| seasonal and geographical variation of organochlorine residues in birds from northwest mexico. | eight species of birds (129 individuals) were collected from three agricultural areas with long histories of pesticide use in northwestern mexico. plucked carcasses were analyzed for organochlorine (oc) pesticides and polychlorobiphenyls (pcbs). dde was found in all of the samples and at higher levels than other ocs. mean (geometric) dde concentrations varied from 0.04 (microgram/g) ppm in mourning doves (zenaida macroura) to 5.05 ppm in double-crested cormorants (phalacrocorax auritus). hexachl ... | 1991 | 1722080 |
| polybrominated diphenyl ether trends in eggs of marine and freshwater birds from british columbia, canada, 1979-2002. | temporal, spatial, and interspecific trends in polybrominated diphenyl ether (pbde) flame retardants were determined in eggs of marine and freshwater bird species from the province of british columbia, canada. temporal trends in the fraser river estuary, 1983-2002, were examined by analysis of eggs of great blue herons (ardea herodias) and from the strait of georgia marine ecosystem, 1979-2002, in eggs of double-crested cormorants (phalacrocorax auritus). results were compared to those from eggs ... | 2005 | 16124290 |
| isolation of newcastle disease virus and salmonella typhimurium from the brain of double-crested cormorants (phalacrocorax auritus). | avian paramyxovirus type 1 (newcastle disease virus) and salmonella typhimurium were isolated from the brain and lung tissues of double-crested cormorants (phalacrocorax auritus) from lac canard, alberta, canada. more than 100 birds died during this outbreak in 1999. affected birds presented signs of central nervous system disease characterized by unilateral wing and leg paralysis. other geographic locations in the provinces of alberta and saskatchewan have reported cases of cormorants suffering ... | 2001 | 11332490 |
| newcastle disease in wild water birds in western canada, 1990. | this report describes the investigation of mortality of double-crested cormorants (phalacrocorax auritus), white pelicans (pelecanus erythrorhynchos), and gulls (larus spp.) in alberta, saskatchewan, and manitoba during late summer 1990. techniques used varied among areas, but virological and histopathological examination of birds was done in each area. the major clinical sign in cormorants was inability to fly, often with unilateral wing or leg paralysis. focal nonsuppurative inflammation was p ... | 1993 | 17424240 |
| the 1992 epizootic of newcastle disease in double-crested cormorants in north america. | in the summer of 1992, morbidity and mortality in juvenile double-crested cormorants (phalacrocorax auritus; dcc) attributable to newcastle disease virus (ndv) was observed for the first time in seven northern usa states and one canadian province, and recurred in three western canadian provinces. based on clinical signs and laboratory diagnostic findings, dcc mortality from ndv occurred in 59 of the 63 nesting colonies and two of three non-colony sites investigated. an estimate of in excess of 2 ... | 1999 | 10231759 |
| an epidemic of newcastle disease in double-crested cormorants from saskatchewan. | a newcastle disease epidemic in double-crested cormorants (phalacrocorax auritus) occurred in july and august 1995, during a 1994-96 study of a breeding colony of this species on doré lake (saskatchewan, canada). clinical signs and mortality were observed from a tunnel-and-blind system, and moribund and freshly dead birds were examined virologically. yolks from cormorant eggs and sera from cormorants and other birds were tested for hemagglutination inhibiting antibodies to newcastle disease viru ... | 1998 | 9706555 |
| elemental profiles in feather samples from a mercury-contaminated lake in central california | flight feathers from six bird species at clear lake, ca were analyzed to determine the extent and distribution of mercury contamination from an abandoned mercury mine and associated levels of 14 other elements. feather samples were collected from adult and juvenile osprey (pandion haliaetus), including juvenile osprey from three additional comparison sites; adult western grebes (aechmophorus occidentalis); adult great blue herons (ardea herodias); adult mallards (anas platyrhynchos); adult turke ... | 1998 | 9601923 |
| organochlorine contaminants in double-crested cormorants from green bay,wisconsin: ii. effects of an extract derived from cormorant eggs onthe chicken embryo | white leghorn chicken (gallus domesticus) eggswere injected prior to incubation with one of four concentrations (0.001,0.01, 0.1, and 1.0 egg-equivalent) of an extract derived from 1,000double-crested cormorant (phalacrocorax auritus) eggs collected atspider island adjacent to green bay in lake michigan. one egg-equivalentcorresponded to the concentration of contaminants present in an averagecormorant egg. this was approximately 322 pg toxic equivalents (teqs)/g, wwegg with polychlorinatedbiphen ... | 1997 | 9096082 |
| diagnostic findings in the 1992 epornitic of neurotropic velogenic newcastle disease in double-crested cormorants from the upper midwestern united states. | neurotropic velogenic newcastle disease (nvnd) occurred in juvenile double-crested cormorants, phalacrocorax auritus, simultaneously in nesting colonies in minnesota, north dakota, south dakota, and nebraska and in lakes michigan, superior, huron, and ontario during the summer of 1992. mortality as high as 80%-90% was estimated in some of the nesting colonies. clinical signs observed in 4- to 6-wk-old cormorants included torticollis, tremors, ataxia, curled toes, and paresis or weakness of legs, ... | 1997 | 9087334 |
| biological effects of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in double-crested cormorant chicks (phalacrocorax auritus). | the present project assessed the effect of environmental contamination with polychlorinated dibenzo-p-dioxins (pcdds), dibenzofurans (pcdfs), and biphenyls (pcbs) on hepatic microsomal ethoxyresorufin o-deethylase (erod) activities and morphological parameters in matched double-crested cormorant (phalacrocorax auritus) hatchlings from egg clutches chosen for chemical analysis. double-crested cormorant eggs were collected from five colonies across canada, with differing levels of contamination. l ... | 1994 | 8301702 |
| hepatic microsomal ethoxyresorufin o-deethylase-inducing potency in ovo and cytosolic ah receptor binding affinity of 2,3,7,8-tetrachlorodibenzo-p-dioxin: comparison of four avian species. | the hepatic microsomal ethoxyresorufin o-deethylase (erod)-inducing potency in ovo of 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) was determined in the domestic chicken (gallus gallus), domestic pigeon (columba livia), great blue heron, and double-crested cormorant. dose-response curves were produced by injecting various doses of [3h]tcdd into the air sac of developing eggs during the latter third part of incubation. hepatic erod activities were measured in day-old hatchlings. liver, yolk, and wh ... | 1995 | 7747276 |
| neurotropic velogenic newcastle disease in cormorants in michigan: pathology and virus characterization. | excessive unexplained mortality was observed in flocks of double-crested cormorants located at snake island in green bay, michigan, in june 1992. clinical signs included weakness, lethargy, diarrhea, respiratory distress, paralysis of the wings and legs, torticollis, and incoordination. the most significant and consistent gross lesions included edema of the eyelids and periocular tissues, pulmonary edema and congestion, marked splenomegaly, hepatic necrosis, and scattered hemorrhages in visceral ... | 1994 | 7702523 |
| investigation of the life cycle and adult morphology of the avian blood fluke austrobilharzia variglandis (trematoda: schistosomatidae) from connecticut. | this study was undertaken to expand the current knowledge of the life cycle and adult morphology of the avian schistosome austrobilharzia variglandis, which causes a marine cercarial dermatitis in new england. the specific objectives were to: (1) investigate the seasonality of the infection in the molluscan intermediate host, ilyanassa obsoleta; (2) determine which bird species are acting as natural definitive hosts for the parasite; and (3) characterize the morphology of the parasite using scan ... | 1995 | 7623201 |
| the double crested cormorant, phalacrocorax auritus, natural host of neogogatea kentuckiensis (cable, 1935) hoffman and dunbar, 1963. | | 1972 | 5042069 |
| heavy metal and metallothionein concentrations in atlantic canadian seabirds. | 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 l ... | 1992 | 1554255 |
| antimicrobial resistant salmonella spp. isolated from double-crested cormorants (phalacrocorax auritus) and common loons (gavia immer) in florida. | antimicrobial resistant salmonella spp. were found in double-crested cormorants and common loons in florida. single or multiple resistance occurred in all salmonella agona isolates from cormorants, primarily to ampicillin, sulfonamids, streptomycin, neomycin, and kanamycin. similar patterns of resistance were found in s. agona isolates from common loons. in addition, isolates of s. saint paul from loons were found resistant to tetracycline and streptomycin, while 2 of 7 isolates of s. infantis w ... | 1979 | 384026 |
| shell thinning and residues of organochlorines and mercury in seabird eggs, eastern canada, 1970-76. | organochlorine and mercury concentrations are reported for 252 eggs of leach's storm-petrel (oceanodroma leucorhoa), double-crested cormorant (phalarocorax auritus), common eider (somateria mollissima), common tern (sterna hirundo), razorbill (alca torda), common murre (uria aalge) black guillemot (cepphus grylle), and atlantic puffin (fratercula arctica) from the bay of fundy, the gulf of st. lawrence, and the open atlantic shore of canada during 1970-76. concentrations of all organochlorines e ... | 1979 | 117427 |
| heavy metals and selenium in grebe eggs from agassiz national wildlife refuge in northern minnesota. | metal levels in eggs can often be used as an indicator of exposure and of potential effects. in previous work at agassiz national wildlife refuge, northwestern minnesota, the levels of several heavy metals were shown to be significantly higher in the eggs of eared grebes (podiceps nigricollis) compared to those in the eggs of franklin's gulls (larus pipixcan), black-crowned night-herons (nycticorax nycticorax) and double-crested cormorants (phalacrocorax auritus, except for mercury). in the pres ... | 2005 | 16418918 |
| factors affecting the toxicity of methylmercury injected into eggs. | we developed a standardized protocol for comparing the sensitivities of the embryos of different bird species to methylmercury when methylmercury was injected into their eggs. during the course of developing this protocol, we investigated the effects of various factors on the toxicity of the injected methylmercury. most of our experiments were done with chicken (gallus domesticus), mallard (anas platyrhynchos), and ring-necked pheasant (phasianus colchicus) eggs, all of which were purchased in l ... | 2006 | 16307214 |
| nesting ardeid colonies are not a focus of elevated west nile virus activity in southern california. | a large nesting colony of ardeid birds at the finney-ramer wildlife refuge in imperial county, california, did not appear to be a focus of west nile virus (wnv) amplification during the summer of 2004. blood samples taken during june and july from 155 nestlings of four species of ardeid birds (cattle egrets, black-crowned night herons, great egrets, and snowy egrets) and five nestling double-crested cormorants yielded a single wnv isolation from a 3-week-old cattle egret. antibody was detected b ... | 2005 | 16187895 |
| morphologic and molecular identifications of digenetic trematodes in double-crested cormorants (phalacrocorax auritus) from the mississippi delta, usa. | increasing numbers of double-crested cormorants (phalacrocorax auritus) in the mississippi river delta, usa, have been observed over the past few decades. this piscivorous bird is a definitive host for numerous digenetic trematodes, some of which may cause pathology in a fish host. we conducted a 2-yr survey of intestinal trematodes in 35 double-crested cormorants collected in the mississippi delta. we counted gastrointestinal trematodes, identified them to species using morphometric and molecul ... | 2014 | 24171572 |
| wintering of neurotropic velogenic newcastle disease virus and west nile virus in double-crested cormorants (phalacrocorax auritus) from the florida keys. | during november 2002, six double-crested cormorants (dccs; phalacrocorax auritus) were found moribund in big pine key, fl, exhibiting clinical signs indicative of neurologic disease. postmortem diagnostic evaluations were performed on two adult birds. virulent newcastle disease virus (ndv) was isolated from a cloacal swab from cormorant 1. west nile virus (wnv) was isolated from the brain and lung of cormorant 2. nucleotide sequence analysis of a portion of the fusion (f) protein gene of the ndv ... | 2005 | 16094838 |
| bacterial flora of free-living double-crested cormorant (phalacrocorax auritus) chicks on prince edward island, canada, with reference to enteric bacteria and antibiotic resistance. | cloacal and pharyngeal swabs from 100 tree-nesting double-crested cormorant (dcc) chicks were examined by culture for commensal and potentially pathogenic bacteria. no salmonella or erysipelothrix were isolated from the cloacal swabs. twenty-two cloacal swabs were positive for campylobacter, of which 14 were c. jejuni, c. coli, and 1 c. lari. none belonged to common serotypes isolated from humans or animals in recent years in canada. tests for antimicrobial drug resistance among 187 commensal es ... | 2005 | 15563955 |
| catalytic and immunochemical properties of hepatic cytochrome p450 1a in three avian species treated with beta-naphthoflavone or isosafrole. | induction of cytochrome p450 1a (cyp1a) can be used as a biomarker of exposure to planar halogenated aromatic hydrocarbons (phahs). our objective was to characterize the induction of cyp1a activity and protein in three avian species following in vivo treatment with beta-naphthoflavone (bnf) and/or isosafrole. alkoxyresorufin-o-dealkylase (alk-rod) activities of hepatic microsomes from herring gulls (larus argentatus) (hgs), double-crested cormorants (phalacrocorax auritus) (dccs) and chickens (g ... | 2001 | 11544144 |
| effect of in ovo exposure to an organochlorine mixture extracted from double crested cormorant eggs (phalacrocorax auritus) and pcb 126 on immune function of juvenile chickens. | organochlorine (oc) contaminants including polychlorinated biphenyls (pcbs) and p, p'-dichlorodiphenyldichloroethylene (dde) have been associated with immune modulation in wild fish-eating birds from the great lakes. the objective of this study was to evaluate the immune function of juvenile chickens after in ovo exposure to pcb 126 or an environmentally relevant oc mixture extracted from eggs of double crested cormorants (phalacrocorax auritus) from green bay, lake michigan, usa. fertile white ... | 2007 | 17882474 |
| causes of morbidity and mortality and their effect on reproductive success in double-crested cormorants from saskatchewan. | the objectives of this study were to describe causes of morbidity and mortality in a breeding colony of double-crested cormorants (phalacrocorax auritus) on doré lake (saskatchewan, canada), and to determine cause-specific mortality rates of juvenile birds. morbidity and mortality were monitored every third day during the breeding season from 1994 to 1996 from inside a tunnel-and-blind system. affected eggs and birds were collected for examination and diagnosis. the cause of mortality was determ ... | 1999 | 10231760 |
| newcastle disease virus in double-crested cormorants in alabama, florida, and mississippi. | in order to understand the epidemiology of newcastle disease (nd) outbreaks in double-crested cormorants (phalacrocorax auritus), a study was conducted on wintering migratory cormorants (p. a. auritus) in alabama and mississippi (usa) and non-migratory cormorants (p. a. floridanus) that breed in florida (usa). antibodies against nd virus were detected by the hemagglutination-inhibition method in sera from 86 of 183 (47%) migratory cormorants over-wintering in eight roosting sites in alabama and ... | 2001 | 11763745 |
| pathology of newcastle disease in double-crested cormorants from saskatchewan, with comparison of diagnostic methods. | newcastle disease (nd) in juvenile double-crested cormorants (phalacrocorax auritus) occurred several times since 1975, but there are relatively few studies on its pathology and diagnosis. in order to describe the distribution of newcastle disease virus (ndv) and associated lesions in cormorants with nd and to compare diagnostic methods, 25 cormorants with nervous signs from a nd epizootic in saskatchewan in 1995 (nde cormorants) were compared with 18 negative control cormorants. tissues of thes ... | 1999 | 10073341 |
| 3,3',4,4'-tetrachlorobiphenyl oxidation in fish, bird and reptile species: relationship to cytochrome p450 1a inactivation and reactive oxygen production. | previously we showed that the polychlorinated biphenyl 3,3',4,4'-tetrachlorobiphenyl (tcb) caused a release of reactive oxygen species (ros) from cytochrome p450 1a (cyp1a) of the fish scup (stenotomus chrysops), and from rat and human cyp1a1. this was linked to a tcb- and nadph-dependent oxidative inactivation of the enzyme, which in scup and rat was inversely related to the rates of tcb oxidation. we examined the relationship between rates of tcb oxidation, cyp1a inactivation and ros productio ... | 2000 | 11790349 |
| ecosystem-based management of predator-prey relationships: piscivorous birds and salmonids. | predator-prey relationships are often altered as a result of human activities. where prey are legally protected, conservation action may include lethal predator control. in the columbia river basin (pacific northwest, usa and canada), piscivorous predators have been implicated in contributing to a lack of recovery of several endangered anadromous salmonids (oncorhynchus spp.), and lethal and nonlethal control programs have been instituted against both piscine and avian species. to determine the ... | 2008 | 18488627 |
| molecular evidence for the occurrence of contracaecum rudolphii a (nematoda: anisakidae) in shag phalacrocorax aristotelis (linnaeus) (aves: phalacrocoracidae) from sardinia (western mediterranean sea). | specimens of contracaecum rudolphii hartwich, 1964 (nematoda: anisakidae) from phalacrocorax aristotelis (linnaeus) from the archipelago of la maddalena (sardinia, western mediterranean sea) were characterised genetically and compared with c. rudolphii a sensu d'amelio et al. 1990 and c. rudolphii b sensu d'amelio et al. 1990 from phalacrocorax carbo sinensis (blumenbach) from north-eastern italy, and with c. rudolphii c sensu d'amelio et al. 2007 from phalacrocorax auritus (lesson) from west-ce ... | 2008 | 18571974 |
| nineteenth century mercury: hazard to wading birds and cormorants of the carson river, nevada. | contemporary mercury interest relates to atmospheric deposition, contaminated fish stocks and exposed fish-eating wildlife. the focus is on methylmercury (mehg) even though most contamination is of inorganic (iohg) origin. however, iohg is readily methylated in aquatic systems to become more hazardous to vertebrates. in response to a classic episode of historical (1859-1890) iohg contamination, we studied fish-eating birds nesting along the lower carson river, nevada. adult double-crested cormor ... | 2002 | 12211695 |
| linear and branched perfluorooctane sulfonate isomers in technical product and environmental samples by in-port derivatization-gas chromatography-mass spectrometry. | perfluorooctane sulfonate (pfos) is found globally as an environmental contaminant and is highly bioaccumulative in exposed biota including humans. however, there is a dearth of environmental information on the isomeric profile of pfos, especially in biological samples, which requires suitable analysis methods for the identification and quantification of ultratrace amounts. in the present study, a novel method was developed that incorporates clean up by solid-phase extraction (spe) wax cartridge ... | 2009 | 19402680 |
| species differences in the sensitivity of avian embryos to methylmercury. | 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 ... | 2009 | 18421496 |
| characterization of the life cycle of a fish eye fluke, austrodiplostomum ostrowskiae (digenea: diplostomidae), with notes on two other diplostomids infecting biomphalaria havanensis (mollusca: planorbidae) from catfish aquaculture ponds in mississippi, usa. | ocular diplostomiasis is caused by trematode species in the family diplostomidae, specifically those in the genera austrodiplostomum, diplostomum, and tylodelphys. diplostomid trematodes are globally distributed parasites of fish. heavy infections of diplostomids that parasitize the eyes of fish can result in acute mortality while chronic infections are often characterized by impaired vision or blindness. in the southeastern united states, commercial catfish production is threatened by piscivoro ... | 2016 | 26741049 |
| the phylogenetic position of the galápagos cormorant. | the endangered galápagos cormorant, phalacrocorax harrisi, is unique among the species of the phalacrocoracidae in being flightless and sequentially polyandrous. it has had a vexed taxonomic history, variously being lumped with all the species in phalacrocorax, being accorded its own genus, nannopterum, or being included in leucocarbo or compsohalieus. different authorities have similarly suggested a number of different species as being its closest relative. here we use novel mitochondrial dna s ... | 2009 | 19523526 |
| excretion of pathogenic newcastle disease virus by double-crested cormorants (phalacrocorax auritus) in absence of mortality or clinical signs of disease. | pathogenic newcastle disease virus (ndv) caused several epidemics of newcastle disease in double-crested cormorants (phalacrocorax auritus) in recent years. eleven 16-week-old cormorants were infected with, or exposed to, pathogenic ndv from one of these epidemics and monitored for 70 days. no birds died, four birds had transient ataxia between 12 and 27 days post-infection (d.p.i.), and one bird had neuronal necrosis and non-suppurative encephalitis characteristic for newcastle disease. the mea ... | 1998 | 18484041 |
| species-specific accumulation of polybrominated diphenyl ether flame retardants in birds of prey from the chesapeake bay region, usa. | compared to organochlorines, little is known about polybrominated diphenyl ether (pbde) contamination of birds of prey breeding in the chesapeake bay, the largest estuary in the u.s. this study examined and compared pbde contamination in eggs of osprey, double-crested cormorant, brown pelican and peregrine falcon from this area. several legacy persistent organic pollutants such as pcbs and dde were also investigated. the level of urbanization of the landscape appeared to influence the level of p ... | 2010 | 19948372 |
| evolutionary changes affecting rapid identification of 2008 newcastle disease viruses isolated from double-crested cormorants. | a morbidity-mortality event involving virulent newcastle disease virus (ndv) in wild double-crested cormorants (phalacrocorax auritus) occurred in north america in the summer of 2008. all 22 viruses isolated from cormorants were positively identified by the usda-validated real-time reverse transcription-pcr assay targeting the matrix gene. however, the usda-validated reverse transcription-pcr assay targeting the fusion gene that is specific for virulent isolates identified only 1 of these 22 iso ... | 2010 | 20107098 |
| correlation between an in vitro and an in vivo measure of dioxin sensitivity in birds. | we describe a statistically significant correlation between two well-characterized responses to dioxin-like compounds in birds; induction of 7-ethoxyresorufin-o-deethylase (erod) activity in cultured hepatocytes, and embryo mortality. data were obtained from a review of the literature. erod ec50 values for 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) and 6 polychlorinated biphenyls (pcbs) were strongly correlated with ld50 values in chicken embryos (r(2) = 0.93, p < 0.005). similarly, erod ec50 va ... | 2010 | 19784771 |
| description and phylogeny of a new species of eimeria from double-crested cormorants (phalacrocorax auritus) near fort gaines, georgia. | the renal parasite eimeria auritusi has caused several mortality events in double-crested cormorants (dcc; phalacrocorax auritus) in the midwest and southeastern united states. this parasite has only been detected during large-scale outbreaks, and its presence and prevalence in healthy populations of cormorants is unknown. in this study, 80 dcc were collected from the chattahoochee river near fort gaines, georgia, and examined for kidney and intestinal coccidia. eighteen (22.5%) and 56 (70%) of ... | 2006 | 16729699 |
| key amino acids in the aryl hydrocarbon receptor predict dioxin sensitivity in avian species. | dioxin-like compounds are toxic to most vertebrates, but significant differences in sensitivity exist among species. a recent study suggests that the amino acid residues corresponding to ile324 and ser380 in the chicken aryl hydrocarbon receptor 1 (ahr1) are important determinants of differential biochemical responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) in chickens and common terns. here, we investigate whether the identity of these amino acid residues can predict embryonic sensitivity ... | 2008 | 18939598 |
| polybrominated diphenyl ether flame retardants in eggs may reduce reproductive success of ospreys in oregon and washington, usa. | spatial and temporal assessments and reports of polybrominated diphenyl ether (pbde) flame retardants in birds remain sparse. in the present study, pbdes were detected in all 120 osprey (pandion haliaetus) eggs collected. the eggs were collected from nests along the columbia, willamette and yakima rivers of oregon (or) and washington (wa) and in puget sound (wa) between 2002 and 2007. pbde congeners: 17, 28, 47, 49, 66, 85, 99, 100, 138, 153, 154 (possible coelution with brominated biphenyl 153 ... | 2009 | 19513829 |
| a comparison of the teratogenicity of methylmercury and selenomethionine injected into bird eggs. | methylmercury chloride and seleno-l: -methionine were injected separately or in combinations into the fertile eggs of mallards (anas platyrhynchos), chickens (gallus gallus), and double-crested cormorants (phalacrocorax auritus), and the incidence and types of teratogenic effects were recorded. for all three species, selenomethionine alone caused more deformities than did methylmercury alone. when mallard eggs were injected with the lowest dose of selenium (se) alone (0.1 μg/g), 28 of 44 embryos ... | 2011 | 22042039 |
| experimental bolbophorus damnificus (digenea: bolbophoridae) infections in piscivorous birds. | in order to determine potential definitive hosts of the digenetic trematode, bolbophorus damnificus, two american white pelicans (pelecanus erythrorhynchos), two double-crested cormorants (phalacrocorax auritus), two great blue herons (ardea herodias), and two great egrets (ardea alba) were captured, treated with praziquantel, and fed channel catfish (ictalurus punctatus) infected with b. damnificus metacercariae. patent infections of b. damnificus, which developed in both american white pelican ... | 2009 | 19617478 |
| temporal trends of perfluoroalkyl substances (pfas) in eggs of coastal and offshore birds: increasing pfas levels associated with offshore bird species breeding on the pacific coast of canada and wintering near asia. | perfluoroalkyl substances (pfas) such as perfluoroalkyl carboxylates (pfcas) and perfluoroalkyl sulfonates (pfsas) have become virtually ubiquitous throughout the environment, and, based on laboratory studies, have known toxicological consequences. various national and international voluntary phase-outs and restrictions on these compounds have been implemented over the last 10 to 15 years. in the present study, we examine trends (1990/1991-2010/2011) in aquatic birds (ancient murrelet, synthlibo ... | 2015 | 25989421 |
| brominated flame retardant trends in aquatic birds from the salish sea region of the west coast of north america, including a mini-review of recent trends in marine and estuarine birds. | polybrominated diphenyl ethers (pbdes) increased in many matrices during the 1990s and early 2000s. since voluntary restrictions and regulations on pbdes were implemented in north america circa early 2000s, decreases in pbdes have occurred in many of these same matrices. to examine temporal trends in the north pacific, we retrospectively analysed pbdes and eight non-pbde flame retardants (fr) in eggs of two aquatic bird species, great blue herons, ardea herodias, and double-crested cormorants, p ... | 2015 | 25241209 |
| brevetoxicosis in seabirds naturally exposed to karenia brevis blooms along the central west coast of florida. | harmful algal bloom events caused by the dinoflagellate karenia brevis occurred along the central west florida, usa, coast from february 2005 through december 2005 and from august 2006 through december 2006. during these events, from 4 february 2005 through 28 november 2006, live, debilitated seabirds admitted for rehabilitation showed clinical signs that included disorientation, inability to stand, ataxia, and seizures. testing of blood, biologic fluids, and tissues for brevetoxin by enzyme-lin ... | 2013 | 23568900 |
| spatial and temporal patterns of avian paramyxovirus-1 outbreaks in double-crested cormorants (phalacrocorax auritus) in the usa. | morbidity and mortality events caused by avian paramyxovirus-1 (apmv-1) in double-crested cormorant (dcco; phalacrocorax auritus) nesting colonies in the us and canada have been sporadically documented in the literature. we describe apmv-1 associated outbreaks in dcco in the us from the first reported occurrence in 1992 through 2012. the frequency of apmv-1 outbreaks has increased in the us over the last decade, but the majority of events have continued to occur in dcco colonies in the midwester ... | 2015 | 25390762 |
| prevalence of avian paramyxovirus 1 and avian influenza virus in double-crested cormorants (phalacrocorax auritus) in eastern north america. | although it is well established that wild birds, such as cormorants, carry virulent avian paramyxovirus serotype 1 (apmv-1; causative agent of newcastle disease) and avian influenza virus (aiv), the prevalence of these viruses among double-crested cormorants (phalacrocorax auritus) in the great lakes region of north america has not been rigorously studied. we determined the prevalences of apmv-1 and aiv in double-crested cormorants from the interior population of eastern north america. from 2009 ... | 2013 | 24502724 |
| organochlorine contaminants in eggs of seabirds in the northwest atlantic, 1968-1984. | eggs of three seabird species, double-crested cormorant (phalacrocorax auritus). leach's storm-petrel (oceanodroma leucorhoa), and atlantic puffin (fratercula arctica) were collected at four-year intervals from 1968 to 1984, from colonies in eastern canada and analyzed for organochlorines. this monitoring study was established to provide data on contamination of the marine environment and possible implications for seabird health. long-term trend data are presented for pcbs, dde, dieldrin, hcb, o ... | 1989 | 15092478 |
| marine foraging birds as bioindicators of mercury in the gulf of maine. | from existing databases, we compiled and evaluated 604 total mercury (hg) levels in the eggs and blood of 17 species of marine foraging birds from 35 gulf of maine islands to provide baseline data and to determine the best tissue, age class, and species for future biomonitoring. while mean hg levels in most species did not exceed adverse effects thresholds, levels in some individual eggs did; for all species arithmetic mean egg hg levels ranged from 0.04 to 0.62 (microg/g, wet weight). piscivoro ... | 2008 | 19277786 |
| clinicopathological characterization in poultry of three strains of newcastle disease virus isolated from recent outbreaks. | newcastle disease is a severe threat to the poultry industry and is caused by newcastle disease virus, a member of the genus avulavirus, family paramyxoviridae. the virus is rapidly evolving, and several new genotypes have been discovered in the past few years. characterization of these strains is important to evaluate field changes, anticipate new outbreaks, and develop adequate control measures. three newcastle disease isolates (apmv-1/duck/vietnam, long bien/78/2002, apmv-1/chicken/australia/ ... | 2011 | 20685918 |
| perfluoroalkylphosphinic acids in northern pike (esox lucius), double-crested cormorants (phalacrocorax auritus), and bottlenose dolphins (tursiops truncatus) in relation to other perfluoroalkyl acids. | perfluoroalkyl phosphinic acids (pfpias) are perfluoroalkyl acids (pfaas) that are used for their surfactant properties in a variety of applications, resulting in their presence in environmental waters; however, they have not been widely studied in biota. a survey of pfpias was conducted in fish, dolphins, and birds from various locations in north america. northern pike (esox lucius) were collected at two locations in 2011 near montréal island in the st. lawrence river, canada, double-crested co ... | 2016 | 27677975 |
| free and forced diving in birds. | heart rates were measured during free and forced diving on each of two species of aquatic birds: the double-crested cormorant (phalacrocorax auritus), a true diver, and the canada goose (branta candensis), a bottom feeder in shallow water. when they immersed voluntarily they showed no bradycardia, but when the same birds were forcibly held under water there was a rapid drop in heart rate to well below that at rest. this decrease indicates that ther may be a large component of emotional stress in ... | 1981 | 7192883 |
| local and interannual variations in mercury and cadmium in eggs of eight seabird species of the sinaloa coast, méxico. | 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). t ... | 2016 | 26887632 |
| heat increment of feeding in double-crested cormorants (phalacrocorax auritus) and its potential for thermal substitution. | diving endotherms inhabiting polar regions face potentially high thermoregulatory costs. unless properly insulated, these animals will lose vast amounts of heat when diving in cold water, which has to be balanced by heat production. heat generated as a by-product of digestion (heat increment of feeding, hif) or from exercising muscles might be important in maintaining thermal balance under such conditions, as it would reduce the need for shivering thermogenesis. recording the rate of oxygen cons ... | 2008 | 18083732 |
| food web bioaccumulation model for polychlorinated biphenyls in san francisco bay, california, usa. | we document the development and application of a food web bioaccumulation model for polychlorinated biphenyls (pcbs) in san francisco bay, california, usa. the model calculates spatial distributions of pcb concentrations in a range of invertebrate, fish, avian, and mammalian organisms, including harbor seals, double-crested cormorants, and forster's terns. the performance of the model is evaluated against independent empirical pcb concentrations and shows a mean deviation between observed and mo ... | 2010 | 20821583 |
| heavy metal and selenium levels in birds at agassiz national wildlife refuge, minnesota: food chain differences. | the levels of heavy metals and selenium in the eggs and in breast feathers of adult doublecrested cormorant (phalacrocorax auritus), black-crowned night heron (nycticorax nycticorax), and franklin's gull (larus pipixcan) nesting at agassiz national wildlife refuge in marshall county, northwestern minnesota were examined. also examined were metal levels in the feathers of fledgling night herons and gulls, in the feathers of adult and fledgling american bittern (botaurus lentiginosus), in eggs of ... | 1996 | 24193900 |
| nutrient transfer from sea to land: the case of gulls and cormorants in the gulf of maine. | 1. the structure of communities is influenced by the transport of resources across ecosystem boundaries. seabirds are capable of introducing large amounts of marine-derived nutrients to land, thereby modifying resource availability to terrestrial species. 2. in this study we investigated the hypothesis that variation in nesting densities of great black-backed gulls larus marinus and double-crested cormorants phalacrocorax auritus would modify the effect of these species on soil nutrients and pla ... | 2006 | 16638009 |
| brominated and chlorinated flame retardants in san francisco bay sediments and wildlife. | restrictions on the use of polybrominated diphenyl ethers (pbdes) have resulted in the use of alternative flame retardants in consumer products to comply with flammability standards. in contrast to pbdes, information on the occurrence and fate of these alternative compounds in the environment is limited, particularly in the united states. in this study, a survey of flame retardants in san francisco bay was conducted to evaluate whether pbde replacement chemicals and other current use flame retar ... | 2012 | 22766500 |
| use of a novel double-crested cormorant toxchip pcr array and the erod assay to determine effects of environmental contaminants in primary hepatocytes. | in vitro screening tools and 'omics methods are increasingly being incorporated into toxicity studies to determine mechanistic effects of chemicals and mixtures. to date, the majority of these studies have been conducted with well-characterized laboratory animal models. in the present study, well-established methods developed for chicken embryonic hepatocyte (ceh) studies were extended to a wild avian species, the double-crested cormorant (dcco; phalacrocorax auritus), in order to compare the ef ... | 2016 | 26894911 |
| changes in white cell estimates and plasma chemistry measurements following oral or external dosing of double-crested cormorants, phalacocorax auritus, with artificially weathered mc252 oil. | scoping studies were designed whereby double-crested cormorants (phalacocorax auritus) were dosed with artificially weathered deepwater horizon (dwh) oil either daily through oil injected feeder fish, or by application of oil directly to feathers every three days. preening results in oil ingestion, and may be an effective means of orally dosing birds with toxicant to improve our understanding of the full range of physiological effects of oral oil ingestion on birds. blood samples collected every ... | 2017 | 28844686 |
| the influence of geographical location, host maturity and sex on intestinal helminth communities of the double-crested cormorant phalacrocorax auritus from the eastern united states. | here the intestinal helminth infracommunities of 218 double-crested cormorants (phalacrocorax auritus) from 11 locations in alabama, minnesota, mississippi and vermont are documented. trematode infections were present in 98% of hosts; 65% of cormorants carried cestode infections, 4% were infected with acanthocephalans and 66% had nematode intestinal parasites. parasite infracommunities of hosts collected on wintering grounds had higher richness and diversity than did birds collected on breeding ... | 2016 | 27677375 |
| widespread detection of antibodies to eastern equine encephalitis, west nile, st. louis encephalitis, and turlock viruses in various species of wild birds from across the united states. | wild birds serve as amplifying hosts for many arboviruses, and are thought to be responsible for introducing these viruses into new areas during migration as well as reintroducing them to places where winter temperatures disrupt mosquito-borne transmission. to learn more about four mosquito-borne arboviruses of concern to human or animal health, we tested sera from 997 wild birds of 54 species and 17 families across 44 states of the united states collected from january 1, 2013, through september ... | 2016 | 27162269 |
| testing of an oral dosing technique for double-crested cormorants, phalacocorax auritus, laughing gulls, leucophaeus atricilla, homing pigeons, columba livia, and western sandpipers, calidris mauri, with artificially weather mc252 oil. | scoping studies were designed to determine if double-crested cormorants (phalacocorax auritus), laughing gulls (leucophaues atricilla), homing pigeons (columba livia) and western sandpipers (calidris mauri) that were gavaged with a mixture of artificially weathered mc252 oil and food for either a single day or 4-5 consecutive days showed signs of oil toxicity. where volume allowed, samples were collected for hematology, plasma protein electrophoresis, clinical chemistry and electrolytes, oxidati ... | 2017 | 28781207 |
| a new species of drepanocephalus dietz, 1909 (digenea: echinostomatidae) from the double-crested cormorant phalacrocorax auritus (lesson) (aves: phalacrocoracidae) in north america. | drepanocephalus auritus n. sp. is described based on specimens from the double-crested cormorant phalacrocorax auritus (lesson) in north america. the new species differs from its congeners in its very narrow, elongate body, long uterine field and widely separated testes. sequences of the nuclear rrna gene cluster, spanning the 3' end of the nuclear ribosomal 18s rrna gene, internal transcribed spacer region (its1+5.8s gene+its2) and partial 28s gene (2,345 bp), were identical in specimens collec ... | 2015 | 25693456 |
| genetic characterization of members of the genus contracaecum (nematoda: anisakidae) from fish-eating birds from west-central florida, usa, with evidence of new species. | specimens of contracaecum spp. from phalacrocorax auritus and pelecanus occidentalis from florida were characterized by sequencing of the small subunit of the mitochondrial ribosomal rna gene (rrns) and by pcr-based rflp analysis of the same gene and of the internal transcribed spacers (its) of nuclear ribosomal dna. analyses of the rrns sequence data using the mp and upgma approaches yielded trees with similar topologies, delineating 3 main clusters. specimens from ph. auritus, morphologically ... | 2007 | 17352849 |
| description of a new eimeria sp. and associated lesions in the kidneys of double-crested cormorants (phalocrocorax auritus). | a new eimeria sp. is described as the cause of an outbreak of renal coccidiosis in double-crested cormorants (phalacrocorax auritus) in georgia. sporulated oocysts were spherical to subspherical and measured 16.1 x 16.5 (13.8-18 x 14-19) microm, with an average length-width ratio of 1:1. oocyst wall was thin (1 microm), greenish, and pitted on the outer surface. micropyle, micropylar cap, stieda body, and polar bodies were absent. small oocyst residuum (4-8 granules) was usually absent but occas ... | 2002 | 12537118 |
| great lakes embryo mortality, edema, and deformities syndrome (glemeds) in colonial fish-eating birds: similarity to chick-edema disease. | several species of colonial fish-eating birds nesting in the great lakes basin, including herring gulls, common terns and double-crested cormorants, have exhibited chronic impairment of reproduction. in addition to eggshell thinning caused by high levels of ddt and metabolites, the reproductive impairment is characterized by high embryonic and chick mortality, edema, growth retardation, and deformities, hence the name great lakes embryo mortality, edema, and deformities syndrome (glemeds). the h ... | 1991 | 1875430 |
| embryonic abnormalities and organochlorine contamination in double-crested cormorants (phalacrocorax auritus) and caspian terns (hydroprogne caspia) from the upper great lakes in 1988. | persistent organochlorine contaminants including polychlorinated dibenzo-p-dioxins (pcdds), polychlorinated dibenzofurans (pcdfs) and polychlorinated biphenyls (pcbs) were determined in eggs with normal and deformed embryos collected in 1988 from different colonies during an epizootiological survey of double-crested cormorants (phalacrocorax auritus) and caspian terns (hydroprogne caspia) from the upper great lakes. pcbs and p,p'-dde were found in the highest concentrations in eggs of both speci ... | 1993 | 15091901 |
| tracking overwintering areas of fish-eating birds to identify mercury exposure. | migration patterns are believed to greatly influence concentrations of contaminants in birds due to accumulation in spatially and temporally distinct ecosystems. two species of fish-eating birds, the double-crested cormorant (phalacrocorax auritus) and the caspian tern (hydroprogne caspia) breeding in lake ontario were chosen to measure the impact of overwintering location on mercury concentrations ([hg]). we characterized (1) overwintering areas using stable isotopes of hydrogen (δ(2)h) and ban ... | 2015 | 25514043 |
| contamination of mercury during the wintering period influences concentrations at breeding sites in two migratory piscivorous birds. | many aquatic fish-eating birds migrate long distances and are exposed to different mercury concentrations ([hg]) during their annual cycle. here we examined the importance of migration on [hg] in two colonial migratory fish-eating bird species. we determined temporal trends of [hg] and stable isotopes of carbon (δ(13)c) and nitrogen (δ(15)n) during the annual cycle in double-crested cormorants (phalacrocorax auritus) and caspian terns (hydroprogne caspia) breeding in lake ontario by a repeated s ... | 2014 | 25380025 |
| dermal exposure to weathered mc252 crude oil results in echocardiographically identifiable systolic myocardial dysfunction in double-crested cormorants (phalacrocorax auritus). | during the deepwater horizon natural resource damage assessment, gross morphologic cardiac abnormalities, including softer, more distensible musculature, were noted upon gross necropsy in hearts from laughing gulls and double-crested cormorants exposed to weathered mc252 crude oil. a species specific, echocardiographic technique was developed for antemortem evaluation of function that was used to evaluate and better characterize cardiac dysfunction. control (n=12) and treated (n=13) cormorant gr ... | 2017 | 28666537 |
| tracking the history and ecological changes of rising double-crested cormorant populations using pond sediments from islands in eastern lake ontario. | 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 ... | 2015 | 26214177 |
| reprint of: assay validation of the cardiac isoform of troponin i in double crested cormorant (phalacrocorax auritus) plasma for diagnosis of cardiac damage. | cardiac abnormalities, initially found in deepwater horizon weathered mc252 crude oil exposed double crested cormorants (dccos) upon gross necropsy, were further investigated using echocardiography. clinical and statistically significant changes including decreased ventricular myocardial contractility and arrhythmia were elucidated by echocardiography and interpreted by boarded cardiologists as potentially life threatening. the objective of this investigation was to initiate development of an an ... | 2017 | 28571623 |
| reprint of: development of methods for avian oil toxicity studies using the double crested cormorant (phalacrocorax auritus). | oral and external dosing methods replicating field exposure were developed using the double crested cormorant (dcco) to test the toxicity of artificially weathered deepwater horizon mississippi canyon 252 oil. the majority of previous oil dosing studies conducted on wild-caught birds used gavage methods to dose birds with oil and determine toxicity. however, rapid gut transit time of gavaged oil likely reduces oil absorption. in the present studies, dosing relied on injection of oil into live fe ... | 2017 | 28571622 |
| immunological and reproductive health assessment in herring gulls and black-crowned night herons in the hudson-raritan estuary. | 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 nycti ... | 2013 | 23212976 |
| athabasca oil sands petcoke extract elicits biochemical and transcriptomic effects in avian hepatocytes. | petroleum coke or "petcoke" is a granular carbonaceous material produced during the upgrading of heavy crude oils, including bitumen. petcoke dust was recently reported as an environmental contaminant in the athabasca oil sands region, but the ecotoxicological hazards posed by this complex bitumen-derived material-including those to avian species-have not been characterized. in this study, solvent extracts (x) of delayed and fluid petcoke (xdp and xfp) were prepared and dissolved in dimethyl sul ... | 2017 | 28453253 |
| polychlorinated naphthalenes, -biphenyls, -dibenzo-p-dioxins, and -dibenzofurans in double-crested cormorants and herring gulls from michigan waters of the great lakes. | concentrations of polychlorinated dibenzo-p-dioxins (pcdds), dibenzofurans (pcdfs), naphthalenes (pcns), and biphenyls (pcbs) were measured in eggs of double-crested cormorants and herring gulls collected from michigan waters of the great lakes. concentrations of pcns in eggs of double-crested cormorants and herring gulls were in the ranges of 380-2400 and 83-1300 pg/g, wet wt, respectively. concentrations of 2,3,7,8-substituted pcdds and pcdfs were 10-200 times less than those of pcns in eggs w ... | 2001 | 11351712 |
| effects of egg size on double-crested cormorant (phalacrocorax auritus) egg composition and hatchling phenotype. | maternal investment of yolk and albumen in avian eggs varies with egg mass and contributes to variation in hatchling mass. here we use the natural variation in mass and composition of double-crested cormorant (phalacrocorax auritus) eggs to examine consequences of variation in yolk and albumen mass on hatchling phenotype. the double-crested cormorant, a large bird with altricial young, lays eggs ranging in mass from 40 to 60 g and containing an average of 82% albumen and 18% yolk. variation in c ... | 2009 | 19000773 |
| development of methods for avian oil toxicity studies using the double crested cormorant (phalacrocorax auritus). | oral and external dosing methods replicating field exposure were developed using the double crested cormorant (dcco) to test the toxicity of artificially weathered deepwater horizon mississippi canyon 252 oil. the majority of previous oil dosing studies conducted on wild-caught birds used gavage methods to dose birds with oil and determine toxicity. however, rapid gut transit time of gavaged oil likely reduces oil absorption. in the present studies, dosing relied on injection of oil into live fe ... | 2017 | 28349871 |
| organ weights and histopathology of double-crested cormorants (phalacrocorax auritus) dosed orally or dermally with artificially weathered mississippi canyon 252 crude oil. | a series of toxicity tests were conducted to assess the effects of low to moderate exposure to artificially weathered deepwater horizon mississippi canyon 252 crude oil on representative avian species as part of the natural resource damage assessment. the present report summarizes effects of oral exposure (n=26) of double-crested cormorants (dcco; phalacrocorax auritus) to 5 or 10ml oil kg(-1) day(-1) for up to 21 days or dermal application (n=25) of 13ml oil to breast and back feathers every th ... | 2017 | 28734790 |
| weathered mc252 crude oil-induced anemia and abnormal erythroid morphology in double-crested cormorants (phalacrocorax auritus) with light microscopic and ultrastructural description of heinz bodies. | injury assessment of birds following the deepwater horizon (dwh) oil spill in 2010 was part of the natural resource damage assessment. one reported effect was hemolytic anemia with the presence of heinz bodies (hb) in birds, however, the role of route and magnitude of exposure to oil is unknown. the purpose of the present study was to determine if double-crested cormorants (phalacocorax auritis; dcco) exposed orally and dermally to artificially weathered crude oil would develop hemolytic anemia ... | 2017 | 28734789 |
| assay validation of the cardiac isoform of troponin i in double crested cormorant (phalacrocorax auritus) plasma for diagnosis of cardiac damage. | cardiac abnormalities, initially found in deepwater horizon weathered mc252 crude oil exposed double crested cormorants (dccos) upon gross necropsy, were further investigated using echocardiography. clinical and statistically significant changes including decreased ventricular myocardial contractility and arrhythmia were elucidated by echocardiography and interpreted by boarded cardiologists as potentially life threatening. the objective of this investigation was to initiate development of an an ... | 2017 | 28314141 |
| no one saw this coming: endoparasitic mites behind the eyes of a double-crested cormorant. | we found hundreds of mites behind the eyes of a double-crested cormorant, phalacrocorax auritus (suliformes: phalacrocoracidae). the mites were neottialges evansi (acari: hypoderatidae), representing the first report of this parasite in p. auritus from western north america. deutonymphs of n. evansi are endoparasites, typically reported infecting fat deposits over the pectoral muscles, axillary areas, and vent of cormorants. here mites infected only orbital tissues, a new infection site for hypo ... | 2017 | 28165862 |
| using species distribution models to define nesting habitat of the eastern metapopulation of double-crested cormorants. | when organisms with similar phenotypes have conflicting management and conservation initiatives, approaches are needed to differentiate among subpopulations or discrete groups. for example, the eastern metapopulation of the double-crested cormorant (phalacrocorax auritus) has a migratory phenotype that is culled because they are viewed as a threat to commercial and natural resources, whereas resident birds are targeted for conservation. understanding the distinct breeding habitats of resident ve ... | 2017 | 28070303 |
| isotopic discrimination in the double-crested cormorant (phalacrocorax auritus). | the diet-tissue discrimination factor is the amount by which a consumer's tissue varies isotopically from its diet, and is therefore a key element in models that use stable isotopes to estimate diet composition. in this study we measured discrimination factors in blood (whole blood, red blood cells and plasma), liver, muscle and feathers of double-crested cormorants (phalacrocorax auritus) for stable isotope ratios of carbon, nitrogen and sulfur. cormorants exhibited discrimination factors that ... | 2015 | 26473353 |
| dietary intake of deepwater horizon oil-injected live food fish by double-crested cormorants resulted in oxidative stress. | the deepwater horizon oil spill released 134 million gallons of crude oil into the gulf of mexico making it the largest oil spill in us history and exposing fish, birds, and marine mammals throughout the gulf of mexico to its toxicity. fish eating waterbirds such as the double-crested cormorant (phalacrocorax auritus) were exposed to the oil both by direct contact with the oil and orally through preening and the ingestion of contaminated fish. this study investigated the effects of orally ingest ... | 2017 | 28688517 |
| reprint of: cyp1a protein expression and catalytic activity in double-crested cormorants experimentally exposed to deepwater horizon mississippi canyon 252 oil. | double-crested cormorants (phalacrocorax auritus, dcco) were orally exposed to deepwater horizon mississippi canyon 252 (dwh) oil to investigate oil-induced toxicological impacts. livers were collected for multiple analyses including cytochrome p4501a (cyp1a) enzymatic activity and protein expression. cyp1a enzymatic activity was measured by alkoxyresorufin o-dealkylase (arod) assays. activities specific to the o-dealkylation of four resorufin ethers are reported: benzyloxyresorufin o-debenzylas ... | 2017 | 28571624 |
| a positive correlation between mercury and oxidative stress-related gene expression (gpx3 and gstm3) is measured in female double-crested cormorant blood. | mercury (hg) is a widespread contaminant that has been shown to induce a wide range of adverse health effects in birds including reproductive, physiological and neurological impairments. here we explored the relationship between blood total hg concentrations ([thg]) and oxidative stress gene induction in the aquatic piscivorous double-crested cormorants (phalacrocorax auritus) using a non-lethal technique, i.e., blood gene expression analysis. p. auritus blood was sampled at five sites across th ... | 2014 | 24788667 |
| geographic segregation and evidence of density-dependent changes in sex ratios in an abundant colonial waterbird. | demographic information, such as geographic segregation of sexes and sex ratio data, is needed to develop, model and evaluate conservation and management strategies for wildlife. a variety of physiological, behavioral and environmental factors can influence segregation of sexes and sex ratios, many of which originate with density-dependent processes. departure from 50:50 sex ratios of double-crested cormorants (phalacrocorax auritus) collected during control efforts in breeding and wintering are ... | 2014 | 24750575 |
| differential trends in mercury concentrations in double-crested cormorant populations of the canadian prairies. | mercury and selenium concentrations were measured in double-crested cormorants (phalacrocorax auritus), piscivorous fish, and common prey items in five lakes in two ecoregions in saskatchewan, canada. hg and se concentrations in cormorants were within the natural ranges of birds living in un-impacted sites. site explained a significant proportion of the variation in total hg (thg) and methylmercury (mehg) concentrations in both cormorant breast muscle and livers. birds nesting on more northern l ... | 2014 | 24515398 |
| social contagion of risk perceptions in environmental management networks. | an important requisite for improving risk communication practice related to contentious environmental issues is having a better theoretical understanding of how risk perceptions function in real-world social systems. our study applied scherer and cho's social network contagion theory of risk perception (snctrp) to cormorant management (a contentious environmental management issue) in the great lakes basin to: (1) assess contagion effects on cormorant-related risk perceptions and individual facto ... | 2013 | 23231537 |
| double-crested cormorant (phalacrocorax auritus) nesting effects on understory composition and diversity on island ecosystems in lake erie. | the context for this study is the management concerns over the severity and extent of the impact of cormorants on island flora in the recent past on lake erie islands. accordingly, this study sought to quantify the nesting colonies' influence on coarse woody litter and how nest densities and litter depth may influence the herbaceous layer, the seed bank composition and viability across the extent of three lake erie islands. the data for this study were collected from 2004 to 2008 on east sister ... | 2012 | 22643824 |
| genetic sequence data identifies the cercaria of drepanocephalus spathans (digenea: echinostomatidae), a parasite of the double-crested cormorant (phalacrocorax auritus), with notes on its pathology in juvenile channel catfish (ictalurus punctatus). | an unidentified xiphidio-type cercaria, previously thought inconsequential to catfish health, was found to be released from marsh rams-horn snails (planorbella trivolvis) inhabiting ponds on a commercial catfish operation in the mississippi delta. a preliminary challenge of cohabiting channel catfish ( ictalurus punctatus ) with snails actively shedding the unidentified cercariae resulted in death of some fish. a second cohabitation trial yielded similar results, as did a third challenge of 250 ... | 2012 | 22519725 |
| connecting breeding and wintering habitats of migratory piscivorous birds: implications for tracking contaminants (hg) using multiple stable isotopes. | contaminant concentrations in migratory species are complicated by differential accumulation and elimination among geographically separated biomes. double-crested cormorants ( phalacrocorax auritus ) are used as monitors of hg in north america; however, migration from northern breeding colonies to southern marine, freshwater, and aquaculture systems exposes individuals to spatiotemporal variations in contaminant uptake. we used stable isotopes (δ(34)s, δ(13)c, δ(15)n, δ(2)h) in primary feathers ... | 2012 | 22385064 |
| bone laminarity in the avian forelimb skeleton and its relationship to flight mode: testing functional interpretations. | wing bone histology in three species of birds was characterized in order to test hypotheses related to the relationship between skeletal microstructure and inferred wing loading during flight. data on the degree of laminarity (the proportion of circular vascular canals) and the occurrence of secondary osteons were obtained from three species that utilize different primary flight modes: the double-crested cormorant, a continuous flapper; the brown pelican, a static soarer; and the laysan albatros ... | 2012 | 22241723 |
| perfluoroalkyl compounds (pfcs) in wildlife from an urban estuary. | previous research has documented the bioaccumulation of perfluoroalkyl compounds (pfcs) in apex predators in remote locations but few studies have evaluated urban estuaries. to assess the importance of pfcs in san francisco bay, two apex predators in the san francisco bay, double-crested cormorants (phalacrocorax auritus) and pacific harbor seals (phoca vitulina richardii), were sampled. prey fish (atherinops affinis and menidia audens) were also evaluated to better understand potential sources ... | 2012 | 22134832 |
| assessing the validity of the accelerometry technique for estimating the energy expenditure of diving double-crested cormorants phalacrocorax auritus. | over the past few years, acceleration-data loggers have been used to provide calibrated proxies of energy expenditure: the accelerometry technique. relationships between rate of oxygen consumption and a derivation of acceleration data termed "overall dynamic body acceleration" (odba) have now been generated for a range of species, including birds, mammals, and amphibians. in this study, we examine the utility of the accelerometry technique for estimating the energy expended by double-crested cor ... | 2011 | 21460533 |