobilharzia intermedia (Digenea). Tetrabothrius cylindraceus, A. armata and O. capensis are new parasite records for this host. The dependence of yellow-legged-gulls on fishery discards is supported by the dominance of parasites transmitted through marine intermediate hosts with interest to fisheries in the study area. However, the shift in diet from natural resources to food derived from human activities seems not to affect the parasitic fauna of yellow-legged gull. Besides of direct physical contact between individuals in nesting and resting habitats, the high availability of fishery discards could increase the risk of Audouin's gulls to be infected by common parasites of yellow-legged gull. PMID:26203998

  4. Seasonal variations in aldrin epoxidase (MFO) activity of yellow-legged herring gulls: the relationship to breeding and PCB residues

    SciTech Connect

    Fossi, C.; Leonzio, C.; Focardi, S.; Renzoni, A.

    1988-09-01

    The hepatic mixed function oxidases (MFO) constitute a defense mechanism which enables the organism to make xenobiotics more polar and thus render them more readily excretable. The degree of induction of this system is an expression of its exposure to xenobiotics, but it is also a function of endogenous physiological mechanisms. These two forms of induction may lead to mutual interference: foreign compounds may stimulate hepatic hydroxylation and affect the metabolism of steroid hormones; the later may in turn stimulate the activity of the MFO system favoring the degradation of the xenobiotics. Induction and detoxication processes of endogenous and exogenous compounds have been observed in mammals in laboratory experiments. Relationships between MRO activity, the reproductive cycle and variations in tissue levels of liposoluble xenobiotics, have been reported for marine organisms. In birds, seasonal variations of MFO levels have been observed, but the relationship between these enzyme variations and the levels of contaminants in the animal tissues has never been made clear. The authors aim to clarify this relationship by determining the levels of PCBs residues and aldrin epoxidase activities in Yellow-legged Herring gull (Larus cachinnans) specimens from different areas of Italy collected during two phases of the annual cycle, namely those of reproduction (spring) and of sexual inactivity (autumn). This species was chosen because of its wide distribution, its opportunistic feeding habits and its adaptive capacity in polluted environments.

  5. Nereidid polychaetes as the major diet of migratory shorebirds on the estuarine tidal flats at Fujimae-higata in Japan.

    PubMed

    Iwamatsu, Shinichiro; Suzuki, Akiko; Sato, Masanori

    2007-07-01

    The dietary items of five migratory shorebirds, Dunlin (Calidris alpina), Red-necked Stint (C. ruficollis), Grey Plover (Pluvialis squatarola), Whimbrel (Numenius phaeopus) and Black-headed Gull (Larus ridibundus), were examined by analyses of fecal droppings during the birds' migration or wintering and by surveys of macrobenthic fauna around their foraging sites on the tidal flats of Fujimae-higata, Nagoya, central Japan. Body parts of nereidid, capitellid, and spionid polychaetes and crustaceans were found in fecal droppings from all of these shorebirds. Two nereidid species (Hediste diadroma and Neanthes succinea) with relatively large body sizes seemed to be the majority dietary items. At one site, H. diadroma was dominant in terms of biomass (40-370 g/m(2)) throughout year except, for less than 1 g/m(2) in March and May (within or just after reproduction of this species). Monthly changes in the occurrence of food items in fecal droppings of C. alpina were examined in 1999 and 2000. Most (85-100%) of the fecal droppings contained nereidid body parts, including Hediste-specific simple chaetae from November to April, whereas only 23% of the droppings contained them in May. Chaetae of capitellid or spionid polychaetes were frequently found from January to April (38-86% of droppings). Crustacean body parts, including amphipod appendages, were frequently found from March to May (86-100% of droppings). The relationship between foraging habits of the shorebirds and the life history of their major prey nereidid species is discussed. PMID:17824775

  6. Susceptibility of avian hosts to experimental Gymnophalloides seoi infection.

    PubMed

    Ryang, Y S; Yoo, J C; Lee, S H; Chai, J Y

    2001-04-01

    To determine whether avian species are susceptible to infection with Gymnophalloides seoi (a human-infecting intestinal trematode), we exposed 7 species of birds with metacercariae obtained from oysters. The birds were necropsied at days 2, 4, and 6 postinfection (PI). The highest worm recovery at day 6 PI was obtained from the Kentish plover (Charadrius alexandrinus; mean = 56.0%), followed by the Mongolian plover (C. mongolus; 49.3%), and the grey plover (Pluvialis squatarola; 32.3%). In contrast, no mature worms were recovered from the great knot (Calidris tenuirostris), dunlin (C. alpina), black-tailed gull (Larus crassirostris), and mallard (Anas platyrhynchos). Among the plovers, the worms attained the greatest size at day 6 PI (254.1 x 190.4 microm) in the Kentish plover, with a significantly higher number of eggs in the uterus. The 3 species of plovers are highly susceptible to experimental G. seoi infection, suggesting that they could play a role as definitive hosts for these worms in nature. PMID:11318587

  7. Waterbirds (other than Laridae) nesting in the middle section of Laguna Cuyutlán, Colima, México.

    PubMed

    Mellink, Eric; Riojas-López, Mónica E

    2008-03-01

    Laguna de Cuyutlán, in the state of Colima, Mexico, is the only large coastal wetland in a span of roughly 1150 km. Despite this, the study of its birds has been largely neglected. Between 2003 and 2006 we assessed the waterbirds nesting in the middle portion of Laguna Cuyutlán, a large tropical coastal lagoon, through field visits. We documented the nesting of 15 species of non-Laridae waterbirds: Neotropic Cormorant (Phalacrocorax brasilianus), Tricolored Egret (Egretta tricolor), Snowy Egret (Egretta thula), Little Blue Heron (Egretta caerulea), Great Egret (Ardea alba), Cattle Egret (Bubulcus ibis), Black-crowned Night-heron (Nycticorax nycticorax), Yellow-crowned Night-heron (Nyctanassa violacea), Green Heron (Butorides virescens), Roseate Spoonbill (Platalea ajaja), White Ibis (Eudocimus albus), Black-bellied Whistling-duck (Dendrocygna autumnalis), Clapper Rail (Rallus longirostris), Snowy Plover (Charadrius alexandrinus), and Black-necked Stilt (Himantopus mexicanus). These add to six species of Laridae known to nest in that area: Laughing Gulls (Larus atricilla), Royal Terns (Thalasseus maximus), Gull-billed Terns (Gelochelidon nilotica), Forster's Terns (S. forsteri), Least Terns (Sternula antillarum), and Black Skimmer (Rynchops niger), and to at least 57 species using it during the non-breeding season. With such bird assemblages, Laguna Cuyutlán is an important site for waterbirds, which should be given conservation status. PMID:18624252

  8. Persistent organic pollution in a high-Arctic top predator: sex-dependent thresholds in adult survival

    PubMed Central

    Erikstad, Kjell Einar; Sandvik, Hanno; Reiertsen, Tone Kristin; Bustnes, Jan Ove; Strøm, Hallvard

    2013-01-01

    In long-lived species, any negative effect of pollution on adult survival may pose serious hazards to breeding populations. In this study, we measured concentrations of various organochlorines (OCs) (polychlorinated biphenyl and OC pesticides) in the blood of a large number of adult glaucous gulls (Larus hyperboreus) breeding on Bjørnøya (Bear Island) in the Norwegian Arctic, and modelled their local survival using capture–recapture analysis. Survival was negatively associated with concentrations of OCs in the blood. The effect of OCs was nonlinear and evident only among birds with the highest concentrations (the uppermost deciles of contamination). The threshold for depressed survival differed between the sexes, with females being more sensitive to contamination. For birds with lower OC concentration, survival was very high, i.e. at the upper range of survival rates reported from glaucous and other large gull species in other, presumably less contaminated populations. We propose two non-exclusive explanations. First, at some threshold of OC concentration, parents (especially males) may abandon reproduction to maximize their own survival. Second, high contamination of OC may eliminate the most sensitive individuals from the population (especially among females), inducing a strong selection towards high-quality and less sensitive phenotypes. PMID:23966640

  9. Interspecific differences in concentrations and congener profiles of chlorinated and brominated organic pollutants in three insectivorous bird species.

    PubMed

    Dauwe, Tom; Van den Steen, Evi; Jaspers, Veerle L B; Maes, Koen; Covaci, Adrian; Eens, Marcel

    2009-02-01

    We investigated the accumulation of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs) in eggs of three insectivorous bird species, the great tit (Parus major), the Northern lapwing (Vanellus vanellus) and the Mediterranean gull (Larus melanocephalus), near the harbour of Antwerp (Belgium). Our results show that lapwing eggs had the highest median concentrations of PCBs (4358 ng/g lw) and PBDEs (109 ng/g lw). Mediterranean gulls feed during breeding on ground-dwelling invertebrates on agricultural fields, which is reflected in higher OCP concentrations in eggs (1235 ng/g lw). Apart from differences in accumulation, also interspecific differences in contaminant profiles were investigated. Significant differences among species were found in the profile of PCBs, PBDEs and OCPs. These differences could be attributed to differences in diet, behaviour and metabolic capacity. Interestingly, the OCP profile in lapwing eggs deviated extremely from the two other species. In both great tit and Mediterranean gull eggs p,p'-DDE was by far the most important compound, whereas in lapwing eggs hexachlorobenzene, oxychlordane, trans-nonachlor and even p,p'-DDT were relatively more abundant than p,p'-DDE. The high p,p'-DDT/p,p'-DDE ratio has previously been described in lapwings, which suggests that low p,p'-DDE accumulation in eggs might be inherent for this species. PMID:18947874

  10. The influence of trophic level and feeding location of the levels of organochlorine contaminants in seabird eggs as revealed by stable carbon and nitrogen isotope analysis

    SciTech Connect

    Hobson, K.; Jarman, W.M.; Bott, J.A.; Bacon, C.E.; Sydeman, W.

    1994-12-31

    Seabird eggs have been used extensively to assay contaminants in marine food webs, but links to trophic level or feeding location have remained poorly understood due to limitations inherent in conventional dietary studies. Stable-isotope analysis of bird eggs may be used to infer trophic position and feeding location of adult seabirds and can be readily correlated with measurements of egg contaminant levels. The authors measured stable-carbon ({delta}{sup 13}C) and nitrogen ({delta}{sup 15}N) isotope abundance, and organochlorine contaminants (DDTs, PCBs, chlordanes, etc.) in eggs from Cassin`s Auklet (Ptychoramphus aleutica), Common Murre (Uria aalge), Pigeon Guillemot (Cepphus columba). Rhinoceros Auklet (Cerorhinca monocerata), Pelagic Cormorant (Phalacrocorax pelagicus), Brandt`s Cormorant (Phalacrocorax penicillatus), and Western Gull (Larus) from Southeast Farallon Island together with rockfish (Sebastes spp.), anchovy (Engraulis spp.), and euphausiid prey from the Gulf of the Farallones. Consistent with its planktivorous diet and pelagic feeding habits, Cassin`s Auklet showed the lowest mean {delta}{sup 15}N value and the least enriched {delta}{sup 13}C values. Measures of trophic level and foraging location were constructed for all other seabirds relative to these isotopic endpoints. Contaminant levels in the eggs and fish will be interpreted in light of the stable-isotope results.

  11. Maternal transfer of organohalogen contaminants and metabolites to eggs of Arctic-breeding glaucous gulls.

    PubMed

    Verreault, Jonathan; Villa, Rosa A; Gabrielsen, Geir W; Skaare, Janneche U; Letcher, Robert J

    2006-12-01

    Eggs of seabirds have routinely been used as indicators of environmental pollution in the Arctic. However, the variability in organohalogen concentration and composition associated with the laying sequence, have not been defined. We examined a suite of PCBs, organochlorine (OC) pesticides and by-products, polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs) and methylsulfonyl- (MeSO2) PCBs in complete 3-egg clutches of glaucous gulls (Larus hyperboreus), and plasma samples of the laying females collected from the Norwegian Arctic. SigmaPCB, SigmaOC and SigmaPBDE, but not SigmaMeSO2-PCB, concentrations in eggs were positively associated, with increasing magnitude and significance from the first through the last-laid egg, with concentrations in female plasma. However, the concentrations of these organohalogen classes fluctuated irrespective of the laying order in the clutch. In general, maternal transfer favored low K(ow) and/or less persistent compounds, whereas the recalcitrant and/or higher-halogenated compounds were less readily transferred, and consequently more selectively retained in the mother. PMID:16563578

  12. Distribution of marine birds on the mid- and North-Atlantic US outer continental shelf. Technical progress report, January 1978-July 1980

    SciTech Connect

    Powers, K.D.; Pittman, G.L.; Fitch, S.J.

    1980-09-01

    The species composition, distribution, and abundance of marine birds on continental shelf waters from Cape Hatteras to the Bay of Fundy were examined using ships-of-opportunity. Northern Fulmar, Cory's Shearwater, Greater Shearwater, Sooty Shearwater, Wilson's Storm-Petrel, Gannet, Red Phalarope, Great Black-backed Gull, Herring Gull, and Black-legged Kittiwake were the most abundant and common species. These species were ecologically dominant within the bird community in numbers and biomass. Georges Bank and Gulf of Marine regions generally had greatest estimates of standing stock and biomass; whereas, in the Middle Atlantic region these estimates were consistently lowest. Species diversity throughout the study area was greatest in spring and least in fall. Oceanic fronts at the continental shelf break and at Nantucket Shoals influenced the distribution of Wilson's Storm-Petrels and Red Phalaropes. Fishing activities were particularly important to Larus gull distribution. Fishes, squids, and crustaceans were the most important groups of prey items in diets of nine bird species. An oiled bird or pollution index was developed. According to the index, frequency of oiled birds was greatest in winter and spring, and gulls made up the majority of species with oiled plumages.

  13. Nesting biology of Lesser Canada Geese, Branta canadensis parvipes, along the Tanana River, Alaska

    USGS Publications Warehouse

    Ely, C.R.; Pearce, J.M.; Ruess, R.W.

    2008-01-01

    Lesser Canada Geese (Branta canadensis parvipes) are widespread throughout interior regions of Alaska and Canada, yet there have been no published studies documenting basic aspects of their nesting biology. We conducted a study to determine reproductive parameters of Lesser Canada Geese nesting along the Tanana River near the city of Fairbanks, in interior Alaska. Fieldwork was conducted in May of 2003, and consisted of locating nests along the riparian corridor between Fairbanks and Northpole, Alaska. Nests were found on gravel islands and shore habitats along the Tanana River, and were most commonly observed among driftwood logs associated with patches of alder (Alnus spp.) and willow (Salix spp.). Peak of nest initiation was 3-8 May, with a range from 27 April to 20 May; renesting was likely. Clutches ranged in size from 2 to 7 eggs and averaged 4.6 eggs. There was a negative correlation between clutch size and date of nest initiation. Egg size (X?? mass = 128 g) was similar to other medium-sized Canada Geese. A positive correlation between egg size and clutch size was likely related to female age. Nineteen of 28 nests (68%) were active when visited; nests located on islands with nesting Mew Gulls (Larus canus) were more likely to be active than nests located elsewhere. Evidence at nest sites implicated Bald Eagles (Haliaeetus leucocephalus) and Red Foxes (Vulpes vulpes) as nest predators.

  14. Selenium and metal concentrations in waterbird eggs and chicks at Agassiz National Wildlife Refuge, Minnesota

    USGS Publications Warehouse

    Custer, T.W.; Custer, Christine M.; Eichhorst, B.A.; Warburton, D.

    2007-01-01

    Exceptionally high cadmium (Cd) and chromium (Cr) concentrations were reported in eggs, feathers, or livers of selected waterbird species nesting at Agassiz National Wildlife Refuge (Agassiz) in 1994. Ten- to 15-day-old Franklin's gull (Larus pipixcan), black-crowned night-heron (Nycticorax nycticorax), and eared grebe (Podiceps nigricollis) chicks were collected in 1998, 1999, and 2001 at Agassiz and analyzed for selenium (Se) and metals including Cd and Cr. Freshly laid eggs were collected in 2001 from Franklin's gull, black-crowned night-heron, eared grebe, and pied-billed grebe (Podilymbus podiceps) nests at Agassiz. Based on a multivariate analysis, the pattern of Se and metal concentrations differed among species for eggs, chick feathers, and chick livers. Low Cd and Cr concentrations were measured in eggs, chick livers, and chick feathers of all four species. Mercury concentrations in black-crowned night-heron and eared grebe eggs collected from Agassiz in 2001 were lower than concentrations reported in 1994. Se and metal concentrations, including Cd and Cr, in waterbird eggs and chicks collected at Agassiz in 1998, 1999, and 2001 were not at toxic levels. ?? 2007 Springer Science+Business Media, LLC.

  15. Detection of a novel Rickettsia sp. in soft ticks (Acari: Argasidae) in Algeria.

    PubMed

    Lafri, Ismail; Leulmi, Hamza; Baziz-Neffah, Fadhila; Lalout, Reda; Mohamed, Chergui; Mohamed, Karakallah; Parola, Philippe; Bitam, Idir

    2015-01-01

    Argasid ticks are vectors of viral and bacterial agents that can infect humans and animals. In Africa, relapsing fever borreliae are neglected arthropod-borne pathogens that cause mild to deadly septicemia and miscarriage. It would be incredibly beneficial to be able to simultaneous detect and identify other pathogens transmitted by Argasid ticks. From 2012 to 2014, we conducted field surveys in 4 distinct areas of Algeria. We investigated the occurrence of soft ticks in rodent burrows and yellow-legged gull (Larus michahellis) nests in 10 study sites and collected 154 soft ticks. Molecular identification revealed the occurrence of two different soft tick genera and five species, including Carios capensis in yellow-legged gull nests and Ornithodoros occidentalis, Ornithodoros rupestris, Ornithodoros sonrai, Ornithodoros erraticus in rodent burrows. Rickettsial DNA was detected in 41/154, corresponding to a global detection rate of 26.6%. Sequences of the citrate synthase (gltA) gene suggest that this agent is a novel spotted fever group Rickettsia. For the first time in Algeria, we characterize a novel Rickettsia species by molecular means in soft ticks. PMID:26408401

  16. The human influence on seabird nesting success: Conservation implications

    USGS Publications Warehouse

    Anderson, D.W.; Keith, J.O.

    1980-01-01

    Based on studies of brown pelicans Pelecanus occidentalis californicus and Heermann's gulls Larus heermanni, disturbances by recreationists, educational groups, local fishermen and scientists alike can be seriously disruptive and damaging to breeding seabirds in the Gulf of California and off the west coast of Baja California. Similar instances have been identified throughout the world?the problem is not difficult to document, but it is difficult to eliminate. The increasing human-seabird contacts on islands in the Gulf of California and along the west coast of Baja California raise serious questions and immediate concern about the continued preservation of nesting colonies of marine birds in those areas. Conservation measures must consider the extreme sensitivity of many seabirds to the inter- and intraspecific behavioural imbalances created by human disturbances. In some cases, total exclusion of humans may be required; in others, limited access might be possible under closely managed conditions at certain times of the year. A symbiotic relationship between seabird conservation, legitimate research and tourism should be the desired goal.

  17. Winter marine bird and sea otter abundance of Prince William Sound, Alaska: Trends following the t/v Exxon Valdez oil spill from 1990-94. Restoration project 94159. Exxon Valdez oil spill restoration project final report

    SciTech Connect

    Agler, B.A.; Seiser, P.E.; Kendall, S.J.; Irons, D.B.

    1995-05-01

    We conducted small boat surveys to determine population abundance of marine birds and sea otters (Enhydra lutris) in Prince William Sound, Alaska during March 1994. We observed 45 bird and 8 mammal species in Prince William Sound, and we estimated that 320,470 + or - 63,640 marine birds were present. We estimated trends in the March population estimates from 1990-94 by determining whether estimates in the oiled zone changed at the same rate as those in the unoiled zone. For Prince William Sound as a whole, we also examined the population trends from 1990-94 using regression analyses. We found significant positive trends for harlequin duck (Histrionicus), goldeneye, merganser, bald eagle (Haliaeetus leucocephalus), black-legged kittiwake (Rissa tridactyla) and gull (Larus and Rissa spp.) populations. We also examined the relative abundance of marine bird species groups from 1972 to 1994. During March 1994, we estimated that the sea otter population was 7,746 + or - 2,073 otters. We found no difference in the rate of change between the oiled and unoiled zones from 1990-94, and there was no significant trend in the total number of sea otters in Prince William Sound from 1990-94.

  18. Stable isotope analysis of avian eggs: Determining diet, feeding source and role of endogenous reserves

    SciTech Connect

    Hobson, K.A.

    1995-12-31

    Contemporary and archived avian eggs have been used extensively as a means of assessing and monitoring contaminants in the environment. Eggs can also be analyzed for stable-isotope ratios to provide dietary information that may be used to link diet of laying females with contaminant levels in eggs. Various egg components can provide integrated dietary information based on periods ranging from about a day (e.g. albumen, shell carbonate) to a week (egg yolk). In addition, some species may mobilize stored proteins and lipids from endogenous reserves during egg formation and this needs to be considered when correlating contaminant levels in eggs with dietary patterns in adult females. The role of endogenous reserves in egg formation may be assessed if individuals move between food webs with distinct isotopic profiles. This approach is illustrated using isotopic investigations of captive quail, falcons and waterfowl raised on controlled diets and of wild birds (Phalacrocorax auritus, Larus argentatus, Stema caspia, Chen caerulescens) that migrate between marine and terrestrial biomes using a variety of isotopes ({sup 13}C, {sup 15}N, {sup 34}S and D) . Whereas {sup 15}N measurements may provide information primarily of trophic level, {sup 13}C, {sup 34}S and D measurements reveal important information on source of feeding and origin of endogenous reserves.

  19. Bald eagle predation on common loon egg

    USGS Publications Warehouse

    DeStefano, Stephen; McCarthy, Kyle P.; Laskowski, Tom

    2010-01-01

    The Common Loon (Gavia immer) must defend against many potential egg predators during incubation, including corvids, Herring Gulls (Larus argentatus), raccoons (Procyon lotor), striped skunk (Mephitis mephitis), fisher (Martes pennanti), and mink (Neovison vison) (McIntyre 1988, Evers 2004, McCann et al. 2005). Bald Eagles (Haliaeetus leucocephalus) have been documented as predators of both adult Common Loons and their chicks (Vliestra and Paruk 1997, Paruk et al. 1999, Erlandson et al. 2007, Piper et al. 2008). In Wisconsin, where nesting Bald Eagles are abundant (>1200 nesting pairs, >1 young/pair/year), field biologists observed four instances of eagle predation of eggs in loon nests during the period 2002–2004 (M. Meyer pers. comm.). In addition, four cases of eagle predation of incubating adult loons were inferred from evidence found at the loon nest (dozens of plucked adult loon feathers, no carcass remains) and/or loon leg, neck, and skull bones beneath two active eagle nests, including leg bones containing the bands of the nearby (<25 m) incubating adult loon. However, although loon egg predation has been associated with Bald Eagles, predation events have yet to be described in peer-reviewed literature. Here we describe a photographic observation of predation on a Common Loon egg by an immature Bald Eagle as captured by a nest surveillance video camera on Lake Umbagog, a large lake (32 km2) at Umbagog National Wildlife Refuge (UNWR) in Maine.

  20. Lead and cadmium accumulation in eggs and fledgling seabirds in the New York Bight

    SciTech Connect

    Burger, J. ); Gochfeld, M. )

    1993-02-01

    The authors measured lead and cadmium concentrations in eggs and in the breast feathers of fledglings of common tern (Sterna hirundo), roseate tern (S. dougallii), Forster's tern (S. forsteri), black skimmer (Rynchops niger), and herring gull (Larus argentatus) nesting in mixed-species colonies in the New York Bight in 1989. Metal concentrations in fledgling feathers represent in part metals sequestered in the egg by females and accumulation from food brought back to chicks by parents, and thus may be a measure of local metal acquisition. There were significant interspecific differences in lead in eggs, and lead and cadmium in fledgling feathers. Herring gulls had the most lead in eggs, whereas the terns had the least. Cadmium concentrations were generally low in all examined eggs. Lead concentrations were high in fledgling feathers in some populations of all species. Cadmium was highest in fledgling terns, the roseate tern had the highest concentrations. For all species except herring gull, the feathers of fledglings had higher levels of metals than did eggs.

  1. Extinction risk to bird populations caused by DDT exposure.

    PubMed

    Nakamaru, Mayuko; Iwasa, Yoh; Nakanishi, Junko

    2003-10-01

    The impact of toxic chemicals on wild animals and plants can be quantified in terms of the enhanced risk of population extinction. To illustrate a method for doing this, we estimated such impact for two bird species: herring gull (Larus argentatus) in Long Island, NY, and sparrowhawk (Accipiter nisus) in eastern England, when they were exposed to DDT (p,p(')-dichlorodiphenyltrichloroethane) and its metabolites (called DDTs). The method we used is based on a formula of the mean time to population extinction derived for a stochastic differential equation (the canonical model). The intrinsic rate of natural population growth was estimated from an exponentially growing population, and the intensity of the environmental fluctuation was estimated from the magnitude of population size fluctuation. The effect of exposure to DDTs in reducing the population growth rate was evaluated based on an age-structured population model, by assuming that age-specific fertility is density-dependent and sensitive to DDTs exposure, but age-specific survivorship is not. The results are expressed in terms of the risk equivalent--the decrease in carrying capacity K that causes the same enhancement of extinction risk as chemical exposure at a given level. The risk equivalent can be used in mitigation banking. PMID:12946395

  2. Extinction risk to herring gull populations from DDT exposure.

    PubMed

    Nakamaru, Mayuko; Iwasa, Yoh; Nakanishi, Junko

    2002-01-01

    The impact of toxic chemicals on wild animals and plants can be quantified in terms of the enhanced risk of population extinction. To illustrate the method, we estimated it for herring gull (Larus argentatus) populations in Long Island (NY, USA) exposed to DDT (p,p'-dichlorodiphenyltrichloroethane) and its metabolites (abbreviated as DDTs) with a strong biomagnification effect. The method is based on a formula of the mean time to population extinction derived for a stochastic differential equation (the canonical model). The intrinsic rate of natural population growth was estimated from the doubling time of an exponentially growing population and the intensity of the environmental fluctuation from the magnitude of population size fluctuation. The effect of exposure to DDTs in reducing the population growth rate was evaluated based on an age-structured population model by assuming that age-specific fertilities (including chick survivorship) are density dependent and sensitive to DDTs exposure but age-specific survivorships are not. The results are expressed in terms of the risk equivalent-the decrease in the carrying capacity K that causes the same enhancement of extinction risk as chemical exposure at a given level. The high concentration reported in Long Island in the 1960s corresponds to the equivalent loss of carrying capacity by 42.5% when K is 100 (the number of breeding females), and coefficient of variation (CV) = 0.2 (sigma2 = 0.0298) [corrected]. Risk equivalent allows us to compare different risk factors and is useful in mitigation banking. PMID:11804054

  3. Erysipelothrix rhusiopathiae isolated from gull-inflicted wounds in southern right whale calves.

    PubMed

    Fiorito, Carla D; Bentancor, Adriana; Lombardo, Daniel; Bertellotti, Marcelo

    2016-08-31

    Southern right whales Eubalaena australis from Peninsula Valdés, Argentina, show wounds produced by kelp gulls Larus dominicanus that feed on the whales' dorsal skin and blubber. During the 2013 whale season, several calves were reported showing kelp gull injuries with a swollen area surrounded by rhomboid-shaped raised edges. Samples from 9 calves were taken in order to establish the etiology of these rhomboid-shaped wounds; 2 calves (one living, one dead) showed gull-inflicted injuries with rhomboid-shaped edges. Samples from the dead calf were histologically characterized by the presence of dermal congestion, suppurative dermatitis and panniculitis, necrotizing vasculitis and vascular thrombosis. Erysipelothrix rhusiopathiae was detected by culture and PCR in samples from both calves. In this study we report, for the first time to our knowledge, the isolation of E. rhusiopathiae from wounds produced by gull attacks on southern right whale calves, supplying evidence that these wounds may act as an entry route for pathogens. This work provides new information about the consequences of gull-inflicted injuries for whale health. PMID:27596861

  4. What`s normal?: Body condition in Great Lakes herring gulls

    SciTech Connect

    Hebert, C.E.; Shutt, J.L.

    1994-12-31

    The Canadian Wildlife Service`s herring gull (Larus argentatus) surveillance program has demonstrated the usefulness of this species as a monitor of spatial and temporal trends in contaminant levels. However, the effects of environmental contaminants on gulls are difficult to distinguish from the effects of other anthropogenic stressors such as the introduction of exotic species, overfishing and habitat loss. To understand the relative importance of these factors in regulating the success of individual gulls and, hence, gull populations, the authors must first have a better understanding of what constitutes a ``normal`` bird. Improving the ability to differentiate between normal and abnormal birds is crucial in any health assessment of Great Lakes gulls. Body condition has been shown to be an important measure of a bird`s ability to provide energy for egg production, migration etc. Numerous approaches have been used to assess condition, most of which required that the bird be sacrificed. In this study, the authors describe a nonlethal technique to quantify body condition in herring gulls. Multivariate statistics are used to quantify body size, relate body size to total mass and from that, determine relative body condition. Initially, body condition is assessed in gulls from a reference colony where reproductive success is normal and anthropogenic influences are limited. This reference population is then used as a baseline against which other gull populations are compared.

  5. Metals and polycyclic aromatic hydrocarbons in colonial waterbird eggs from Lake Athabasca and the Peace-Athabasca Delta, Canada.

    PubMed

    Hebert, Craig E; Weseloh, D V Chip; Macmillan, Stuart; Campbell, David; Nordstrom, Wayne

    2011-05-01

    In 2009, aquatic bird eggs from a variety of species were collected from three sites in northern Alberta, Canada. Two sites were located in receiving waters of the Athabasca River, which drains the oil sands industrial region north of Fort McMurray, Alberta. The third site, located on the Peace River, was remote from the influence of the Athabasca River. Levels of mercury, arsenic, and polycyclic aromatic hydrocarbons (PAHs) were measured in the eggs along with nitrogen stable isotopes (δ¹⁵N) as an indicator of bird trophic position. Levels of As and PAHs in eggs were low, whereas Hg was measureable in all samples. Egg Hg levels increased with δ¹⁵N values (a proxy of food web trophic position); however, some eggs exhibited Hg levels greater than expected based on trophic position. These eggs were from sites in receiving waters of the Athabasca River, namely, Mamawi Lake and Egg Island. Levels of Hg in egg pools were correlated with naphthalene levels, perhaps indicating a common source of contamination. Temporal comparison of Hg levels in California gull (Larus californicus) eggs from the Lake Athabasca colony indicated that egg Hg burdens increased 40% from 1977 to 2009. More research is required to evaluate temporal trends in levels of environmental contaminants and to identify sources. PMID:21312251

  6. Perfluoroalkyl and polyfluoroalkyl substances in entire clutches of Audouin's gulls from the Ebro Delta.

    PubMed

    Vicente, Joana; Sanpera, Carola; García-Tarrasón, Manuel; Pérez, Alba; Lacorte, Silvia

    2015-01-01

    The aim of the present study was to determine the distribution of per- and polyfluoroalkyl substances (PFASs) in three-egg clutches of Audouin's gull (Larus audouinii) breeding in Ebro Delta's colony according to the laying order (a, b and c eggs). Five PFASs were analyzed in 30 eggs (yolk and albumen separately), corresponding to 10 three-egg clutches. Carbon and nitrogen stable isotopes were measured as dietary tracers. PFASs were not detected in albumen. In egg yolks, perfluorooctane sulfonate (PFOS) was the main compound detected followed by perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHS) and perfluorooctanoic acid (PFOA). Perfluorooctane sulfonate (PFBS) was not detected. Mean ΣPFASs for a-eggs was of 236±57 ng g(-1) yolk wet weight (ww), for b-eggs was of 140±56 ng g(-1) yolk ww and for c-eggs, 133±54 ng g(-1) yolk ww. PFOS concentration decreased according to the laying order of the eggs, showing significant differences between consecutive eggs. In addition, significant correlation (rs2=0.7-0.9) was observed for PFOS concentration within the eggs from the same clutch. No relationship was found between PFOS levels and stable isotopes signatures. Capsule: In Audouin gull's eggs, PFOS was the main PFASs detected and its concentration decreased according to the laying sequence. PMID:24815900

  7. Feathered Detectives: Real-Time GPS Tracking of Scavenging Gulls Pinpoints Illegal Waste Dumping

    PubMed Central

    Grémillet, David; Afán, Isabel; Ramírez, Francisco; Bouten, Willem; Forero, Manuela G.

    2016-01-01

    Urban waste impacts human and environmental health, and waste management has become one of the major challenges of humanity. Concurrently with new directives due to manage this human by-product, illegal dumping has become one of the most lucrative activities of organized crime. Beyond economic fraud, illegal waste disposal strongly enhances uncontrolled dissemination of human pathogens, pollutants and invasive species. Here, we demonstrate the potential of novel real-time GPS tracking of scavenging species to detect environmental crime. Specifically, we were able to detect illegal activities at an officially closed dump, which was visited recurrently by 5 of 19 GPS-tracked yellow-legged gulls (Larus michahellis). In comparison with conventional land-based surveys, GPS tracking allows a much wider and cost-efficient spatiotemporal coverage, even of the most hazardous sites, while GPS data accessibility through the internet enables rapid intervention. Our results suggest that multi-species guilds of feathered detectives equipped with GPS and cameras could help fight illegal dumping at continental scales. We encourage further experimental studies, to infer waste detection thresholds in gulls and other scavenging species exploiting human waste dumps. PMID:27448048

  8. Experimental infection and pathology of clade 2.2 H5N1 virus in gulls.

    PubMed

    Gulyaeva, Marina A; Sharshov, Kirill A; Zaykovskaia, Anna V; Shestopalova, Lidia V; Shestopalov, Aleksander M

    2016-06-30

    During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls. PMID:26243601

  9. Monitoring potential geographical distribution of four wild bird species in China

    NASA Astrophysics Data System (ADS)

    Dai, S.; Feng, D.; Xu, B.

    2015-12-01

    The outbreak of highly pathogenic avian influenza (HPAI) of the H5N1 subtype in wild birds and poultry have caught worldwide attention. To explore the association between wild bird migration and avian influenza virus transmission, we monitored potential geographical distribution of four wild bird species that might carry the avian influenza viruses in China. They are Bar-headed geese (Anser indicus), Ruddy Shelduck (Tadorna ferruginea), Whooper Swan (Cygnus cygnus) and Black-headed Gull (Larus ridibundus). They served as major reservoir of the avian influenza viruses. We used bird watching records with the precise latitude/longitude coordinates from January 2002 to August 2014, and environmental variables with a pixel resolution of 5 km × 5 km from 2002 to 2014. The study utilized maximum entropy (MaxEnt) model based on ecological niche model approaches, and got the following results: 1) MaxEnt model have good discriminatory ability with the area under the curve (AUC) of the receiver operating curve (ROC) of 0.86-0.97; 2) The four wild bird species were estimated to concentrate in the North China Plain, the middle and lower region of the Yangtze River, Qinghai Lake, Tianshan Mountain and Tarim Basin, part of Tibet Plateau, and Hengduan Mountains; 3) Radiation and the minimum temperature were found to provide the most significant information. Our findings will help to understand the spread of avian influenza viruses by wild bird migration in China, which benefits for effective monitoring strategies and prevention measures.

  10. Heavy metals in laughing gulls: Gender, age and tissue differences

    SciTech Connect

    Gochfeld, M. |; Belant, J.L.; Shukla, T.; Benson, T.; Burger, J. |

    1996-12-01

    The authors examined concentrations of lead, cadmium, mercury, manganese, selenium, and chromium in feathers, liver, kidney, heart, and muscle of known-aged laughing gulls (Larus atricilla) that hatched in Barnegat Bay, New Jersey and were collected at John F. Kennedy International Airport, New York 1 to 7 years later. Concentrations differed significantly among tissues, and tissue entered all the regression models explaining the greatest variation in metal levels. Age of bird contributed significantly to the models for lead, cadmium, selenium, and chromium. Although there were significant gender differences in all body measurements except wing length, there were few differences in metal levels. Males had significantly higher lead levels in feathers, and females had significantly higher selenium levels in heart and muscle tissue. For lead, 3-year olds had the highest levels in the heart, liver, and kidney, and levels were lower thereafter. Mercury levels in feathers and heart decreased significantly with age. Cadmium levels increased significantly with age for feathers, heart, liver, and muscle, although there was a slight decrease in the 7-year olds. Selenium levels decreased significantly with age for all tissues. Chromium levels increased with age for liver and heart.

  11. Antibiotic resistance patterns in Escherichia coli from gulls in nine European countries

    PubMed Central

    Stedt, Johan; Bonnedahl, Jonas; Hernandez, Jorge; McMahon, Barry J.; Hasan, Badrul; Olsen, Björn; Drobni, Mirva; Waldenström, Jonas

    2014-01-01

    Background The prevalence of antibiotic resistant faecal indicator bacteria from humans and food production animals has increased over the last decades. In Europe, resistance levels in Escherichia coli from these sources show a south-to-north gradient, with more widespread resistance in the Mediterranean region compared to northern Europe. Recent studies show that resistance levels can be high also in wildlife, but it is unknown to what extent resistance levels in nature conform to the patterns observed in human-associated bacteria. Methods To test this, we collected 3,158 faecal samples from breeding gulls (Larus sp.) from nine European countries and tested 2,210 randomly isolated E. coli for resistance against 10 antibiotics commonly used in human and veterinary medicine. Results Overall, 31.5% of the gull E. coli isolates were resistant to ≥1 antibiotic, but with considerable variation between countries: highest levels of isolates resistant to ≥1 antibiotic were observed in Spain (61.2%) and lowest levels in Denmark (8.3%). For each tested antibiotic, the Iberian countries were either the countries with the highest levels or in the upper range in between-country comparisons, while northern countries generally had a lower proportion of resistant E. coli isolates, thereby resembling the gradient of resistance seen in human and food animal sources. Conclusion We propose that gulls may serve as a sentinel of environmental levels of antibiotic resistant E. coli to complement studies of human-associated microbiota. PMID:24427451

  12. Productivity, diet, and environmental contaminants in bald eagles nesting near the Wisconsin shoreline of Lake Superior.

    PubMed

    Kozie, K D; Anderson, R K

    1991-01-01

    Bald eagles (Haliaeetus leucocephalus) nesting in the Apostle Islands National Lakeshore and along the Wisconsin shoreline of Lake Superior produced an average of 0.8 young/occupied nest and had an average nest success of 57% during 1983-1988, compared to 1.3 young/occupied nest and 77% nest success in inland Wisconsin. Contaminant levels in nestling bald eagle carcasses collected from nests near Lake Superior were higher than those collected inland, suggesting local contamination. Prey remains collected at nests consisted of fish (50%); birds, primarily herring gulls (Larus argentatus) (48.4%); and mammals (1.2%). Organochlorine and polychlorinated biphenyl (PCB) residues were present at low levels (DDE: means = 0.07 micrograms/g wet wt, PCP: means = 0.21 micrograms/g wet wt) in fish. Herring gulls contained higher concentrations (DDE: means = 5.5 micrograms/g wet wt, PCB: means = 16.95 micrograms/g wet wt) and appear to be the major source of elevated contaminant levels in bald eagles nesting near Lake Superior. PMID:1996910

  13. The effects of testosterone manipulation on the body condition of captive male yellow-legged gulls.

    PubMed

    Alonso-Alvarez, Carlos; Ferrer, Miguel; Figuerola, Jordi; Veira, José A R; Estepa, Julio; Torres, Luis M

    2002-02-01

    Persistently high testosterone levels are believed to be costly to males due to their negative effect on body condition. However, this assumption could not be validated when we analysed birds isolated from all social interactions. The hypothesis was tested on birds kept in isolation in order to analyse the effects of testosterone per se, and thereby exclude the influence of social interactions. Adult male yellow-legged gulls (Larus cachinnans) were captured, and after a period of adjustment, some individuals were subcutaneously implanted with testosterone, while the rest were used as controls. The gulls received ad libitum food for 10 days and were then fasted for 4 days. Thyroid hormones, body-mass change, daily food intake, hematocrit and several plasma biochemical parameters were analysed. Treated (T)-males maintained constant levels of plasma total protein throughout the experiment, whilst control (C)-males showed a decrease. We did not find any other differences between groups for the other variables analysed. Since the implanted birds sustained high testosterone levels for a number of days, any cost to body condition would have been revealed if these costs levels were actually important. Our results do not support the hypothesis that a reduction in body condition can be directly produced by plasma testosterone, although total protein changes do suggest different anabolic patterns in testosterone-treated gulls. PMID:11818219

  14. A broad cocktail of environmental pollutants found in eggs of three seabird species from remote colonies in Norway.

    PubMed

    Huber, Sandra; Warner, Nicholas A; Nygård, Torgeir; Remberger, Mikael; Harju, Mikael; Uggerud, Hilde T; Kaj, Lennart; Hanssen, Linda

    2015-06-01

    Eggs of 3 seabird species, common eider (Somateria mollisima), European shag (Phalacrocorax aristotelis aristotelis), and European herring gull (Larus argentatus), were surveyed for a broad range of legacy and emerging pollutants to assess chemical mixture exposure profiles of seabirds from the Norwegian marine environment. In total, 201 chemical substances were targeted for analysis ranging from metals, organotin compounds, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and associated metabolites, chlorinated paraffins, chlorinated and nonchlorinated organic pesticides, per- and polyfluoroalkyl substances (PFAS), dechlorane plus, octachlorostyrene, brominated flame retardants (BFRs), organophosphorous compounds, brominated and alkyl phenols, cyclic siloxanes, and phthalates. Of the chemicals targeted, 149 substances were found above the detection limits, with metals dominating the contaminant profile and comprising 60% of the total contaminant load. Polychlorinated biphenyls, pesticides, organophosphorous compounds, and PFAS were the dominant contaminant classes of organic pollutants found within the seabird species, with the highest loads occurring in herring gulls, followed by shag, and common eider. New generation pollutants (e.g., PFAS, organophosphorous compounds, and alkylphenols) were detected at similar or higher concentrations than the legacy persistent organic pollutants (POPs). Time trends of reported concentrations of legacy POPs appear to have decreased in recent decades from the Norwegian coastal environment. Concentrations of detected pollutants do not appear to have a negative effect on seabird population development within the sampling area. Additional stress caused by pollutants, however, may affect seabird health more at the individual level. PMID:25728907

  15. Feathered Detectives: Real-Time GPS Tracking of Scavenging Gulls Pinpoints Illegal Waste Dumping.

    PubMed

    Navarro, Joan; Grémillet, David; Afán, Isabel; Ramírez, Francisco; Bouten, Willem; Forero, Manuela G

    2016-01-01

    Urban waste impacts human and environmental health, and waste management has become one of the major challenges of humanity. Concurrently with new directives due to manage this human by-product, illegal dumping has become one of the most lucrative activities of organized crime. Beyond economic fraud, illegal waste disposal strongly enhances uncontrolled dissemination of human pathogens, pollutants and invasive species. Here, we demonstrate the potential of novel real-time GPS tracking of scavenging species to detect environmental crime. Specifically, we were able to detect illegal activities at an officially closed dump, which was visited recurrently by 5 of 19 GPS-tracked yellow-legged gulls (Larus michahellis). In comparison with conventional land-based surveys, GPS tracking allows a much wider and cost-efficient spatiotemporal coverage, even of the most hazardous sites, while GPS data accessibility through the internet enables rapid intervention. Our results suggest that multi-species guilds of feathered detectives equipped with GPS and cameras could help fight illegal dumping at continental scales. We encourage further experimental studies, to infer waste detection thresholds in gulls and other scavenging species exploiting human waste dumps. PMID:27448048

  16. Changes in the nesting populations of colonial waterbirds in Jamaica Bay Wildlife Refuge, New York, 1974-1998

    USGS Publications Warehouse

    Brown, K.M.; Tims, J.L.; Erwin, R.M.; Richmond, M.E.

    2001-01-01

    The Jamaica Bay Wildlife Refuge (JBWR) represents the largest protected area for over 300 species of migratory and resident birds on Long Island (LI), New York, and occupies a key position along the Atlantic flyway. We identified changes in nesting populations for 18 species of colonial waterbirds in JBWR and on LI, during 1974 - 1998, to provide a basis for future wildlife management decisions in JBWR and also at nearby John F. Kennedy International Airport. None of the populations was stable over the past 25 years in JBWR or on LI. Some populations in JBWR increased (Laughing Gull L. atricilla Linnaeus, Great Black-backed Gull L. marinus Linnaeus, Forster's Tern Sterna forsteri Nuttall) while others decreased (Herring Gull Larus argentatus Coues, Snowy Egret Egretta thula Molina), but only Cattle Egrets (Bubulcus ibis Linnaeus) have disappeared from the refuge. Common Tern (S. hitundo Linnaeus), Least Tern (S. antillarum Lesson), Roseate Tern (S. dougallii Montagu), Black Skimmer (Rynchops niger Linnaeus), Black-crowned Night Heron (Nycticorax nycticorax Linnaeus) and Great Egret (Ardea alba Linnaeus) populations all increased on LI over the sampling period although the Common Tern colonies in JBWR have been declining since 1986. The continued protection of the colony sites, particularly saltmarsh islands, in JBWR will be important to the conservation efforts of many colonial waterbird populations on Long Island. The JBWR colonies may serve as a source of emigrants to other Long Island colonies, and in some cases, act as a 'sink' for birds immigrating from New Jersey and elsewhere.

  17. Chlamydiaceae in North Atlantic Seabirds Admitted to a Wildlife Rescue Center in Western France.

    PubMed

    Aaziz, R; Gourlay, P; Vorimore, F; Sachse, K; Siarkou, V I; Laroucau, K

    2015-07-01

    Birds are the primary hosts of Chlamydia psittaci, a bacterium that can cause avian chlamydiosis in birds and psittacosis in humans. Wild seabirds are frequently admitted to wildlife rescue centers (WRC) at European Atlantic coasts, for example, in connection with oil spills. To investigate the extent of chlamydial shedding by these birds and the resulting risk for animals in care and the medical staff, seabirds from a French WRC were sampled from May 2011 to January 2014. By use of a quantitative PCR (qPCR), 195 seabirds belonging to 4 orders, 5 families and 13 species were examined, of which 18.5% proved to be Chlamydiaceae positive. The highest prevalence of shedders was found in northern gannets (Morus bassanus) (41%), followed by European herring gulls (Larus argentatus) (14%) and common murres (Uria aalge) (7%). Molecular characterization and phylogenetic analysis of qPCR-positive northern gannet samples revealed two variants of a strain closely related to C. psittaci. In European herring gulls and in one common murre, strains showing high sequence similarity to the atypical Chlamydiaceae-like C122 previously found in gulls were detected. Our study shows that seabirds from the northeastern Atlantic Ocean carry several chlamydial organisms, including C. psittaci-related strains. The staff in WRCs should take protective measures, particularly in the case of mass admissions of seabirds. PMID:25934619

  18. Tracking the History and Ecological Changes of Rising Double-Crested Cormorant Populations Using Pond Sediments from Islands in Eastern Lake Ontario

    PubMed Central

    Stewart, Emily M.; Michelutti, Neal; Shenstone-Harris, Sarah; Grooms, Christopher; Weseloh, Chip; Kimpe, Linda E.; Blais, Jules M.; Smol, John P.

    2015-01-01

    In the Laurentian Great Lakes region, the double-crested cormorant (Phalacrocorax auritus) has seen a thousand-fold population increase in recent decades. These large colonies of birds now often conflict with socioeconomic interests, particularly due to perceived competition with fisheries and the destruction of terrestrial vegetation in nesting habitats. Here we use dated sediment cores from ponds on islands in eastern Lake Ontario that receive waste inputs from dense colonies of cormorants and ring-billed gulls (Larus delawarensis) to chronicle the population rise of these species and assess their long-term ecological impacts. Modern water chemistry sampling from these sites reveals drastically elevated nutrient and major ion concentrations compared to reference ponds not influenced by waterbirds. Geochemical tracers in dated sediment cores, particularly δ15N and chlorophyll-a concentrations, track waterbird influences over time. Fossil diatom assemblages were dominated by species tolerant of hyper-eutrophic and polluted systems, which is in marked contrast to assemblages in reference sites. In addition to establishing long-term ecological impacts, this multi-proxy paleoecological approach can be used to determine whether islands of concern have been long-term nesting sites or were only recently colonized by cormorant or ring-billed gull populations across the Great Lakes, facilitating informed management decisions about controversial culling programs. PMID:26214177

  19. Waterbird predation on fish in western Lake Erie: a bioenergetics model application

    USGS Publications Warehouse

    Madenjian, Charles P.; Gabrey, Steven W.

    1995-01-01

    To better understand the role of piscivorous waterbirds in the food web of western Lake Erie, we applied a bioenergetics model to determine their total fish consumption, The important nesting species included the Herring Gull (Larus argentatus), Ring-billed Gull (L. delawarensis), Double-crested Cormorant (Phalacrocorax auritus), Great Blue Heron (Ardea herodias), Black-crowned Night-Heron (Nycticorax nycticorax), and Great Egret (Casmerodius albus). The impact of migrant waterbirds, including the Red-breasted Merganser (Mergus serrator), on western Lake Erie fish biomass was also considered in the analysis. According to the modeling results, during the early 1990s, piscivorous waterbirds consumed 13,368 tonnes of fish from western Lake Erie each year. This tonnage was equivalent to 15.2% of the prey fish biomass needed to support the walleye (Stizostedion vitreum) population in western Lake Erie during a single growing season. The model application was useful in quantifying energy flow between birds and fish in a large lake ecosystem.

  20. Avian Hemosporidian Parasite Lineages in Four Species of Free-ranging Migratory Waterbirds from Mongolia, 2008.

    PubMed

    Seimon, Tracie A; Gilbert, Martin; Neabore, Scott; Hollinger, Charlotte; Tomaszewicz, Ania; Newton, Alisa; Chang, Tylis; McAloose, Denise

    2016-07-01

    Avian hemosporidian parasites have been detected in Asia, but little information is known about the hemosporidian parasite lineages that circulate in waterbirds that migrate along the East Asian and Central Asian migratory flyways to breed in Mongolia. To gather baseline data on hemosporidian parasite presence in Mongolian waterbirds, 151 blood-spot samples (81 hatch year [HY] and 70 after hatch year [AHY]) from Bar-headed Goose (Anser indicus), Ruddy Shelduck (Tadorna ferruginea), Great Cormorant ( Phalacrocorax carbo ), and Mongolian Gull (Larus mongolicus) were screened for three genera of apicomplexan parasites, Plasmodium, Haemoproteus, and Leucocytozoon, using nested PCR. Of these, 17 samples (11%, 95% confidence interval: 7.1-17.4%), representing all four species, were positive. We identified 10 species (six Plasmodium, one Haemoproteus, and three Leucocytozoon) through mitochondrial DNA sequencing of the cytochrome b gene and BLAST analysis. One lineage shared 100% nucleotide identity to a hemosporidian parasite lineage that has been previously identified as Plasmodium relictum (SGS1). Six lineages were found in AHY birds and five in HY birds, the latter confirming that infection with some of the identified hemosporidian parasites occurred on the breeding grounds. Our data provide important baseline information on hemosporidian parasite lineages found in AHY waterbirds that breed and migrate through Mongolia as well as in HY offspring. PMID:27243330

  1. Distribution and abundance of marine bird and pinniped populations within Port Foster, Deception Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Kendall, Katrina A.; Ruhl, Henry A.; Wilson, Robert C.

    2003-06-01

    Seabirds and pinnipeds were surveyed during four cruises from March 1999 to November 2000 at Port Foster, Deception Island, Antarctica. Abundances and distributions of three species of pinnipeds, Arctocephalus gazella (Antarctic fur seals), Leptonychotes weddelli (Weddell seals), and Lobodon carcinophagus (crabeater seals), and 11 species of marine birds were documented within Port Foster. A. gazella was the dominant pinniped within Port Foster; its abundance has increased since the 1986/87 austral summer season. A. gazella were concentrated at the entrance to Port Foster. More pinnipeds were observed during the austral summer than during the spring. The most dominant seabird, Pygoscelis antarctica (chinstrap penguin), was concentrated along the rocky cliffs behind the beaches where A. gazella hauled out. Larus dominicanus (kelp gull) and Daption capense (cape petrel) were the most dominant flying seabirds. All other seabird species were more widely distributed around Port Foster than P. antarctica. There was no clear trend in abundances of seabirds over the study period. It is possible that the protected area of Port Foster provides refuge for vagrants of colonies along the outer periphery of the island and as a stopover point for migrating species.

  2. Effects of seagulls on ecosystem respiration, soil nitrogen and vegetation cover on a pristine volcanic island, Surtsey, Iceland

    NASA Astrophysics Data System (ADS)

    Sigurdsson, B. D.; Magnusson, B.

    2010-03-01

    When Surtsey rose from the North Atlantic Ocean south of Iceland in 1963, it became a unique natural laboratory on how organisms colonize volcanic islands and form ecosystems with contrasting structures and functions. In July, 2004, ecosystem respiration rate (Re), soil properties and surface cover of vascular plants were measured in 21 permanent research plots distributed among the juvenile communities of the island. The plots were divided into two main groups, inside and outside a seagull (Larus spp.) colony established on the island. Vegetation cover of the plots was strongly related to the density of gull nests. Occurrence of nests and increased vegetation cover also coincided with significant increases in Re, soil carbon, nitrogen and C:N ratio, and with significant reductions in soil pH and soil temperatures. Temperature sensitivity (Q10 value) of Re was determined as 5.3. When compared at constant temperature the Re was found to be 59 times higher within the seagull colony, similar to the highest fluxes measured in drained wetlands or agricultural fields in Iceland. The amount of soil nitrogen, mainly brought onto the island by the seagulls, was the critical factor that most influenced ecosystem fluxes and vegetation development on Surtsey. The present study shows how ecosystem activity can be enhanced by colonization of animals that transfer resources from a nearby ecosystem.

  3. Does garbage in diet improve Glaucous Gull reproductive output?

    USGS Publications Warehouse

    Powell, Abby N.; Weiser, Emily L.

    2010-01-01

    Anthropogenic subsidies are used by a variety of predators in areas developed for human use or residence. If subsidies promote population growth, these predators can have a negative effect on local prey species. The Glaucous Gull (Larus hyperboreus) is an abundant predator in northern Alaska that is believed to benefit from garbage as a supplemental food source, but this supposition has never been tested. In summer 2008 and 2009, we recorded the Glaucous Gull's diet and reproduction at 10 breeding colonies in northern Alaska. Colonies were in industrial, residential, and undeveloped areas and ranged from 5 to 75 km from the nearest landfill. By colony, garbage occurred in zero to 85% of pellets and food remains produced during the chick-rearing period, and the average number of chicks fledged per pair ranged from zero to 2.9. Random-forest analysis indicated that percent occurrence of garbage in the diet was the second most important factor (after number of eggs per pair) explaining variance in fledging rate. There was a significant positive correlation between percent occurrence of garbage in the diet and fledging rate in each year. If this correlation reflects a causal relationship, it suggests that human development that increases gulls' access to garbage could result in increased local gull populations. Such an increase could affect the gulls' natural prey species, including at least 14 species of shorebirds and waterfowl of conservation concern.

  4. Does garbage in the diet improve reproductive output of Glaucous Gulls

    USGS Publications Warehouse

    Weiser, E.L.; Powell, A.N.

    2010-01-01

    Anthropogenic subsidies are used by a variety of predators in areas developed for human use or residence. If subsidies promote population growth, these predators can have a negative effect on local prey species. The Glaucous Gull (Larus hyperboreus) is an abundant predator in northern Alaska that is believed to benefit from garbage as a supplemental food source, but this supposition has never been tested. In summer 2008 and 2009, we recorded the Glaucous Gull's diet and reproduction at 10 breeding colonies in northern Alaska. Colonies were in industrial, residential, and undeveloped areas and ranged from 5 to 75 km from the nearest landfill. By colony, garbage occurred in zero to 85% of pellets and food remains produced during the chick-rearing period, and the average number of chicks fledged per pair ranged from zero to 2.9. Random-forest analysis indicated that percent occurrence of garbage in the diet was the second most important factor (after number of eggs per pair) explaining variance in fledging rate. There was a significant positive correlation between percent occurrence of garbage in the diet and fledging rate in each year. If this correlation reflects a causal relationship, it suggests that human development that increases gulls' access to garbage could result in increased local gull populations. Such an increase could affect the gulls' natural prey species, including at least 14 species of shorebirds and waterfowl of conservation concern. ?? The Cooper Ornithological Society 2010.

  5. Glaucous gull predation of goslings on the Yukon-Kuskokwim Delta, Alaska

    USGS Publications Warehouse

    Bowman, T.D.; Stehn, R.A.; Scribner, K.T.

    2004-01-01

    Glaucous Gulls (Larus hyperboreus) nesting on the Yukon-Kuskokwim (Y-K) Delta frequently prey on juvenile waterfowl. We collected 434 Glaucous Gulls from late June to early August 1994 to examine diet. Identification of undigested prey tissue, based on DNA microsatellite loci, showed three species of goslings in gull stomachs: Emperor Goose (Chen canagica), White-fronted Goose (Anser albifrons), and Cackling Canada Goose (Branta canadensis minima). Gulls that nested inland and were collected > 1.6 km from the coast accounted for approximately 70% of the total gull predation on Emperor and Canada Geese, and 96% on White-fronted Geese. Our stratified sample of gull stomachs and aerial survey estimates of population size and distribution of gulls and juvenile geese enabled extrapolation of species-specific predation rates to the entire Y-K Delta. We estimated that a minimum of 21 000 Emperor Goose, 34 000 Canada Goose, and 16 000 White-fronted Goose goslings were consumed by 12 600 Glaucous Gulls during the brood-rearing period on the Y-K Delta in 1994. Minimum estimated take by gulls represented 33% of Cackling Canada Goose, 47% of Emperor Goose, and 39% of White-fronted Goose eggs estimated to have hatched in the same area as gull collections. Gulls selected the three species of geese approximately in proportion to their abundance. Although gull predation caused significant gosling mortality, its role in regulating goose populations on Y-K Delta remains unresolved.

  6. Migration and wintering areas of glaucous-winged Gulls from south-central Alaska

    USGS Publications Warehouse

    Hatch, Shyla A.; Gill, V.A.; Mulcahy, D.M.

    2011-01-01

    We used satellite telemetry to investigate the migration patterns and wintering areas of Glaucouswinged Gulls (Larus glaucescens) from Middleton Island, Alaska, where this species' population increased tenfold from the 1970s to the 1990s. Fall migration spanned 11 weeks, including numerous stopovers en route, apparently for feeding. Spring migration from wintering sites to Middleton Island was shorter (4 weeks) and more direct. One juvenile spent several months in southern Prince William Sound. An adult spent several months near Craig, southeast Alaska, while three others overwintered in southern British Columbia. For all four wintering adults use of refuse-disposal sites was evident or strongly suggested. Commensalism with humans may have contributed to the increase on Middleton, but a strong case can also be made for a competing explanation-regional recruitment of gulls to high-quality nesting habitat in Alaska created after the earthquake of 1964. An analysis of band returns reveals broad overlap in the wintering grounds of gulls from different Alaska colonies and of gulls banded on the west coast from British Columbia to California. The seasonal movement of many gulls from Alaska is decidedly migratory, whereas gulls from British Columbia, Washington, and Oregon disperse locally in winter. ?? The Cooper Ornithological Society 2011.

  7. Plastic ingestion by a generalist seabird on the coast of Uruguay.

    PubMed

    Lenzi, Javier; Burgues, María Fernanda; Carrizo, Daniel; Machín, Emanuel; Teixeira-de Mello, Franco

    2016-06-15

    We analyzed plastic ingestion by Kelp Gull (Larus dominicanus) from 806 pellets collected between 2011 and 2013. Employing a Raman spectroscopy, we characterized those polymers used to produce the plastics ingested. Debris was recorded in 143 pellets (%FO=17.7%, n=202, 92.58g). Plastic was found in 119 pellets (%FO=83%) and non-plastic occurred in 56 pellets (%FO=39%). The most important debris category was plastic film with 55.3% (n=79). Plastic bags were observed in 19 pellets (%FO=2.4%, weight=25.02g). Glass was the second most important component (%FO=18.9%) followed by plastic fragments (%FO=17.8%). Plastic debris represented the 65.3% of the debris fragments (n=132, weight=58.84g), and was composed by polyethylene (52%), polypropylene (26%), polyamide (12%), polystyrene (6%), polyvinyl chloride (2%), and polyethylene terephthalate (2%). How plastics were obtained by gulls and the effects on individuals are discussed, as well as environmental considerations about plastic pollution on coastal environments. PMID:27098991

  8. Consecutive cohort effects driven by density-dependence and climate influence early-life survival in a long-lived bird.

    PubMed

    Payo-Payo, A; Genovart, M; Bertolero, A; Pradel, R; Oro, D

    2016-04-27

    Conditions during early life, including maternal cohort effects, can influence the future fitness of individuals. This may be particularly true for long-distance migrating birds, because, apart from conditions experienced by cohorts during rearing, conditions during early life in regions far from breeding grounds may also influence their population dynamics. Very little is known about the fitness consequences of those conditions experienced by juveniles after independence, especially in wild populations and for long-lived birds. We used multi-event capture-recapture-recovery models and a unique 26-year dataset for the Audouin's gull (Larus audouinii) to assess for the first time whether survival was influenced by early conditions, both during the rearing period (i.e. a maternal cohort effect potentially affected by density dependence) and the first winter (i.e. a cohort effect driven by climate when birds disperse to wintering grounds). Our results show that juvenile survival was highly sensitive to early-life conditions and that survival decreased with stronger density dependence and harsh climate. The two consecutive cohort effects were of similar magnitude and they may represent a selection filter. Thus, early-life conditions had a strong impact on survival, and neglecting this complexity may hinder our understanding on how populations of long-lived animals fluctuate and respond to perturbations. PMID:27122556

  9. Flap or soar? How a flight generalist responds to its aerial environment.

    PubMed

    Shamoun-Baranes, Judy; Bouten, Willem; van Loon, E Emiel; Meijer, Christiaan; Camphuysen, C J

    2016-09-26

    The aerial environment is heterogeneous in space and time and directly influences the costs of animal flight. Volant animals can reduce these costs by using different flight modes, each with their own benefits and constraints. However, the extent to which animals alter their flight modes in response to environmental conditions has rarely been studied in the wild. To provide insight into how a flight generalist can reduce the energetic cost of movement, we studied flight behaviour in relation to the aerial environmental and landscape using hundreds of hours of global positioning system and triaxial acceleration measurements of the lesser black-backed gull (Larus fuscus). Individuals differed largely in the time spent in flight, which increased linearly with the time spent in flight at sea. In general, flapping was used more frequently than more energetically efficient soaring flight. The probability of soaring increased with increasing boundary layer height and time closer to midday, reflecting improved convective conditions supportive of thermal soaring. Other forms of soaring flight were also used, including fine-scale use of orographic lift. We explore the energetic consequences of behavioural adaptations to the aerial environment and underlying landscape and implications for individual energy budgets, foraging ecology and reproductive success.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'. PMID:27528785

  10. Migration And wintering areas Of Glaucous-winged Gulls From south-central Alaska

    USGS Publications Warehouse

    Hatch, Scott A.; Gill, V.A.; Mulcahy, Daniel M.

    2011-01-01

    We used satellite telemetry to investigate the migration patterns and wintering areas of Glaucous-winged Gulls (Larus glaucescens) from Middleton Island, Alaska, where this species' population increased tenfold from the 1970s to the 1990s. Fall migration spanned 11 weeks, including numerous stopovers en route, apparently for feeding. Spring migration from wintering sites to Middleton Island was shorter (4 weeks) and more direct. One juvenile spent several months in southern Prince William Sound. An adult spent several months near Craig, southeast Alaska, while three others overwintered in southern British Columbia. For all four wintering adults use of refuse-disposal sites was evident or strongly suggested. Commensalism with humans may have contributed to the increase on Middleton, but a strong case can also be made for a competing explanation-regional recruitment of gulls to high-quality nesting habitat in Alaska created after the earthquake of 1964. An analysis of band returns reveals broad overlap in the wintering grounds of gulls from different Alaska colonies and of gulls banded on the west coast from British Columbia to California. The seasonal movement of many gulls from Alaska is decidedly migratory, whereas gulls from British Columbia, Washington, and Oregon disperse locally in winter.

  11. Gull contributions of phosphorus and nitrogen to a Cape Cod kettle pond

    USGS Publications Warehouse

    Portnoy, J.W.; Soukup, M.A.

    1990-01-01

    Nutrient excretion rates and the annual contribution of P from the feces of the gulls Larus argentatus and L. marinus (and of N from L. argentatus) to the nutrient budget of Gull Pond (Wellfleet), a soft water seepage lake, have been estimated. Intensive year-round gull counts by species were combined with determinations of defecation rate and the nutrient content of feces to quantitatively assess the P loading rates associated with regular gull use of this coastal pond on a seasonal and annual basis. Total P loading from gulls was estimated to be 52 kg yr?1, with 17 kg from L. argentatus and 35 kg from L. marinus, resulting from about 5.0 ? 106 h yr?1 and 1.7 ? 106 h yr?1 of pond use. This compares with P loading estimates of 67 kg yr?1 from upgradient septic systems, 2 kg yr?1 from precipitation and 3 kg yr?1 from unpolluted ground water. Fifty-six percent of annual gull P loading was associated with migratory activity in late fall. Estimated annual N loading by L. argentatus was 14 kg TKN, 206 g NO3-N, and 1.85 g g NH3-N.

  12. Microsatellites identify depredated waterfowl remains from glaucous gull stomachs

    USGS Publications Warehouse

    Scribner, K.T.; Bowman, T.D.

    1998-01-01

    Prey remains can provide valuable sources of information regarding causes of predation and the species composition of a predator's diet. Unfortunately, the highly degraded state of many prey samples from gastrointestinal tracts often precludes unambiguous identification. We describe a procedure by which PCR amplification of taxonomically informative microsatellite loci were used to identify species of waterfowl predated by glaucous gulls (Larus hyperboreus). We found that one microsatellite locus unambiguously distinguished between species of the subfamily Anserinae (whistling ducks, geese and swans) and those of the subfamily Anatidae (all other ducks). An additional locus distinguished the remains of all geese and swan species known to nest on the Yukon-Kuskokwim delta in western Alaska. The study focused on two waterfowl species which have experienced precipitous declines in population numbers: emperor geese (Chen canagica) and spectacled eiders (Somateria fischeri). No evidence of predation on spectacled eiders was observed. Twenty-six percent of all glaucous gull stomachs examined contained the remains of juvenile emperor geese.

  13. Ecosystem respiration, vegetation development and soil nitrogen in relation to breeding density of seagulls on a pristine volcanic island, Surtsey, Iceland

    NASA Astrophysics Data System (ADS)

    Sigurdsson, B. D.; Magnusson, B.

    2009-08-01

    Since its birth in 1963 by volcanic eruption in the North Atlantic Ocean off Iceland, Surtsey has been a unique natural laboratory on how organisms colonize volcanic islands and form ecosystems with contrasting structure and function. In July, 2004, ecosystem respiration rate, soil properties and surface cover of vascular plants were measured on 21 plots distributed among the main plant communities found 40 years after the primary succession started. The plots could be divided into two groups, inside and outside seagull (Larus sp.) colonies found on the island. Vegetation cover of the plots was strongly related to the density of seagull nests within and around them. The occurrence of seagull nests and increased vegetation also coincided with significant increase in ecosystem respiration, soil carbon and nitrogen, and with significantly lower soil pH and soil temperatures. The ecosystem respiration was high inside the gull colonies, similar to the highest fluxes measured in drained wetlands or agricultural fields in Iceland. The most important factor for vegetation succession and ecosystem function on Surtsey seems to be the amount of nitrogen, which was mainly brought in by the seagulls.

  14. Nest-density distribution patterns in a yellow-legged gull archipelago colony

    NASA Astrophysics Data System (ADS)

    Vidal, Eric; Roche, Philip; Bonnet, Véronique; Tatoni, Thierry

    2001-12-01

    The nest density distribution of yellow-legged gulls Larus cachinnans was investigated on the large Marseille archipelago colony (south-east France) which houses c. 18 000 breeding pairs. The study was performed at two investigation scales, including both mean nesting density on the nine study islands and density distribution within 171 sampling plots. The mean nesting density on each island was negatively correlated with island surface area and with the distance from the initial colony location (south-east end of the archipelago). No significant correlation was found with the other island parameters analysed (maximum elevation, shape index and distance from continent). A partial least squares regression performed between denstiy data from 171 500 m 2 sampling plots and environmental variables showed that the mostly explaining factors were island isolation and percentage of rocks in the plots (positive correlation), and distance of the island from the south-east end of the archipelago, island area, distance from plot to seaside and percentage of stone in the plots (negative correlation). Thus in our case, vegetation parameters (cover and height) were not influencial factors in nest density distribution.

  15. A pelagic outbreak of avian cholera in North American gulls: Scavenging as a primary mechanism for transmission?

    USGS Publications Warehouse

    Wille, Michelle; McBurney, Scott; Robertson, Gregory J.; Wilhelm, Sabine; Blehert, David; Soos, Catherine; Dunphy, Ron; Whitney, Hugh

    2016-01-01

    Avian cholera, caused by the bacterium Pasteurella multocida, is an endemic disease globally, often causing annual epizootics in North American wild bird populations with thousands of mortalities. From December 2006 to March 2007, an avian cholera outbreak caused mortality in marine birds off the coast of Atlantic Canada, largely centered 300–400 km off the coast of the island of Newfoundland. Scavenging gulls (Larus spp.) were the primary species detected; however, mortality was also identified in Black-legged Kittiwakes (Rissa tridactyla) and one Common Raven (Corvus corax), a nonmarine species. The most common gross necropsy findings in the birds with confirmed avian cholera were acute fibrinous and necrotizing lesions affecting the spleen, air sacs, and pericardium, and nonspecific hepatomegaly and splenomegaly. The etiologic agent, P. multocida serotype 1, was recovered from 77 of 136 carcasses examined, and confirmed or probable avian cholera was diagnosed in 85 cases. Mortality observed in scavenging gull species was disproportionately high relative to their abundance, particularly when compared to nonscavenging species. The presence of feather shafts in the ventricular lumen of the majority of larid carcasses diagnosed with avian cholera suggests scavenging of birds that died from avian cholera as a major mode of transmission. This documentation of an outbreak of avian cholera in a North American pelagic environment affecting primarily scavenging gulls indicates that offshore marine environments may be a component of avian cholera dynamics.

  16. Structure of marine predator and prey communities along environmental gradients in a glaciated fjord

    USGS Publications Warehouse

    Renner, Martin; Arimitsu, Mayumi L.; Piatt, John F.

    2012-01-01

    Spatial patterns of marine predator communities are influenced to varying degrees by prey distribution and environmental gradients. We examined physical and biological attributes of an estuarine fjord with strong glacier influence to determine the factors that most influence the structure of predator and prey communities. Our results suggest that some species, such as walleye pollock (Theragra chalcogramma), black-legged kittiwake (Rissa tridactyla), and glaucous-winged gull (Larus glaucescens), were widely distributed across environmental gradients, indicating less specialization, whereas species such as capelin (Mallotus villosus), harbor seal (Phoca vitulina), and Kittlitz's murrelet (Brachyramphus brevirostris) appeared to have more specialized habitat requirements related to glacial influence. We found that upper trophic level communities were well correlated with their mid trophic level prey community, but strong physical gradients in photic depth, temperature, and nutrients played an important role in community structure as well. Mid-trophic level forage fish communities were correlated with the physical gradients more closely than upper trophic levels were, and they showed strong affinity to tidewater glaciers. Silica was closely correlated with the distribution of fish communities, the mechanisms of which deserve further study.

  17. Distribution and status of marine birds breeding along the coasts of the Chukchi and Bering seas

    USGS Publications Warehouse

    Bartonek, J.C.; Sealy, S.G.

    1979-01-01

    The Alaska coast fronting on the Chukchi and Bering seas, exclusive of the Aleutian Islands, supports seven complexes of marine bird colonies numbering more than 1 million birds each, nine colonies of 100,000 to almost 1 million birds, and many smaller colonies. Colonies are found on most headlands and islands and are dominated numerically by alcids and kittiwakes (Rissa sp.). Estuarine habitats (mainly the lowlands of northern Seward Peninsula, Yukon-Kuskokwim delta, and the north side of the Alaska Peninsula) are extremely important for breeding and migrating marine waterfowl, shorebirds, gulls (Larus sp.), and terns (Sterna sp.). Information on population size and distribution of breeding marine birds within this area is extensive for only a few of the more heavily hunted species of waterfowl. Except for the intensive and systematic censusing of a few colonies in this region, population data on cliff-, burrow-, and crevice-nesting birds are such that all but gross changes in numbers may go unnoticed, and if noticed they could not be measured.

  18. Skin pentosidine and telomere length do not covary with age in a long-lived seabird.

    PubMed

    Rattiste, Kalev; Klandorf, Hillar; Urvik, Janek; Sepp, Tuul; Asghar, Muhammad; Hasselquist, Dennis; Cooey, Crissa; Hõrak, Peeter

    2015-08-01

    The questions about why and how senescence occurs in the wild are among the most pertinent ones in evolutionary ecology. Telomere length is a commonly used marker for aging, while other biomarkers of aging have received considerably less attention. Here we studied how another potent indicator of aging-skin pentosidine concentration-relates to age and blood telomere length in a long-lived seabird with well-documented reproductive senescence. We found no associations between telomere length, skin pentosidine and chronological age in male common gulls (Larus canus), aging from 2 to 30 years. However, the variance in telomere length was 4.6 times higher among the birds older than 13 years, which hints at relaxed selection on telomere length among the birds that have passed their prime age of reproduction. These results suggest that physiological and chronological ages may be largely uncoupled in our study system. Furthermore, our findings do not support a hypothesis about the presence of a common physiological factor (e.g., such as oxidative stress) that would cause covariation between two independent markers of aging. PMID:25726322

  19. Molecular characterization of Giardia intestinalis haplotypes in marine animals: variation and zoonotic potential.

    PubMed

    Lasek-Nesselquist, Erica; Bogomolni, Andrea L; Gast, Rebecca J; Welch, David Mark; Ellis, Julie C; Sogin, Mitchell L; Moore, Michael J

    2008-08-19

    Giardia intestinalis is a microbial eukaryotic parasite that causes diarrheal disease in humans and other vertebrates worldwide. The negative effect on quality of life and economics caused by G. intestinalis may be increased by its potential status as a zoonosis, or a disease that can be transmitted from animals to humans. The zoonotic potential of G. intestinalis has been implied for over 2 decades, with human-infecting genotypes (belonging to the 2 major subgroups, Assemblages A and B) occurring in wildlife and domesticated animals. There are recent reports of G. intestinalis in shellfish, seals, sea lions and whales, suggesting that marine animals are also potential reservoirs of human disease. However, the prevalence, genetic diversity and effect of G. intestinalis in marine environments and the role that marine animals play in transmission of this parasite to humans are relatively unexplored. Here, we provide the first thorough molecular characterization of G. intestinalis in marine vertebrates. Using a multi-locus sequencing approach, we identify human-infecting G. intestinalis haplotypes of both Assemblages A and B in the fecal material of dolphins, porpoises, seals, herring gulls Larus argentatus, common eiders Somateria mollissima and a thresher shark Alopias vulpinus. Our results indicate that G. intestinalis is prevalent in marine ecosystems, and a wide range of marine hosts capable of harboring zoonotic forms of this parasite exist. The presence of G. intestinalis in marine ecosystems raises concerns about how this disease might be transmitted among different host species. PMID:18828561

  20. Reproductive Dynamics of Sterna hirundinacea Lesson, 1831 in Ilha dos Cardos, Santa Catarina, Brazil

    PubMed Central

    Fracasso, Hélio Augusto Alves; Branco, Joaquim Olinto; Efe, Márcio Amorim

    2014-01-01

    In this work, we intend to describe the reproductive dynamics of Sterna hirundinacea in an island from South Brazil. We studied the reproductive biology of this species in its natural environment and provide data on their growth, survival, and reproductive success in Ilha dos Cardos, Santa Catarina, South Brazil. Samplings were carried out daily on the island throughout the reproductive seasons of 2003, 2005, and 2006 and the different stages of development of the chicks were characterized according to age, length of the beak, and plumage characteristics. We provide a basic equation Lm = 167.91 (1 − e−0.062t−(−0.23)) to determine the approximate age of individuals using their body mass. The main cause of chick mortality on the island was natural (63.17% in 2003, 81.41% in 2005, and 79.96% in 2006), whereas predation contributed to mortality in a proportion of 38.83% in 2003, 18.59% in 2005, and 20.04% in 2006. The absence in the area of the chicks' main predator, Kelp gull (Larus dominicanus), the large number of chicks that reached the final stages of development, and their reproductive success demonstrate that Ilha dos Cardos is an important breeding site for the species in southern Brazil. PMID:24977100

  1. Reduction of garbage in the diet of nonbreeding glaucous gulls corresponding to a change in waste management

    USGS Publications Warehouse

    Weiser, E.L.; Powell, A.N.

    2011-01-01

    Glaucous gulls (Larus hyperboreus) are major predators in the Arctic and may benefit from human development. We studied use of garbage by glaucous gulls in Barrow, Alaska, in 2007, when municipal waste was disposed of in a landfill, and in 2008, when it was incinerated. In both years, diet samples from breeding adult gulls contained less garbage than those from loafing nonbreeding gulls (mostly subadults of less than four years), possibly because the breeding colony was more distant than many loafing sites from the landfills. Although breeding gull samples showed no change, garbage in regurgitated pellets and food remains of nonbreeding gulls was significantly less prevalent in 2008 than in 2007 (28% vs. 43% occurrence in diet samples), and this reduction could be explained by the switch from landfill to waste incineration. Yet garbage remained a substantial part of nonbreeding gull diet after the management change. Other aspects of waste management, such as storage prior to disposal, may also be important in limiting scavengers' access to garbage and thus reducing the indirect impact of human development on prey species of conservation concern. ?? The Arctic Institute of North America.

  2. The herring gull complex is not a ring species.

    PubMed Central

    Liebers, Dorit; de Knijff, Peter; Helbig, Andreas J.

    2004-01-01

    Under what circumstances speciation in sexually reproducing animals can occur without geographical disjunction is still controversial. According to the ring-species model, a reproductive barrier may arise through 'isolation by distance' when peripheral populations of a species meet after expanding around some uninhabitable barrier. The classical example of this kind of speciation is the herring gull (Larus argentatus) complex, with a circumpolar distribution in the Northern Hemisphere. Based on mitochondrial DNA variation among 21 gull taxa, we show that members of this complex differentiated largely in allopatry following multiple vicariance and long-distance-colonization events, not primarily through isolation by distance. Reproductive isolation evolved more rapidly between some lineages than between others, irrespective of their genetic distance. Extant taxa are the result of divergent as well as reticulate evolution between two ancestral lineages originally separated in a North Atlantic refugium and a continental Eurasian refugium, respectively. Continental birds expanded along the entire north Eurasian coast and via Beringia into North America. Contrary to the ring-species model, we find no genetic evidence for a closure of the circumpolar ring through colonization of Europe by North American herring gulls. However, closure of the ring in the opposite direction may be imminent, with lesser black-backed gulls about to colonize North America. PMID:15255043

  3. Induction of in vitro EROD activity and in vivo caffeine metabolism in two species of New Zealand birds.

    PubMed

    Numata, Mihoko; Fawcett, J Paul; Rosengren, Rhonda J

    2008-05-01

    In birds, induction of cytochrome P4501A (CYP1A) is usually assessed as liver microsomal ethoxyresorufin O-deethylase (EROD) activity, but in mammals, it can be determined by a caffeine metabolism blood test. We investigated both of these measures in two species of New Zealand birds. Administration of a model CYP1A inducer, β-naphthoflavone (BNF) (80mg/kg i.p. twice 2 days apart), to paradise shelducks (Tadorna variegata; herbivore) and southern black-backed gulls (Larus dominicanus; omnivore) (n=5 or 6) caused marked increases in EROD activity (80- and 20-fold, respectively). In both species, BNF treatment also caused significant increases (>8-fold) in caffeine metabolism determined prior to sacrifice as the serum concentration ratio of the major metabolite, paraxanthine, to caffeine, after caffeine administration (1mg/kg i.p.). The results suggest in vivo caffeine metabolism is a potentially useful non-destructive biomarker of CYP1A induction in wild birds. PMID:21783874

  4. Hepatic cytochrome P450 activity and pollutant concentrations in paradise shelducks and southern black-backed gulls in the South Island of New Zealand.

    PubMed

    Numata, Mihoko; Fawcett, J Paul; Saville, Dorothy J; Rosengren, Rhonda J

    2008-11-01

    Cytochrome P450 (CYP) enzymes catalyse the oxidative metabolism of various xenobiotics including environmental pollutants. We investigated liver microsomal CYP marker activities in 60 paradise shelducks (Tadorna variegata; herbivore) and 77 southern black-backed gulls (Larus dominicanus; omnivore) collected at three sites with putatively different levels of pollution in the South Island of New Zealand. Ethoxyresorufin O-deethylase (EROD) activity was high in birds at an urban landfill site compared to those at a relatively pristine and an agricultural site. Analysis of p-nitrophenol hydroxylase and erythromycin demethylase activities indicated the presence of two additional CYP isoforms in shelducks but no additional form in gulls. Total polychlorinated biphenyl (PCB) concentrations (ranges: shelducks, 0.073-6.2; gulls, 8.2-330 ng/g wet weight) were high in landfill samples suggesting a link to EROD induction and, in landfill shelducks, EROD was independently associated with Hg and Pb concentration. PCB congener-specific assessments indicated the metabolism of at least two congeners (#28 and #74) is induced in shelducks. DDE concentrations (ranges: shelducks, 0.85-320; gulls, 44-4800 ng/g) were high in birds at the landfill and agricultural sites. Body weight tended to be lower in landfill birds, but whether this reflects the greater energetic demands of pollutant detoxification remains to be investigated. PMID:18473165

  5. Maternal testosterone influences a begging component that makes fathers work harder in chick provisioning.

    PubMed

    Noguera, José C; Kim, Sin-Yeon; Velando, Alberto

    2013-06-01

    In species with biparental care, parents disagree evolutionarily over the amount of care that each of them is willing to provide to offspring. It has recently been hypothesised that females may try to manipulate their mates by modifying offspring begging behaviour through yolk hormone deposition, shifting the division of labour in their own favour. To test this hypothesis we first investigated how yellow-legged gull (Larus michaellis) parents feed offspring in relation to each component of complex begging behaviour and if feeding behaviour varies between sexes. Then we investigated the effect of yolk testosterone on chicks' begging by experimentally increasing yolk testosterone levels. Our results revealed that yolk testosterone has a component-specific effect on chicks' begging, specifically increasing the number of chatter calls. Parental feeding effort was influenced by the number of chatter calls emitted by chicks, but most importantly, the influence was stronger in male than in female parents. Moreover, chick body mass increased with the number of paternal feeds. In conclusion, these results show that female gulls may use yolk testosterone deposition to exploit their partners as predicted by the 'Manipulating Androgen Hypothesis (MAH)'. PMID:23651611

  6. Bottom-Up Control of Macrobenthic Communities in a Guanotrophic Coastal System

    PubMed Central

    Signa, Geraldina; Mazzola, Antonio; Costa, Valentina; Vizzini, Salvatrice

    2015-01-01

    Soft bottom macrobenthic communities were studied seasonally in three coastal ponds (Marinello ponds, Italy) at increasing distances from a gull (Larus michahellis) colony to investigate the effect of seabird-induced eutrophication (i.e. guanotrophication) on macrobenthic fauna. We hypothesized that enhanced nutrient concentration and organic load caused by guano input significantly alter the trophic and sedimentological condition of ponds, affecting benthic fauna through a bottom-up control. The influence of a set of environmental features on macrobenthic assemblages was also tested. Overall, the lowest macrobenthic abundances and functional group diversity were found in deeper sites, especially in the pond characterised by severe guanotrophication, where the higher disturbance resulted in a decline in suspension feeders and carnivores in favour of deposit feeders. An increase in opportunistic/tolerant taxa (e.g. chironomid larvae and paraonids) and totally azoic sediments were also found as an effect of the harshest environmental conditions, resulting in a very poor ecological status. We conclude that macrobenthic assemblages of the Marinello coastal system display high spatial variability due to a synergistic effect of trophic status and the geomorphological features of the ponds. The macrobenthic response to guanotrophication, which was a clear decrease in abundance, diversity and trophic functional groups, was associated with the typical response to severe eutrophication, magnified by the geomorphological features. PMID:25679400

  7. Plant functional traits in relation to fire in crown-fire ecosystems

    USGS Publications Warehouse

    Pausas, J.G.; Bradstock, R.; Keith, D.; Keeley, J.E.

    2004-01-01

    Significant decreases in eggshell thickness were found in 15 of 22 species of aquatic birds in Texas in 1970. Shell thickness reductions of 9 to 15 percent were found in white pelicans (Pelecanus erythrorhynchos), brown pelicans (P .occidentalis), and great blue herons (Ardea herodias). DDT family compounds were found in all eggs, and mean residues ranged from 0.4 ppm in white ibis (Eudocimus albus) to 23.2 ppm in great egrets (Casmerodius albus). GDDT residues were negatively correlated with shell thickness in five species; PCBs were negatively correlated in two. Residues in marine birds were generally lower and more uniform than levels in birds feeding in fresh and brackish water. DDT and dieldrin residues were higher in eggs from colonies near agricultural areas where these insecticides were heavily used; higher PCB residues were consistently associated with urban and industrial areas. Populations of five species have declined and deserve continued study: brown pelican, reddish egret (Dichromanassa rufescens), white-faced ibis (Plegadis chihi), laughing gull (Larus atricilla), and Forster's tern (Sterna forsteri). Population trends of four other species were undetermined and should be followed closely in future years.

  8. Depredation of common eider, Somateria mollissima, nests on a central Beaufort Sea barrier island: A case where no one wins

    USGS Publications Warehouse

    Reed, J.A.; Lacroix, D.L.; Flint, P.L.

    2007-01-01

    Along the central Beaufort Sea, Pacific Common Eiders (Somateria mollissima v-nigra) nest on unvegetated, barrier islands; often near nesting Glaucous Gulls (Larus hyperboreus). Nest-site choice likely reflects a strategy of predator avoidance: nesting on islands to avoid mammalian predators and near territorial gulls to avoid other avian predators. We observed a nesting colony of Common Eiders from first nest initiation through nesting termination on Egg Island near Prudhoe Bay, Alaska (2002 - 2003). Resident gulls depredated many eider nests, mostly during initiation. All nests failed when an Arctic Fox (Alopex lagopus) visited the island and flushed hens from their nests, exposing the eggs to depredation by the fox and gulls (resident and non-resident). Common Eiders actively defended nests from gulls, but not from foxes. Likely all three species (i.e., eiders, gulls, and foxes) ultimately achieved negligible benefit from their nest-site selection or predatory activity: (a) island nesting provided no safety from mammalian predators for eiders or gulls, (b) for Common Eiders, nesting near gulls increased egg loss, (c) for Glaucous Gulls, nesting near colonial eiders may have reduced nest success by attracting the fox, and (d) for Arctic Foxes, the depredation was of questionable value, as most eggs were cached and probably not recoverable (due to damage from fall storms). Thus, the predator-prey interactions we observed appear to be a case where little or no fitness advantage was realized by any of the species involved.

  9. Sexing California gulls using morphometrics and discriminant function analysis

    USGS Publications Warehouse

    Herring, G.; Ackerman, J.T.; Eagles-Smith, C. A.; Takekawa, J.Y.

    2010-01-01

    A discriminant function analysis (DFA) model was developed with DNA sex verification so that external morphology could be used to sex 203 adult California Gulls (Larus californicus) in San Francisco Bay (SFB). The best model was 97% accurate and included head-to-bill length, culmen depth at the gonys, and wing length. Using an iterative process, the model was simplified to a single measurement (head-to-bill length) that still assigned sex correctly 94% of the time. A previous California Gull sex determination model developed for a population in Wyoming was then assessed by fitting SFB California Gull measurement data to the Wyoming model; this new model failed to converge on the same measurements as those originally used by the Wyoming model. Results from the SFB discriminant function model were compared to the Wyoming model results (by using SFB data with the Wyoming model); the SFB model was 7% more accurate for SFB California gulls. The simplified DFA model (head-to-bill length only) provided highly accurate results (94%) and minimized the measurements and time required to accurately sex California Gulls.

  10. Susceptibility of North American Ducks and Gulls to H5N1 Highly Pathogenic Avian Influenza Viruses

    PubMed Central

    Stallknecht, David E.; Beck, Joan R.; Suarez, David L.; Swayne, David E.

    2006-01-01

    Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have been associated with deaths in numerous wild avian species throughout Eurasia. We assessed the clinical response and extent and duration of viral shedding in 5 species of North American ducks and laughing gulls (Larus atricilla) after intranasal challenge with 2 Asian H5N1 HPAI viruses. Birds were challenged at ≈10 to 16 weeks of age, consistent with temporal peaks in virus prevalence and fall migration. All species were infected, but only wood ducks (Aix sponsa) and laughing gulls exhibited illness or died. Viral titers were higher in oropharyngeal swabs than in cloacal swabs. Duration of viral shedding (1–10 days) increased with severity of clinical disease. Both the hemagglutination-inhibition (HI) and agar gel precipitin (AGP) tests were able to detect postinoculation antibodies in surviving wood ducks and laughing gulls; the HI test was more sensitive than the AGP in the remaining 4 species PMID:17283615

  11. Comparison of Helicobacter spp. genetic sequences in wild and captive seals, and gulls.

    PubMed

    Oxley, Andrew P A; McKay, David B

    2005-06-01

    Helicobacter species are widely distributed in the gastrointestinal system of humans and many animal taxa. Investigations of natural infections are essential to elucidating their role within the host. The feces of fur seals Arctocephalus pusillus doriferus and sea lions Neophoca cinerea from 3 separate captive populations, as well as a wild colony from Kangaroo Island, Australia, were examined for the occurrence of Helicobacter spp. The feces from several wild silver gulls Larus novahollandiae were also investigated. As detected by PCR, 18 of 21 samples from captive and 12 of 16 samples from wild seals were positive for Helicobacter spp. Three species were identified in these animals. Whilst one possibly novel type was identified from wild fur seals, the majority of wild and captive individuals had the same species. This species also occurred in more than 1 seal type and in silver gulls, and shared a 98.1 to 100% identity to other Helicobacter spp. from harp seals and sea otters. A similar sequence type to species identified from cetaceans was also detected in several captive seals. This study reports for the first time the presence of Helicobacter spp. in wild and captive seals and demonstrates the diversity and broad-host range of these organisms in the marine host. PMID:16060262

  12. Maternally derived testosterone and 17beta-estradiol in the eggs of Arctic-breeding glaucous gulls in relation to persistent organic pollutants.

    PubMed

    Verboven, Nanette; Verreault, Jonathan; Letcher, Robert J; Gabrielsen, Geir W; Evans, Neil P

    2008-08-01

    It is largely unknown if and how persistent organic pollutants (POPs) affect the transfer of maternal hormones to eggs. This occurs despite an increasing number of studies relating environmental conditions experienced by female birds at the time of egg formation to maternal hormonal effects. Here we report the concentrations of maternal testosterone, 17beta-estradiol and major classes of POPs (organochlorines, brominated flame retardants and metabolically-derived products) in the yolk of unincubated, third-laid eggs of the glaucous gull (Larus hyperboreus), a top-predator in the Arctic marine environment. Controlled for seasonal and local variation, positive correlations were found between the concentrations of certain POPs and testosterone. Contaminant-related changes in the relative concentrations of testosterone and 17beta-estradiol were also observed. In addition, yolk steroid concentrations were associated with contaminant profiles describing the proportions of different POPs present in the yolk. Eggs from nests in which two sibling eggs hatched or failed to hatch differed in POP profiles and in the relative concentrations of testosterone and 17beta-estradiol. Although the results of this correlative study need to be interpreted with caution, they suggest that contaminant-related changes in yolk steroids may occur, possibly affecting offspring performance over and above toxic effects brought about by POPs in eggs. PMID:18550446

  13. Experimental infection and pathology of clade 2.2 H5N1 virus in gulls

    PubMed Central

    Gulyaeva, Marina A.; Zaykovskaia, Anna V.; Shestopalova, Lidia V.; Shestopalov, Aleksander M.

    2016-01-01

    During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls. PMID:26243601

  14. Contaminant exposure of birds nesting in Green Bay, Wisconsin, USA

    USGS Publications Warehouse

    Custer, Thomas W.; Dummer, Paul M.; Custer, Christine M.; Franson, J. Christian; Jones, Michael

    2014-01-01

    In earlier studies, elevated concentrations of polychlorinated biphenyl (PCB) and p,p'-dichlorodiphenyldichloroethylene (DDE) were reported in double-crested cormorant (Phalacrocorax auritus) eggs and tree swallow (Tachycineta bicolor) eggs and nestlings collected from lower Green Bay (WI, USA) in 1994 and 1995 and black-crowned night-heron (Nycticorax nycticorax) eggs collected in 1991. Comparable samples collected in 2010 and 2011 indicated that concentrations of PCBs were 35%, 62%, 70%, and 88% lower than in the early 1990s in tree swallow eggs, tree swallow nestlings, double-crested cormorant eggs, and black-crowned night-heron eggs, respectively; concentrations of DDE were 47%, 43%, 51%, and 80% lower, respectively. These declines are consistent with regional contaminant trends in other species. Concentrations of PCBs were higher in herring gull (Larus argentatus) than in black-crowned night-heron eggs collected from Green Bay in 2010; PCB concentrations in double-crested cormorant and tree swallow eggs were intermediate. The estimated toxicity of the PCB mixture in eggs of the insectivorous tree swallow was the equal to or greater than toxicity in the 3 piscivorous bird species. A multivariate analysis indicated that the composition percentage of lower-numbered PCB congeners was greater in eggs of the insectivorous tree swallow than in eggs of the 3 piscivorous species nesting in Green Bay. Dioxin and furan concentrations and the toxicity of these chemicals were also higher in tree swallows than these other waterbird species nesting in Green Bay.

  15. Contaminant exposure of birds nesting in Green Bay, Wisconsin, USA.

    PubMed

    Custer, Thomas W; Dummer, Paul M; Custer, Christine M; Franson, J Christian; Jones, Michael

    2014-08-01

    In earlier studies, elevated concentrations of polychlorinated biphenyl (PCB) and p,p'-dichlorodiphenyldichloroethylene (DDE) were reported in double-crested cormorant (Phalacrocorax auritus) eggs and tree swallow (Tachycineta bicolor) eggs and nestlings collected from lower Green Bay (WI, USA) in 1994 and 1995 and black-crowned night-heron (Nycticorax nycticorax) eggs collected in 1991. Comparable samples collected in 2010 and 2011 indicated that concentrations of PCBs were 35%, 62%, 70%, and 88% lower than in the early 1990s in tree swallow eggs, tree swallow nestlings, double-crested cormorant eggs, and black-crowned night-heron eggs, respectively; concentrations of DDE were 47%, 43%, 51%, and 80% lower, respectively. These declines are consistent with regional contaminant trends in other species. Concentrations of PCBs were higher in herring gull (Larus argentatus) than in black-crowned night-heron eggs collected from Green Bay in 2010; PCB concentrations in double-crested cormorant and tree swallow eggs were intermediate. The estimated toxicity of the PCB mixture in eggs of the insectivorous tree swallow was the equal to or greater than toxicity in the 3 piscivorous bird species. A multivariate analysis indicated that the composition percentage of lower-numbered PCB congeners was greater in eggs of the insectivorous tree swallow than in eggs of the 3 piscivorous species nesting in Green Bay. Dioxin and furan concentrations and the toxicity of these chemicals were also higher in tree swallows than these other waterbird species nesting in Green Bay. PMID:24733712

  16. Selenium and metal concentrations in waterbird eggs and chicks at Agassiz National Wildlife Refuge, Minnesota.

    PubMed

    Custer, Thomas W; Custer, Christine M; Eichhorst, Bruce A; Warburton, David

    2007-07-01

    Exceptionally high cadmium (Cd) and chromium (Cr) concentrations were reported in eggs, feathers, or livers of selected waterbird species nesting at Agassiz National Wildlife Refuge (Agassiz) in 1994. Ten- to 15-day-old Franklin's gull (Larus pipixcan), black-crowned night-heron (Nycticorax nycticorax), and eared grebe (Podiceps nigricollis) chicks were collected in 1998, 1999, and 2001 at Agassiz and analyzed for selenium (Se) and metals including Cd and Cr. Freshly laid eggs were collected in 2001 from Franklin's gull, black-crowned night-heron, eared grebe, and pied-billed grebe (Podilymbus podiceps) nests at Agassiz. Based on a multivariate analysis, the pattern of Se and metal concentrations differed among species for eggs, chick feathers, and chick livers. Low Cd and Cr concentrations were measured in eggs, chick livers, and chick feathers of all four species. Mercury concentrations in black-crowned night-heron and eared grebe eggs collected from Agassiz in 2001 were lower than concentrations reported in 1994. Se and metal concentrations, including Cd and Cr, in waterbird eggs and chicks collected at Agassiz in 1998, 1999, and 2001 were not at toxic levels. PMID:17464443

  17. Chlamydiaceae in North Atlantic Seabirds Admitted to a Wildlife Rescue Center in Western France

    PubMed Central

    Aaziz, R.; Gourlay, P.; Vorimore, F.; Sachse, K.; Siarkou, V. I.

    2015-01-01

    Birds are the primary hosts of Chlamydia psittaci, a bacterium that can cause avian chlamydiosis in birds and psittacosis in humans. Wild seabirds are frequently admitted to wildlife rescue centers (WRC) at European Atlantic coasts, for example, in connection with oil spills. To investigate the extent of chlamydial shedding by these birds and the resulting risk for animals in care and the medical staff, seabirds from a French WRC were sampled from May 2011 to January 2014. By use of a quantitative PCR (qPCR), 195 seabirds belonging to 4 orders, 5 families and 13 species were examined, of which 18.5% proved to be Chlamydiaceae positive. The highest prevalence of shedders was found in northern gannets (Morus bassanus) (41%), followed by European herring gulls (Larus argentatus) (14%) and common murres (Uria aalge) (7%). Molecular characterization and phylogenetic analysis of qPCR-positive northern gannet samples revealed two variants of a strain closely related to C. psittaci. In European herring gulls and in one common murre, strains showing high sequence similarity to the atypical Chlamydiaceae-like C122 previously found in gulls were detected. Our study shows that seabirds from the northeastern Atlantic Ocean carry several chlamydial organisms, including C. psittaci-related strains. The staff in WRCs should take protective measures, particularly in the case of mass admissions of seabirds. PMID:25934619

  18. Pacific Continental Shelf Environmental Assessment (PaCSEA): aerial seabird and marine mammal surveys off northern California, Oregon, and Washington, 2011-2012

    USGS Publications Warehouse

    Adams, Josh; Felis, Jonathan J.; Mason, John W.; Takekawa, John Y.

    2014-01-01

    counted (19,033) with Common Murres (Uria aalge) representing the majority of individuals counted (70.4% of total). The remaining six most abundant taxa included: Surf/White-winged Scoters (Melanitta perspicillata/M. fusca; 4.8% of total), Herring/Thayer’s Gulls (Larus argentatus/L. thayeri; 3.8% of total), Cassin’s Auklets (Ptychoramphus aleuticus; 3.8% of total), Glaucous-winged Gulls (Larus glaucescens; 3.7% of total), Black-legged Kittiwakes (Rissa tridactyla; 2.0% of total), and Western Gulls (Larus occidentalis; 1.9% of total). During summer, five species comprised >95% of the total number of birds counted (17,063) with the majority comprised of Common Murres (54.1% of total) and Sooty Shearwaters (Puffinus griseus; 34.4% of total). The remaining most abundant three taxa included: Fork-tailed Storm-Petrels (Oceanodroma furcata; 3.3% of total), Western Gulls (2.1% of total), and Leach’s Storm-Petrels (Oceanodroma leucorhoa; 1.1% of total). During fall, nine species comprised >85% of the total number of birds counted (23,376) with the majority comprised of Common Murres (50.0% of total) and Sooty Shearwaters (10.5% of total). The remaining seven taxa included Cassin’s Auklets (5.2% of total), Surf/White-winged Scoters (5.1% of total), Fork-tailed Storm-Petrels (3.8% of total), Red/Red-necked Phalaropes (Phalaropus fulicarius/P. lobatus; 3.2% of total), California Gulls (Larus californicus; 3.1% of total), Northern Fulmars (Fulmarus glacialis; 2.7% of total), and Sabine’s Gulls (Xema sabini; 2.2% of total). Throughout the entire PaCSEA survey area, average densities (± SE) at sea for all marine birds combined were similar between fall (23.7 ± 1.9 birds km-2) and winter (24.0 ± 1.9 birds km-2) and least during summer (16.3 ± 2.2 birds km-2). Marine bird densities at sea varied according to bathymetric domain and season. Throughout the entire PaCSEA study area average densities (± SE) for all marine birds combined were greatest over the inner-shelf domain

  19. Human-Induced Long-Term Shifts in Gull Diet from Marine to Terrestrial Sources in North America's Coastal Pacific: More Evidence from More Isotopes (δ2H, δ34S).

    PubMed

    Hobson, Keith A; Blight, Louise K; Arcese, Peter

    2015-09-15

    Measurements of naturally occurring stable isotopes in tissues of seabirds and their prey are a powerful tool for investigating long-term changes in marine foodwebs. Recent isotopic (δ(15)N, δ(13)C) evidence from feathers of Glaucous-winged Gulls (Larus glaucescens) has shown that over the last 150 years, this species shifted from a midtrophic marine diet to one including lower trophic marine prey and/or more terrestrial or freshwater foods. However, long-term isotopic patterns of δ(15)N and δ(13)C cannot distinguish between the relative importance of lower trophic-level marine foods and terrestrial sources. We examined 48 feather stable-hydrogen (δ(2)H) and -sulfur (δ(34)S) isotope values from this same 150-year feather set and found additional isotopic evidence supporting the hypothesis that gulls shifted to terrestrial and/or freshwater prey. Mean feather δ(2)H and δ(34)S values (± SD) declined from the earliest period (1860-1915; n = 12) from -2.5 ± 21.4 ‰ and 18.9 ± 2.7 ‰, respectively, to -35.5 ± 15.5 ‰ and 14.8 ± 2.4 ‰, respectively, for the period 1980-2009 (n = 12). We estimated a shift of ∼ 30% increase in dependence on terrestrial/freshwater sources. These results are consistent with the hypothesis that gulls increased terrestrial food inputs in response to declining forage fish availability. PMID:26302356

  20. Biological impact of eutrophication in the bay of somme and the induction and impact of anoxia

    NASA Astrophysics Data System (ADS)

    Desprez, M.; Rybarczyk, H.; Wilson, J. G.; Ducrotoy, J. P.; Sueur, F.; Olivesi, R.; Elkaim, B.

    The first effects of eutrophication in the Bay of Somme became apparent in the years 1982-1985, when the cockle population collapsed. Areas of high mortality were mapped. Following exceptionally high summer temperatures, other effects were seen in 1982, 1983 and 1989, notably a mass mortality of the benthos. It appeared that the mortality of the benthos was a direct result of anoxia in the water promoted by phytoplankton blooms which were due to high nitrogen levels (nitrates from river and land runoff; ammonium from estuarine bivalve populations). Effects from the change in the benthic community (the disappearance of Cerastoderma edule and the proliferation of Pygospio elegans) were also apparent higher up in the food chain, viz. changes in the diet of the two main predators of the bivalve, the oystercatcher ( Haematopus ostralegus) and the common gull ( Larus canus). Following respirometry measurements of the water, sediment and the major macrobenthic species ( Cerastoderma edule, Macoma balthica, Nereis diversicolor, Hydrobia ulvae), a model for anoxia was constructed.

  1. Accumulation of chlorinated benzenes in earthworms

    SciTech Connect

    Beyer, W.N.

    1996-12-31

    Chlorinated benzenes are widespread in the environment. Hexachlorobenzene, pentachlorobenzene and all isomers of dichlorobenzenes, trichlorobenzenes, and tetrachlorobenzenes, have been detected in fish, water, and sediments from the Great Lakes. They probably entered the water as leachates from chemical waste dumps and as effluents from manufacturing. Hexachlorobenzene and pentachlorobenzene are commonly present in Herring gull (Larus argentatus) eggs from the Great Lakes, and some of the isomers of trichlorobenzene and tetrachlorobenzene are occasionally detected at low concentrations. Hexachlorobenzene, which was formerly used as a fungicide, has been the most thoroughly studied chlorinated benzene, and has been detected in many species. Its use as a fungicide in the United States was canceled in 1984. Since about 1975 hexachlorobenzene has been formed mainly in the production of chlorinated solvents. It is highly persistent in the environment and some species are poisoned by hexachlorobenzene at very low chronic dietary exposures. As little as 1 ppm in the diet of mink (Mustela vison) reduced the birth weights of young, and 5 ppm in the diet of Japanese quail (Coturnix coturnix japonica) caused slight liver damage. This paper describes a long-term (26 wk) experiment relating the concentrations of chlorinated benzenes in earthworms to length of exposure and three 8 wk experiments relating concentration to the concentration in soil the soil organic matter content, and the degree of chlorination. 20 refs., 3 figs., 1 tab.

  2. The Efficiency of an Integrated Program Using Falconry to Deter Gulls from Landfills

    PubMed Central

    Thiériot, Ericka; Patenaude-Monette, Martin; Molina, Pierre; Giroux, Jean-François

    2015-01-01

    Simple Summary We evaluated the long-term effect of an intensive integrated program based on falconry to deter gulls, mostly ring-billed gulls (Larus delawarensis), from a landfill. Gulls were counted at different periods each day, and the annual sum of the maximum count at any observation period each day declined from over 1.1 million to only 20,300 during the 20 years of the study. This could not be explained by a decline in the local breeding population that remained relatively large throughout this period as determined in a concomitant study. The effectiveness of the falconry program was also confirmed by tracking individual birds fitted with GPS data loggers. The tagged gulls stopped less often and spent less time at the landfill with falconry than at another one where a selective culling program was conducted. We conclude that the use of an integrated program using falconry, which we consider more socially acceptable than culling, can be effective in deterring gulls from landfills. Abstract Gulls are commonly attracted to landfills, and managers are often required to implement cost-effective and socially accepted deterrence programs. Our objective was to evaluate the effectiveness of an intensive program that integrated the use of trained birds of prey, pyrotechnics, and playback of gull distress calls at a landfill located close to a large ring-billed gull (Larus delawarensis) colony near Montreal, Quebec, Canada. We used long-term survey data on bird use of the landfill, conducted behavioral observations of gulls during one season and tracked birds fitted with GPS data loggers. We also carried out observations at another landfill located farther from the colony, where less refuse was brought and where a limited culling program was conducted. The integrated program based on falconry resulted in a 98% decrease in the annual total number of gulls counted each day between 1995 and 2014. A separate study indicated that the local breeding population of ring

  3. Species differences in the sensitivity of avian embryos to methylmercury

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.; Klimstra, J.D.; Stebbins, K.R.; Kondrad, S.L.; Erwin, C.A.

    2009-01-01

    We injected doses of methylmercury into the air cells of eggs of 26 species of birds and examined the dose-response curves of embryo survival. For 23 species we had adequate data to calculate the median lethal concentration (LC50). Based on the dose-response curves and LC50s, we ranked species according to their sensitivity to injected methylmercury. Although the previously published embryotoxic threshold of mercury in game farm mallards (Anas platyrhynchos) has been used as a default value to protect wild species of birds, we found that, relative to other species, mallard embryos are not very sensitive to injected methylmercury; their LC50 was 1.79 ug/g mercury on a wet-weight basis. Other species we categorized as also exhibiting relatively low sensitivity to injected methylmercury (their LC50s were 1 ug/g mercury or higher) were the hooded merganser (Lophodytes cucullatus), lesser scaup (Aythya affinis), Canada goose (Branta canadensis), double-crested cormorant (Phalacrocorax auritus), and laughing gull (Larus atricilla). Species we categorized as having medium sensitivity (their LC50s were greater than 0.25 ug/g mercury but less than 1 ug/g mercury) were the clapper rail (Rallus longirostris), sandhill crane (Grus canadensis), ring-necked pheasant (Phasianus colchicus), chicken (Gallus gallus), common grackle (Quiscalus quiscula), tree swallow (Tachycineta bicolor), herring gull (Larus argentatus), common tern (S terna hirundo), royal tern (Sterna maxima), Caspian tern (Sterna caspia), great egret (Ardea alba), brown pelican (Pelecanus occidentalis), and anhinga (Anhinga anhinga). Species we categorized as exhibiting high sensitivity (their LC50s were less than 0.25 ug/g mercury) were the American kestrel (Falco sparverius), osprey (Pandion haliaetus), white ibis (Eudocimus albus), snowy egret (Egretta thula), and tri-colored heron (Egretta tricolor). For mallards, chickens, and ring-necked pheasants (all species for which we could compare the toxicity of our

  4. Species differences in the sensitivity of avian embryos to methylmercury.

    PubMed

    Heinz, Gary H; Hoffman, David J; Klimstra, Jon D; Stebbins, Katherine R; Kondrad, Shannon L; Erwin, Carol A

    2009-01-01

    We injected doses of methylmercury into the air cells of eggs of 26 species of birds and examined the dose-response curves of embryo survival. For 23 species we had adequate data to calculate the median lethal concentration (LC(50)). Based on the dose-response curves and LC(50)s, we ranked species according to their sensitivity to injected methylmercury. Although the previously published embryotoxic threshold of mercury in game farm mallards (Anas platyrhynchos) has been used as a default value to protect wild species of birds, we found that, relative to other species, mallard embryos are not very sensitive to injected methylmercury; their LC(50 )was 1.79 microg/g mercury on a wet-weight basis. Other species we categorized as also exhibiting relatively low sensitivity to injected methylmercury (their LC(50)s were 1 microg/g mercury or higher) were the hooded merganser (Lophodytes cucullatus), lesser scaup (Aythya affinis), Canada goose (Branta canadensis), double-crested cormorant (Phalacrocorax auritus), and laughing gull (Larus atricilla). Species we categorized as having medium sensitivity (their LC(50)s were greater than 0.25 microg/g mercury but less than 1 microg/g mercury) were the clapper rail (Rallus longirostris), sandhill crane (Grus canadensis), ring-necked pheasant (Phasianus colchicus), chicken (Gallus gallus), common grackle (Quiscalus quiscula), tree swallow (Tachycineta bicolor), herring gull (Larus argentatus), common tern (Sterna hirundo), royal tern (Sterna maxima), Caspian tern (Sterna caspia), great egret (Ardea alba), brown pelican (Pelecanus occidentalis), and anhinga (Anhinga anhinga). Species we categorized as exhibiting high sensitivity (their LC(50)s were less than 0.25 microg/g mercury) were the American kestrel (Falco sparverius), osprey (Pandion haliaetus), white ibis (Eudocimus albus), snowy egret (Egretta thula), and tri-colored heron (Egretta tricolor). For mallards, chickens, and ring-necked pheasants (all species for which we

  5. Influence of food availability on demography and local population dynamics in a long-lived seabird.

    PubMed Central

    Oro, Daniel; Cam, Emmanuelle; Pradel, Roger; Martínez-Abraín, Alejandro

    2004-01-01

    Few studies have addressed the effects of food availability as a proximate factor affecting local adult survival in long-lived organisms and their consequences at local population dynamics. We used capture-recapture analysis of resightings of 10 birth cohorts of ringed Audouin's gulls, Larus audouinii, to estimate adult survival and dispersal (both emigration and immigration). For the first time, permanent emigration (the transient effect in capture-recapture analysis) was modelled for the whole population and not only for the newly marked birds. Gulls exploit to a large extent fishes discarded from trawlers, and a trawling moratorium established since 1991 has decreased food supply for the colony. This was used as a natural experiment of food availability to assess its effects on adult survival and emigration. These and other demographic parameters were used in a projection modelling to assess the probabilities of extinction of the colony under two scenarios of lower and higher food availability. Food availability (together with the age of individuals) influenced emigration probabilities, but not adult survival, which was estimated at 0.91 (s.e. = 0.02). When food was in shorter supply during the chick-rearing period, emigration was very high (ca. 65%) for younger breeders, although this rate decreased sharply with age. Probabilities of extinction were very high when food availability was low, and when environmental stochasticity was introduced, and only stochastic immigration from the outside seemed to prevent extinction. The results highlight the importance of dispersal processes in the population dynamics of long-lived organisms. PMID:15101698

  6. DNA barcoding of Dutch birds

    PubMed Central

    Aliabadian, Mansour; Beentjes, Kevin K.; Roselaar, C.S. (Kees); van Brandwijk, Hans; Nijman, Vincent; Vonk, Ronald

    2013-01-01

    Abstract The mitochondrial cytochrome c oxidase subunit I (COI) can serve as a fast and accurate marker for the identification of animal species, and has been applied in a number of studies on birds. We here sequenced the COI gene for 387 individuals of 147 species of birds from the Netherlands, with 83 species being represented by > 2 sequences. The Netherlands occupies a small geographic area and 95% of all samples were collected within a 50 km radius from one another. The intraspecific divergences averaged 0.29% among this assemblage, but most values were lower; the interspecific divergences averaged 9.54%. In all, 95% of species were represented by a unique barcode, with 6 species of gulls and skua (Larus and Stercorarius) having at least one shared barcode. This is best explained by these species representing recent radiations with ongoing hybridization. In contrast, one species, the Lesser Whitethroat Sylvia curruca showed deep divergences, averaging 5.76% and up to 8.68% between individuals. These possibly represent two distinct taxa, S. curruca and S. blythi, both clearly separated in a haplotype network analysis. Our study adds to a growing body of DNA barcodes that have become available for birds, and shows that a DNA barcoding approach enables to identify known Dutch bird species with a very high resolution. In addition some species were flagged up for further detailed taxonomic investigation, illustrating that even in ornithologically well-known areas such as the Netherlands, more is to be learned about the birds that are present. PMID:24453549

  7. Activity periods and questing behavior of the seabird tick Ixodes uriae (Acari: Ixodidae) on Gull Island, Newfoundland: the role of puffin chicks.

    PubMed

    Muzaffar, Sabir B; Jones, Ian L

    2007-04-01

    Questing behavior of Ixodes uriae and their associated seasonal, host-feeding patterns are crucial to our understanding of tick life history strategies and the ecology of diseases that they transmit. Consequently, we quantified questing behavior of nymphs and adult female I. uriae ticks at Gull Island, a seabird colony in Newfoundland, Canada, to examine seasonal variation of off-host and on-host tick activity. We sampled a total of 133 adult Atlantic puffins (Fratercula arctica), 152 puffin chicks, and 145 herring gull (Larus argentatus) chicks for ticks during the breeding seasons of 2004 and 2005. Questing ticks were sampled by dragging a white flannel cloth across the grassy breeding areas during the mo of May, June, July, and August. Nymph questing activity reached a peak during mid-July (79 and 110 individuals/hr in 2004 and 2005, respectively). The prevalence of nymphs and adult female ticks on different seabird hosts varied between years and during the seasons. Puffin chicks had the highest prevalence (above 70% in July) of nymphs in both years and this was correlated with questing activity. Female ticks rarely fed on puffin chicks, but were prevalent on adult puffins and gulls, although prevalence and questing of ticks were not correlated in these hosts. These patterns of off-host and on-host tick activity suggests that I. uriae ticks likely use a combination of questing and passive waiting, e.g., in puffin burrows, to detect hosts, depending on the tick stage and the host species. PMID:17539407

  8. Toxicity of ingested crude petroleum oil to marine birds: pathology and pathogenesis

    SciTech Connect

    Leighton, F.A.

    1984-01-01

    A series of experiments was carried out to identify toxic effects of ingested Prudhoe Bay crude oil in nestling herring gulls (Larus argentatus) and Atlantic puffins (Fratercula arctica). Wild-caught birds were brought to the laboratory, maintained on a marine diet and given oral doses of oil. Initial results identified anemia as a toxic effect of oil ingestion and subsequent experiments focussed on the erythron as a target tissue. Hemolytic anemia with Heinz bodies in red blood cells ocurred in gulls and puffins that ingested greater than or equal to 10 ml oil per kg per day for 4-5 days. Anemia developed precipitously as a hemolytic crisis. Structural lesions in red cells included Heinz body formation, anisocytosis, severe distortions of cell shape, plasma membrane crenulation, mineralization of mitochondria, formation of abnormal cytoplasmic vesicles, and both abnormally high and abnormally low cytoplasmic density. These data permitted correlative evaluation of ultrastructural and biochemical changes in red cells experiencing oxidant stress due to oil ingestion. Several other lesions occurred on both oil-dosed and control birds but were significantly more prevalent in the former. These lesions were focal adrenal necrosis, depletion of adrenal lipid, depletion of lymphocytes in thymus and bursa of Fabricius, and virus infection of the bursa of Fabricius. These latter lesions suggested immunosuppression in oil-dosed birds. In a pilot study, oral doses of disulfiram prevented the usual induction of hepatic mixed-function oxidases caused by ingestion of oil by gulls, and also prevented development of Heinz bodies and of increased GSH in red cells of gulls given large oral doses of oil.

  9. The Efficiency of an Integrated Program Using Falconry to Deter Gulls from Landfills.

    PubMed

    Thiériot, Ericka; Patenaude-Monette, Martin; Molina, Pierre; Giroux, Jean-François

    2015-01-01

    Gulls are commonly attracted to landfills, and managers are often required to implement cost-effective and socially accepted deterrence programs. Our objective was to evaluate the effectiveness of an intensive program that integrated the use of trained birds of prey, pyrotechnics, and playback of gull distress calls at a landfill located close to a large ring-billed gull (Larus delawarensis) colony near Montreal, Quebec, Canada. We used long-term survey data on bird use of the landfill, conducted behavioral observations of gulls during one season and tracked birds fitted with GPS data loggers. We also carried out observations at another landfill located farther from the colony, where less refuse was brought and where a limited culling program was conducted. The integrated program based on falconry resulted in a 98% decrease in the annual total number of gulls counted each day between 1995 and 2014. A separate study indicated that the local breeding population of ring-billed gulls increased and then declined during this period but remained relatively large. In 2010, there was an average (±SE) of 59 ± 15 gulls/day using the site with falconry and only 0.4% ± 0.2% of these birds were feeding. At the other site, there was an average of 347 ± 55 gulls/day and 13% ± 3% were feeding. Twenty-two gulls tracked from the colony made 41 trips towards the landfills: twenty-five percent of the trips that passed by the site with falconry resulted in a stopover that lasted 22 ± 7 min compared to 85% at the other landfill lasting 63 ± 15 min. We concluded that the integrated program using falconry, which we consider more socially acceptable than selective culling, was effective in reducing the number of gulls at the landfill. PMID:26479231

  10. Soils of the Galindez Island, Argentine archipelago, Western Antarctica

    NASA Astrophysics Data System (ADS)

    Abakumov, Evgeny; Parnikoza, Ivan

    2015-04-01

    Antarctic Peninsula is a part of Antarctica which is characterized by increased soil diversity, caused by specific of parent materials and diversity of non-vascular and vascular plants. Soils of Galindez Island have been investigated during the 18-th Ukranian Antarctic Expedition 2013/14. This Island situated in Argentine archipelago (coastal part of Antarctic Peninsula). Soils of Galindez Island presented by following types: Leptosols, Lithosols, Histic Lithosols and Leptosols and some Gleyic soils, located in lowlands and coastal parts. An average solum profile thickness is 3-19 cm which result from the small depth of debris's, underplayed by massive crystallic rocks. The permafrost layer is located within the massive rock, but not in coarse friable parent material. The soils with bird influence are widely spread both in coastal and central part of Island. In the coastal parts we can find typical Ornithosols in the penguin rockeries areas. The main aim of our investigation was characterization of soils formed under vegetation, exactly under Deschampsia antarctica Desv. localities. Argentine Islands is the central part of D. antarctica spreading area in region of Antarctic peninsula. Probably, these islands colonized by hairgrass mainly due to ornitogenic activity. So, coastal population appearance related with Larus dominicanus nest areas and feeding activity. Thus, we found typical post ornithogenic soils here. This kind of soils we also observed in population of hairgrass of Galindez mainland where it was connected with the other Antarctic bird - Catharacta maccormicki activity. Thus, the soil diversity and soil geochemistry of the Galindez Island are closely related to the activity of birds. The spatial pattern of soils, their chemistry and organic matter quality is discussed in relation with distribution of bird nesting and feeding activity.

  11. Immunological and reproductive health assessment in herring gulls and black-crowned night herons in the Hudson-Raritan Estuary.

    PubMed

    Grasman, Keith A; Echols, Kathy R; May, Thomas M; Peterman, Paul H; Gale, Robert W; Orazio, Carl E

    2013-03-01

    Previous studies have shown inexplicable declines in breeding waterbirds within western New York/New Jersey Harbor between 1996 and 2002 and elevated polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs) in double-crested cormorant (Phalacrocorax auritus) eggs. The present study assessed associations between immune function, prefledgling survival, and selected organochlorine compounds and metals in herring gulls (Larus argentatus) and black-crowned night herons (Nycticorax nycticorax) in lower New York Harbor during 2003. In pipping gull embryos, lymphoid cells were counted in the thymus and bursa of Fabricius (sites of T and B lymphocyte maturation, respectively). The phytohemagglutinin (PHA) skin response assessed T cell function in gull and heron chicks. Lymphocyte proliferation was measured in vitro in adult and prefledgling gulls. Reference data came from the Great Lakes and Bay of Fundy. Survival of prefledgling gulls was poor, with only 0.68 and 0.5 chicks per nest surviving to three and four weeks after hatch, respectively. Developing lymphoid cells were reduced 51% in the thymus and 42% in the bursa of gull embryos from New York Harbor. In vitro lymphocyte assays demonstrated reduced spontaneous proliferation, reduced T cell mitogen-induced proliferation, and increased B cell mitogen-induced proliferation in gull chicks from New York Harbor. The PHA skin response was suppressed 70 to 80% in gull and heron chicks. Strong negative correlations (r = -0.95 to -0.98) between the PHA response and dioxins and PCBs in gull livers was strong evidence suggesting that these chemicals contribute significantly to immunosuppression in New York Harbor waterbirds. PMID:23212976

  12. Perfluorinated sulfonate and carboxylate compounds and precursors in herring gull eggs from across the Laurentian Great Lakes of North America: Temporal and recent spatial comparisons and exposure implications.

    PubMed

    Letcher, Robert J; Su, Guanyong; Moore, Jeremy N; Williams, Lisa L; Martin, Pamela A; de Solla, Shane R; Bowerman, William W

    2015-12-15

    Chemicals of emerging concern (CECs) in the basin of the Laurentian Great Lakes of North America include per- and poly-fluoroalkyl substances (PFASs) classified as perfluoroalkyl acids. We investigated several PFASs, and specifically 13 C4-C16 perfluorinated carboxylic acids (PFCAs), 4 (C4, C6, C8 and C10) perfluorinated sulfonates (PFSAs), perfluoro-4-ethylcyclohexane sulfonate (PFEtCHxS) and selected precursors (e.g. perfluorobutane sulfonamide and perfluorooctane sulfonamide) in herring gull (Larus argentatus) eggs collected in 2012-2013 from 19 Canadian and U.S. colony sites across the Great Lakes. C6, C8 and C10 PFSAs, PFEtCHxS, and C7-14 and C16 PFCAs were quantifiable at >97% of the 114 egg samples. PFEtCHxS concentrations ranged from n.d. to 3.1ng/g ww (highest in Lake Michigan eggs). Mean Σ4PFSA (92 to 97% perfluorooctane sulfonate (PFOS)) and Σ9PFCA concentration ranges were 44 to 740 and 4.8 to 118ng/g ww, respectively. Σ4PFSA showed a clear increasing concentration trend from the northwest to the southeast colonies. Also, Σ4PFCA to Σ9PFSA concentration ratios in gull eggs were greater in eggs from Lake Superior relative to colonies in the other lakes. PFOS concentrations in some egg samples were greater than some of the known lowest observed effect concentrations (LOECs) measured and reported in captive bird model studies. This study showed the increasing complexity of PFAS-CECs, and emphasized the importance of continuing monitoring of bioaccumulative PFAS in Great Lakes herring gulls. PMID:26318684

  13. Avian botulism type E in waterbirds of Lake Michigan, 2010–2013

    USGS Publications Warehouse

    Chipault, Jennifer G.; White, C. LeAnn; Blehert, David S.; Jennings, Susan K.; Strom, Sean M.

    2015-01-01

    During 2010 to 2013, waterbird mortality surveillance programs used a shared protocol for shoreline walking surveys performed June to November at three areas in northern Lake Michigan. In 2010 and 2012, 1244 total carcasses (0.8 dead bird/km walked) and 2399 total carcasses (1.2 dead birds/km walked), respectively, were detected. Fewer carcasses were detected in 2011 (353 total carcasses, 0.2 dead bird/km walked) and 2013 (451 total carcasses, 0.3 dead bird/km walked). During 3 years, peak detection of carcasses occurred in October and involved primarily migratory diving and fish-eating birds, including long-tailed ducks (Clangula hyemalis; 2010), common loons (Gavia immer; 2012), and red-breasted mergansers (Mergus serrator; 2013). In 2011, peak detection of carcasses occurred in August and consisted primarily of summer residents such as gulls (Larus spp.) and double-crested cormorants (Phalacrocorax auritus). A subset of fresh carcasses was collected throughout each year of the study and tested for botulinum neurotoxin type E (BoNT/E). Sixty-one percent of carcasses (57/94) and 10 of 11 species collected throughout the sampling season tested positive for BoNT/E, suggesting avian botulism type E was a major cause of death for both resident and migratory birds in Lake Michigan. The variety of avian species affected by botulism type E throughout the summer and fall during all 4 years of coordinated surveillance also suggests multiple routes for bird exposure to BoNT/E in Lake Michigan.

  14. Diets of aquatic birds reflect changes in the Lake Huron ecosystem

    USGS Publications Warehouse

    Hebert, Craig E.; Weseloh, D.V. Chip; Idrissi, Abode; Arts, Michael T.; Roseman, Edward F.

    2009-01-01

    Human activities have affected the Lake Huron ecosystem, in part, through alterations in the structure and function of its food webs. Insights into the nature of food web change and its ecological ramifications can be obtained through the monitoring of high trophic level predators such as aquatic birds. Often, food web change involves alterations in the relative abundance of constituent species and/or the introduction of new species (exotic invaders). Diet composition of aquatic birds is influenced, in part, by relative prey availability and therefore is a sensitive measure of food web structure. Using bird diet data to make inferences regarding food web change requires consistent measures of diet composition through time. This can be accomplished by measuring stable chemical and/or biochemical “ecological tracers” in archived avian samples. Such tracers provide insights into pathways of energy and nutrient transfer. In this study, we examine the utility of two groups of naturally-occurring intrinsic tracers (stable isotopes and fatty acids) to provide such information in a predatory seabird, the herring gull (Larus argentatus). Retrospective stable nitrogen and carbon isotope analysis of archived herring gull eggs identified declines in gull trophic position and shifts in food sources in Lake Huron over the last 25 years and changes in gull diet composition were inferred from egg fatty acid patterns. These independent groups of ecological tracers provided corroborating evidence of dietary change in this high trophic level predator. Gull dietary shifts were related to declines in prey fish abundance which suggests large-scale alterations to the Lake Huron ecosystem. Dietary shifts in herring gulls may be contributing to reductions in resources available for egg formation. Further research is required to evaluate how changes in resource availability may affect population sustainability in herring gulls and other waterbird species. Long-term biological monitoring

  15. Gut content analysis of Lake Michigan waterbirds in years with avian botulism type E mortality, 2010–2012

    USGS Publications Warehouse

    Essian, David A.; Chipault, Jennifer G.; Lafrancois, Brenda M.; Leonard, Jill B.K.

    2016-01-01

    Waterbird die-offs caused by Clostridium botulinum neurotoxin type E (BoNT/E) have occurred sporadically in the Great Lakes since the late 1960s, with a recent pulse starting in the late 1990s. In recent die-offs, round gobies (Neogobius melanostomus) have been implicated as vectors for the transfer of BoNT/E to fish-eating birds due to the round goby invasion history and their importance as prey. Dreissenid mussels (Dreissena spp.) are also potentially involved in BoNT/E transmission to birds and round gobies. We examined gut contents of waterbirds collected in Lake Michigan during die-offs in 2010–2012, and the gut contents of culled, presumably BoNT/E-free double-crested cormorants (Phalacrocorax auritus). Round gobies were found in 86% of the BoNT/E-positive individuals, 84% of the BoNT/E-negative birds, and 94% of the BoNT/E-free cormorants examined. Double-crested cormorants, ring-billed gulls (Larus delewarensis), and common loons (Gavia immer) consumed larger-sized round gobies than horned and red-necked grebes (Podiceps auritus and Podiceps grisegena), white-winged scoters (Melanitta deglandi), and long-tailed ducks (Clangula hymealis). Other common prey included dreissenid mussels, terrestrial insects, and alewives (Alosa pseudoharengus). Our data emphasize the importance of round gobies and mussels in diets of Lake Michigan waterbirds and suggest they may play a role in the transfer of BoNT/E to waterbirds; however, round gobies and mussels were found in BoNT/E-positive, -negative, and -free individuals, suggesting that other factors, such as alternative trophic pathways for toxin transfer, bird migratory timing and feeding locations, prey behavior, and individual physiological differences across birds may affect the likelihood that a bird will succumb to BoNT/E intoxication.

  16. Habitat comparisons and productivity in nesting common terns on the mid-Atlantic coast

    USGS Publications Warehouse

    Erwin, R.M.; Smith, D.C.

    1985-01-01

    Nesting Common Terns (Sterna hirundo) were studied at a number of barrier beaches and small islands of tidal salt marsh in New Jersey and the Eastern Shore of Maryland-Virginina from 1980 through 1982. Data were collected on clutch sizes, nest spacing, and nesting success. The principal null hypothesis tested was that no difference in reproductive success exists between beach and marsh habitats. Nests were monitored from egg-laying in mid-May until mid-July when young fledged. Clutch sizes varied among colonies and across years but no systematic effect of year, habitat, or colony size on mean clutch size per colony was detected. Analyses of nest productivity (estimated using both the Mayfield method and using a colony average) failed to reveal significant effects of habitat or colony size but showed a stronger year effect. Storm tide flooding and egg chick disappearance (presumably predation by Herring Gulls Larus argentatus and Laughing Gulls L. atricilla nesting nearby) accounted for most nest failures. Losses due to both these mortality factors were unpredictable from year to year. Nest spacing in salt marsh colonies was much closer than it was on barrier beaches. In mixed-species colonies with Black Skimmers (Rynchops niger), distances between tern and skimmer nests were also much smaller in marsh colonies than they were on beaches. The limited amount of wrack (windrows of dead, matted vegetation) preferred by marsh-nesting terns probably explains these spacing differences. Several lines of evidence suggest that terns prefer beaches to marshes for nesting, however, the uncertainty of predation and flooding may often obscure any intrinsic differences in habitat quality. Long-term field studies are essential for testing hypotheses related to differential fitness of individuals among habitats.

  17. Varying foraging patterns in response to competition? A multicolony approach in a generalist seabird.

    PubMed

    Corman, Anna-Marie; Mendel, Bettina; Voigt, Christian C; Garthe, Stefan

    2016-02-01

    Reducing resource competition is a crucial requirement for colonial seabirds to ensure adequate self- and chick-provisioning during breeding season. Spatial segregation is a common avoidance strategy among and within species from neighboring breeding colonies. We determined whether the foraging behaviors of incubating lesser black-backed gulls (Larus fuscus) differed between six colonies varying in size and distance to mainland, and whether any differences could be related to the foraging habitats visited. Seventy-nine incubating individuals from six study colonies along the German North Sea coast were equipped with GPS data loggers in multiple years. Dietary information was gained by sampling food pellets, and blood samples were taken for stable isotope analyses. Foraging patterns clearly differed among and within colonies. Foraging range increased with increasing colony size and decreased with increasing colony distance from the mainland, although the latter might be due to the inclusion of the only offshore colony. Gulls from larger colonies with consequently greater density-dependent competition were more likely to forage at land instead of at sea. The diets of the gulls from the colonies furthest from each other differed, while the diets from the other colonies overlapped with each other. The spatial segregation and dietary similarities suggest that lesser black-backed gulls foraged at different sites and utilized two main habitat types, although these were similar across foraging areas for all colonies except the single offshore island. The avoidance of intraspecific competition results in colony-specific foraging patterns, potentially causing more intensive utilization of terrestrial foraging sites, which may offer more predictable and easily available foraging compared with the marine environment. PMID:26941940

  18. Terrestrial and Marine Foraging Strategies of an Opportunistic Seabird Species Breeding in the Wadden Sea.

    PubMed

    Garthe, Stefan; Schwemmer, Philipp; Paiva, Vitor H; Corman, Anna-Marie; Fock, Heino O; Voigt, Christian C; Adler, Sven

    2016-01-01

    Lesser black-backed gulls Larus fuscus are considered to be mainly pelagic. We assessed the importance of different landscape elements (open sea, tidal flats and inland) by comparing marine and terrestrial foraging behaviours in lesser black-backed gulls breeding along the coast of the southern North Sea. We attached GPS data loggers to eight incubating birds and collected information on diet and habitat use. The loggers recorded data for 10-19 days to allow flight-path reconstruction. Lesser black-backed gulls foraged in both offshore and inland areas, but rarely on tidal flats. Targets and directions were similar among all eight individuals. Foraging trips (n = 108) lasted 0.5-26.4 h (mean 8.7 h), and ranges varied from 3.0-79.9 km (mean 30.9 km). The total distance travelled per foraging trip ranged from 7.5-333.6 km (mean 97.9 km). Trips out to sea were significantly more variable in all parameters than inland trips. Presence in inland areas was closely associated with daylight, whereas trips to sea occurred at day and night, but mostly at night. The most common items in pellets were grass (48%), insects (38%), fish (28%), litter (26%) and earthworms (20%). There was a significant relationship between the carbon and nitrogen isotope signals in blood and the proportional time each individual spent foraging at sea/land. On land, gulls preferentially foraged on bare ground, with significantly higher use of potato fields and significantly less use of grassland. The flight patterns of lesser black-backed gulls at sea overlapped with fishing-vessel distribution, including small beam trawlers fishing for shrimps in coastal waters close to the colony and large beam-trawlers fishing for flatfish at greater distances. Our data show that individuals made intensive use of the anthropogenic landscape and seascape, indicating that lesser black-backed gulls are not a predominantly marine species during the incubation period. PMID:27525661

  19. Variation in the Markers of Nutritional and Oxidative State in a Long-Lived Seabird: Associations with Age and Longevity.

    PubMed

    Urvik, Janek; Meitern, Richard; Rattiste, Kalev; Saks, Lauri; Hõrak, Peeter; Sepp, Tuul

    2016-01-01

    Age-related declines in life-history traits have been widely observed in free-living animals. Several theories link senescence to oxidative stress. The aim of this study was to measure several widely used markers of oxidative and nutritional state in a long-lived seabird, the common gull (Larus canus), in order to assess the suitability of these markers for describing deterioration in physiological condition associated with chronological age and survival. Associations with longevity and individual consistency of these parameters over the years (repeatability) were also assessed. Senescence in fitness parameters was observed during the study period: in females, laying date and clutch mass were related to bird age in a curvilinear manner, with middle-aged birds breeding earlier and laying heavier eggs. The only parameter associated with aging processes was glutathione concentration in erythrocytes, which was lower in female birds with longer life spans. Of indexes of nutritional state, plasma triglyceride concentration showed a between-individual increase with age, suggesting selective mortality of birds with low levels. Additionally, total plasma protein levels of individual males increased with age. The mostly negative results of this study hint that the commonly used parameters of physiological condition and oxidative state used in this study do not adequately reflect an individual's long-term health condition. Alternatively, it is possible that in common gulls, senescence occurs in reproductive mechanisms but not in mechanisms responsible for maintaining an organism's redox balance, consistent with the idea that different aspects of an organism's physiological condition age at different rates. Significant interannual repeatability was detected in three plasma constituents-carotenoids, uric acid, and total protein-all of which can possibly be linked to variation in dietary habits. PMID:27617362

  20. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    PubMed

    Takekawa, John Y; Ackerman, Joshua T; Brand, L Arriana; Graham, Tanya R; Eagles-Smith, Collin A; Herzog, Mark P; Topping, Brent R; Shellenbarger, Gregory G; Kuwabara, James S; Mruz, Eric; Piotter, Sara L; Athearn, Nicole D

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  1. Balancing Energy Budget in a Central-Place Forager: Which Habitat to Select in a Heterogeneous Environment?

    PubMed Central

    Patenaude-Monette, Martin; Bélisle, Marc; Giroux, Jean-François

    2014-01-01

    Foraging animals are influenced by the distribution of food resources and predation risk that both vary in space and time. These constraints likely shape trade-offs involving time, energy, nutrition, and predator avoidance leading to a sequence of locations visited by individuals. According to the marginal-value theorem (MVT), a central-place forager must either increase load size or energy content when foraging farther from their central place. Although such a decision rule has the potential to shape movement and habitat selection patterns, few studies have addressed the mechanisms underlying habitat use at the landscape scale. Our objective was therefore to determine how Ring-billed gulls (Larus delawarensis) select their foraging habitats while nesting in a colony located in a heterogeneous landscape. Based on locations obtained by fine-scale GPS tracking, we used resource selection functions (RSFs) and residence time analyses to identify habitats selected by gulls for foraging during the incubation and brood rearing periods. We then combined this information to gull survey data, feeding rates, stomach contents, and calorimetric analyses to assess potential trade-offs. Throughout the breeding season, gulls selected landfills and transhipment sites that provided higher mean energy intake than agricultural lands or riparian habitats. They used landfills located farther from the colony where no deterrence program had been implemented but avoided those located closer where deterrence measures took place. On the other hand, gulls selected intensively cultured lands located relatively close to the colony during incubation. The number of gulls was then greater in fields covered by bare soil and peaked during soil preparation and seed sowing, which greatly increase food availability. Breeding Ring-billed gulls thus select habitats according to both their foraging profitability and distance from their nest while accounting for predation risk. This supports the

  2. The identification of a new Giardia duodenalis assemblage in marine vertebrates and a preliminary analysis of G. duodenalis population biology in marine systems✯

    PubMed Central

    Lasek-Nesselquist, Erica; Welch, David Mark; Sogin, Mitchell L.

    2010-01-01

    Giardia duodenalis is an intestinal parasite of many vertebrates. The presence of G. duodenalis in the marine environment due to anthropogenic and wildlife activity is well documented, including the contributions from untreated sewage and storm water, agricultural run-off, and droppings from terrestrial animals. Recently, studies have detected this protistan parasite in the feces of marine vertebrates such as whales, dolphins, seals and shore birds. To explore the population biology of G. duodenalis in marine life, we determined the prevalence of G. duodenalis in two species of seal (Halichoerus grypus, Phoca vitulina vitulina and Phoca vitulina richardsi) from the east and west coasts of the USA, sequenced two loci from G. duodenalis-positive samples to assess molecular diversity, and examined G. duodenalis distribution among these seals and other marine vertebrates along the east coast. We found a significant difference in the presence of G. duodenalis between east and west coast seal species. Only the zoonotic lineages of G. duodenalis, Assemblages A and B and a novel lineage, which we designated as Assemblage H, were identified in marine vertebrates. Assemblages A and B are broadly distributed geographically and show a lack of host specificity. Only grey seal (Halichoerus grypus) samples and one gull sample (Larus argentatus) from a northern location of Cape Cod, Massachusetts, USA showed the presence of Assemblage H haplotypes; only one other study of harbor seals from the Puget Sound region of Washington, USA previously recorded the presence of an Assemblage H haplotype. Assemblage H sequences form a monophyletic clade that appears as divergent from the other seven Assemblages of G. duodenalis as these assemblages are from each other. The discovery of a previously uncharacterized lineage of G. duodenalis suggests that this parasite has more genetic diversity and perhaps a larger host range than previously believed. PMID:20361967

  3. Comparative skeletal muscle fibre morphometry among wild birds with different locomotor behaviour

    PubMed Central

    TORRELLA, J. R.; FOUCES, V.; PALOMEQUE, J.; VISCOR, G.

    1998-01-01

    Six muscles of the mallard duck (Anas platyrhynchos), the common coot (Fulica atra) and the yellow-legged gull (Larus cachinnans) were analysed morphometrically, with special emphasis on their functional implications and physiological needs. Oxidative fibres always had significantly smaller size than anaerobic fibres, although no differences in the number of capillaries per fibre were found. This resulted in greater capillary counts per unit of fibre area and perimeter in oxidative than anaerobic fibres, which indicates that the greater demand for oxygen supply may be achieved by decreasing the size of the muscle fibre rather than by increasing the number of associated capillaries. Fast oxidative fibres of the pectoralis and the triceps of the gull had greater sizes than the fast oxidative fibres of the mallard and the coot, which correlates with the difference in energetic demands between flapping and gliding flight. Greater fibre cross-sectional areas and perimeters seem suited to afford the long-lasting activity with low metabolic demands required during gliding. By contrast, mallards and coots attain a high oxidative metabolism, during sustained flapping flight, by reducing fibre size at the expense of a diminished ability for force generation. Between-species comparisons of the hindlimb muscles only yielded differences for the anaerobic fibres of the gastrocnemius, as an important adaptive response to force generation during burst locomotion. The need to manage sustained swimming abilities effectively may result in similar FOG fibre morphometry of the hindlimb muscles studied, indicating that a compromise between the oxygen flux to the muscle cell and the development of power is highly optimised in oxidative fibres of the bird species studied. PMID:9643422

  4. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions

    USGS Publications Warehouse

    Takekawa, John Y.; Ackerman, Joshua T.; Brand, Arriana; Graham, Tanya R.; Eagles-Smith, Collin A.; Herzog, Mark; Topping, Brent R.; Shellenbarger, Gregory; Kuwabara, James S.; Mruz, Eric; Piotter, Sara L.; Athearn, Nicole D.

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  5. A nonlethal microsampling technique to monitor the effects of mercury on wild bird eggs

    USGS Publications Warehouse

    Stebbins, K.R.; Klimstra, J.D.; Eagles-Smith C.A.; Ackerman, J.T.; Heinz, G.H.

    2009-01-01

    Methylmercury is the predominant chemical form of mercury reported in the eggs of wild birds, and the embryo is the most sensitive life stage to methylmercury toxicity. Protective guidelines have been based mainly on captive-breeding studies with chickens (Gallus gallus), mallards (Anas platyrhynchos), and ring-necked pheasants (Phasianus colchicus) or on field studies where whole eggs were collected and analyzed and the effects of the mercury were measured based on the reproductive success of the remaining eggs. However, both of these methods have limitations. As an alternative, we developed a technique that involves extracting a small sample of albumen from a live egg, sealing the egg, returning the egg to its nest to be naturally incubated by the parents, and then relating the hatching success of this microsampled egg to its mercury concentration. After first developing this technique in the laboratory using chicken and mallard eggs, we selected the laughing gull (Larus atricilla) and black-necked stilt (Himantopus mexicanus) as test subjects in the field. We found that 92% of the microsampled laughing gull eggs met our reproductive endpoint of survival to the beginning of hatching compared to 100% for the paired control eggs within the same nests. Microsampled black-necked stilt eggs exhibited 100% hatching success compared to 93% for the paired control eggs. Our results indicate that microsampling is an effective tool for nonlethally sampling mercury concentrations in eggs and, as such, can be used for monitoring sensitive species, as well as for improving studies that examine the effects of mercury on avian reproduction.

  6. A century of ecosystem change: human and seabird impacts on plant species extirpation and invasion on islands

    PubMed Central

    Bennett, Joseph R.; Blight, Louise K.; Giesen, Marissa; Janssen, Michael H.; Schaminée, Joop J.H.J.; Arcese, Peter

    2016-01-01

    We used 116 years of floral and faunal records from Mandarte Island, British Columbia, Canada, to estimate the indirect effects of humans on plant communities via their effects on the population size of a surface-nesting, colonial seabird, the Glaucous-winged gull (Larus glaucescens). Comparing current to historical records revealed 18 extirpations of native plant species (32% of species historically present), 31 exotic species introductions, and one case of exotic introduction followed by extirpation. Contemporary surveys indicated that native species cover declined dramatically from 1986 to 2006, coincident with the extirpation of ‘old-growth’ conifers. Because vegetation change co-occurred with an increasing gull population locally and regionally, we tested several predictions from the hypothesis that the presence and activities of seabirds help to explain those changes. Specifically, we predicted that on Mandarte and nearby islands with gull colonies, we should observe higher nutrient loading and exotic plant species richness and cover than on nearby islands without gull colonies, as a consequence of competitive dominance in species adapted to high soil nitrogen and trampling. As predicted, we found that native plant species cover and richness were lower, and exotic species cover and richness higher, on islands with versus without gull colonies. In addition, we found that soil carbon and nitrogen on islands with nesting gulls were positively related to soil depth and exotic species richness and cover across plots and islands. Our results support earlier suggestions that nesting seabirds can drive rapid change in insular plant communities by increasing nutrients and disturbing vegetation, and that human activities that affect seabird abundance may therefore indirectly affect plant community composition on islands with seabird colonies. PMID:27547531

  7. A century of ecosystem change: human and seabird impacts on plant species extirpation and invasion on islands.

    PubMed

    Lameris, Thomas K; Bennett, Joseph R; Blight, Louise K; Giesen, Marissa; Janssen, Michael H; Schaminée, Joop J H J; Arcese, Peter

    2016-01-01

    We used 116 years of floral and faunal records from Mandarte Island, British Columbia, Canada, to estimate the indirect effects of humans on plant communities via their effects on the population size of a surface-nesting, colonial seabird, the Glaucous-winged gull (Larus glaucescens). Comparing current to historical records revealed 18 extirpations of native plant species (32% of species historically present), 31 exotic species introductions, and one case of exotic introduction followed by extirpation. Contemporary surveys indicated that native species cover declined dramatically from 1986 to 2006, coincident with the extirpation of 'old-growth' conifers. Because vegetation change co-occurred with an increasing gull population locally and regionally, we tested several predictions from the hypothesis that the presence and activities of seabirds help to explain those changes. Specifically, we predicted that on Mandarte and nearby islands with gull colonies, we should observe higher nutrient loading and exotic plant species richness and cover than on nearby islands without gull colonies, as a consequence of competitive dominance in species adapted to high soil nitrogen and trampling. As predicted, we found that native plant species cover and richness were lower, and exotic species cover and richness higher, on islands with versus without gull colonies. In addition, we found that soil carbon and nitrogen on islands with nesting gulls were positively related to soil depth and exotic species richness and cover across plots and islands. Our results support earlier suggestions that nesting seabirds can drive rapid change in insular plant communities by increasing nutrients and disturbing vegetation, and that human activities that affect seabird abundance may therefore indirectly affect plant community composition on islands with seabird colonies. PMID:27547531

  8. [Microphallus kurilensis sp. nov., a new species of microphallids from the pygmaeus species group (Trematoda, Microphallidae) from the coastal areas of Okhotsk and Bering Seas].

    PubMed

    Galaktionov, K V; Regel', K V; Atrashkevich, G I

    2010-01-01

    The pygmaeus-species group is composed of close related species from the genus Microphallus in which metacercariae develop inside daughter sporocysts without encystment. Infection of periwinkles Littorina (Neritremna) spp. with intramolluscan stages of a new species of this group (Microphallus kurilensis sp. nov.) was recorded on the coasts of Sakhalin and Kuril islands, north of the Sea of Okhotsk and Chukchi Peninsula (the Bering Sea). Application of molecular methods allowed us to establish that M. kurilensis metacercariae are conspecific with one of the morphotypes of microphallid adults obtained from the intestine of the Pacific common eider (Somateria mollissima v-nigrum), which was shot in the north of the Sea of Okhotsk (Galaktionov, Olson, and Blasco-Costa, in press). The adults of the same morphotype were recorded in the Pacific common eider from the northwestern part of the Bering Sea (Chukchi Peninsula). In the course of experimental infection of the slaty-backed gull Larus schistisagus chicks with metacercariae of M. kurilensis, few microphallid adults were obtained. These adults were identical in their morphology with specimens of the microphallid morphotype from the Pacific common eider, which had been identified as M. kurilensis based on molecular data. Morphological description of metacercaria and adult of M. kurilensis and list of their differences from the same developmental stages of other species from pygmaeus-group are provided. It is concluded that M. kurilensis is transmitted in the host system including periwinkle Littorina (Neritrema) and seaducks (predominately, Pacific common eider). Most probably, distribution of M. kurilensis is not limited by the north Asiatic coast but expanded to the North American coast of the Pacific Ocean. PMID:21427958

  9. [The mutation spectrum of the GJB2 gene in Belarussian patients with hearing loss. Results of pilot genetic screening of hearing impairment in newborns].

    PubMed

    Bliznets, E A; Marcul', D N; Khorov, O G; Markova, T G; Poliakov, A V

    2014-02-01

    A total of 111 unrelated probands and their 8 sibs from Grodno oblast (Belarus) with bilateral isolated sensorineural hearing impairment were studied for the presence of mutations in the connexin 26--GJB2gene. Mutations were detected in 51 probands (46% of the sample). A significantly higher frequency of the GJB2gene mutations was observed in familial cases of the disease with the autosomal recessive type of inheritance (in 78% of families). Detected peculiarities of the GJB2 gene mutation spectrum demonstrated that use of the algorithm, which was developed for Russian patients, is optimal for the molecular study of patients from Be- larus. In the sample of patients with hearing loss, the highest (among other similar samples studied in the world) allele frequency of c.313_326de114 mutation (7% out of all pathological GJB2 alleles) was registered; Polish origin of this deletion was suggested. It was demonstrated that detection of the GJB2 gene mutation on only one patient's chromosome is insufficient to confirm a molecular genetic diagnosis of hearing loss of the DFNB1 genetic type (autosomal recessive hearing loss caused by the GJB2 gene mutations). Pilot screening in the presence of GJB2 gene mutations in newborns from Grodno oblast was conducted. The material from 235 children was studied during the screening; nine heterozygous carriers of the mutation were found. The c.35delG mutation was detected in a homozygous state in a single newborn (hearing loss of moderate severity was subsequently audiologically confirmed in this child). PMID:25711030

  10. Bald eagles and sea otters in the Aleutian Archipelago: indirect effects of trophic cascades.

    PubMed

    Anthony, Robert G; Estes, James A; Ricca, Mark A; Miles, A Keith; Forsman, Eric D

    2008-10-01

    Because sea otters (Enhydra lutris) exert a wide array of direct and indirect effects on coastal marine ecosystems throughout their geographic range, we investigated the potential influence of sea otters on the ecology of Bald Eagles (Haliaeetus leucocephalus) in the Aleutian Islands, Alaska, USA. We studied the diets, productivity, and density of breeding Bald Eagles on four islands during 1993-1994 and 2000-2002, when sea otters were abundant and scarce, respectively. Bald Eagles depend on nearshore marine communities for most of their prey in this ecosystem, so we predicted that the recent decline in otter populations would have an indirect negative effect on diets and demography of Bald Eagles. Contrary to our predictions, we found no effects on density of breeding pairs on four islands from 1993-1994 to 2000-2002. In contrast, diets and diet diversity of Bald Eagles changed considerably between the two time periods, likely reflecting a change in prey availability resulting from the increase and subsequent decline in sea otter populations. The frequency of sea otter pups, rock greenling (Hexagammus lagocephalus), and smooth lumpsuckers (Aptocyclus ventricosus) in the eagle's diet declined with corresponding increases in Rock Ptarmigan (Lagopus mutus), Glaucous-winged Gulls (Larus glaucescens), Atka mackerel (Pleurogrammus monopterygius), and various species of seabirds during the period of the recent otter population decline. Breeding success and productivity of Bald Eagles also increased during this time period, which may be due to the higher nutritional quality of avian prey consumed in later years. Our results provide further evidence of the wide-ranging indirect effects of sea otter predation on nearshore marine communities and another apex predator, the Bald Eagle. Although the indirect effects of sea otters are widely known, this example is unique because the food-web pathway transcended five species and several trophic levels in linking one apex predator

  11. Bald eagles and sea otters in the Aleutian Archipelago: indirect effects of trophic cascades.

    USGS Publications Warehouse

    Anthony, R.G.; Estes, J.A.; Ricca, M.A.; Miles, A.K.; Forsman, E.D.

    2008-01-01

    Because sea otters (Enhydra lutris) exert a wide array of direct and indirect effects on coastal marine ecosystems throughout their geographic range, we investigated the potential influence of sea otters on the ecology of Bald Eagles (Haliaeetus leucocephalus) in the Aleutian Islands, Alaska, USA. We studied the diets, productivity, and density of breeding Bald Eagles on four islands during 1993-1994 and 2000-2002, when sea otters were abundant and scarce, respectively. Bald Eagles depend on nearshore marine communities for most of their prey in this ecosystem, so we predicted that the recent decline in otter populations would have an indirect negative effect on diets and demography of Bald Eagles. Contrary to our predictions, we found no effects on density of breeding pairs on four islands from 1993-1994 to 2000-2002. In contrast, diets and diet diversity of Bald Eagles changed considerably between the two time periods, likely reflecting a change in prey availability resulting from the increase and subsequent decline in sea otter populations. The frequency of sea otter pups, rock greenling (Hexagammus lagocephalus), and smooth lumpsuckers (Aptocyclus ventricosus) in the eagle's diet declined with corresponding increases in Rock Ptarmigan (Lagopus mutus), Glaucous-winged Gulls (Larus glaucescens), Atka mackerel (Pleurogrammus monopterygius), and various species of seabirds during the period of the recent otter population decline. Breeding success and productivity of Bald Eagles also increased during this time period, which may be due to the higher nutritional quality of avian prey consumed in later years. Our results provide further evidence of the wide-ranging indirect effects of sea otter predation on nearshore marine communities and another apex predator, the Bald Eagle. Although the indirect effects of sea otters are widely known, this example is unique because the food-web pathway transcended five species and several trophic levels in linking one apex predator

  12. Forster's tern chick survival in response to a managed relocation of predatory California gulls

    USGS Publications Warehouse

    Ackerman, Joshua T.; Herzog, Mark P.; Hartman, C. Alex; Herring, Garth

    2014-01-01

    Gull populations can severely limit the productivity of waterbirds. Relocating gull colonies may reduce their effects on nearby breeding waterbirds, but there are few examples of this management strategy. We examined gull predation and survival of Forster's tern (Sterna forsteri) chicks before (2010) and after (2011) the managed relocation of the largest California gull (Larus californicus) colony (24,000 adults) in San Francisco Bay, California. Overall, survival of radio-marked Forster's tern chicks from hatching to fledging was 0.22 ± 0.03 (mean ± SE), and daily survival rates increased with age. Gulls were the predominant predator of tern chicks, potentially causing 54% of chick deaths. Prior to the gull colony relocation, 56% of radio-marked and 20% of banded tern chicks from the nearest tern colony were recovered dead in the gull colony, compared to only 15% of radio-marked and 4% of banded chicks recovered dead from all other tern colonies. The managed relocation of the gull colony substantially increased tern chick survival (by 900%) in the nearby (3.8 km) reference tern colony (0.29 ± 0.10 in 2010 and 0.25 ± 0.09 in 2011). Among 19 tern nesting islands, fledging success was higher when gull abundance was lower at nearby colonies and when gull colonies were farther from the tern colony. Our results indicate that the managed relocation of gull colonies away from preferred nesting areas of sensitive waterbirds can improve local reproductive success, but this conservation strategy may shift gull predation pressure to other areas or species.

  13. Premature feather loss among common tern chicks in Ontario: the return of an enigmatic developmental anomaly

    PubMed Central

    Tyerman, Donald J.; Crump, Doug; Williams, Kim L.; Oswald, Stephen A.

    2016-01-01

    In July 2014, we observed premature feather loss (PFL) among non-sibling, common tern Sterna hirundo chicks between two and four weeks of age at Gull Island in northern Lake Ontario, Canada. Rarely observed in wild birds, to our knowledge PFL has not been recorded in terns since 1974, despite the subsequent banding of hundreds of thousands of tern chicks across North America alone. The prevalence, 5% of chicks (9/167), and extent of feather loss we report is more extreme than in previous reports for common terns but was not accompanied by other aberrant developmental or physical deformities. Complete feather loss from all body areas (wing, tail, head and body) occurred over a period of a few days but all affected chicks appeared vigorous and quickly began to grow replacement feathers. All but one chick (recovered dead and submitted for post-mortem) most likely fledged 10–20 days after normal fledging age. We found no evidence of feather dystrophy or concurrent developmental abnormalities unusual among affected chicks. Thus, the PFL we observed among common terns in 2014 was largely of unknown origin. There was striking temporal association between the onset of PFL and persistent strong southwesterly winds that caused extensive mixing of near-shore surface water with cool, deep lake waters. One hypothesis is that PFL may have been caused by unidentified pathogens or toxins welling up from these deep waters along the shoreline but current data are insufficient to test this. PFL was not observed among common terns at Gull Island in 2015, although we did observe similar feather loss in a herring gull Larus argentatus chick in that year. Comparison with sporadic records of PFL in other seabirds suggests that PFL may be a rare, but non-specific, response to a range of potential stressors. PFL is now known for gulls, penguins and terns. PMID:27231646

  14. Population control of an overabundant species achieved through consecutive anthropogenic perturbations.

    PubMed

    Payo-Payo, Ana; Oro, Daniel; Igual, José Manuel; Jover, Lluis; Sanpera, Carolina; Tavecchia, Giacomo

    2015-12-01

    The control of overabundant vertebrates is often problematic. Much work has focused on population-level responses and overabundance due to anthropogenic subsidies. However, far less work has been directed at investigating responses following the removal of subsidies. We investigate the consequences of two consecutive perturbations, the closure of a landfill and an inadvertent poisoning event, on the trophic ecology (δ13C, δ15N, and δ34S), survival, and population size of an overabundant generalist seabird species, the Yellow-legged Gull (Larus michahellis). We expected that the landfill closure would cause a strong dietary shift and the inadvertent poisoning a decrease in gull population size. As a long-lived species, we also anticipated adult survival to be buffered against the decrease in food availability but not against the inadvertent poisoning event. Stable isotope analysis confirmed the dietary shift towards marine resources after the disappearance of the landfill. Although the survival model was inconclusive, it did suggest that the perturbations had a negative effect on survival, which was followed by a recovery back to average values. Food limitation likely triggered dispersal to other populations, while poisoning may have increased mortality; these two processes were likely responsible for the large fall in population size that occurred after the two consecutive perturbations. Life-history theory suggests that perturbations may encourage species to halt existing breeding investment in order to ensure future survival. However, under strong perturbation pulses the resilience threshold might be surpassed and changes in population density can arise. Consecutive perturbations may effectively manage overabundant species. PMID:26910951

  15. Climate change, reproductive performance and diet composition of marine birds in the southern California Current system, 1969 1997

    NASA Astrophysics Data System (ADS)

    Sydeman, William J.; Hester, Michelle M.; Thayer, Julie A.; Gress, Franklin; Martin, Paige; Buffa, Joelle

    We studied the effects of low-frequency climate change on the reproductive performance of 11 species of marine bird in the southern California Current system, 1969-1997. Reproductive performance of Brown Pelican ( Pelecanus occidentalis) and Double-crested Cormorant ( Phalacrocrax auritus) in southern California demonstrated an increase in the 1970s and early 1980s, attributable to recovery from organochlorine contamination (primarily DDE). Brandt's Cormorant ( Phalacrocorax penicillatus) in central California was the only species to demonstrate a secular increase in performance through time, a pattern that remains unexplained. Ashy Storm-petrel ( Oceanodroma homochroa) and Pelagic Cormorant ( Phalacrocorax pelagicus) demonstrated curvilinear patterns of change, with decreasing reproductive performance in the past decade. All other species including Western Gull ( Larus occidentalis), Pigeon Guillemot ( Cepphus columba), Xantus's Murrelet ( Synthiloboramphus hypoleucus), Common Murre ( Uria aalge), Cassin's Auklet ( Ptychoramphus aleuticus) and Rhinoceros Auklet ( Cerorhinca monocerata) showed diminishing reproductive performance through time. Patterns of change for the murre and auklets were not significant, presumably because of a lack of reproductive variation for these species, which display a conservative breeding effort (i.e. single-egg clutches). Changes in the birds' abilities to provision young and maintain chick survival during May-July each year appeared most closely related to overall changes in reproductive performance. Dietary change indicated a decline in use of juvenile rockfish ( Sebastes spp.) by marine birds in central California. There was also significant interannual variability in consumption of juvenile rockfish and the euphausiid Thysanoessa spinifera. Patterns of change in marine bird reproductive performance were generally concordant between southern and central California after considering the period of recovery for Brown Pelican and

  16. Associations between organohalogen concentrations and transcription of thyroid-related genes in a highly contaminated gull population.

    PubMed

    Técher, Romy; Houde, Magali; Verreault, Jonathan

    2016-03-01

    A number of studies have reported altered circulating thyroid hormone levels in birds exposed either in controlled settings or in their natural habitat to ubiquitous organohalogen compounds including organochlorines (OCs) and polybrominated diphenyl ether (PBDE) flame retardants. However, limited attention has been paid to underlying homeostatic mechanisms in wild birds such as changes in the expression of genes in the hypothalamic-pituitary-thyroid (HPT) axis. The objective of the present study was to investigate the relationships between hepatic concentrations of major organohalogens (PBDEs and OCs), and circulating thyroid hormone (free and total thyroxine (T4) and triiodothyronine (T3)) levels and transcription of 14 thyroid-related genes in three tissues (thyroid, brain, and liver) of an urban-adapted bird exposed to high organohalogen concentrations in the Montreal area (QC, Canada), the ring-billed gull (Larus delawarensis). Positive correlations were found between liver concentrations of several polychlorinated biphenyls (PCBs), PBDEs as well as chlordanes and total plasma T4 levels. Hepatic concentrations of several PBDEs were negatively correlated with mRNA levels of deiodinase type 3, thyroid peroxidase, and thyroid hormone receptor β (TRβ) in the thyroid gland. Liver PCB (deca-CB) correlated positively with mRNA levels of sodium-iodide symporter and TRα. In brain, concentrations of most PBDEs were positively correlated with mRNA levels of organic anion transporter protein 1C1 and transthyretin, while PCBs positively correlated with expression of TRα and TRβ as well as deiodinase type 2. These multiple correlative linkages suggest that organohalogens operate through several mechanisms (direct or compensatory) involving gene transcription, thus potentially perturbing the HPT axis of this highly organohalogen-contaminated ring-billed gull population. PMID:26747993

  17. Geographic, temporal, and age-specific variation in diets of Glaucous Gulls in western Alaska

    USGS Publications Warehouse

    Schmutz, J.A.; Hobson, K.A.

    1998-01-01

    We collected boluses and food remains of adult Glaucous Gulls (Larus hyperboreus) at or near nests and chicks, and digestive tracts from adults at three sites on the Yukon-Kuskokwim Delta, Alaska that differed in proximity to marine and terrestrial foods. We observed both geographic and temporal variation in diet; gulls consumed proportionately more terrestrial prey after peak hatch in late June, and gulls near the coast consumed proportionately more marine prey than gulls at two inland areas. Goslings occurred in > 60% of all samples from these inland areas. We compared these data to those from a previous study in western Alaska and found no marked differences. Evidence for similar patterns of geographic and temporal variation in diet was found using measurements of stable-carbon and nitrogen isotopes in gull and prey tissues. Stable isotope analysis further revealed that adult gulls consumed proportionately more marine prey (saffron cod, Eleginus gracilis) than they fed to their young. Using isotopic models, we estimated that 7-22% and 10-23% of the diet of adult and juvenile Glaucous Gulls, respectively, was comprised of terrestrial species. In addition to significant age-related variation, dietary estimates varied among geographic areas and between pre- and post-hatch periods. Overall, our isotopic estimates of the contribution of terrestrial prey to the diet of Glaucous Gulls was less than what may be inferred from conventional methods of diet analysis. Our study emphasizes the benefit of combining stable-isotope and conventional analyses to infer temporal and geographic changes in diet of wild birds and other organisms.

  18. Premature feather loss among common tern chicks in Ontario: the return of an enigmatic developmental anomaly.

    PubMed

    Arnold, Jennifer M; Tyerman, Donald J; Crump, Doug; Williams, Kim L; Oswald, Stephen A

    2016-01-01

    In July 2014, we observed premature feather loss (PFL) among non-sibling, common tern Sterna hirundo chicks between two and four weeks of age at Gull Island in northern Lake Ontario, Canada. Rarely observed in wild birds, to our knowledge PFL has not been recorded in terns since 1974, despite the subsequent banding of hundreds of thousands of tern chicks across North America alone. The prevalence, 5% of chicks (9/167), and extent of feather loss we report is more extreme than in previous reports for common terns but was not accompanied by other aberrant developmental or physical deformities. Complete feather loss from all body areas (wing, tail, head and body) occurred over a period of a few days but all affected chicks appeared vigorous and quickly began to grow replacement feathers. All but one chick (recovered dead and submitted for post-mortem) most likely fledged 10-20 days after normal fledging age. We found no evidence of feather dystrophy or concurrent developmental abnormalities unusual among affected chicks. Thus, the PFL we observed among common terns in 2014 was largely of unknown origin. There was striking temporal association between the onset of PFL and persistent strong southwesterly winds that caused extensive mixing of near-shore surface water with cool, deep lake waters. One hypothesis is that PFL may have been caused by unidentified pathogens or toxins welling up from these deep waters along the shoreline but current data are insufficient to test this. PFL was not observed among common terns at Gull Island in 2015, although we did observe similar feather loss in a herring gull Larus argentatus chick in that year. Comparison with sporadic records of PFL in other seabirds suggests that PFL may be a rare, but non-specific, response to a range of potential stressors. PFL is now known for gulls, penguins and terns. PMID:27231646

  19. Immunological and reproductive health assessment in herring gulls and black-crowned night herons in the Hudson–Raritan Estuary and Black-Crowned Night Herons in the Hudson-Raritan Estuary

    USGS Publications Warehouse

    Grasman, Keith A.; Echols, Kathy R.; May, Thomas M.; Peterman, Paul H.; Gale, Robert W.; Orazio, Carl E.

    2013-01-01

    Previous studies have shown inexplicable declines in breeding waterbirds within western New York/New Jersey Harbor between 1996 and 2002 and elevated polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs) in double-crested cormorant (Phalacrocorax auritus) eggs. The present study assessed associations between immune function, prefledgling survival, and selected organochlorine compounds and metals in herring gulls (Larus argentatus) and black-crowned night herons (Nycticorax nycticorax) in lower New York Harbor during 2003. In pipping gull embryos, lymphoid cells were counted in the thymus and bursa of Fabricius (sites of T and B lymphocyte maturation, respectively). The phytohemagglutinin (PHA) skin response assessed T cell function in gull and heron chicks. Lymphocyte proliferation was measured in vitro in adult and prefledgling gulls. Reference data came from the Great Lakes and Bay of Fundy. Survival of prefledgling gulls was poor, with only 0.68 and 0.5 chicks per nest surviving to three and four weeks after hatch, respectively. Developing lymphoid cells were reduced 51% in the thymus and 42% in the bursa of gull embryos from New York Harbor. In vitro lymphocyte assays demonstrated reduced spontaneous proliferation, reduced T cell mitogen-induced proliferation, and increased B cell mitogen-induced proliferation in gull chicks from New York Harbor. The PHA skin response was suppressed 70 to 80% in gull and heron chicks. Strong negative correlations (r = –0.95 to –0.98) between the PHA response and dioxins and PCBs in gull livers was strong evidence suggesting that these chemicals contribute significantly to immunosuppression in New York Harbor waterbirds.

  20. Relationships between polybrominated diphenyl ethers and transcription and activity of type 1 deiodinase in a gull highly exposed to flame retardants.

    PubMed

    François, Anthony; Técher, Romy; Houde, Magali; Spear, Philip; Verreault, Jonathan

    2016-09-01

    Deca-brominated diphenyl ether (deca-BDE), composed mainly of BDE-209, is subject to usage restrictions in North America and Europe, although global action on its continued use has yet to be undertaken. Relatively large concentrations of polybrominated diphenyl ethers (PBDEs), especially BDE-209 and its higher brominated degradation products, have been reported in tissues of ring-billed gulls (Larus delawarensis) breeding near the densely populated city of Montreal (QC, Canada). There is limited knowledge of BDE-209 biotransformation and toxicokinetics in birds. Deiodinases, a class of enzymes catalyzing thyroid hormone conversion, have been suggested to be involved in BDE-209 debromination in birds. The objective of the present study was to investigate the relationships between PBDE concentrations and type 1 deiodinase (D1) transcription and in vitro activity (microsomes) in livers of Montreal-breeding ring-billed gulls. The ring-billed gulls exhibiting the highest D1 activity in liver microsomes accumulated the greatest liver concentrations of hepta-BDEs and octa-BDEs. Activity of D1 was inversely related to concentration ratios of BDE-209 to octa-BDEs and ∑hepta-BDE. An even stronger inverse relation was found between D1 activity and BDE-209 to ∑nona + octa + hepta-BDE concentration ratios. The messenger ribonucleic acid (mRNA) levels of D1 in gull livers were inversely associated with liver concentrations of ∑octa-BDE. The present study's findings suggest that D1 is potentially involved in BDE-209 biotransformation and accumulation of higher brominated PBDEs in livers of ring-billed gulls. Environ Toxicol Chem 2016;35:2215-2222. © 2016 SETAC. PMID:27336952

  1. Temporal trends of mercury in eggs of five sympatrically breeding seabird species in the Canadian Arctic.

    PubMed

    Braune, Birgit M; Gaston, Anthony J; Mallory, Mark L

    2016-07-01

    We compared temporal trends of total mercury (Hg) in eggs of five seabird species breeding at Prince Leopold Island in the Canadian high Arctic. As changes in trophic position over time have the potential to influence contaminant temporal trends, Hg concentrations were adjusted for trophic position (measured as δ(15)N). Adjusted Hg concentrations in eggs of thick-billed murres (Uria lomvia) and northern fulmars (Fulmarus glacialis) increased from 1975 to the 1990s, followed by a plateauing of levels from the 1990s to 2014. Trends of adjusted Hg concentrations in eggs of murres, fulmars, black guillemots (Cepphus grylle) and black-legged kittiwakes (Rissa tridactyla) had negative slopes between 1993 and 2013. Adjusted Hg concentrations in glaucous gull (Larus hyperboreus) eggs decreased by 50% from 1993 to 2003 before starting to increase again. Glaucous gull eggs had the highest Hg concentrations followed by black guillemot eggs, and black-legged kittiwake eggs had the lowest concentrations consistently in the five years compared between 1993 and 2013. Based on published toxicological thresholds for Hg in eggs, there is little concern for adverse reproductive effects due to Hg exposure in these birds, although the levels in glaucous gull eggs warrant future scrutiny given the increase in Hg concentrations observed in recent years. There is evidence that the Hg trends observed reflect changing anthropogenic Hg emissions. It remains unclear, however, to what extent exposure to Hg on the overwintering grounds influences the Hg trends observed in the seabird eggs at Prince Leopold Island. Future research should focus on determining the extent to which Hg exposure on the breeding grounds versus the overwintering areas contribute to the trends observed in the eggs. PMID:27074200

  2. Toxoplasma gondii Infection in Seagull Chicks Is Related to the Consumption of Freshwater Food Resources.

    PubMed

    Cabezón, Oscar; Cerdà-Cuéllar, Marta; Morera, Virginia; García-Bocanegra, Ignacio; González-Solís, Jacob; Napp, Sebastian; Ribas, Maria P; Blanch-Lázaro, Berta; Fernández-Aguilar, Xavier; Antilles, Noelia; López-Soria, Sergio; Lorca-Oró, Cristina; Dubey, Jitender P; Almería, Sonia

    2016-01-01

    Understanding the spread of Toxoplasma gondii (T. gondii) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (Larus michahellis) and Audouin's gull (L. audouinii)) from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT) for the presence of antibodies against T. gondii. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall T. gondii seroprevalence was 21.0% (IC95% 17.5-24.4). A generalized linear mixed-effects model indicated that year (2009) and food source (freshwater) were risk factors associated to the individual risk of infection by T. gondii, while age (days) was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of T. gondii. Year differences could indicate fluctuating rates of exposure of seagull chicks to T. gondii. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07), supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report T. gondii antibodies in Yellow-legged and Audouin's gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology. PMID:26974667

  3. Short-term fasts increase levels of halogenated flame retardants in tissues of a wild incubating bird.

    PubMed

    Marteinson, Sarah C; Drouillard, Ken G; Verreault, Jonathan

    2016-04-01

    Many species are adapted for fasting during parts of their life cycle. For species undergoing extreme fasts, lipid stores are mobilized and accumulated contaminants can be released to exert toxicological effects. However, it is unknown if short-term fasting events may have a similar effect. The objective of this study was to determine if short successive fasts are related to contaminant levels in liver and plasma of birds. In ring-billed gulls (Larus delawarensis), both members of the pair alternate between incubating the nest for several hours (during which they fast) and foraging, making them a useful model for examining this question. Birds were equipped with miniature data loggers recording time and GPS position for two days to determine the proportion and duration of time birds spent in these two activities. Liver and plasma samples were collected, and halogenated flame retardants (HFRs) (PBDEs and dechlorane plus) and organochlorines (OCs) (PCBs, DDTs, and chlordane-related compounds) were determined. Most birds (79%) exhibited plasma lipid content below 1%, indicating a likely fasted state, and plasma lipid percent declined with the number of hours spent at the nest site. The more time birds spent at their nest site, the higher were their plasma and liver concentrations of HFRs. However, body condition indices were unrelated to either the amount of time birds fasted at the nest site or contaminant levels, suggesting that lipid mobilization might not have been severe enough to affect overall body condition of birds and to explain the relationship between fasting and HFR concentrations. A similar relationship between fasting and OC levels was not observed, suggesting that different factors are affecting short-term temporal variations in concentrations of these two classes of contaminants. This study demonstrates that short fasts can be related to increased internal contaminant exposure in birds and that this may be a confounding factor in research and

  4. In Vitro Metabolism of Photolytic Breakdown Products of Tetradecabromo-1,4-diphenoxybenzene Flame Retardant in Herring Gull and Rat Liver Microsomal Assays.

    PubMed

    Su, Guanyong; Greaves, Alana K; Teclechiel, Daniel; Letcher, Robert J

    2016-08-01

    Tetradecabromo-1,4-diphenoxybenzene (TeDB-DiPhOBz) is used as a flame retardant chemical and has been hypothesized to be the precursor of methoxylated polybrominated diphenoxybenzene (MeO-PB-DiPhOBz) contaminants reported in herring gulls from sites across the Laurentian Great Lakes. Here, by irradiating the parent TeDB-DiPhOBz (solution 1) with natural sunlight or UV, we prepared three solutions where solution 2 was dominated by the Br8-11-PB-DiPhOBzs, along with Br5-8-PB-DiPhOBzs (solution 3) and Br4-6-PB-DiPhOBzs (solution 4). The in vitro metabolism of TeDB-DiPhOBz and PB-DiPhOBzs was investigated using harvested wild herring gull (Larus argentatus) and adult male Wister-Han rat liver microsomal assays. After a 90 min incubation period of solution 1 in gull or rat microsomal assays, there was no significant (p > 0.05) depletion of TeDB-DiPhOBz. OH-PB-DiPhOBz metabolites were detectable after gull and rat microsomal assay incubation with solutions 3 or 4, and showed clear species-specific differences. Also detected were two polybrominated hydroxylated metabolites having polybenzofuran structures. Overall, this study suggested that TeDB-DiPhOBz is slowly metabolized in vitro, and also indicated that if wild herring gulls are exposed (e.g., via the diet) to photolytic products of TeDB-DiPhOBz, OH-PB-DiPhOBz and other metabolites could be formed. OH-PH-DiPhOBz are likely precursors to MeO-PB-DiPhOBz contaminants that we reported previously in eggs of wild Great Lakes herring gulls. PMID:27351066

  5. Habitat change by the formation of alien Crassostrea-reefs in the Wadden Sea and its role as feeding sites for waterbirds

    NASA Astrophysics Data System (ADS)

    Markert, Alexandra; Esser, Wiebke; Frank, Dietrich; Wehrmann, Achim; Exo, Klaus-Michael

    2013-10-01

    Non-indigenous Pacific oysters (Crassostrea gigas) have been invading the central Wadden Sea since 1998, predominantly settling on intertidal blue mussel (Mytilus edulis) beds which are increasingly transformed into Crassostrea-reefs. Pacific oysters are strong ecosystem engineers and the habitat change is considered to be a threat for waterbirds losing important feeding sites in the intertidal of the Wadden Sea. This study has increased our understanding of the use of foraging habitats by birds according to changing food resources. During the spring and autumn migration period in 2007, we recorded bird densities at two reef types varying in Pacific oyster density and at the adjacent sand flat as a reference site. We also recorded feeding behaviour, choice of prey and assessed peck and intake rate of three target species: Eurasian oystercatcher Haematopus ostralegus, Eurasian curlew Numenius arquata and European herring gull Larus argentatus. To evaluate the use of the Crassostrea-reef in the central Wadden Sea, we compared bird densities of the target species at different intertidal feeding habitats in various regions and compared the biomass intake of Eurasian oystercatcher feeding on different prey species. We show that Eurasian oystercatcher and Eurasian curlew have adapted to the new situation and learned to exploit the food supply offered by Crassostrea-reefs. While foraging mainly on Pacific oysters, Eurasian oystercatchers attained sustainable intake rates even though food resource at dense reef during autumn was very poor due to a lack in harvestable oysters. Consolidation of reefs limits the accessibility of prey for Eurasian oystercatchers whereas a successful recruitment of Pacific oysters enhances the suitability of the habitat. Eurasian curlew was promoted by the engineering effects of the Pacific oyster while feeding extensively on shore crabs at the reefs. In contrast, European herring gulls appear hampered in foraging during low tide and hereby

  6. Yolk testosterone affects growth and promotes individual-level consistency in behavioral lateralization of yellow-legged gull chicks.

    PubMed

    Possenti, Cristina Daniela; Romano, Andrea; Caprioli, Manuela; Rubolini, Diego; Spiezio, Caterina; Saino, Nicola; Parolini, Marco

    2016-04-01

    Behavioral lateralization is common in animals and may be expressed at the individual- and at the population-level. The ontogenetic processes that control lateralization, however, are largely unknown. Well-established sex-dependence in androgen physiology and sex-dependent variation in lateralization have led to the hypothesis that testosterone (T) has organizational effects on lateralization. The effects of T exposure in early life on lateralization can be efficiently investigated by manipulating T levels in the cleidoic eggs of birds, because the embryo is isolated from maternal and sibling physiological interference, but this approach has been adopted very rarely. In the yellow-legged gull (Larus michahellis) we increased yolk T concentration within the physiological limits and tested the effects on the direction of lateralization in two functionally fundamental behaviors (begging for parental care and escape to cover) of molecularly sexed hatchlings. We also speculated that T may intervene in regulating consistency, rather than direction of lateralization, and therefore tested if T affected the 'repeatability' of lateral preference in consecutive behavioral trials. T treatment had no effect on the direction of lateralization, but enhanced the consistency of lateral preference in escape responses. Sex did not predict lateralization. Neither behavior was lateralized at the population-level. We therefore showed for the first time in any species an effect of egg T on consistency in lateralization. The implications of the effect of T for the evolution of trade-offs in maternal allocation of egg hormones, and the evolutionary interpretations of findings from our studies on lateralization among unmanipulated birds are discussed. PMID:26836770

  7. Spatio-temporal trends and monitoring design of perfluoroalkyl acids in the eggs of gull (Larid) species from across Canada and parts of the United States.

    PubMed

    Gewurtz, Sarah B; Martin, Pamela A; Letcher, Robert J; Burgess, Neil M; Champoux, Louise; Elliott, John E; Weseloh, D V Chip

    2016-09-15

    A large spatial dataset of perfluoroalkyl acid (PFAA) concentrations in eggs of herring gulls (Larus argentatus or congeneric species) collected from late April to early June between 2009 and 2014 from 28 colonies across Canada and parts of the Unites States was used to evaluate location-specific patterns in chemical concentrations and to generate hypotheses on the major sources affecting PFAA distributions. The highly bioaccumulative perfluorooctane sulfonic acid (PFOS) as well as other perfluoroalkyl sulfonic acids (PFSAs) showed the greatest concentrations in eggs from the lower Great Lakes of southern Ontario as well as from the St. Lawrence River. Despite the 2000 to 2002 phase-out of PFOS and related C8 chemistry by the major manufacturer at the time, ongoing losses from consumer products during use and disposal in urban/industrial locations continue to be major sources to the environment and are influencing the spatial trends of PFOS in Canada. In comparison to PFOS, perfluoroalkyl carboxylic acids (PFCAs) were not as concentrated in eggs in close proximity to urbanized/industrialized centers, but had surprisingly elevated levels in relatively remote regions such as Great Slave Lake, NT and East Bay in Hudson Bay, NU. The present results support the hypothesis that atmospheric transport and degradation of precursor chemicals, such as the fluorotelomer alcohols 8:2 FTOH and 10:2 FTOH, are influencing the spatial trends of PFCAs in Canada. A power analysis conducted on a representative urbanized/industrialized colony in the Toronto Harbour, ON, and a relatively remote colony in Lake Superior, emphasized the importance of consistent and long-term data collection in order to detect the anticipated changes in PFAA concentrations in Canadian gull eggs. PMID:27183458

  8. Regular habitat switch as an important feeding strategy of an opportunistic seabird species at the interface between land and sea

    NASA Astrophysics Data System (ADS)

    Schwemmer, Philipp; Garthe, Stefan

    2008-03-01

    During deteriorated prey availability, purely pelagic, specialised seabird species have to alter their feeding strategy by extending foraging radii and/or time spent at sea or reducing feeding intervals of chicks. In contrast, more generalised species such as the opportunistic black-headed gull ( Larus ridibundus) breeding at the German North Sea coast, can be assumed to react on prey shortages by switching foraging habitats. The coastal zone of the German North Sea provides a rich habitat mosaic consisting of the offshore zone, tidal flats and terrestrial habitats. Thus, we expected distinct temporal and spatial patterns of habitat switch in accordance with prey availability and environmental constraints. We carried out ship-based and aerial surveys as well as dietary analyses and observations on flight activity. We found a significant switch from terrestrial to marine feeding sites both on a daily basis (related to tidal cycle) and over the whole breeding season. Most likely, the latter switch is the result of lower prey availability in the terrestrial habitats and an increasing quality (in terms of prey abundance and energy intake) of the marine area. While there was only moderate variability in habitat use among different years, we revealed significant differences in the diet of birds from different colonies. The high dietary plasticity and flexible feeding strategy, switching between terrestrial and marine prey is certainly of major importance for the success of an opportunistic avian top predator in a complex coastal zone. It is suggested that - compared to situations elsewhere - the number of breeding pairs of black-headed gulls in the German North Sea coast are still stable due to the switch of foraging habitats performed by individuals in this region.

  9. Evaluating gull diets: A comparison of conventional methods and stable isotope analysis

    USGS Publications Warehouse

    Weiser, E.L.; Powell, A.N.

    2011-01-01

    Samples such as regurgitated pellets and food remains have traditionally been used in studies of bird diets, but these can produce biased estimates depending on the digestibility of different foods. Stable isotope analysis has been developed as a method for assessing bird diets that is not biased by digestibility. These two methods may provide complementary or conflicting information on diets of birds, but are rarely compared directly. We analyzed carbon and nitrogen stable isotope ratios of feathers of Glaucous Gull (Larus hyperboreus) chicks from eight breeding colonies in northern Alaska, and used a Bayesian mixing model to generate a probability distribution for the contribution of each food group to diets. We compared these model results with probability distributions from conventional diet samples (pellets and food remains) from the same colonies and time periods. Relative to the stable isotope estimates, conventional analysis often overestimated the contributions of birds and small mammals to gull diets and often underestimated the contributions of fish and zooplankton. Both methods gave similar estimates for the contributions of scavenged caribou, miscellaneous marine foods, and garbage to diets. Pellets and food remains therefore may be useful for assessing the importance of garbage relative to certain other foods in diets of gulls and similar birds, but are clearly inappropriate for estimating the potential impact of gulls on birds, small mammals, or fish. However, conventional samples provide more species-level information than stable isotope analysis, so a combined approach would be most useful for diet analysis and assessing a predator's impact on particular prey groups. ?? 2011 Association of Field Ornithologists.

  10. Local and interannual variations in mercury and cadmium in eggs of eight seabird species of the Sinaloa coast, México.

    PubMed

    Ceyca, Juan P; Castillo-Guerrero, J Alfredo; García-Hernández, Jaqueline; Fernández, Guillermo; Betancourt-Lozano, Miguel

    2016-09-01

    Mercury (Hg) and cadmium (Cd) concentrations in eggs of 8 seabird species inhabiting 5 coastal ecosystems in Sinaloa, México were determined during 2 breeding seasons (2012 and 2013): blue-footed booby (Sula nebouxii), brown booby (Sula leucogaster), double-crested cormorant (Phalacrocorax auritus), magnificent frigatebird (Fregata magnificens), brown pelican (Pelecanus occidentalis), royal tern (Thalasseus maximus), laughing gull (Leucophaeus atricilla), and Heermann's gull (Larus heermanni). The interspecific differences found in the concentrations of both metals were attributed to the diet and foraging ecology of the species. The highest Hg concentrations were detected in piscivorous species (brown pelican, 0.42 µg/g; brown booby, 0.31 µg/g; blue-footed booby, 0.26 µg/g; and double-crested cormorant, 0.23 µg/g); whereas species with more varied diets presented the highest Cd concentrations (Heermann's gull, 0.31 µg/g; laughing gull, 0.27 µg/g; and magnificent frigatebird, 0.27 µg/g). Cadmium concentrations were significantly greater in 2013 than 2012 for most species, and brown pelican and laughing gull also had higher Hg concentrations in 2013 in Santa María Bay, suggesting a relationship as a result of the changes either in oceanographic conditions or in continental runoff. Mercury concentrations in brown pelican and Cd concentrations in Heermann's gull and laughing gull were above threshold levels for adverse effects on reproduction and survival. Environ Toxicol Chem 2016;35:2330-2338. © 2016 SETAC. PMID:26887632

  11. The identification of a new Giardia duodenalis assemblage in marine vertebrates and a preliminary analysis of G. duodenalis population biology in marine systems.

    PubMed

    Lasek-Nesselquist, Erica; Welch, David Mark; Sogin, Mitchell L

    2010-08-01

    Giardia duodenalis is an intestinal parasite of many vertebrates. The presence of G. duodenalis in the marine environment due to anthropogenic and wildlife activity is well documented, including the contributions from untreated sewage and storm water, agricultural run-off and droppings from terrestrial animals. Recently, studies have detected this protistan parasite in the faeces of marine vertebrates such as whales, dolphins, seals and shore birds. To explore the population biology of G. duodenalis in marine life, we determined the prevalence of G. duodenalis in two species of seal (Halichoerus grypus, Phoca vitulina vitulina and Phoca vitulina richardsi) from the east and west coasts of the USA, sequenced two loci from G. duodenalis-positive samples to assess molecular diversity and examined G. duodenalis distribution amongst these seals and other marine vertebrates along the east coast. We found a significant difference in the presence of G. duodenalis between east and west coast seal species. Only the zoonotic lineages of G. duodenalis, Assemblages A and B and a novel lineage, which we designated as Assemblage H, were identified in marine vertebrates. Assemblages A and B are broadly distributed geographically and show a lack of host specificity. Only grey seal (Halichoerus grypus) samples and one gull sample (Larus argentatus) from a northern location of Cape Cod, Massachusetts, USA, showed the presence of Assemblage H haplotypes; only one other study of harbour seals from the Puget Sound region of Washington, USA previously recorded the presence of an Assemblage H haplotype. Assemblage H sequences form a monophyletic clade that appears as divergent from the other seven Assemblages of G. duodenalis as these assemblages are from each other. The discovery of a previously uncharacterised lineage of G. duodenalis suggests that this parasite has more genetic diversity and perhaps a larger host range than previously believed. PMID:20361967

  12. Unintended Consequences of Management Actions in Salt Pond Restoration: Cascading Effects in Trophic Interactions

    PubMed Central

    Takekawa, John Y.; Ackerman, Joshua T.; Brand, L. Arriana; Graham, Tanya R.; Eagles-Smith, Collin A.; Herzog, Mark P.; Topping, Brent R.; Shellenbarger, Gregory G.; Kuwabara, James S.; Mruz, Eric; Piotter, Sara L.; Athearn, Nicole D.

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  13. Thirty-seventh supplement to the American Ornithologists' Union checklist of North American birds

    USGS Publications Warehouse

    Monroe, Burt L.; Banks, Richard C.; Fitzpatrick, John W.; Howell, Thomas R.; Johnson, Ned K.; Ouellet, Henri; Remsen, J.V.; Storer, Robert W.

    1989-01-01

    This third supplement subsequent to the 6th edition (1983) of the A.O.U. "Check-list of North American Birds" consists of changes adopted by the Committee on Classification and Nomenclature as of 1 March 1989. The changes fall into nine categories: (1) six species are added to the main list (Pterodroma longirostris, Larus crassirostris, Streptopelia decaocto, Cocccyzus julieni, Chrysolampis mosquitus, Emberiza aureola) because of new distributional information; (2) five species (Ara cubensis, Chlorostilbon bracei, Empidonax occidentalis, Polioptila californica, Pipilo crissalis) are added to the main list because of the splitting of species already on the list; (3) one name (Anthus rubescens) is changed because of the splitting of a species from outside the Checklist area; (4) two names (Morus bassanus, Nyctanassa violacea) is removed from the main list to Appendix B because of re-evaluation of Northern Hemisphere records; (6) three species (Pterodrama rostrata, P. alba, P. solandri) are moved from Appendix A to Appendix B, and one (P. defilippiana) is added to Appendix B because of questionable sight records; (7)A.O.U. numbers are added to three species (Ciccaba virgata, Myiopagis viridicata, Molothrus bonariensis) on the basis on new distributional records or supporting data; (8) several corrections in spelling or citations are made; and (9) English names are changed for twelve species to accommodate worldwide usage of these names. No new distributional information is included except as indicated above (i.e. minor changes of distribution are not noted). These actions bring the number of species recognized as occurring in North America (main list) to 1,945.

  14. Evaluating cleansing effects on trace elements and stable isotope values in feathers of oiled birds.

    PubMed

    Valladares, Sonia; Moreno, Roćio; Jover, Lluis; Sanpera, Carola

    2010-01-01

    Feathers of seabirds are widely used as a nondestructive tissue for pollution monitoring of trace elements, as well as convenient samples for trophic ecology studies by means of stable isotope analysis (SIA). Nevertheless, feathers can be occasionally impregnated with oil from deliberate ship discharges and from massive oil spill accidents. The feather structure makes them effective traps for particles and are subject to external contamination. It is unknown to what extent the oil adhered to feathers can change trace element concentrations or stable isotope signatures. This study has two primary objectives: (1) to assess if there are differences between trace element concentrations and stable isotope signatures of oiled and clean feathers, and (2) to determine if the cleansing of oiled feathers using commonly applied techniques such as sodium hydroxide (NaOH) washes in combination with an organic solvent (hexane) is more effective than using NaOH alone. In order to do this, we analysed trace elements (Se, Hg, Pb, Cu and Zn) and stable isotopes (delta(13)C and delta(15)N) of individual feathers of yellow-legged gulls (Larus michahellis) which were affected by the 2002 Prestige oil spill in Galicia (NW Spain). Two sets of feathers were analysed, one group were oil-free (Control group) and the other had oil adhered to its surface (Oiled group). We expected to find differences between control and oiled feathers when cleaning exclusively with NaOH and no differences when using hexane. Our results did not show significant differences between Control and Oiled groups as a consequence of the cleansing method used. Unexpectedly, the additional cleansing with hexane resulted in decreasing selenium concentrations and increasing zinc and delta(15)N values in all groups of feathers. PMID:19731016

  15. Summer distribution of seabirds in the North-East Water polynya, Greenland

    NASA Astrophysics Data System (ADS)

    Joiris, Claude R.; Kampp, Kaj; Tahon, Jacques; Kristensen, Reinhardt Møbjerg

    1997-10-01

    The distribution at sea of seabirds was studied in the North-East Water (NEW) polynya, Greenland, during transect counts in the summers of 1991, 1992 and 1993 on board the ice-breaking RVs Polarstern and Polar Sea. Data collected within the polynya 'box' (78-82°N; 5-18°W) concern observations of 8000 birds counted during 1350 half-hour counts. Distribution is presented as density (N/km 2) and calculated daily food intake. Five bird species were selected for discussion, representing more than 95% of the total numbers encountered: Fulmar ( Fulmarus glacialis), Ivory Gull ( Pagophila eburnea), Kittiwake ( Rissa tridactyla), Glaucous Gull ( Larus hyperboreus) and Ross's Gull ( Rhodostethia rosea). For these species, densities are comparable in the NE Greenland polynya and in other European Arctic seas. The main difference is the absence in NEW of the species playing the main role in Arctic seas: Brünnich's Guillemot ( Uria lomvia) and Little Auk ( Alle alle). In the absence of fish-eating birds and of birds consuming zooplankton in the water column, the NEW polynya ecosystem is thus dominated by surface feeders and, closer to the coast, by benthic feeders like eiders, Somateria mollissima and S. spectabilis, and walrus, Odobenus rosmarus. The density and daily food intake for all seabirds are one order of magnitude lower in the polynya than in the Arctic seas. The distribution and abundance of seabirds in the NEW polynya seems to reflect a very low density of pelagic fish and Zooplankton in the water column, while Zooplankton must be present at 'normal' concentrations in the upper layer.

  16. DNA fingerprinting reveals elevated mutation rates in herring gulls inhabiting a genotoxically contaminated site

    SciTech Connect

    Yauk, C.L.; Quinn, J.S.

    1995-12-31

    The authors used multi-locus DNA fingerprinting to examine families of herring gulls (Larus argentatus) from a genotoxically contaminated site (Hamilton Harbour) and from a pristine location (Kent Island, Bay of Fundy) to show significant differences in mutation rates between the locations. Overall the authors identified 17 mutant bands from 15 individuals of the 35 examined from Hamilton Harbour, and 7 mutant fragments from 7 individuals, of the 43 examined from Kent Island; a mutation frequency of 0.429 per nestling for Hamilton Harbour and 0.163 for Kent Island. The total number of individuals with mutant bands was significantly higher at Hamilton Harbour than at Kent Island (X{sup 2}=6.734; df = 1; P < 0.01). Ongoing analysis of other less contaminated sites also reveals lower mutation rates than those seen in Hamilton Harbour. With multi-locus DNA fingerprinting many regions of the genome can be surveyed simultaneously. The tandemly repeated arrays of nucleotides examined with DNA fingerprinting are known to have elevated rates of mutation. Furthermore, the mutations seen with DNA fingerprinting are predominantly heritable. Other biomarkers currently used in situ are not able to monitor direct and heritable DNA mutation, or measure biological endpoints that frequently result in spontaneous abortion creating difficulty in observing significantly elevated levels in viable offspring. The authors suggest that multilocus DNA fingerprinting can be used as a biomarker to identify potentially heritable risks before the onset of other types of ecological damage. This approach provides a direct measure of mutation in situ and in vivo in a vertebrate species under ambient conditions.

  17. Heavy metal and metallothionein concentrations in Atlantic Canadian seabirds.

    PubMed

    Elliott, J E; Scheuhammer, A M; Leighton, F A; Pearce, P A

    1992-01-01

    Seabird tissues, collected during the 1988 breeding season from colonies on the Atlantic coast of Canada, were analyzed for toxic metals--Cd, Hg and Pb--and 18 other trace elements. Metallothionein (MT) was measured in kidney, and kidneys and livers underwent histopathological examination. Levels of most essential trace elements appear to be closely regulated in seabird tissues; values were in good agreement with those previously reported in the published literature. Liver-Se concentrations in Leach's storm-petrels (Oceanodroma leukorrhea) (77.6 + 7.49 micrograms/g dry weight) were much higher than values normally reported for free-living birds and mammals. Cd levels varied greatly among individuals, but were always higher in kidney than in liver. Highest mean Cd concentrations (183 + 65 micrograms/g dry weight) were in kidneys of the planktivorous Leach's storm-petrels from the Gulf of St. Lawrence. A few individuals of this species had values greater than 300 micrograms/g dry weight. Cd and metallothionein (MT) concentrations were positively correlated in kidneys of Leach's storm-petrels (r = 0.692), Atlantic puffin (Fratercula arctica) (r = 0.845) and herring gull (Larus argentatus) (r = 0.866). Concentrations of total Hg varied greatly among species and individuals, but were consistently higher in liver than in kidney. Highest mean levels (21 + 28 micrograms/g) were in livers of the piscivorous double-crested cormorant (Phalacrocorax auritus) from Saint John Harbour in the Bay of Fundy. Concentrations of Hg and Se were positively correlated (r = 0.736) in livers of Leach's storm-petrel, but not in other species. Pb concentrations were consistently greatest in bone, with mean levels being highest in herring gulls from a colony in the Bay of Fundy (63 + 36 micrograms/g). Histological examination of liver and kidney failed to reveal indications of tissue damage associated with elevated levels of heavy metals. PMID:1554255

  18. Polycyclic Aromatic Hydrocarbons in Biota from the Brisbane River Estuary, Australia

    NASA Astrophysics Data System (ADS)

    Kayal, S.; Connell, D. W.

    1995-05-01

    Six species of aquatic organisms from the Brisbane River estuarine system were sampled and their tissues analysed for polycyclic aromatic hydrocarbons (PAHs). These were the sea mullet, Mugil cephalus, bony bream, Nematolosa come, blue catfish, Arius graffei, mud crab, Scylla serrata, pelican, Pelecanus conspicillatus, and silver gull, Larus novaehollandiae. PAHs in the muscle (fish and birds) and soft (crab) tissue samples were isolated by first hydrolysing these samples and then solvent extraction followed by column chromatography. The compounds were then identified and quantified by gas chromatography and gas chromatography coupled with mass spectrometry. The samples contained low levels of PAHs that ranged in molecular weight from 128 (naphthalene) to 252 (benzo[k]fluoranthene). The highest total PAH level of 195 ng g -1, wet weight, was recorded in mullet samples whereas the blue catfish samples yielded the lowest level of 43 ng g -1. Relative ratios of low molecular weight (≤3-rings) compounds to those with high molecular weights (≤4-rings) suggested a petroleum related origin for the PAHs detected in the organisms. Results indicated that significant biomagnification of PAHs in the estuarine ecosystem sampled is highly unlikely. Characteristics such as the trophic level and size/age were not significant factors in determining the corresponding tissue PAH levels in the fish and crab species. Tissue lipid content, however, was found to be a primary factor in determining the PAH concentrations in fish species. PAH levels recorded in the samples are comparable to those levels reported from similarly urbanized areas in other geographical locations.

  19. Parrot bornavirus-2 and -4 RNA detected in wild bird samples in Japan are phylogenetically adjacent to those found in pet birds in Japan.

    PubMed

    Sassa, Yukiko; Bui, Vuong Nghia; Saitoh, Keisuke; Watanabe, Yukiko; Koyama, Satoshi; Endoh, Daiji; Horie, Masayuki; Tomonaga, Keizo; Furuya, Tetsuya; Nagai, Makoto; Omatsu, Tsutomu; Imai, Kunitoshi; Ogawa, Haruko; Mizutani, Tetsuya

    2015-10-01

    Bornaviruses (family Bornaviridae) are non-segmented negative-strand RNA viruses. Avian bornaviruses (ABVs), which are causative agents of proventricular dilatation disease, are a genetically diverse group with at least 15 genotypes, including parrot bornaviruses (PaBVs) and aquatic bird bornavirus 1(ABBV-1). Borna disease virus 1(BoDV-1), which infects mammals and causes neurological diseases, has also been reported to infect avian species, although the numbers of the cases have been markedly fewer than those of ABVs. In this study, we conducted genetic surveillance to detect ABVs (PaBV-1 to -5 and ABBV-1) and BoDV-1 in wild birds in Japan. A total of 2078 fecal or cloacal swab samples were collected from wild birds in 2006, 2007, 2008, and 2011, in two regions of Japan. The results demonstrated the presence of PaBV-2 and -4 RNA, while no positive results for other PaBVs, ABBV-1, and BoDV-1 were obtained. PaBV-2 and -4 RNA were detected in 18 samples (0.9 %) of the genera Anas, Grus, Larus, Calidris, Haliaeetus, and Emberiza, in which either PaBV-2 RNA or PaBV-4 RNA, or both PaBV-2 and -4 RNA were detected in 15 (0.7 %), 5 (0.2 %), and 2 (0.1 %) samples, respectively. The nucleotide sequences of PaBV-2 and -4 detected in these samples from wild birds are phylogenetically close to those found in samples from pet birds in Japan, with identities ranging from 99.8 to 100 % and from 98.2 to 99.4 %, respectively. To the best of our knowledge, this is the first report on the detection of PaBV-2 and -4 RNA detected in samples from wild birds. PMID:26315330

  20. Sex-specific foraging behavior in response to fishing activities in a threatened seabird

    PubMed Central

    García-Tarrasón, Manuel; Bécares, Juan; Bateman, Santiago; Arcos, José Manuel; Jover, Lluís; Sanpera, Carolina

    2015-01-01

    Some seabird species have learnt to efficiently exploit fishing discards from trawling activities. However, a discard ban has been proposed as necessary in Europe to ensure the sustainability of the seas. It is of crucial importance for the management and conservation purposes to study the potential consequences of a discard ban on the foraging ecology of threatened seabirds. We assessed the influence of fishing activities on the feeding habits of 22 male and 15 female Audouin's gulls (Larus audouinii) from the Ebro Delta (Mediterranean Sea) during the breeding period using GPS loggers together with Stable Isotope Analysis (SIA), which provided new insights into their foraging behavior and trophic ecology, respectively. GPS data revealed different sex-specific foraging patterns between workdays and weekends. Females were highly consistent in that they foraged at sea throughout the week even though discarding stops at weekends. In contrast, males switched from foraging at sea during the week (when discards are produced) to an increased use of rice field habitats at weekends (when fishermen do not work). This sex-specific foraging behavior could be related to specific nutritional requirements associated with previous egg production, an energetically demanding period for females. However, on a broader time scale integrated by the SIA, both sexes showed a high degree of individual specialization in their trophic ecology. The need to obtain detailed information on the dependence and response of seabirds to fishing activities is crucial in conservation sciences. In this regard, sex-specific foraging behavior in relation to fisheries has been overlooked, despite the ecological and conservation implications. For instance, this situation may lead to sex differentiation in bycatch mortality in longlines when trawlers do not operate. Moreover, any new fisheries policy will need to be implemented gradually to facilitate the adaptation of a specialized species to a discard ban

  1. Sex-specific foraging behavior in response to fishing activities in a threatened seabird.

    PubMed

    García-Tarrasón, Manuel; Bécares, Juan; Bateman, Santiago; Arcos, José Manuel; Jover, Lluís; Sanpera, Carolina

    2015-06-01

    Some seabird species have learnt to efficiently exploit fishing discards from trawling activities. However, a discard ban has been proposed as necessary in Europe to ensure the sustainability of the seas. It is of crucial importance for the management and conservation purposes to study the potential consequences of a discard ban on the foraging ecology of threatened seabirds. We assessed the influence of fishing activities on the feeding habits of 22 male and 15 female Audouin's gulls (Larus audouinii) from the Ebro Delta (Mediterranean Sea) during the breeding period using GPS loggers together with Stable Isotope Analysis (SIA), which provided new insights into their foraging behavior and trophic ecology, respectively. GPS data revealed different sex-specific foraging patterns between workdays and weekends. Females were highly consistent in that they foraged at sea throughout the week even though discarding stops at weekends. In contrast, males switched from foraging at sea during the week (when discards are produced) to an increased use of rice field habitats at weekends (when fishermen do not work). This sex-specific foraging behavior could be related to specific nutritional requirements associated with previous egg production, an energetically demanding period for females. However, on a broader time scale integrated by the SIA, both sexes showed a high degree of individual specialization in their trophic ecology. The need to obtain detailed information on the dependence and response of seabirds to fishing activities is crucial in conservation sciences. In this regard, sex-specific foraging behavior in relation to fisheries has been overlooked, despite the ecological and conservation implications. For instance, this situation may lead to sex differentiation in bycatch mortality in longlines when trawlers do not operate. Moreover, any new fisheries policy will need to be implemented gradually to facilitate the adaptation of a specialized species to a discard ban

  2. Assessment of risks of brodifacoum to non-target birds and mammals in New Zealand.

    PubMed

    Eason, Charles T; Murphy, Elaine C; Wright, Geoffrey R G; Spurr, Eric B

    2002-02-01

    The risks to non-target birds and other wildlife from the use of vertebrate pesticides, including anticoagulant rodenticides, are determined to a significant extent by species' intrinsic susceptibility, and the toxicokinetics of the compounds used. Brodifacoum is highly toxic to birds and mammals. The acute toxicity of brodifacoum to birds in New Zealand varies from <1 mg/kg in pukeko (Porphyrio p. melanotus), the native swamp hen, to >20 mg/kg in the paradise shelduck (Tadorna variegata). Like other second-generation anticoagulants brodifacoum is strongly bound to vitamin K epoxide reductase and will persist, apparently for at least 6 months, in organs and tissue containing this enzyme, e.g., liver, kidney, and pancreas. The unique toxicokinetics of this class of compound exacerbates the risk of primary and secondary poisoning of non-target species. Vertebrate pest control programmes in New Zealand using bait containing brodifacoum have resulted in the primary and secondary poisoning and sub-lethal contamination of non-target species. These include native raptors, such as the Australasian harrier (Circus approximans) and morepork (Ninox novaeseelandiae), other native birds such as the pukeko, weka (Gallirallus australis), southern black-backed gull (Larus dominicanus), and kiwi (Apteryx spp.), and introduced mammals, including game animals. There are increasing numbers of reports worldwide of wildlife contamination and toxicosis after the use of second-generation anticoagulants. All pest control activities require careful risk-benefit assessment in view of their potential to cause adverse environmental impact. Monitoring of wildlife for pesticide residues will provide data that can be used to reduce the risk of anticoagulant bioaccumulation and mortality in non-target species. PMID:11898799

  3. Toxoplasma gondii Infection in Seagull Chicks Is Related to the Consumption of Freshwater Food Resources

    PubMed Central

    Cabezón, Oscar; Cerdà-Cuéllar, Marta; Morera, Virginia; García-Bocanegra, Ignacio; González-Solís, Jacob; Napp, Sebastian; Ribas, Maria P.; Blanch-Lázaro, Berta; Fernández-Aguilar, Xavier; Antilles, Noelia; López-Soria, Sergio; Lorca-Oró, Cristina; Dubey, Jitender P.; Almería, Sonia

    2016-01-01

    Understanding the spread of Toxoplasma gondii (T. gondii) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (Larus michahellis) and Audouin’s gull (L. audouinii)) from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT) for the presence of antibodies against T. gondii. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall T. gondii seroprevalence was 21.0% (IC95% 17.5–24.4). A generalized linear mixed-effects model indicated that year (2009) and food source (freshwater) were risk factors associated to the individual risk of infection by T. gondii, while age (days) was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of T. gondii. Year differences could indicate fluctuating rates of exposure of seagull chicks to T. gondii. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07), supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report T. gondii antibodies in Yellow-legged and Audouin’s gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology. PMID:26974667

  4. Monitoring West Nile virus (WNV) infection in wild birds in Serbia during 2012: first isolation and characterisation of WNV strains from Serbia.

    PubMed

    Petrović, T; Blazquez, A B; Lupulović, D; Lazić, G; Escribano-Romero, E; Fabijan, D; Kapetanov, M; Lazić, S; Saiz, Jc

    2013-01-01

    West Nile virus (WNV), a neurovirulent mosquito-transmissible zoonotic virus, has caused recent outbreaks in Europe, including Serbia from August until October 2012. Although humans can be infected, birds are the main natural WNV reservoir. To assess WNV circulation in northern Serbia, 133 wild birds were investigated. These comprised resident and migratory birds, collected between January and September 2012 in the Vojvodina province. The birds belonged to 45 species within 27 families. Blood sera (n=92) and pooled tissues from respective birds (n=81) were tested by enzyme-linked immunosorbent assay (ELISA), plaque reduction neutralisation test (PRNT) and real-time reverse transcription-polymerase chain reaction (RT-qPCR). WNV antibodies were detected in seven (8%) sera: four from Mute Swans (Cygnus olor), two from White-tailed Eagles (Haliaeetus albicillas), and one from a Common Pheasant (Phasianus colchicus). Five sera neutralised WNV but not Usutu virus. For the first time in Serbia, WNV RNA was detected by RT-qPCR in pooled tissue samples of eight respective birds. WNV RNA was also derived from an additional bird, after a serum sample resulted infective in cell culture. The total nine WNV RNA positive birds included three Northern Goshawks (Accipiter gentilis), two White-tailed Eagles, one Legged Gull (Larus michahelis), one Hooded Crow (Corvus cornix), one Bearded Parrot-bill (Panarus biramicus), and one Common Pheasant. Phylogenetic analysis of partial E region sequences showed the presence of, at least, two lineage 2 Serbian clusters closely related to those responsible for recent human and animal outbreaks in Greece, Hungary and Italy. Full genomic sequence from a goshawk isolate corroborated this data. These results confirm WNV circulation in Serbia and highlight the risk of infection for humans and horses, pointing to the need for implementing WNV surveillance programmes. PMID:24176657

  5. Satellite Tracking on the Flyways of Brown-Headed Gulls and Their Potential Role in the Spread of Highly Pathogenic Avian Influenza H5N1 Virus

    PubMed Central

    Ratanakorn, Parntep; Wiratsudakul, Anuwat; Wiriyarat, Witthawat; Eiamampai, Krairat; Farmer, Adrian H.; Webster, Robert G.; Chaichoune, Kridsada; Suwanpakdee, Sarin; Pothieng, Duangrat; Puthavathana, Pilaipan

    2012-01-01

    Brown-headed gulls (Larus brunnicephalus), winter visitors of Thailand, were tracked by satellite telemetry during 2008–2011 for investigating their roles in the highly pathogenic avian influenza (HPAI) H5N1 virus spread. Eight gulls negative for influenza virus infection were marked with solar-powered satellite platform transmitters at Bang Poo study site in Samut Prakarn province, Thailand; their movements were monitored by the Argos satellite tracking system, and locations were mapped. Five gulls completed their migratory cycles, which spanned 7 countries (China, Bangladesh, India, Myanmar, Thailand, Cambodia, and Vietnam) affected by the HPAI H5N1 virus. Gulls migrated from their breeding grounds in China to stay overwinter in Thailand and Cambodia; while Bangladesh, India, Myanmar, and Vietnam were the places of stopovers during migration. Gulls traveled an average distance of about 2400 km between Thailand and China and spent 1–2 weeks on migration. Although AI surveillance among gulls was conducted at the study site, no AI virus was isolated and no H5N1 viral genome or specific antibody was detected in the 75 gulls tested, but 6.6% of blood samples were positive for pan-influenza A antibody. No AI outbreaks were reported in areas along flyways of gulls in Thailand during the study period. Distance and duration of migration, tolerability of the captive gulls to survive the HPAI H5N1 virus challenge and days at viral shedding after the virus challenging suggested that the Brown-headed gull could be a potential species for AI spread, especially among Southeast Asian countries, the epicenter of H5N1 AI outbreak. PMID:23209623

  6. Comparative body compartment composition and in ovo transfer of organophosphate flame retardants in North American Great Lakes herring gulls.

    PubMed

    Greaves, Alana K; Letcher, Robert J

    2014-07-15

    Although recent usage of organophosphate (OP) flame retardants has increased substantially, very few studies have reported on OPs in biota including wildlife, and essentially there is no information on OP body compartment composition and in ovo or in utero transfer for any given wildlife species. Concentrations and patterns of 16 OP triesters were presently screened for and/or determined in six body compartments from female herring gulls (Larus argentatus; n=8) and the separate egg yolk and albumen of their entire clutches of eggs (n=16) (collected in 2010 from a Lake Huron colony site, Laurentian Great Lakes of North America). Fat (32.3±9.8 ng/g wet weight; ww) contained the highest ΣOP concentration, followed by egg yolk (14.8±2.4 ng/g ww)≈egg albumen (14.8±5.9 ng/g ww)>muscle (10.9±5.1 ng/g ww)≫red blood cells (1.00±0.62 ng/g ww), whereas in liver, blood plasma, and brain all OPs were not detectable. Nine OPs accumulated in herring gulls, but the concentrations and proportions of OPs were dependent on the body and egg compartment. For example, tris(2-butoxyethyl) phosphate (TBOEP) accounted for 66% of the ΣOP concentration in albumen, but only for 13% in yolk. Tri-n-butyl phosphate (TNBP) accounted for 25% of the ΣOP concentration in yolk, but was not detected in albumen. Estimates showed that overall OP burdens in the body (3.5 μg) were greater than in the whole egg (1.2 μg), although depuration via in ovo transfer was substantial. PMID:24905208

  7. Changes in lagoonal marsh morphology at selected northeastern Atlantic coast sites of significance to migratory waterbirds

    USGS Publications Warehouse

    Erwin, R.M.; Sanders, G.M.; Prosser, D.J.

    2004-01-01

    Five lagoonal salt marsh areas, ranging from 220 ha to 3,670 ha, were selected from Cape Cod, Massachusetts to the southern DelMarVa peninsula, Virginia, USA to examine the degree to which Spartina marsh area and microhabitats had changed from the early or mid- 1900s to recent periods. We chose areas based on their importance to migratory bird populations, agency concerns about marsh loss and sea-level rise, and availability of historic imagery. We georeferenced and processed aerial photographs from a variety of sources ranging from 1932 to 1994. Of particular interest were changes in total salt marsh area, tidal creeks, tidal flats, tidal and non-tidal ponds, and open water habitats. Nauset Marsh, within Cape Cod National Seashore, experienced an annual marsh loss of 0.40% (19% from 1947 to 1994) with most loss attributed to sand overwash and conversion to open water. At Forsythe National Wildlife Refuge in southern New Jersey, annual loss was 0.27% (17% from 1932 to 1995), with nearly equal attribution of loss to open water and tidal pond expansion. At Curlew Bay, Virginia, annual loss was 0.20% (9% from 1949 to 1994) and almost entirely due to perimeter erosion to open water. At Gull Marsh, Virginia, a site chosen because of known erosional losses, we recorded the highest annual loss rate, 0.67% per annum, again almost entirely due to erosional, perimeter loss. In contrast, at the southernmost site, Mockhorn Island Wildlife Management Area, Virginia, there was a net gain of 0.09% per annum (4% from 1949 to 1994), with tidal flats becoming increasingly vegetated. Habitat. implications for waterbirds are considerable; salt marsh specialists such as laughing gulls (Larus atricilla), Forster's terns (Sterna forsteri), black rail, (Laterallus jamaicensis), seaside sparrow (Ammodramus maritimus), and saltmarsh sharp-tailed sparrow (Ammodramus caudacutus) are particularly at risk if these trends continue, and all but the laughing gull are species of concern to state

  8. Antibiotic-Resistant Escherichia coli Bacteria, Including Strains with Genes Encoding the Extended-Spectrum Beta-Lactamase and QnrS, in Waterbirds on the Baltic Sea Coast of Poland▿

    PubMed Central

    Literak, Ivan; Dolejska, Monika; Janoszowska, Dagmar; Hrusakova, Jolana; Meissner, Wlodzimierz; Rzyska, Hanna; Bzoma, Szymon; Cizek, Alois

    2010-01-01

    Individual cloacal swabs of mallards (Anas platyrhynchos) and of herring gulls (Larus argentatus), as well as samples of waterbird feces obtained in 2008 and 2009, were cultivated for Escherichia coli. Isolates of E. coli were tested for susceptibilities to 12 antimicrobial agents by the disk diffusion method. Moreover, the samples were subcultivated on MacConkey agar (MCA) containing cefotaxime (2 mg liter−1) to detect E. coli with extended-spectrum beta-lactamase (ESBL) and subsequently on MCA supplemented with ciprofloxacin (0.05 mg liter−1) and MCA with nalidixic acid (20 mg liter−1) to isolate fluoroquinolone-resistant E. coli. PCR was used to detect specific antibiotic resistance genes. We found 9 E. coli isolates producing ESBL with bla genes: blaCTX-M-1 (6 isolates), blaCTX-M-9 plus blaTEM-1b (1 isolate), blaCTX-M-15 plus blaOXA-1 (1 isolate), and blaSHV-12 (1 isolate). In the isolate with blaCTX-M-15, the gene aac(6)-Ib-cr was also detected. The bla genes were harbored by transferable plasmids of the IncN and IncI1 groups. Nine quinolone-resistant E. coli isolates with qnrS genes were found and characterized. The gene qnrS was associated with a Tn3-like transposon on the IncX1 plasmid together with blaTEM-1 in two isolates. The gene qnrS was also harbored by conjugative plasmids of the IncN and IncX2 groups. Even if populations of wild birds are not directly influenced by antibiotic practice, we have demonstrated that antibiotic-resistant E. coli strains, including strains with various ESBL and qnrS genes, are found in the feces of wild birds on the coast of the Baltic Sea in Poland. PMID:20952638

  9. Antibiotic-resistant Escherichia coli bacteria, including strains with genes encoding the extended-spectrum beta-lactamase and QnrS, in waterbirds on the Baltic Sea Coast of Poland.

    PubMed

    Literak, Ivan; Dolejska, Monika; Janoszowska, Dagmar; Hrusakova, Jolana; Meissner, Wlodzimierz; Rzyska, Hanna; Bzoma, Szymon; Cizek, Alois

    2010-12-01

    Individual cloacal swabs of mallards (Anas platyrhynchos) and of herring gulls (Larus argentatus), as well as samples of waterbird feces obtained in 2008 and 2009, were cultivated for Escherichia coli. Isolates of E. coli were tested for susceptibilities to 12 antimicrobial agents by the disk diffusion method. Moreover, the samples were subcultivated on MacConkey agar (MCA) containing cefotaxime (2 mg liter(-1)) to detect E. coli with extended-spectrum beta-lactamase (ESBL) and subsequently on MCA supplemented with ciprofloxacin (0.05 mg liter(-1)) and MCA with nalidixic acid (20 mg liter(-1)) to isolate fluoroquinolone-resistant E. coli. PCR was used to detect specific antibiotic resistance genes. We found 9 E. coli isolates producing ESBL with bla genes: bla(CTX-M-1) (6 isolates), bla(CTX-M-9) plus bla(TEM-1b) (1 isolate), bla(CTX-M-15) plus bla(OXA-1) (1 isolate), and bla(SHV-12) (1 isolate). In the isolate with bla(CTX-M-15), the gene aac(6)-Ib-cr was also detected. The bla genes were harbored by transferable plasmids of the IncN and IncI1 groups. Nine quinolone-resistant E. coli isolates with qnrS genes were found and characterized. The gene qnrS was associated with a Tn3-like transposon on the IncX1 plasmid together with bla(TEM-1) in two isolates. The gene qnrS was also harbored by conjugative plasmids of the IncN and IncX2 groups. Even if populations of wild birds are not directly influenced by antibiotic practice, we have demonstrated that antibiotic-resistant E. coli strains, including strains with various ESBL and qnrS genes, are found in the feces of wild birds on the coast of the Baltic Sea in Poland. PMID:20952638

  10. Reproductive success of the Black-crowned Night Heron at Alcatraz Island, San Francisco Bay, California, 1990-2002

    USGS Publications Warehouse

    Hothem, R.L.; Hatch, D.

    2004-01-01

    Nesting chronology, habitat use, subcolony use, and hatchability were documented for the Black-crowned Night Heron (Nycticorax nycticorax) nesting at Alcatraz Island, San Francisco Bav, California during 1990-2002. Reproductive success was estimated using the Mayfield method and compared among years. Totals of monitored nests per year ranged from 68 in 2001 to 341 in 1996, with a trend of declining numbers since 1996. An increase in numbers of the Western Gull (Larus occidentalis), the Black-crowned Night Heron's primary competitor, occurred during the same period. Overall reproductive success of the Black-crowned Night Heron at Alcatraz Island was below the 13-year average of 56.4% since 1996. During the study, the average number of chicks fledged per nest each year ranged from 0.46 to 1.27, which is less than the two chicks per nest suggested as a requirement for a sustained population. Embryos in five of 187 failed Black-crowned Night Heron eggs were deformed. In 1990 and 1991, eggs were analyzed for a wide range of contaminants, but none appeared to be sufficiently elevated to have caused the observed deformities. Based on these relatively low levels of contaminants, a high hatchability rate (94.5%), and relatively low levels of embryotoxicity, contaminants did not appear to significantly affect Black-crowned Night Heron reproduction at Alcatraz Island. However, predation by the Common Raven (Corvus corax) and Western Gull, interspecific competition with the Western Gull, habitat deterioration, and possible human disturbance are likely factors contributing to the decline in Black-crowned Night Heron reproductive success on Alcatraz Island in recent years.

  11. Breeding productivity of Smith Island black ducks

    USGS Publications Warehouse

    Haramis, G.M.; Jorde, D.G.; Olsen, G.H.; Stotts, D.B.; Harrison, M.K.

    2002-01-01

    We investigated the breeding performance of American black ducks (Anas rubripes) on Smith Island, Chesapeake Bay, to improve our understanding of island black duck breeding ecology and to make management recommendations to enhance productivity. During 1995-96, we implanted 56 female black ducks with 20-g radio transmitters and tracked 35 of the individuals through the breeding season to locate nests, determine nest fate, and identify brood habitat. We also increased preseason banding efforts and compared capture characteristics over 12 years with those from the Deal Island Wildlife Management Area, a banding site on the mainland of Tangier Sound. A low rate of nesting (37%), lack of renesting, and poor hatching success (31%) indicated that island salt marsh habitats present a harsh environment for breeding black ducks. Black ducks located 11 of 13 nests (85%) in black needlerush (Juncus roemerianus) marsh where they were vulnerable to flooding from extreme tides and to egg predators. No nests were found on forested tree hammocks, a feature that distinguishes Smith Island from nearby South Marsh and Bloodsworth Islands. Nest predators included red foxes (Vulpes vulpes), herring gulls (Larus argentams), fish crows (Corvus ossifragus), and, potentially, Norway rats (Rattus norvegicus). Unlike mainland red foxes, foxes radio tracked on Smith Island were found to be capable swimmers and effective low marsh predators. We found shoreline meadows of widgeon grass (Ruppia maritima) to be important foraging sites for black ducks and suspected that the virtual absence of fresh water in this high salinity environment (1217+ ppt) to incur some cost in terms of growth and survival of ducklings. Preseason bandings revealed a high proportion of banded adults and a strong positive correlation in age ratios with the Deal Island banding site. This latter finding strongly suggests a negative universal effect of storm tides on nest success for Tangier Sound black ducks. Management to

  12. Species density of waterbirds in offshore habitats in western Lake Erie

    USGS Publications Warehouse

    Stapanian, M.A.; Waite, Thomas A.

    2003-01-01

    Offshore censuses of birds are lacking for inland seas, such as the Laurentian Great Lakes, but may provide valuable information for managing species that are in conflict with human interests. Birds were counted along 31 established transects in four habitats in western Lake Erie: offshore of waterbird refuges, offshore of beaches with human development, on reefs and shoals, and in open water. A total of 161 10-min counts were conducted between 24 April and 1 September 2000. The mean number of aquatic bird species/kmA? (species density) was greater offshore of refuges than on open water. For all habitats combined, species density increased over time. This was mainly due to the arrival of Bonaparte's Gulls (Larus philadelphia) and Great Black-backed Gulls (L. marinus), two fall and winter residents that do not breed in the study area, and increased use of open water and reefs and shoals by Herring Gulls (L argentatus) and Ring-billed Gulls (L delawarensis) after the nesting season. Species density was not strongly spatially autocorrelated, either for all species or for only those species that were floating on the water when recorded. Neither Double-crested Cormorants (Phalacrocorax auritus) nor Herring Gulls exhibited spatial autocorrelation. In contrast, Bonaparte's and Ring-billed gulls exhibited positive spatial autocorrelations. Unlike marine studies, species density was only weakly associated with water depth. This result was due mainly to Double-crested Cormorants, the only diving bird species that lived year-round in the area, which preferred reefs and shoals (depth 3-6 m) over open water (10 m). The results suggest that offshore habitat influences species density in this area during the breeding and immediate post-breeding seasons.

  13. A nonlethal microsampling technique to monitor the effects of mercury on wild bird eggs.

    PubMed

    Stebbins, Katherine R; Klimstra, Jon D; Eagles-Smith, Collin A; Ackerman, Joshua T; Heinz, Gary H

    2009-03-01

    Methylmercury is the predominant chemical form of mercury reported in the eggs of wild birds, and the embryo is the most sensitive life stage to methylmercury toxicity. Protective guidelines have been based mainly on captive-breeding studies with chickens (Gallus gallus), mallards (Anas platyrhynchos), and ring-necked pheasants (Phasianus colchicus) or on field studies where whole eggs were collected and analyzed and the effects of the mercury were measured based on the reproductive success of the remaining eggs. However, both of these methods have limitations. As an alternative, we developed a technique that involves extracting a small sample of albumen from a live egg, sealing the egg, returning the egg to its nest to be naturally incubated by the parents, and then relating the hatching success of this microsampled egg to its mercury concentration. After first developing this technique in the laboratory using chicken and mallard eggs, we selected the laughing gull (Larus atricilla) and black-necked stilt (Himantopus mexicanus) as test subjects in the field. We found that 92% of the microsampled laughing gull eggs met our reproductive endpoint of survival to the beginning of hatching compared to 100% for the paired control eggs within the same nests. Microsampled black-necked stilt eggs exhibited 100% hatching success compared to 93% for the paired control eggs. Our results indicate that microsampling is an effective tool for nonlethally sampling mercury concentrations in eggs and, as such, can be used for monitoring sensitive species, as well as for improving studies that examine the effects of mercury on avian reproduction. PMID:18937540

  14. Comparative reproductive biology of sympatric species: nest and chick survival of American avocets and black-necked stilts

    USGS Publications Warehouse

    Ackerman, Joshua T.; Herzog, Mark P.; Takekawa, John Y.; Hartman, Christopher A.

    2014-01-01

    Identifying differences in reproductive success rates of closely related and sympatrically breeding species can be useful for understanding limitations to population growth. We simultaneously examined the reproductive ecology of American avocets Recurvirostra americana and black-necked stilts Himantopus mexicanus using 1274 monitored nests and 240 radio-marked chicks in San Francisco Bay, California. Although there were 1.8 times more avocet nests than stilt nests, stilts nonetheless fledged 3.3 times more chicks. Greater production by stilts than avocets was the result of greater chick survival from hatching to fledging (avocet: 6%; stilt: 40%), and not because of differences in clutch size (avocet: 3.84; stilt: 3.77), nest survival (avocet: 44%; stilt: 35%), or egg hatching success (avocet: 90%; stilt: 92%). We reviewed the literature and confirmed that nest survival and hatching success are generally similar when avocets and stilts breed sympatrically. In addition to species, chick survival was strongly influenced by age, site, and year. In particular, daily survival rates increased rapidly with chick age, with 70% of mortalities occurring ≤ 1 week after hatch. California gulls Larus californicus caused 55% of avocet, but only 15% of stilt, chick deaths. Differential use of micro-habitats likely reduced stilt chick’s vulnerability to gull predation, particularly during the first week after hatch, because stilts nested in vegetation 2.7 times more often than avocets and vegetation height was 65% taller at stilt nests compared with avocet nests. Our results demonstrate that two co-occurring and closely related species with similar life history strategies can differ markedly in reproductive success, and simultaneous studies of such species can identify differences that limit productivity.

  15. Evaluation of beach grooming techniques on Escherichia coli density in foreshore sand at North Beach, Racine, WI

    USGS Publications Warehouse

    Kinzelman, Julie L.; Whitman, Richard L.; Byappanahalli, Muruleedhara N.; Jackson, Emma; Bagley, Robert C.

    2003-01-01

    Elevated levels of Escherichia coli(E. coli) in bathing waters at North Beach, a popular recreational site in Racine, Wisconsin, have been a persistent problem often resulting in the issuance of poor water quality advisories. Moreover, waterfowl (mostly Larus delawarensis and L. argentatus) in nearshore and offshore areas are common and may serve as non-point sources for bacterial contamination of recreational waters. Current beach management practice involves daily mechanical grooming of the nearshore sand for aesthetics and removal of hazardous debris. However, this practice has not been evaluated in terms of its effects on E. coli loading to beach sand and potential introduction to contiguous swimming water. In this study, we tested E. coli responses to three treatments: mechanical groomer, daily and twice weekly hand raking, and a control (no raking/grooming). A randomized block design consisted of replicated treatments and one control (10 each), for a total of 40 blocks sampled daily for 10 days. Foreshore sand samples were collected by hand coring to an average depth of 10 cm. Median E. colirecovered were 73 (mechanically groomed), 27 (hand-raked daily), 32 (hand-raked twice weekly), and 22 (control) colony-forming units (CFU) per gram dry weight sand. E. colicounts in sand that was groomed were significantly higher than hand rakings and control (p <0.0001), and there was no significant difference between control and raking treatments (p<0.01). This study demonstrates the beach management implications related to grooming efficacy and the importance of understanding non-point sources of bacterial contamination.

  16. Using Seabird Habitat Modeling to Inform Marine Spatial Planning in Central California’s National Marine Sanctuaries

    PubMed Central

    McGowan, Jennifer; Hines, Ellen; Elliott, Meredith; Howar, Julie; Dransfield, Andrea; Nur, Nadav; Jahncke, Jaime

    2013-01-01

    Understanding seabird habitat preferences is critical to future wildlife conservation and threat mitigation in California. The objective of this study was to investigate drivers of seabird habitat selection within the Gulf of the Farallones and Cordell Bank National Marine Sanctuaries to identify areas for targeted conservation planning. We used seabird abundance data collected by the Applied California Current Ecosystem Studies Program (ACCESS) from 2004–2011. We used zero-inflated negative binomial regression to model species abundance and distribution as a function of near surface ocean water properties, distances to geographic features and oceanographic climate indices to identify patterns in foraging habitat selection. We evaluated seasonal, inter-annual and species-specific variability of at-sea distributions for the five most abundant seabirds nesting on the Farallon Islands: western gull (Larus occidentalis), common murre (Uria aalge), Cassin’s auklet (Ptychorampus aleuticus), rhinoceros auklet (Cerorhinca monocerata) and Brandt’s cormorant (Phalacrocorax penicillatus). The waters in the vicinity of Cordell Bank and the continental shelf east of the Farallon Islands emerged as persistent and highly selected foraging areas across all species. Further, we conducted a spatial prioritization exercise to optimize seabird conservation areas with and without considering impacts of current human activities. We explored three conservation scenarios where 10, 30 and 50 percent of highly selected, species-specific foraging areas would be conserved. We compared and contrasted results in relation to existing marine protected areas (MPAs) and the future alternative energy footprint identified by the California Ocean Uses Atlas. Our results show that the majority of highly selected seabird habitat lies outside of state MPAs where threats from shipping, oil spills, and offshore energy development remain. This analysis accentuates the need for innovative marine

  17. Changing gull diet in a changing world: a 150-year stable isotope (δ13C, δ15N) record from feathers collected in the Pacific Northwest of North America.

    PubMed

    Blight, Louise K; Hobson, Keith A; Kyser, T Kurt; Arcese, Peter

    2015-04-01

    The world's oceans have undergone significant ecological changes following European colonial expansion and associated industrialization. Seabirds are useful indicators of marine food web structure and can be used to track multidecadal environmental change, potentially reflecting long-term human impacts. We used stable isotope (δ(13)C, δ(15)N) analysis of feathers from glaucous-winged gulls (Larus glaucescens) in a heavily disturbed region of the northeast Pacific to ask whether diets of this generalist forager changed in response to shifts in food availability over 150 years, and whether any detected change might explain long-term trends in gull abundance. Sampled feathers came from birds collected between 1860 and 2009 at nesting colonies in the Salish Sea, a transboundary marine system adjacent to Washington, USA and British Columbia, Canada. To determine whether temporal trends in stable isotope ratios might simply reflect changes to baseline environmental values, we also analysed muscle tissue from forage fishes collected in the same region over a multidecadal timeframe. Values of δ(13)C and δ(15)N declined since 1860 in both subadult and adult gulls (δ(13)C, ~ 2-6‰; δ(15)N, ~4-5‰), indicating that their diet has become less marine over time, and that birds now feed at a lower trophic level than previously. Conversely, forage fish δ(13)C and δ(15)N values showed no trends, supporting our conclusion that gull feather values were indicative of declines in marine food availability rather than of baseline environmental change. Gradual declines in feather isotope values are consistent with trends predicted had gulls consumed less fish over time, but were equivocal with respect to whether gulls had switched to a more garbage-based diet, or one comprising marine invertebrates. Nevertheless, our results suggest a long-term decrease in diet quality linked to declining fish abundance or other anthropogenic influences, and may help to explain regional

  18. Influence of trophic position on organochlorine concentrations and compositional patterns in a marine food web.

    PubMed

    Ruus, Anders; Ugland, Karl Inne; Skaare, Janneche Utne

    2002-11-01

    The accumulation of polychlorinated biphenyls (PCBs), DDTs (p,p'-DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane], o,p'-DDT [1,1,1-trichloro-2-(2-chlorophenyl)-2-(4-chlorophenyl)ethane], p,p'-DDD [1,1,-dichloro-2,2-bis(4-chlorophenyl)ethane], o.p'-DDD [1,1-dichloro-2-(2-chlorophenyl)-2-(4-chlorophenyl)ethane], and p,p'-DDE [1,1-dichloro-2,2-bis(4-chlorophenyl)ethene]), chlordanes (trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor and oxychlordane), hexachlorocyclohexanes (alpha-, beta-, and gamma-isomers), hexachlorobenzene, and mirex was investigated in a marine food web from southeastern Norway. The food web consisted of the polychaete Nereis diversicolor, lesser sandeel (Ammodytes tobianus), three species of gobys (Gobiusculus flavescens, Pomatoschistus sp., and Gobius niger), bullrout (Myoxocephalus scorpius), cod (Gadus morhua), herring gull (Larus argentatus), and harbor seal (Phoca vitulina). The results show that interspecies differences in organochlorine (OC) compositional patterns in the food web depend on several factors (allometric, biochemical, physical, and physicochemical) specific to both the chemicals and the organisms. The importance of dietary accumulation and metabolic capacity increases toward higher trophic levels, while the OC patterns are to a larger extent determined by the lipophilicity and water solubility of the compounds at lower trophic levels. Furthermore, stable nitrogen isotopes provided a continuous measure of trophic position, rendering us capable of quantifying the increases in the concentrations of sigma PCB, sigma dichorodiphenyltrichloroethane (DDT), and sigma chlordane (CHL) and the percentages of highly chlorinated PCBs through the food web. The information provided may be important for future modeling of the fate of organochlorine contaminants in marine food webs. PMID:12389914

  19. Examination of the bioaccumulation of halogenated dimethyl bipyrroles in an Arctic marine food web using stable nitrogen isotope analysis.

    PubMed

    Tittlemier, Sheryl A; Fisk, Aaron T; Hobson, Keith A; Norstrom, Ross J

    2002-01-01

    Concentrations of four possibly naturally produced organohalogens--1,1'-dimethyl-3,3',4-tribromo-4,5,5'-trichloro-2,2'-bipyrrole (DBP-Br3Cl3), 1,1'-dimethyl-3,3',4,4'-tetrabromo-5,5'-dichloro-2,2'-bipyrrole (DBP-Br4Cl2), 1,1'-dimethyl-3,3',4,4',5-pentabromo-5'-chloro-2,2'-bipyrrole (DBP-Br5Cl) and 1,1'-dimethyl-3,3',4,4',5,5'-hexabromo-2,2'-bipyrrole (DBP-Br6)--were quantitated and the extent of their magnification through an entire Arctic marine food web [measured as integrated trophic magnification factors (TMFs)] were calculated. The food web consisted of three zooplankton species (Calanus hyperboreus, Mysis oculata, and Sagitta sp.), one fish species [Arctic cod (Boreogadus saida)], four seabird species [dovekie (Alle alle), black guillemot (Cepphus grylle), black-legged kittiwake (Rissa tridactyla), and glaucous gull (Larus hyperboreus)], and one marine mammal species [ringed seal (Phoca hispida)]. Trophic levels in the food web were calculated from ratios of stable isotopes of nitrogen (15N/14N). All halogenated dimethyl bipyrrole (HDBP) congeners were found to significantly (P<0.02) biomagnify, or increase in concentration with trophic level in the invertebrate--fish--seabird food web. DBP-Br4Cl2 (TMF= 14.6) was found to biomagnify to a greater extent than DBP-Br3Cl3 (TMF = 5.2), DBP-Br5Cl (TMF = 6.9), or DBP-Br6 (TMF = 7.0), even though the Kow of DBP-Br4CI2 was predicted to be lower than those of DBP-Br5Cl and DBP-Br6. None of the four HDBP congeners in ringed seals followed the general trend of increasing concentration with trophic level, which was possibly due to an ability of the seals to metabolize HDBPs. PMID:11808557

  20. PCBs in sediments and the coastal food web near a local contaminant source in Saglek Bay, Labrador.

    PubMed

    Kuzyk, Z A; Stow, J P; Burgess, N M; Solomon, S M; Reimer, K J

    2005-12-01

    Polychlorinated biphenyls (PCBs) were measured in marine sediments and the coastal food web in Saglek Bay, Labrador, to investigate the influence of a local PCB source. Saglek Bay has been the site of a military radar station since the late 1950s and there was PCB-contaminated soil at a beach prior to cleanup in 1997-1999. PCB concentrations in marine sediments during 1997-1999 ranged from 0.24 to 62000 ng/g (dry weight) and decreased exponentially with distance from the contaminated beach. Given this gradient, spatial trends of PCBs in the food web were examined over four zones, according to distance from the contaminated beach: within 1.5 km--zone one, 1.5-4.5 km--zone two, 4.5-7.5 km--zone three, and greater than 7.5 km--zone four. PCB concentrations in a bottom-feeding fish (shorthorn sculpin, Myoxocephalus scorpius), decreased significantly from zone one to zone two, three, four, and distant Labrador reference sites. PCB concentrations in the eggs of a diving seabird (black guillemot, Cepphus grylle) were as high as 48000 ng/g during 1997-1999 and average concentrations in zones one and two were 84 and 13 times higher than in zone four. Marine invertebrates closely reflected the concentrations of PCBs in the associated sediment. In contrast to the benthic-based food web, anadromous arctic char (Salvelinus alpinus) showed no evidence of PCB accumulation from the contaminated sediments. Relatively high PCB concentrations were discovered in some great black-backed gulls (Larus marinus) and ringed seals (Phoca hispida) but appear to relate more to their high trophic level than sampling location. Those species that fed on or near the seabed and had limited foraging ranges were strongly influenced by the local contamination. Total PCB concentrations in the benthic-based food web were significantly higher than background levels for a distance of at least 7.5 km from the contaminated beach. This area is small in the context of widely distributed contamination from

  1. Eggshell permeability: a standard technique for determining interspecific rates of water vapor conductance.

    PubMed

    Portugal, Steven J; Maurer, Golo; Cassey, Phillip

    2010-01-01

    Typically, eggshell water vapor conductance is measured on whole eggs, freshly collected at the commencement of a study. At times, however, it may not be possible to obtain whole fresh eggs but rather egg fragments or previously blown eggs. Here we evaluate and describe in detail a technique for modern laboratory analysis of eggshell conductance that uses fragments from fresh and museum eggs to determine eggshell water vapor conductance. We used fresh unincubated eggs of domesticated chickens (Gallus gallus domesticus), ducks (Anas platyrhynchos domesticus), and guinea fowl (Numida meleagris) to investigate the reliability, validity, and repeatability of the technique. To assess the suitability of museum samples, museum and freshly collected black-headed gull eggs (Larus ridibundus) were used. Fragments were cut out of the eggshell from the blunt end (B), equator (E), and pointy end (P). Eggshell fragments were glued to the top of a 0.25-mL micro test tube (Eppendorf) filled with 200 μL of distilled water and placed in a desiccator at 25°C. Eppendorfs were weighed three times at 24-h intervals, and mass loss was assumed to be a result of water evaporation. We report the following results: (1) mass loss between weighing sessions was highly repeatable and consistent in all species; (2) the majority of intraspecific variability in eggshell water vapor conductance between different eggs of the same species was explained through the differences in water vapor conductance between the three eggshell parts of the same egg (B, E, and P); (3) the technique was sensitive enough to detect significant differences between the three domestic species; (4) there was no overall significant difference between water vapor conductance of museum and fresh black-headed gull eggs; (5) there was no significant difference in water vapor conductance for egg fragments taken from the same egg both between different trials and within the same trial. We conclude, therefore, that this technique

  2. Use of Wetland Habitats by Selected Nongame Water Birds in Maine

    USGS Publications Warehouse

    Gibbs, J.P.; Longcore, J.R.; McAuley, D.G.; Ringelman, J.K.

    1991-01-01

    We examined the use of 87 palustrine and lacustrine wetlands by nongame water birds in central and eastern Maine using 3,527 h of observation (1,501 visits) made during April-August, 1977-85. Wetlands used by 15 species of water birds were distinguished from those not used, according to 20 habitat features. The species were the common loon (Gavia immer) , pied-billed grebe (Podilymbus podiceps), double-crested cormorant (Phalacrocorax auritus), American bittern (Botaurus lentiginosus), great blue heron (Ardea herodias), green-backed heron (Butorides striatus), osprey (Pandion haliaetus), bald eagle (Haliaeetus leucocephalus), northern harrier (Circus cyaneus), Virgima rail (Rallus limicola), sora (Porzana carolina), spotted sandpiper (Actitis macularia), common snipe (Gallinago gallinago), herring gull (Larus argentatus), and belted kingfisher (Ceryle alcyon). Predictive models of habitat use were developed for each species. Water birds were classified by similarity of habitats used, and species use was contrasted by wetland type. Smaller, isolated wetlands were used by fewer (P 66%) or open (<33%) wetlands. Low pH typified wetlands used by large-bodied piscivores (common loon, cormorant, osprey). Other water birds were associated with more densely vegetated, chemically buffered wetlands. Habitat features associated with wetland use by each waterbird species are reported, as are numerical responses of waterbird populations to wetland features and estimates of annual variation in habitat occupancy. Lacustrine wetlands supported a distinct, low diversity community of water birds, including most fish-eating species. Waterbird diversity at forested palustrine wetlands was intermediate between lacustrine communities and more species-rich assemblages at palustrine emergent and scrub-shrub wetlands. Regional variation in wetland characteristics and water bird use was associated with surficial geology, soils, and management practices. Management for nongame water birds in

  3. Metals and radionuclides in birds and eggs from Amchitka and Kiska Islands in the Bering Sea/Pacific Ocean ecosystem.

    PubMed

    Burger, Joanna; Gochfeld, Michael

    2007-04-01

    Metals and radionuclide levels in marine birds of the Aleutians are of interest because they are part of subsistence diets of the Aleut people, and can also serve as indicators of marine pollution. We examined geographic and species-specific variations in concentrations of radionuclides in birds and their eggs from Amchitka, the site of underground nuclear tests from 1965 to 1971, and Kiska Islands (a reference site) in the Aleutians, and the levels of lead, mercury and cadmium in eggs. In 2004 we collected common eiders (Somateria mollissima), tufted puffins (Fratercula cirrhata), pigeon guillemot (Cepphus columba) and glaucous-winged gulls (Larus glaucescens) from Amchitka and Kiska, and eggs from eiders and gulls from the two island. We also collected one runt bald eagle (Haliaeetus leucocephalus) chick from both Amchitka and Kiska Islands. For most species, the levels of radionuclide isotopes were below the minimum detectable activity levels (MDA). Out of 74 cesium-137 analyses, only one composite (gulls) was above the MDA, and out of 14 composites tested for plutonium (Pu-239, 240), only one exceeded the MDA (a guillemots). Three composites out of 14 tested had detectable uranium-238. In all cases, the levels were low and close to the MDAs, and were below those reported for other seabirds. There were significant interspecific differences in metal levels in eggs: gulls had significantly higher levels of cadmium and mercury than the eiders, and eiders had higher levels of lead than gulls. There were few significant differences as a function of island, but eiders had significantly higher levels of cadmium in eggs from Kiska, and gulls had significantly higher levels of mercury on Kiska. The levels of cadmium and mercury in eggs of eiders and gulls from this study were above the median for cadmium and mercury from studies in the literature. The levels of mercury in eggs are within the range known to affect avian predators, but seabirds seem less vulnerable to

  4. The potential impact of environmental variation on the concentrations and ecological effects of pollutants in a marine avian top predator.

    PubMed

    Bustnes, J O; Fauchald, P; Tveraa, T; Helberg, M; Skaare, J U

    2008-02-01

    Concentrations of organochlorine contaminants (OCs) and associations between OCs and fitness components were examined in great black-backed gulls (Larus marinus) in three colonies along the coast of northern Norway. In one of the colonies, data were collected in two subsequent seasons. Concentrations of four OCs (HCB, oxychlordane, DDE and PCB) were measured in blood (n=260) and fitness components (reproductive variables and adult return rate between breeding seasons) were recorded. In the first year, in two of the colonies, body condition and reproductive performance among the gulls were poor compared to the third colony, suggesting spatial variation in environmental conditions, especially food availability. However, in the third colony, body condition and reproductive performance were even better in the second season; i.e. environmental conditions varied temporally. OC residues were higher in the colonies where environmental conditions were poor, but much of this variation was explained by differences in body condition among colonies. Moreover, concurrent with improved body condition from one season to the next, the concentrations of OCs were halved. In the two colonies where environmental conditions were poor, female OC residues were negatively related to egg-laying date, egg size and nesting success, and in the colony where the concentrations of OC were highest, gulls with elevated DDE residues had low probability of returning between breeding seasons. In comparison, in the colony where environmental conditions were better in the first year, other types of adverse relationships between OCs and fitness components were found; i.e. chicks from females with high OC concentrations were in poor condition at hatching, suggesting maternal transfer of OCs to the eggs, and males with high OC residues had poor nesting success and chick survival, suggesting OC-mediated behavioural changes. With improved environmental conditions and lower OC concentrations in the second

  5. An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife.

    PubMed

    Fisk, Aaron T; de Wit, Cynthia A; Wayland, Mark; Kuzyk, Zou Zou; Burgess, Neil; Letcher, Robert; Braune, Birgit; Norstrom, Ross; Blum, Susan Polischuk; Sandau, Courtney; Lie, Elisabeth; Larsen, Hans Jørgen S; Skaare, Janneche Utne; Muir, Derek C G

    2005-12-01

    , with the possible exception of PCBs in burbot (Lota lota) in some Yukon lakes, Greenland shark (Somniosus microcephalus), glaucous and great black-backed gulls (Larus hyperboreus and L. marinus), and TEQs of dioxin-like chemicals in seabird eggs. PCB and DDT concentrations in several arctic marine mammal species exceed effects thresholds, although evidence of stress in these populations is lacking. There is little evidence that contaminants are having widespread effects on the health of Canadian arctic organisms, with the possible exception of polar bears. However, further research and better understanding of organohalogen exposure in arctic biota is needed considering factors such as tissue levels that exceed effects thresholds, exposure to "new" organohalogen contaminants of concern, contaminated regions, and climate change. PMID:16154621

  6. Chlordane components and metabolites in seven species of Arctic seabirds from the Northwater Polynya: relationships with stable isotopes of nitrogen and enantiomeric fractions of chiral components.

    PubMed

    Fisk, A T; Moisey, J; Hobson, K A; Karnovsky, N J; Norstrom, R J

    2001-01-01

    The Northwater Polynya (NOW) is a large area of year-round open water found in the high Arctic between Ellesmere Island and Greenland. NOW has high biological productivity compared with other arctic marine areas, and supports large populations of several seabird species. Seven species of seabirds, dovekie (Alle alle, DOVE), thick-billed murre (Uria lomvia, TBMU), black guillemot (Cepphus grylle, BLGU), black-legged kittiwake (Rissa tridactyla, BLKI), ivory gull (Pagophila eburnea, IVGU), glaucous gull (Larus hyperboreus, GLGU) and northern fulmar (Fulmaris glacialis, NOFU) were collected in May and June 1998 to determine chlordane concentrations in liver and fat and to examine species differences, relationships with stable isotopes of nitrogen, and enantiomeric fractions (EFs) of chiral components. sigma CHLOR concentrations varied over an order of magnitude among species, from a low of 176 +/- 19 ng/g (lipid corrected) in TMBU liver to a high of 3190 +/- 656 ng/g (lipid corrected) in NOFU liver. Lipid-corrected concentrations of chlordane did not vary between sex for any species or between fat and liver except for the DOVE, that had fat concentrations that were significantly greater than the liver. delta 15N values described a significant percentage of the variability of concentrations for most chlordane components, although less than what has been reported for whole food chains. Slopes of delta 15N versus concentration of chlordane components and sigma CHLOR were similar with the exception of those which were metabolized (trans-chlordane) or formed through biotransformation (oxychlordane). The relative proportions of chlordane components in seabirds were related to phylogeny; the procellariid (NOFU) had the greatest percentage of oxychlordane (> 70%), followed by the larids (BLKI, IVGU and GLGU; 40-50%) and the alcids (DOVE and BLGU; 10-20%). The exception was TBMU, an alcid, where oxychlordane made up > 40% of its chlordane. EFs of chiral components failed to

  7. Terrestrial and Marine Foraging Strategies of an Opportunistic Seabird Species Breeding in the Wadden Sea

    PubMed Central

    Schwemmer, Philipp; Paiva, Vitor H.; Corman, Anna-Marie; Fock, Heino O.; Voigt, Christian C.; Adler, Sven

    2016-01-01

    Lesser black-backed gulls Larus fuscus are considered to be mainly pelagic. We assessed the importance of different landscape elements (open sea, tidal flats and inland) by comparing marine and terrestrial foraging behaviours in lesser black-backed gulls breeding along the coast of the southern North Sea. We attached GPS data loggers to eight incubating birds and collected information on diet and habitat use. The loggers recorded data for 10–19 days to allow flight-path reconstruction. Lesser black-backed gulls foraged in both offshore and inland areas, but rarely on tidal flats. Targets and directions were similar among all eight individuals. Foraging trips (n = 108) lasted 0.5–26.4 h (mean 8.7 h), and ranges varied from 3.0–79.9 km (mean 30.9 km). The total distance travelled per foraging trip ranged from 7.5–333.6 km (mean 97.9 km). Trips out to sea were significantly more variable in all parameters than inland trips. Presence in inland areas was closely associated with daylight, whereas trips to sea occurred at day and night, but mostly at night. The most common items in pellets were grass (48%), insects (38%), fish (28%), litter (26%) and earthworms (20%). There was a significant relationship between the carbon and nitrogen isotope signals in blood and the proportional time each individual spent foraging at sea/land. On land, gulls preferentially foraged on bare ground, with significantly higher use of potato fields and significantly less use of grassland. The flight patterns of lesser black-backed gulls at sea overlapped with fishing-vessel distribution, including small beam trawlers fishing for shrimps in coastal waters close to the colony and large beam-trawlers fishing for flatfish at greater distances. Our data show that individuals made intensive use of the anthropogenic landscape and seascape, indicating that lesser black-backed gulls are not a predominantly marine species during the incubation period. PMID:27525661

  8. Biogeochemical Indicators in High- and Low-Arctic Marine and Terrestrial Avian Community Changes: Comparative Isotopic (13C, 15N, and 34S) Studies in Alaska and Greenland

    NASA Astrophysics Data System (ADS)

    Causey, D.; Bargmann, N. A.; Burnham, K. K.; Burnham, J. L.; Padula, V. M.; Johnson, J. A.; Welker, J. M.

    2011-12-01

    Understanding the complex dynamics of environmental change in northern latitudes is of paramount importance today, given documented rapid shifts in sea ice, plant phenology, temperatures, deglaciation, and habitat fidelity. This knowledge is particularly critical for Arctic avian communities, which are integral components by which biological teleconnections are maintained between the mid and northern latitudes. Furthermore, Arctic birds are fundamental to Native subsistence lifestyles and a focus for conservation activities. Avian communities of marine and terrestrial Arctic environments represent a broad spectrum of trophic levels, from herbivores (eg., geese Chen spp.), planktivores (eg., auklets Aethia spp.), and insectivores (eg., passerines: Wheatears Oenanthe spp., Longspurs Calcarius spp.), to predators of marine invertebrates (eg., eiders Somateria spp.), nearshore and offshore fish (eg., cormorants Phalacrocorax spp, puffins Fratercula spp.), even other bird species (eg., gulls Larus spp., falcons Peregrinus spp.). This diversity of trophic interconnections is an integral factor in the dynamics of Arctic ecosystem ecology, and they are key indicators for the strength and trajectories of change. We are especially interested in their feeding ecology, using stable isotope-diet relations to examine historical diets and to predict future feeding ecology by this range of species. Since 2009, we have been studying the foodweb ecology using stable isotopes (δ13C, δ15N, δ34S) of contemporaneous coastal and marine bird communities in High Arctic (Northwest Greenland) and Low Arctic (western Aleutian Islands, AK). We are quantifying the isotopic values of blood, organ tissues, and feathers, and have carried out comparisons between native and lipid-extracted samples. Although geographically distant, these communities comprise similar taxonomic and ecological congeners, including several species common to both (eg., Common Eider, Black-legged Kittiwake, Northern

  9. Biomagnification factors (fish to osprey eggs from Willamette River, Oregon, U.S.A.) for PCDDS, PCDFS, PCBS, and OC pesticides

    USGS Publications Warehouse

    Henny, Charles J.; Kaiser, James L.; Grove, Robert A.; Bentley, V.R.; Elliot, J.E.

    2003-01-01

    HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.

  10. Proteomic characterization of vanA-containing Enterococcus recovered from Seagulls at the Berlengas Natural Reserve, W Portugal

    PubMed Central

    2010-01-01

    Background Enterococci have emerged as the third most common cause of nosocomial infections, requiring bactericidal antimicrobial therapy. Although vancomycin resistance is a major problem in clinics and has emerged in an important extend in farm animals, few studies have examined it in wild animals. To determine the prevalence of vanA-containing Enterococcus strains among faecal samples of Seagulls (Larus cachinnans) of Berlengas Natural Reserve of Portugal, we developed a proteomic approach integrated with genomic data. The purpose was to detect the maximum number of proteins that vary in different enterococci species which are thought to be connected in some, as yet unknown, way to antibiotic resistance. Results From the 57 seagull samples, 54 faecal samples showed the presence of Enterococcus isolates (94.7%). For the enterococci, E. faecium was the most prevalent species in seagulls (50%), followed by E. faecalis and E. durans (10.4%), and E. hirae (6.3%). VanA-containing enterococcal strains were detected in 10.5% of the 57 seagull faecal samples studied. Four of the vanA-containing enterococci were identified as E. faecium and two as E. durans. The tet(M) gene was found in all five tetracycline-resistant vanA strains. The erm(B) gene was demonstrated in all six erythromycin-resistant vanA strains. The hyl virulence gene was detected in all four vanA-containing E. faecium isolates in this study, and two of them harboured the purK1 allele. In addition these strains also showed ampicillin and ciprofoxacin resistance. The whole-cell proteomic profile of vanA-containing Enterococcus strains was applied to evaluate the discriminatory power of this technique for their identification. The major differences among species-specific profiles were found in the positions corresponding to 97-45 kDa. Sixty individualized protein spots for each vanA isolate was identified and suitable for peptide mass fingerprinting measures by spectrometry measuring (MALDI/TOF MS) and their

  11. Biomagnification factors (fish to Osprey eggs from Willamette River, Oregon, U.S.A.) for PCDDs, PCDFs, PCBs and OC pesticides.

    PubMed

    Henny, Charles J; Kaiser, James L; Grove, Robert A; Bentley, V Raymond; Elliott, John E

    2003-06-01

    Osprey were compared to BMFs for the resident Herring Gull (Larus argentatus), and differences are discussed. We believe a BMF approach provides some basic understanding of relationships between contaminant burdens in prey species of fish-eating birds and contaminants incorporated into their eggs, and may prove useful in understanding sources of contaminants in migratory species although additional studies are needed. PMID:12807265

  12. Regulation of intertidal food webs by avian predators on New England rocky shores.

    PubMed

    Ellis, Julie C; Shulman, Myra J; Wood, Megan; Witman, Jon D; Lozyniak, Sara

    2007-04-01

    Although there is a large body of research on food webs in rocky intertidal communities, most of the emphasis has been on the marine benthic components. Effects of avian predation on highly mobile predators such as crabs, remains practically unstudied in rocky shore ecosystems. The crab, Cancer borealis, is an important component of the diet of gulls (Larus marinus, L. argentatus) at the Isles of Shoals, Maine, USA. C. borealis prey include the predatory gastropod Nucella lapillus L., the herbivore Littorina littorea, and mussels Mytilus edulis L. We hypothesized that gulls reduce abundance of C. borealis in the low intertidal and shallow subtidal, thereby allowing C. borealis prey to persist in high numbers. A study of crab tidal migration showed that C. borealis density nearly doubled at high tide compared to low tide; thus, crabs from a large subtidal source population migrate into the intertidal zone during high tides and either emigrate or are removed by gulls during low tides. Results from a small-scale (1 m2) predator caging experiment in the low intertidal zone indicated that enclosed crabs significantly reduced L. littorea abundance when protected from gull predation. In a much larger-scale gull exclusion experiment, densities of C. borealis increased significantly during low and high tides in exclosures relative to the controls. C. borealis density was inversely correlated with changes in the abundance of two mesopredators Carcinus maenas and Nucella lapillus, and with the space-occupier M. edulis. There was a similar negative correlation between abundance of C. borealis and the change in abundance of the herbivore L. littorea, but the trend was not significant. Mortality of tethered L. littorea was associated with C. borealis density across sites. However, preferred algae did not change in response to L. littorea density during the experiment. Thus, we found suggestive, but not conclusive, evidence for a three-level cascade involving gulls, crabs, and L

  13. Factors influencing nesting success of king eiders on northern Alaska's Coastal Plain

    USGS Publications Warehouse

    Bentzen, R.L.; Powell, A.N.; Suydam, R.S.

    2008-01-01

    King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2 sites, Teshekpuk and Kuparuk, Alaska, USA, 2002-2005. We evaluated both a priori and exploratory competing models of nest survival that considered importance of nest concealment, seclusion, and incubation constancy as strategies to avoid 2 primary egg predators, avian (Larus spp., Stercorarius spp., and Corvus corax) and fox (Alopex lagopus). We used generalized nonlinear techniques to examine factors affecting nest survival rates and information-theoretic approaches to select among competing models. Estimated nest survival, accounting for a nest visitation effect, varied considerably across sites and years (0.21-0.57); however, given our small sample size, much of this variation maybe attributable to sampling variation (??process = 0.007, 95% CI: 0.003-0.070). Nest survival was higher at Kuparuk than Teshekpuk in all years; however, due to the correlative nature of our data, we cannot determine the underlying causes with any certainty. We found mixed support for the concealed breeding strategy, females derived no benefit from nesting in areas with more willow (Salix spp.; measure of concealment) except that the observer effect diminished as willow cover increased. We suggest these patterns are due to conflicting predation pressures. Nest survival was not higher on islands (measure of seclusion) or with increased incubation constancy but was higher post-fox removal, indicating that predator control on breeding grounds could be a viable management option. Nest survival was negatively affected by our nest visitations, most likely by exposing the nest to avian scavengers. We recommend precautions be taken to limit the effects of nest

  14. Changing landscapes and the cosmopolitism of the eastern Colorado avifauna

    USGS Publications Warehouse

    Knopf, Fritz L.

    1986-01-01

    The avifauna of continental North America has changed dramatically since colonial times. Excessive hunting contributed, at least in part, to the extinction of birds such as the great auk (Pinguinus impennis) and passenger pigeon (Ectopistes migratorius), while more recently organochlorine insecticide residues have resulted in drastic reductions in numbers of brown pelicans (Pelecanus occidentalis) (Anderson et al. 1975) and other species. Generally, however, vertebrate populations change in direct response to changes in their habitats. For example, herring gulls (Larus argentatus) have increased in numners (Kadlec and Drury 1968) with urbanization of the New England coastline, in the same locations formerly occupied by the extinct heath hen (Tympanuchus cupido cupido). Also, passerine birds of forest interiors have declined in numbers with fragmentation of the eastern deciduous forest into small stands; this fragmentation has led to increases in numbers of edge species (Robbins 1979, Ambuel and Temple 1983). Even subtle community shifts can introduce new competitive processes that can augment population changes among species (Brittingham and Temple 1983). Such studies of broad-scale changes in vegetative communities and their influence on native wildlife species have fostered the recent topical emphasis on "conservation biology" (Soule and Wilcox 1980, Soule 1985) and "landscape ecology" (Burgess and Sharpe 1981, Harris 1984:25-43). As changes in landscapes are causing subtle (but potentially dramatic) changes in the distribution of native species, conservation biologists are finding that mere presence-absence data on populations, or even accurate information on reproductive success, is inadequate to evaluate management activities or environmental perturbations. The principles of "conservation genetics" are attracting interest in the management of natural preserves especially (Schonewald-Cox et al. 1983). Changing patterns in landscape complexion or genetic makeup

  15. Ring distributions leading to species formation: a global topographic analysis of geographic barriers associated with ring species

    PubMed Central

    2012-01-01

    Background In the mid 20th century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found. Results Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes). Predicted barriers separate into two distinct categories: (i) single cohesive barriers (< 50,000 km2), associated with taxa that differentiate at smaller spatial scales (salamander: Ensatina eschscholtzii; tree: Acacia karroo); and (ii) composite barriers - formed by groups of barriers (each 184,000 to 1.7 million km2) in close geographic proximity (totaling 1.9 to 2.3 million km2) - associated with taxa that differentiate at larger spatial scales (birds: Phylloscopus trochiloides and Larus (sp. argentatus and fuscus)). When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal. Conclusions While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i) requires no a priori information on the relative

  16. Top-down and bottom-up factors affecting seabird population trends in the California current system (1985-2006)

    NASA Astrophysics Data System (ADS)

    Ainley, David G.; David Hyrenbach, K.

    2010-03-01

    To characterize the environmental factors affecting seabird population trends in the central portion of the California current system (CCS), we analyzed standardized vessel-based surveys collected during the late spring (May-June) upwelling season over 22 yr (1985-2006). We tested the working hypothesis that population trends are related to species-specific foraging ecology, and predicted that temporal variation in population size should be most extreme in diving species with higher energy expenditure during foraging. We related variation in individual species abundance (number km -2) to seasonally lagged (late winter, early spring, late spring) and concurrent ocean conditions, and to long-term trends (using a proxy variable: year) during a multi-decadal period of major fluctuations in the El Niño-Southern oscillation (ENSO) and the Pacific decadal oscillation (PDO). We considered both remote (Multivariate ENSO Index, PDO) and local (coastal upwelling indices and sea-surface temperature) environmental variables as proxies for ocean productivity and prey availability. We also related seabird trends to those of potentially major trophic competitors, humpback ( Megaptera novaeangliae) and blue ( Balaenoptera musculus) whales, which increased in number 4-5-fold midway during our study. Cyclical oscillations in seabird abundance were apparent in the black-footed albatross ( Phoebastria nigripes), and decreasing trends were documented for ashy storm-petrel ( Oceanodroma homochroa), pigeon guillemot ( Cepphus columbus), rhinoceros auklet ( Cerorhinca monocerata), Cassin’s auklet ( Ptychoramphus aleuticus), and western gull ( Larus occidentalis); the sooty shearwater ( Puffinus griseus), exhibited a marked decline before signs of recovery at the end of the study period. The abundance of nine other focal species varied with ocean conditions, but without decadal or long-term trends. Six of these species have the largest global populations in the CCS, and four are highly

  17. Perfluorinated carboxylates and sulfonates and precursor compounds in herring gull eggs from colonies spanning the Laurentian Great Lakes of North America.

    PubMed

    Gebbink, Wouter A; Hebert, Craig E; Letcher, Robert J

    2009-10-01

    Environmentally important perfluorinated carboxylates and sulfonates, as well as per- and polyfluorinated precursor compounds including several sulfonamides, telomer acids, and alcohols were determined in individual herring gull (Larus argentatus) eggs collected (in 2007) from 15 colonies located at Canadian and some American sites across the Laurentian Great Lakes of North America. The pattern of perfluorosulfonates (PFSAs; C6, C8, C10 chain lengths) was dominated by PFOS (> 90% of sigmaPFSA concentration) regardless of collection location. Concentrations of sigmaPFSA were significantly (p < 0.03) higher in eggs from Middle Island (western Lake Erie; 507 +/- 47 ng/g ww), Toronto Harbour (484 +/- 49 ng/g ww), and Strachan Island (486 +/- 59 ng/g ww) (Lake Ontario) compared to eggs from colonies on Lakes Superior, Michigan, and Huron. Perfluorocarboxylic acids (PFCAs) ranging in chain length from C8 to C15 were detected in the eggs, with PFUnA and PFTrA being the dominant compounds. PFOA and PFNA were more abundant in the sigmaPFCA in eggs from Lake Superior and Michigan colonies, and PFUnA and longer chain PFCAs were more abundant in the sigmaPFCA in eggs from Lake Erie and Ontario colonies. In contrast to sigmaPFSA, the highest concentrations of sigmaPFCA were found in eggs from Double Island, Lake Huron (113 +/- 12 ng/g ww) followed by eggs from colonies on Lakes Erie and Ontario. Among the PFOS or PFCA precursor compounds assessed (6:2, 8:2, and 10:2 fluorotelomer alcohols and acids and PFOSA), none were detectable in eggs from any sampling location. The exception was PFOSA (average concentration < 1 ng/g ww), which suggests that PFOS in the gulls and subsequently in their eggs may be due, in part, to biotransformation of PFOSA to PFOS in the gull and/or in their diet and food web. The accumulation of PFSA and PFCA from mainly aquatic dietary sources was suggested, and were highly lake- and/ or colony-dependent especially showing a northwest and southeast

  18. Managing birds and controlling aircraft in the kennedy airport-jamaica bay wildlife refuge complex: the need for hard data and soft opinions.

    PubMed

    Brown, K M; Erwin, R M; Richmond, M E; Buckley, P A; Tanacredi, J T; Avrin, D

    2001-08-01

    During the 1980s, the exponential growth of laughing gull (Larus atricilla) colonies, from 15 to about 7600 nests in 1990, in the Jamaica Bay Wildlife Refuge and a correlated increase in the bird-strike rate at nearby John F. Kennedy International Airport (New York City) led to a controversy between wildlife and airport managers over the elimination of the colonies. In this paper, we review data to evaluate if: (1) the colonies have increased the level of risk to the flying public; (2) on-colony population control would reduce the presence of gulls, and subsequently bird strikes, at the airport; and (3) all on-airport management alternatives have been adequately implemented. Since 1979, most (2987, 87%) of the 3444 bird strikes (number of aircraft struck) were actually bird carcasses found near runways (cause of death unknown but assumed to be bird strikes by definition). Of the 457 pilot-reported strikes (mean = 23 +/- 6 aircraft/yr, N = 20 years), 78 (17%) involved laughing gulls. Since a gull-shooting program was initiated on airport property in 1991, over 50,000 adult laughing gulls have been killed and the number of reported bird strikes involving laughing gulls has declined from 6.9 +/- 2.9 (1983-1990) to 2.6 +/- 1.3 (1991-1998) aircraft/yr; nongull reported bird strikes, however, have more than doubled (6.4 +/- 2.6, 1983-1990; 14.9 +/- 5.1, 1991-1998). We found no evidence to indicate that on-colony management would yield a reduction of bird strikes at Kennedy Airport. Dietary and mark-recapture studies suggest that 60%-90% of the laughing gulls collected on-airport were either failed breeders and/or nonbreeding birds. We argue that the Jamaica Bay laughing gull colonies, the only ones in New York State, should not be managed at least until all on-airport management alternatives have been properly implemented and demonstrated to be ineffective at reducing bird strikes, including habitat alterations and increasing the capability of the bird control unit to

  19. Recommendations on the use of prescribed burning practices in grassland conservation - An evidence-based study from Hungary

    NASA Astrophysics Data System (ADS)

    Tóthmérész, Béla; Valkó, Orsolya; Török, Péter; Végvári, Zsolt; Deák, Balázs

    2015-04-01

    Fire as a natural disturbance has been present in most European grasslands. In parallel controlled use of burning was an important part of the traditional landscape management for millennia. It was used to reduce litter and suppress woody vegetation as well as to maintain open landscapes suitable for farming. Recently, human activities have a considerable impact on natural fire regimes through habitat fragmentation, cessation of traditional grassland management and climate change. Nowadays the majority of human-ignited fires are uncontrolled burnings and arson, which have serious negative impacts on human life, property and can be detrimental also from the nature conservation point of view. Despite fire was widely applied in the past and the considerable extension and frequency of current grassland fires, the impact of fire on the grassland biodiversity is still scarcely documented in Europe. The aim of our study was to gather practical knowledge and experiences from Hungary concerning the effects of fire on grasslands. To fulfil this aim we sent questionnaires to experts from Hungarian national park directorates to gather unpublished data and field observations concerning the effects of burning on grasslands. Based on the answers for the questionnaires fire regularly occur in almost every grassland types in Hungary. We found that effects of fire are habitat-specific. One hand uncontrolled burning and arson have serious detrimental impacts on many endangered species (ground-dwelling birds, such as Asio flammeus, Tringa totanus and Vanellus vanellus; or lizards, such as Ablepharus kitaibelii). On the other hand in several cases fire has a positive effect on the habitat structure and favours species of high nature conservation interest (plant species, such as Adonis volgensis, Chamaecytisus supinus and Pulsatilla grandis; butterflies, such as Euphydryas aurinia; bird species such as Circus aeruginosus and Larus cachinnans). Our results suggest that even uncontrolled

  20. Organohalogen and metabolically-derived contaminants and associations with whole body constituents in Norwegian Arctic glaucous gulls.

    PubMed

    Verreault, J; Shahmiri, S; Gabrielsen, G W; Letcher, R J

    2007-08-01

    Comprehensive surveys of organohalogen contaminants have been conducted in various tissues and blood of glaucous gulls (Larus hyperboreus), a top scavenger-predator species in Svalbard in the Norwegian Arctic. However, the physico-chemical properties of organohalogens (e.g., type and degree of halogenation and the presence or absence of additional phenyl group substituents) that may influence toxicokinetics, and subsequently tissue-specific accumulation, have yet to be studied in this species. We investigated the concentrations, total body burdens, and compositional patterns of legacy chlorinated compounds (PCBs and chlordanes (CHLs)), metabolically-derived PCBs (methylsulfonyl (MeSO(2))- and OH-PCBs), brominated flame retardants (polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), total-hexabromocyclododecane (HBCD)), and PBDE metabolites and/or naturally-occurring compounds with similar structures (MeO- and OH-PBDEs) in liver, blood and whole body homogenate samples of adult glaucous gulls (n=19) from Svalbard. Further, we examined the distribution of these organohalogens and metabolites in relation to whole body composition of glaucous gulls, i.e., the total water, protein, lipid and mineral contents in whole homogenate carcasses. The total body burden of organohalogens and metabolites in glaucous gulls ranged between 3.3 and 33.0 mg. Compound class distribution showed that the relative proportions of sum (Sigma) OH-PCB and SigmaOH-PBDE to the total organohalogen concentrations were significantly highest in blood. Conversely, the SigmaCHL and SigmaPCB showed generally higher proportions in the lipid-rich liver as well as in whole body homogenates. No significant difference in the compositional patterns of individual congeners/compounds was found among tissues/blood, with the exception of the classes comprised of less polar brominated compounds (PBDEs, PBBs and total-(alpha)-HBCD). Total proteins isolated from the whole body homogenates of

  1. Tracking the sources of polybrominated diphenyl ethers in birds: Foraging in waste management facilities results in higher DecaBDE exposure in males

    SciTech Connect

    Gentes, Marie-Line; Mazerolle, Marc J.; Giroux, Jean-François; Patenaude-Monette, Martin; and others

    2015-04-15

    Differences in feeding ecology are now recognized as major determinants of inter-individual variations in contaminant profiles of free-ranging animals, but exceedingly little attention has been devoted to the role of habitat use. Marked inter-individual variations and high levels of polybrominated diphenyl ethers (PBDEs) (e.g., DecaBDE) have previously been documented in ring-billed gulls (Larus delawarensis) breeding in a colony near Montreal (QC, Canada). However, the environmental sources of these compounds, and thus the reasons causing these large inter-individual variations remain unidentified. In the present study, we used GPS-based telemetry (±5 to 10 m precision) to track ring-billed gulls from this colony to reconstruct their movements at the landscape level. We related habitat use of individual gulls (n=76) to plasma concentrations (ng/g ww) and relative contributions (percentages) to Σ{sub 38}PBDEs of major congeners in the internationally restricted PentaBDE and current-use DecaBDE mixtures. Male gulls that visited waste management facilities (WMFs; i.e., landfills, wastewater treatment plants and related facilities; 25% of all GPS-tracked males) exhibited greater DecaBDE (concentrations and percentages) and lower PentaBDE (percentages) relative to those that did not. In contrast, no such relationships were found in females. Moreover, in males, DecaBDE (concentrations and percentages) increased with percentages of time spent in WMFs (i.e., ~5% of total foraging time), while PentaBDE (percentages) decreased. No relationships between percentages of time spent in other habitats (i.e., urban areas, agriculture fields, and St. Lawrence River) were found in either sex. These findings suggest that animals breeding in the vicinity of WMFs as well as mobile species that only use these sites for short stopovers to forage, could be at risk of enhanced DecaBDE exposure. - Highlights: • The study was conducted on breeding gulls with high levels of flame

  2. Managing birds and controlling aircraft in the Kennedy Airport-Jamaica Bay Wildlife Refuge complex: the need for hard data and soft opinions

    USGS Publications Warehouse

    Brown, K.M.; Erwin, R.M.; Richmond, M.E.; Buckley, P.A.; Tanacredi, J.T.; Avrin, D.

    2001-01-01

    During the 1980s, the exponential growth of laughing gull (Larus atrfcilla) colonies, from 15 to about 7600 nests in 1990, in the Jamaica Bay Wildlife Refuge and a correlated increase in the bird-strike rate at nearby John F. Kennedy International Airport (New York City) led to a controversy between wildlife and airport managers over the elimination of the colonies. In this paper, we review data to evaluate if: (1) the colonies have increased the level of risk to the flying public; (2) on-colony population control would reduce the presence of gulls, and subsequently bird strikes, at the airport; and (3) all on-airport management alternatives have been adequately implemented. Since 1979, most (2987, 87%) of the 3444 bird strikes (number of aircraft struck) were actually bird carcasses found near runways (cause of death unknown but assumed to be bird strikes by definition). Of the 457 pilot-reported strikes (mean = 23 + 6 aircraft/yr, N = 20 years), 78 (17%) involved laughing gulls. Since a gull-shooting program was initiated on airport property in 1991, over 50,000 adult laughing gulls have been killed and the number of reported bird strikes involving laughing gulls has declined from 6.9 + 2.9 (1983-1990) to 2.8 + 1.3 (1991-1998) aircraft/yr; nongull reported bird strikes, however, have more than doubled (6.4 + 2.6, 1983-1990; 14.9 + 5.1, 1991-1998). We found no evidence to indicate that on-colony management would yield a reduction of bird strikes at Kennedy Airport. Dietary and mark-recapture studies suggest that 60%-90% of the laughing gulls collected on-airport were either failed breeders and/or nonbreeding birds. We argue that the Jamaica Bay laughing gull colonies, the only ones in New York State, should not be managed at least until all on-airport management alternatives have been properly implemented and demonstrated to be ineffective at reducing bird strikes, including habitat alterations and increasing the capability of the bird control unit to eliminate

  3. Interactions of marine mammals and birds with offshore membrane enclosures for growing algae (OMEGA)

    PubMed Central

    2014-01-01

    Background OMEGA is an integrated aquatic system to produce biofuels, treat and recycle wastewater, capture CO2, and expand aquaculture production. This system includes floating photobioreactors (PBRs) that will cover hundreds of hectares in marine bays. To assess the interactions of marine mammals and birds with PBRs, 9 × 1.3 m flat panel and 9.5 × 0.2 m tubular PBRs were deployed in a harbor and monitored day and night from October 10, 2011 to Janurary 22, 2012 using infrared video. To observe interactions with pinnipeds, two trained sea lions (Zalophus californianus) and one trained harbor seal (Phoca vitulina richardii) were observed and directed to interact with PBRs in tanks. To determine the forces required to puncture PBR plastic and the effects of weathering, Instron measurements were made with a sea otter (Enhydra lutris) tooth and bird beaks. Results A total of 1,445 interactions of marine mammals and birds with PBRs were observed in the 2,424 hours of video recorded. The 95 marine mammal interactions, 94 by sea otters and one by a sea lion had average durations of three minutes (max 44 min) and represented about 1% of total recording time. The 1,350 bird interactions, primarily coots (Fulica americana) and gulls (Larus occidentalis and L. californicus) had average durations of six minutes (max. 170) and represented 5% of recording time. Interactive behaviors were characterized as passive (feeding, walking, resting, grooming, and social activity) or proactive (biting, pecking, investigating, and unspecified manipulating). Mammal interactions were predominantly proactive, whereas birds were passive. All interactions occurred primarily during the day. Ninety-six percent of otter interactions occurred in winter, whereas 73% of bird interactions in fall, correlating to their abundance in the harbor. Trained pinnipeds followed most commands to bite, drag, and haul-out onto PBRs, made no overt undirected interactions with the PBRs, but showed avoidance

  4. Herring gulls and great black-backed gulls as indicators of contaminants in bald eagles in Lake Ontario, Canada.

    PubMed

    Weseloh, D Vaughn; Hughes, Kimberly D; Ewins, Peter J; Best, Dave; Kubiak, Timothy; Shieldcastle, Mark C

    2002-05-01

    In 2000, a pair of bald eagles (Haliaeetus leucocephalus) nested successfully along the shorelines of Lake Ontario in North America for the first time since 1957. However, it is a continuing question whether bald eagles will be able to reproduce successfully as they return to nest on Lake Ontario. Great black-backed gulls (Larus marinus) and herring gulls (L. argentatus) were selected as surrogate species to predict contaminant levels in eggs of bald eagles nesting on Lake Ontario. Because of the suspected overlap in the diets of great black-backed gulls and bald eagles (i.e., fish, gull chicks, and waterfowl), the two species probably occupy a similar trophic level in the Lake Ontario food web and, thus, may have similar contaminant levels. Fresh great black-backed gull and herring gull eggs were collected from three study sites in eastern Lake Ontario in 1993 and 1994 and analyzed for contaminants. Average contaminant levels of dichlorodiphenyldichloroethane (p,p'-DDE), total polychlorinated biphenyls (PCBs), and dieldrin in great black-backed gull eggs were 12.85, 26.27, and 0.27 microg/g, respectively. The mean ratio of contaminant levels in great black-backed gull eggs to contaminant levels in herring gull eggs for these three contaminants was 2.09 (range of means, 1.73-2.38). Predicted levels of contaminants in bald eagle eggs in Lake Ontario would be expected to be similar to the mean levels reported for great black-backed gull eggs. As a comparison, contaminant levels in bald eagle eggs collected from other Great Lakes nesting sites were compared to mean levels reported for herring gull eggs collected from nearby sites in 1986 to 1995. The mean ratio of contaminant levels in bald eagle eggs to contaminant levels in herring gull eggs from these sites for DDE, total PCBs, and dieldrin was 2.40 (range of means, 1.73-3.28). These ratios are very similar to those reported using great black-backed gull eggs, illustrating the apparent similarity in trophic status

  5. The distribution of seabirds and pinnipeds in Marguerite Bay and their relationship to physical features during austral winter 2001

    NASA Astrophysics Data System (ADS)

    Chapman, Erik W.; Ribic, Christine A.; Fraser, William R.

    2004-08-01

    The distribution of seabirds and pinnipeds and their relationship to physical oceanographic variables were investigated as part of the US Southern Ocean Global Ocean Ecosystem Dynamics field program along a study grid centered around Marguerite Bay on the west Antarctic Peninsula during late fall (April-May) and winter (July-August), 2001. Sea-ice conditions during the cruises provided an opportunity to compare the relationship among physical oceanographic variables and species distributions before and after the development of pack ice. During the fall cruise before pack ice development, both sea-ice-affiliated species and open-water-affiliated were observed in the area. The most common ice-affiliated species observed at this time were snow petrel ( Pagodroma nivea, 0.7 individuals km -2) and Antarctic petrel ( Thalassoica antarctica, 0.2 individuals km -2) and the most common open-water-affiliated species were blue petrel ( Halobaena caerulea, 0.4 individuals km -2), cape petrel ( Daption capense, 0.2 individuals km -2), and southern fulmar ( Fulmarus glacialoides, 0.1 individuals km -2). In addition, Antarctic fur seals ( Arctocephalus gazella, 0.1 individuals km -2) and crabeater seals ( Lobodon carcinophagus, 0.4 individuals km -2) were observed in low numbers. Akaike's information criterion was used to assess competing models that predicted predator distributions based on physical oceanographic variables proposed to structure predator distribution in previous research. These analyses indicated that predator distributions were primarily associated with water-mass structure and variability in bottom depth during the fall cruise. Crabeater seal, snow petrel, Antarctic petrel, and southern fulmar had higher densities in Inner Shelf Water, particularly near Alexander Island where a coastal current was present. Blue petrel, kelp gull ( Larus dominicanus), and southern giant petrel ( Macronectes giganteus) were positively associated with variability in bottom depth

  6. A stable isotope ( δ13C, δ15N) model for the North Water food web: implications for evaluating trophodynamics and the flow of energy and contaminants

    NASA Astrophysics Data System (ADS)

    Hobson, Keith A.; Fisk, Aaron; Karnovsky, Nina; Holst, Meike; Gagnon, Jean-Marc; Fortier, Martin

    The North Water Polynya is an area of high biological activity that supports large numbers of higher trophic-level organisms such as seabirds and marine mammals. An overall objective of the Upper Trophic-Level Group of the International North Water Polynya Study (NOW) was to evaluate carbon and contaminant flux through these high trophic-level (TL) consumers. Crucial to an evaluation of the role of such consumers, however, was the establishment of primary trophic linkages within the North Water food web. We used δ15N values of food web components from particulate organic matter (POM) through polar bears ( Ursus maritimus) to create a trophic-level model based on the assumptions that Calanus hyperboreus occupies TL 2.0 and there is a 2.4‰ trophic enrichment in 15N between birds and their diets, and a 3.8‰ trophic enrichment for all other components. This model placed the planktivorous dovekie ( Alle alle) at TL 3.3, ringed seal ( Phoca hispida) at TL 4.5, and polar bear at TL 5.5. The copepods C. hyperboreus, Chiridius glacialis and Euchaeta glacialis formed a trophic continuum (TL 2.0-3.0) from primary herbivore through omnivore to primary carnivore. Invertebrates were generally sorted according to planktonic, benthic and epibenthic feeding groups. Seabirds formed three trophic groups, with dovekie occupying the lowest, black-legged kittiwake ( Rissa tridactyla), northern fulmar ( Fulmarus glacialis), thick-billed murre ( Uria aalge), and ivory gull ( Pagophilia eburnea) intermediate (TL 3.9-4.0), and glaucous gull ( Larus hyperboreus) the highest (TL 4.6) trophic positions. Among marine mammals, walrus ( Odobenus rosmarus) occupied the lowest (TL 3.2) and bearded seal ( Erignathus barbatus), ringed seal, beluga whale ( Delphinapterus leucas), and narwhal ( Monodon monoceros) intermediate positions (TL 4.1-4.6). In addition to arctic cod ( Boreogadus saida), we suggest that lower trophic-level prey, in particular the amphipod Themisto libellula, contribute

  7. The distribution of seabirds and pinnipeds in Marguerite Bay and their relationship to physical features during austral winter 2001

    USGS Publications Warehouse

    Chapman, Erik W.; Ribic, C.A.; Fraser, William R.

    2004-01-01

    The distribution of seabirds and pinnipeds and their relationship to physical oceanographic variables were investigated as part of the US Southern Ocean Global Ocean Ecosystem Dynamics field program along a study grid centered around Marguerite Bay on the west Antarctic Peninsula during late fall (April-May) and winter (July-August), 2001. Sea-ice conditions during the cruises provided an opportunity to compare the relationship among physical oceanographic variables and species distributions before and after the development of pack ice. During the fall cruise before pack ice development, both sea-ice-affiliated species and open-water-affiliated were observed in the area. The most common ice-affiliated species observed at this time were snow petrel (Pagodroma nivea, 0.7 individuals km-2) and Antarctic petrel (Thalassoica antarctica, 0.2 individuals km-2) and the most common open-water-affiliated species were blue petrel (Halobaena caerulea, 0.4 individuals km-2), cape petrel (Daption capense, 0.2 individuals km-2), and southern fulmar (Fulmarus glacialoides, 0.1 individuals km-2). In addition, Antarctic fur seals (Arctocephalus gazella, 0.1 individuals km-2) and crabeater seals (Lobodon carcinophagus, 0.4 individuals km-2) were observed in low numbers. Akaike's information criterion was used to assess competing models that predicted predator distributions based on physical oceanographic variables proposed to structure predator distribution in previous research. These analyses indicated that predator distributions were primarily associated with water-mass structure and variability in bottom depth during the fall cruise. Crabeater seal, snow petrel, Antarctic petrel, and southern fulmar had higher densities in Inner Shelf Water, particularly near Alexander Island where a coastal current was present. Blue petrel, kelp gull (Larus dominicanus), and southern giant petrel (Macronectes giganteus) were positively associated with variability in bottom depth in April

  8. Research, Monitoring, and Evaluation of Avian Predation on Salmonid Smolts in the Lower and Mid-Columbia River, 2006 Final Season Summary.

    SciTech Connect

    Roby, Daniel D.; Collis, Ken; Lyons, Donald E.

    2009-06-18

    This study investigates predation by piscivorous waterbirds on juvenile salmonids (Oncorhynchus spp.) from throughout the Columbia River Basin. During 2006, study objectives in the Columbia River estuary, work funded by the Bonneville Power Administration, were to (1) monitor and evaluate previous management initiatives to reduce Caspian tern (Hydroprogne caspia) predation on juvenile salmonids (smolts); (2) measure the impact of double-crested cormorant (Phalacrocorax auritus) predation on smolt survival, and assess potential management options to reduce cormorant predation; and (3) monitor large colonies of other piscivorous waterbirds in the estuary (i.e., glaucous-winged/western gulls [Larus glaucescens/occidentalis]) to determine the potential impacts on smolt survival. Study objectives on the mid-Columbia River, work funded by the Walla Walla District of the U.S. Army Corps of Engineers, were to (1) measure the impact of predation by Caspian terns and double-crested cormorants on smolt survival; and (2) monitor large nesting colonies of other piscivorous waterbirds (i.e., California gulls [L. californicus], ring-billed gulls [L. delawarensis], American white pelicans [Pelecanus erythrorhynchos]) on the mid-Columbia River to determine the potential for significant impacts on smolt survival. Our efforts to evaluate system-wide losses of juvenile salmonids to avian predation indicated that Caspian terns and double-crested cormorants were responsible for the vast majority of smolt losses to avian predators in the Columbia Basin, with most losses occurring in the Columbia River estuary. In 2006, East Sand Island in the Columbia River estuary supported the largest known breeding colonies of Caspian terns and double-crested cormorants in the world. The Caspian tern colony on East Sand Island consisted of about 9,200 breeding pairs in 2006, up slightly (but not significantly so) from the estimate of colony size in 2005 (8,820 pairs). There has not been a

  9. Abundance, Distribution and Estimated Consumption (kg fish) of Piscivorous Birds Along the Yakima River, Washington State; Implications for Fisheries Management, 2002 Annual Report.

    SciTech Connect

    Major, III, Walter; Grassley, James M.; Ryding, Kristen E.

    2003-05-01

    abundance of fish-eating birds, primarily ring-billed (Larus delawarensis) and California (L. californicus) gulls and monitored their behavior at two man-made structures within the Yakima River in eastern Washington: Horn Rapids Dam, a low-head irrigation dam, and the return pipe for the Chandler Juvenile Fish Handling Facility. Earlier observations of congregations of gulls at these structures suggested an increased likelihood of predation of out-migrating juvenile salmonids. We estimated the number of fish consumed and examined the relationship between river flow and gull numbers and fish taken. Numbers of gulls at the structures varied daily between their arrival in Late March-early April and departure in late June (mean ({+-}SE) - Horn Rapids: 11.7 ({+-}2.0), Chandler: 20.1 ({+-}1.5) ). During the 4-yr study, numbers at Horn Rapids peaked dramatically during the last 2 weeks in May (between 132.9 ({+-}4.2) to 36.6 ({+-}2.2) gulls/day) and appeared to the associated with the release of > 1-mil hatchery juvenile fall chinook (Oncorhynchus tshawytscha) above the 2 study sites. A comparable peak in gull abundance was not observed at Chandler. Diurnal patterns of gull abundance also varied among years and sites. The relationship between foraging efficiency and gull numbers was not consistent among years or sites. Gull numbers were not correlated with river flow when year was considered. However, variations in flow among years appeared to be associated with average gull numbers at each site, but trends were not consistent between sites. Low seasonal flows were associated with increased predation at Chandler, whereas high seasonal flows were associated with increased predation at Horn Rapids. Assuming all fish taken were salmonids, we estimate gulls consumed between 0.1-10.3 % of the juvenile salmonids passing or being released from the Chandler Juvenile Fish Monitoring Facility located above the two structures. Staggered releases of hatchery fish, nocturnal releases of fish

  10. The importance of tidewater glaciers for marine mammals and seabirds in Svalbard, Norway

    NASA Astrophysics Data System (ADS)

    Lydersen, Christian; Assmy, Philipp; Falk-Petersen, Stig; Kohler, Jack; Kovacs, Kit M.; Reigstad, Marit; Steen, Harald; Strøm, Hallvard; Sundfjord, Arild; Varpe, Øystein; Walczowski, Waldek; Weslawski, Jan Marcin; Zajaczkowski, Marek

    2014-01-01

    Approximately 60% of Svalbard's land areas are glaciated at the present time. The Archipelago has more than 1100 glaciers (> 1 km2) and 163 of these are “tidewater glaciers” - that is glaciers that terminate (with their calving front) at the sea. It has been known for a long time that these glacier front areas are important feeding areas for seabirds and marine mammals. Herein, we review current knowledge regarding the importance of these areas for these animals and reflect upon the processes that create these apparent “hotspots”. Kittiwakes Rissa tridactyla, routinely dominate avian assemblages in front of glaciers in Svalbard, but fulmars Fulmarus glacialis, ivory gulls Pagophila eburnea and glaucous gulls Larus hyperboreus also contribute to aggregations, which can sometimes comprise many thousands of individuals. The birds are often found in the so-called “brown zone”, which is an area in front of tidewater glaciers that is ice-free due to currents and muddy due to suspended sediments. Animals at these sites typically have their stomachs full of large zooplankton or fish. These brown zones are also foraging hotspots for Svalbard's ringed seals (Pusa hispida) and white whales (Delphinapterus leucas). Prime breeding habitat for ringed seals in Svalbard occurs deep in the fjords where ice pieces calved from the glacier fronts become frozen into land-fast sea-ice, promoting the accumulation of snow to a depth suitable for ringed seal females to dig out birth lairs above breathing holes in the ice. These pupping areas are important hunting areas for polar bears (Ursus maritimus) in spring, especially female bears with cubs of the year during the period following emergence from the winter/birthing den. Glacier-ice pieces floating in coastal areas are also important for all seal species in the region as dry platforms during moulting and also as general resting platforms for both birds and seals. During the last decade there have been several years with a

  11. Similarities and differences between the massive eel (Anguilla anguilla L.) devastations that occurred in Lake Balaton in 1991 and 1995.

    PubMed

    Bálint, T; Ferenczy, J; Kátai, F; Kiss, I; Kráczer, L; Kufcsák, O; Láng, G; Polyhos, C; Szabó, I; Szegletes, T; Nemcsók, J

    1997-06-01

    In the past few years, two massive eel (Anguilla anguilla L.) devastations occurred in Lake Balaton, Hungary. In 1991, 300 tons of eel perished in the western basin of the lake, while in the summer of 1995 30 tons of eel died in the eastern part of the lake. Investigations carried out to find the causes of these ecocatastrophes included measurements of certain biochemical parameters: the blood sugar level, and the acetylcholinesterase (AChE, EC 3.1.1.7), lactate dehydrogenase (LDH, EC 1.1.2.3), glutamic-oxaloacetic transaminase (GOT, EC 2.6.1.1) and glutamic-pyruvic transaminase (GPT, EC 2.6.1.2) activities in the blood serum of the collected eels. In both 1991 and 1995, deltamethrin (DM), the active ingredient of the insecticide K-OTHRIN 1 ULV used against mosquitoes, was detected in the eels; in 1995 it was demonstrated in several other animal species, i.e., bream (Abramis brama L.), pike perch (Stizostedion lucioperca L.), and the common gull (Larus canus), and in sediment samples from the lake. Additionally, laboratory experiments were carried out to study the effects of DM on eels. In 1991, eels were collected from the western (the site of the devastation) and eastern basins of the lake. The eels from the eastern basin were used as controls. At that time, the AChE activity in the blood serum of the eels from the western basin was significantly inhibited compared to that in animals from the eastern basin (P < 0.05, Student t test). Eels from the western part of the lake had GOT and GPT levels 20 and 100%, respectively, higher than those of eels from the eastern part of the lake. The blood glucose level was much higher in the eels from the affected area of the lake as compared to those from the eastern part. The brain and liver of the eels contained DM residues at 20 micrograms/kg wet tissue (Gönczy, 1992). Gönczy suspected that one of the causes of the massive eel loss in 1991 was the presence of DM in the fish. In 1995, when the eel devastation occurred in

  12. The importance of tidewater glaciers for marine mammals and seabirds in Svalbard, Norway

    NASA Astrophysics Data System (ADS)

    Lydersen, Christian; Assmy, Philipp; Falk-Petersen, Stig; Kohler, Jack; Kovacs, Kit M.; Reigstad, Marit; Steen, Harald; Strøm, Hallvard; Sundfjord, Arild; Varpe, Øystein; Walczowski, Waldek; Weslawski, Jan Marcin; Zajaczkowski, Marek

    2014-01-01

    Approximately 60% of Svalbard's land areas are glaciated at the present time. The Archipelago has more than 1100 glaciers (> 1 km2) and 163 of these are “tidewater glaciers” - that is glaciers that terminate (with their calving front) at the sea. It has been known for a long time that these glacier front areas are important feeding areas for seabirds and marine mammals. Herein, we review current knowledge regarding the importance of these areas for these animals and reflect upon the processes that create these apparent “hotspots”. Kittiwakes Rissa tridactyla, routinely dominate avian assemblages in front of glaciers in Svalbard, but fulmars Fulmarus glacialis, ivory gulls Pagophila eburnea and glaucous gulls Larus hyperboreus also contribute to aggregations, which can sometimes comprise many thousands of individuals. The birds are often found in the so-called “brown zone”, which is an area in front of tidewater glaciers that is ice-free due to currents and muddy due to suspended sediments. Animals at these sites typically have their stomachs full of large zooplankton or fish. These brown zones are also foraging hotspots for Svalbard's ringed seals (Pusa hispida) and white whales (Delphinapterus leucas). Prime breeding habitat for ringed seals in Svalbard occurs deep in the fjords where ice pieces calved from the glacier fronts become frozen into land-fast sea-ice, promoting the accumulation of snow to a depth suitable for ringed seal females to dig out birth lairs above breathing holes in the ice. These pupping areas are important hunting areas for polar bears (Ursus maritimus) in spring, especially female bears with cubs of the year during the period following emergence from the winter/birthing den. Glacier-ice pieces floating in coastal areas are also important for all seal species in the region as dry platforms during moulting and also as general resting platforms for both birds and seals. During the last decade there have been several years with a

  13. List of Participants

    NASA Astrophysics Data System (ADS)

    2008-11-01

    teborg Cornelius Schmidt-ColinetEidgenössische Technische Hochschule (ETH), Zürich Johannes SchmudeSwansea University Waldemar SchulginLaboratoire de Physique Théorique, École Normale Supérieure, Paris Domenico SeminaraUniversità di Firenze Alexander SevrinVrije Universiteit, Brussel Konstadinos SfetsosUniversity of Patras Igor ShenderovichSt Petersburg State University Jonathan ShockUniversidade de Santiago de Compostela Massimo SianiUniversità di Milano-Bicocca Christoph SiegUniversità Degli Studi di Milano Joan SimonUniversity of Edinburgh Paul SmythUniversity of Hamburg Luca SommovigoUniversidad de Valencia Dmitri Sorokin Istituto Nazionale di Fisica Nucleare, Padova Christos SourdisUniversity of Patras Wieland StaessensVrije Universiteit, Brussel Ivan StefanovUniversity of Patras Sigurdur StefanssonUniversity of Iceland Kellogg Stelle Imperial College London Giovanni Tagliabue Università di Milano Laura Tamassia Katholieke Universiteit Leuven Javier TarrioUniversidade de Santiago de Compostela Dimitri TerrynVrije Universiteit, Brussel Larus Thorlacius University of Iceland Mario ToninDipartimento Di Fisica, Sezione Di Padova Mario Trigiante Politecnico di Torino Efstratios TsatisUniversity of Patras Arkady TseytlinImperial College London Pantelis TziveloglouCornell University, New York and CERN, Geneva Angel Uranga CERN, Geneva Dieter Van den Bleeken Katholieke Universiteit Leuven Ernst van Eijk Università di Napoli Federico II Antoine Van Proeyen Katholieke Universiteit Leuven Maaike van ZalkUtrecht University Pierre Vanhove Service de Physique Théorique, CEA Saclay Silvia Vaula Instituto de Física Teórica, Universidad Autónoma de Madrid Cristian Vergu Service de Physique Théorique, CEA Saclay Alessandro VichiÉcole Polytechnique Fédérale de Lausanne (EPFL) Marlene WeissCERN, Geneva and Eidgenössische Technische Hochschule (ETH), Zürich Sebastian Weiss Université de Neuchâtel Alexander WijnsUniversity of Iceland Linus WulffUniversity of Padova Thomas

  14. List of Participants

    NASA Astrophysics Data System (ADS)

    2007-11-01

    de Física Teórica, Madrid Aaron Sim Imperial College, London Woojoo Sim Pohang University of Science and Technology (POSTECH) Sergey Slizovskiy Department of Theoretical Physics, Uppsala University Paul Smyth Katholieke Universiteit Leuven Corneliu Sochichiu Laboratori Nazionali di Frascati Dmitri Sorokin Istituto Nazionale di Fisica Nucleare, Padova Kellogg Stelle Imperial College, London Piotr Surowka Jagiellonian University, Krakow Yasutoshi Takayama Niels Bohr Institute, København Laura Tamassia Katholieke Universiteit Leuven Radu Tatar University of Liverpool Larus Thorlacius University of Iceland Paavo Tiitola Helsinki Institute of Physics Diego Trancanelli Stony Brook University, NY Michele TraplettiInstitut für Theoretische Physik, Universität Heidelberg Mario Trigiante Politecnico di Torino Angel Uranga CERN, Geneva and Instituto de Física Teórica, Madrid Roberto Valandro SISSA, Trieste Dieter Van den Bleeken Katholieke Universiteit Leuven Antoine Van Proeyen Katholieke Universiteit Leuven Thomas Van Riet Centre for Theoretical Physics, University of Groningen Pierre Vanhove Service de Physique Théorique, Saclay Oscar Varela Universidad de Valencia Alessandro Vichi Scuola Normale Superiore di Pisa Massimiliano VinconQueen Mary, University of London John Ward Queen Mary, University of London and CERN, Geneva Brian Wecht Massachusetts Institute of Technology, Cambridge, MA Marlene Weiss Eidgenössische Technische Hochschule, Zürich and CERN, Geneva Sebastian Weiss Université de Neuchâtel Alexander Wijns Vrije Universiteit, Brussel Przemek Witaszczyk Jagiellonian University, Krakow Timm Wrase University of Texas at Austin Jun-Bao Wu SISSA, Trieste Amos Yarom Ludwig-Maximilians-Universität, München Marco Zagermann Max-Planck-Institut für Physik, München Daniela Zanon Dipartimento di Fisica, Università di Milano Andrea Zanzi University of Bonn Andrey Zayakin Moscow State University (MSU) and Institute for Theoretical and Experimental Physics (ITEP