Publications

isolation of salmonella spp. from dead gulls (larus californicus and larus delawarensis) from an idaho irrigation reservoir.	an epizootic of unknown etiology resulting in the death of about 500 sea gulls (larus californicus and larus delawarensis) in 24 hr occurred on an irrigation reservoir in southwestern idaho in april 1975. salmonella spp. were isolated from necropsy specimens from 2 of 6 gulls examined. no salmonella spp. were isolated from fecal specimens or dead gulls collected at a nesting site.	1977	334150
organochlorine poisoning of ring-billed gulls in southern ontario.	clinical, necropsy, bacteriologic, parasitologic, histopathologic, toxicologic and animal inoculation studies suggest that organochlorine (pbc, dieldrin and dde) poisoning was an important factor in causing deaths of free-flying ring-billed gulls (larus delawarensis) in southern ontario in 1969 and 1973. the brains of gulls dying with clinical signs of neurologic involvement, and dead gulls with no other apparent cause of death, contained organochlorine residues of significantly greater levels t ...	1977	410957
prevalence of salmonella spp., campylobacter spp. and listeria spp. in ring-billed gulls (larus delawarensis).	cloacal swabs collected from 264 ring-billed gulls (larus delawarensis) at four sites near montréal, canada were cultured for the presence of salmonella spp., campylobacter spp. and listeria spp. all birds were apparently healthy when captured or killed. of all birds examined, 8.7%, 15.9% and 9.5%, respectively, were infected with salmonella spp., campylobacter spp. and listeria monocytogenes. overall, 29.9% of gulls sampled harbored one or more of these bacteria. gulls probably play only a mino ...	1992	1474648
influenza viruses in birds of the atlantic flyway.	isolation of type a influenza viruses from the feces of 5013 birds of 16 species was attempted during a 33-month study (1977-79). seventy viruses were isolated from the feces of 3403 ring-billed gulls in baltimore, md., during 16 months of sampling. six hemagglutinin (ha) subtypes and seven neuraminidase (na) subtypes in 15 combinations were found. the h13n6 virus was the only subtype found each year and accounted for 40% of the isolates. the rate of isolation from gulls was 0.26% in the cold mo ...	1992	1567297
magnetic maps in pigeons.	the homing of racing pigeons is often slowed down on days of high sun-spot activity or variability in the earth's magnetic field. the orientation of ring-billed gull chicks as well as the vanishing bearings of homing pigeons also seem to change in response to variability in the earth's magnetic field. furthermore, homing pigeons released under sunny skies at locations where the earth's magnetic field is distributed are disoriented, yet pigeons equipped with devices that change the magnetic field ...	1991	1838522
vaccinia recombinant virus expressing the rabies virus glycoprotein: safety and efficacy trials in canadian wildlife.	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 mo ...	1990	2249183
nitrite poisoning in herring gulls (larus argentatus) and ring-billed gulls (larus delawarensis).	landfill disposal of a fertilizer manufacturing waste product was associated with a die-off of gulls in new hanover county, north carolina. an estimated 250 herring and ring-billed gulls were found dead at the site following the initial disposal of this material. chemical analyses revealed that the fertilizer waste contained predominately calcium (12.0 to 22.2%) and nitrite (3.0 to 15.2%). contents of the proventriculi and gizzards of dead gulls also contained calcium (3.0 to 10.9%) and nitrite ...	1986	3016349
strychnine poisoning of aquatic birds.	strychnine poisoning was diagnosed in free-flying mallards (anas platyrhynchos) and a ring-billed gull (larus delawarensis) found dead on a pond in a zoo. the probable source of toxin was improperly applied strychnine-treated grain used for control of rodents on adjacent farm land. ingesta of the birds contained 19.7-85.1 mg/kg of strychnine.	1987	3586216
organochlorine chemical residues in herring gulls, ring-billed gulls, and common terns of western lake superior.		1986	3729548
host range of a/chicken/pennsylvania/83 (h5n2) influenza virus.	the highly pathogenic a/chicken/penn./1370/83 (h5n2) avian influenza virus, which caused 80% mortality in chickens in pennsylvania, produced only mild transient illness in experimentally infected pheasants, little or no clinical signs in ring-billed gulls and pigs, and no clinical signs in pekin ducks. virus could be recovered from only the upper respiratory tract of gulls and pigs for 1-2 days. infection in ducks resulted in intestinal replication of virus in only 1 out of 12 ducks. by contrast ...	1985	3985875
ddt residues in an east coast estuary: a case of biological concentration of a persistent insecticide.	ddt residues in the soil of an extensive salt marsh on the south shore of long island averaged more than 13 pounds per acre (15 kilograms per hectare); the maximum was 32 pounds per acre (36 kilograms per hectare). a systematic sampling of various organisms from the vicinity showed concentrations of ddt increasing with trophic level through more than three orders of magnitude from 0.04 part per million in plankton to 75 parts per million in a ring-billed gull. highest concentrations occurred in ...	1967	6022229
characterization of a novel haemagglutinin subtype (h13) of influenza a viruses from gulls.	influenza a virus strains isolated in the united states of america from ring-billed and franklin gulls (larus delawarensis, l. pipixcan) were found to possess a haemagglutinin (ha) antigen distinct from those of the twelve previously designated haemagglutinin subtypes of influenza a virus. serological assays with antisera to reference strains representing the ha subtypes 1-12 and to a gull isolate, a/gull/maryland/704/77, showed that the haemagglutinin of the gull virus was not related antigenic ...	1983	6194911
a winter outbreak of acute histoplasmosis in northern michigan.	in january 1980, an outbreak of 138 cases of acute pulmonary disease occurred among employees of a michigan limestone quarry. the source of exposure was a vessel repair building (relative risk = 5.8) and the time of exposure was january 10 (relative risk = 2.4). work activities associated with the specific place and time suggested exposure to a pulley which had been stored in a ring-billed gull nesting area as the cause of illness. histoplasma capsulatum was recovered from the nesting area, the ...	1983	6823954
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
impact of the ring-billed gull (larus delawarensis) on the microbiological quality of recreational water.	we evaluated the impact of the ring-billed gull (larus delawarensis) on the microbiological quality of water. we measured fecal coliforms, salmonella spp., and aeromonas spp. in the gull droppings and the number of fecal coliforms in the water prior to and after attracting these birds to the beach with food. gulls can contribute to the bacteriological degradation of recreational water.	1993	8489231
probable epizootic chlamydiosis in wild california (larus californicus) and ring-billed (larus delawarensis) gulls in north dakota.	during the summer of 1986, more than 400 california gulls (larus californicus) and ring-billed gulls (larvus delawarensis), primarily fledglings, died on an island in lake sakakawea near new town, north dakota (usa). mortality was attributed largely to chlamydiosis. necropsy findings in nine carcasses included splenomegaly (n = 9), hepatomegaly (n = 4), and pericarditis (n = 1). livers from three california gulls and two ring-billed gulls, and spleens from the same five birds plus a third ring-b ...	1995	8592370
newcastle disease viruses in birds in the atlantic flyway: isolations, haemagglutination-inhibition and elution-inhibition antibody profiles.	the study involved 15 avian species with 5,012 attempts to isolate newcastle disease viruses (ndv) from their faeces over a three-year period (1977-1979). ndv were isolated from asymptomatic adult canada geese, nestling royal terms, a juvenile european mute swan, and adult tundra swans on the eastern flyway. ring-billed gulls were negative for haemagglutination-inhibition (hi), elution-inhibition (ei) (anti-neuraminidase) antibodies, and ndv despite 3,403 isolation attempts. the ei antibody assa ...	1996	8767883
begging as graded signals of need for food in young ring-billed gulls.	recent models suggest that begging vocalizations are honest signals communicating a chick's nutritional needs to its parents. we investigated the effects on begging of short-term food deprivation ('hunger') and long-term reduction in body condition under controlled laboratory conditions in ring-billed gulls, larus delawarensis. we tested two condition groups (high: fed to satiation; low: fed 75% wet mass of high-condition diet) at three levels of short-term food deprivation (1, 4 and 12 h). begg ...	1998	9710464
proximate and ultimate causes of adoption in ring-billed gulls.	from 1987 to 1994, the annual frequency of adoption by breeding pairs at a lake erie ring-billed gull, larus delawarensis, colony ranged from 3 to 37% (average 8%/year, n=7 years) and, on average, foster parents raised 0.5 fewer of their own chicks to fledging than pairs that did not adopt. the key evolutionary question is: why do some individuals apparently suffer the costs associated with a behaviour that appears to enhance the fitness of others? from 1992 to 1995, i investigated the proximate ...	1998	9933551
seasonal enumeration of fecal coliform bacteria from the feces of ring-billed gulls (larus delawarensis) and canada geese (branta canadensis).	water suppliers have often implicated roosting birds for fecal contamination of their surface waters. geese and gulls have been the primary targets of this blame although literature documenting the fecal coliform content of these birds is quite limited. to determine the actual fecal coliform concentrations of these birds, fecal samples from 249 ring-billed gulls and 236 canada geese in westchester county, n.y., were analyzed over a 2-year period. results indicate that gull feces contain a greate ...	1999	10584032
pulmonary histopathology in ring-billed gulls (larus delawarensis) from colonies near steel mills and in rural areas.		2001	11443324
evidence of avian pneumovirus spread beyond minnesota among wild and domestic birds in central north america.	to detect avian pneumovirus (apv) in central north america, nasal turbinates or choanal deft tissues from domestic turkeys and wild birds were examined for the presence of apv rna by reverse transcriptase-polymerase chain reaction (rt-pcr), whereas serum samples from domestic turkeys were analyzed for apv antibodies by enzyme-linked immunosorbent assay (elisa). in 2002, the seroprevalence of disease in domestic turkeys in minnesota remained high (42.3% of the flocks). in addition, there is evide ...	2004	15666873
comparing the retinal structures and functions in two species of gulls (larus delawarensis and larus modestus) with significant nocturnal behaviours.	ring-billed gulls (larus delawarensis) and gray gulls (larus modestus) are two species active both by day and night. we have investigated the retinal adaptations that allow the diurnal and nocturnal behaviours of these two species. electroretinograms and histological analyses show that both species have a duplex retina in which cones outnumber rods, but the number of rods appears sufficient to provide vision at night. their retinas respond over the same scotopic dynamic range of 3.4logcdm(-2), w ...	2006	16647740
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
prevalence of cryptosporidium species in wildlife populations within a watershed landscape in southeastern new york state.	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-alo ...	2007	17466459
a new genus and species of mite from the nasal cavity of the ring-billed gull (acarina, epidermoptidae).		1949	18153100
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
identification of human enteric pathogens in gull feces at southwestern lake michigan bathing beaches.	ring-billed (larus delawarensis ord, 1815) and herring (larus argentatus pontoppidan, 1763) gulls are predominant species of shorebirds in coastal areas. gulls contribute to the fecal indicator burden in beach sands, which, once transported to bathing waters, may result in water quality failures. the importance of these contamination sources must not be overlooked when considering the impact of poor bathing water quality on human health. this study examined the occurrence of human enteric pathog ...	2008	19096455
escherichia coli populations in great lakes waterfowl exhibit spatial stability and temporal shifting.	populations of escherichia coli from juvenile and adult ring-billed gulls, juvenile common terns, and adult canada geese were sampled over 6 years at five locations on lake superior (duluth, mn, and wisconsin) and lake michigan (wisconsin, illinois, and indiana) to determine the extent of spatial and temporal variability in e. coli strains. strain identity was determined using horizontal fluorophore-enhanced repetitive element palindromic dna fingerprinting. multivariate statistics were used to ...	2009	19139226
bacteroidales diversity in ring-billed gulls (laurus delawarensis) residing at lake michigan beaches.	this study investigated the occurrence and diversity of bacteroidales fecal bacteria in gulls residing in the great lakes region. members of this bacterial order have been widely employed as human and bovine host-specific markers of fecal pollution; however, few studies have focused on gulls, which can be a major source of fecal indicator bacteria and pathogens at beaches. we found a low but consistent occurrence of bacteroidales in gulls at five beaches in three different counties spanning the ...	2009	19151182
avian influenza virus h13 circulating in ring-billed gulls (larus delawarensis) in southern ontario, canada.	avian influenza virus (aiv) was studied in ring-billed gulls (larus delawarensis) in one breeding colony on lake erie in 2000, and two on lake ontario in both 2000 and 2004. antibodies to h13 aiv were detected in 92% of adults in 2000 and 82% in 2004. antibody prevalence in 3-wk-old chicks was 5%-30% (overall 15%) in 2000 and 21% and 76% (overall 48%) in 2004. in 5-wk-old chicks, antibody prevalence was 23%-75% (overall 53%) in 2000 and 53% and 79% (overall 66%) in 2004. geometric mean antibody ...	2010	20521671
perfluoroalkyl carboxylates and sulfonates and precursors in relation to dietary source tracers in the eggs of four species of gulls (larids) from breeding sites spanning atlantic to pacific canada.	in the present study, we identified and examined the spatial trends, sources and dietary relationships of bioaccumulative perfluorinated sulfonate (pfsa; c(6), c(8), and c(10) chain lengths) and carboxylate (pfca; c(6) to c(15) chain lengths) contaminants, as well as precursor compounds including several perfluorinated sulfonamides, and fluorotelomer acids and alcohols, in individual eggs (collected in 2008) from four gull species [glaucous-winged (larus glaucescens), california (larus californi ...	2011	21529948
Waterfowl abundance does not predict the dominant avian source of beach Escherichia coli.	The horizontal, fluorophore enhanced, rep-PCR (HFERP) DNA fingerprinting technique was used to identify potential sources of in water, nearshore sand, and sediment at two beaches in the Duluth-Superior Harbor, near Duluth, MN, and Superior, WI, during May, July, and September 2006. An animal or environmental source could be identified for 35, 29, and 30% of strains in water, sand, and sediments, respectively. Waterfowl, including Canada geese, ring-billed gulls, and mallard ducks, were the lar ...	2011	22031576
egg oiling to reduce hatch-year ring-billed gull numbers on chicago's beaches during swim season and water quality test results.	a burgeoning ring-billed gull population along chicago's lake michigan beaches contributes to degraded water quality through fecal contamination. egg oiling was conducted at chicago's gull colonies to reduce production and the influx of hatch-year (hy) gulls using chicago's beaches, with a second, long-term objective of eventually reducing adult gull numbers through attrition. we also investigated swim season water quality trends through the course of this work. from 2007 to 2009, 52, 80, and 81 ...	2012	22492207
novel flame retardants in urban-feeding ring-billed gulls from the st. lawrence river, canada.	this study investigated the occurrence of a comprehensive suite of polybrominated diphenyl ethers (pbdes) and current-use flame retardants (frs) in ring-billed gulls breeding in a highly industrialized section of the st. lawrence river, downstream from montreal (qc, canada). despite major point-sources and diffuse contamination by frs, nearly no fr data have been reported in birds from this area. bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (behtbp) was detected in 89% of ring-billed gull liver ...	2012	22845168
north american birds as potential amplifying hosts of japanese encephalitis virus.	japanese encephalitis virus (jev) is an emerging arbovirus, and inter-continental spread is an impending threat. the virus is maintained in a transmission cycle between mosquito vectors and vertebrate hosts, including birds. we detected variation in interspecies responses among north american birds to infection with strains of two different jev genotypes (i and iii). several native north american passerine species and ring-billed gulls had the highest average peak viremia titers after inoculatio ...	2012	22927494
replication of 2 subtypes of low-pathogenicity avian influenza virus of duck and gull origins in experimentally infected mallard ducks.	many subtypes of low-pathogenicity avian influenza (lpai) virus circulate in wild bird reservoirs, but their prevalence may vary among species. we aimed to compare by real-time reverse-transcriptase polymerase chain reaction, virus isolation, histology, and immunohistochemistry the distribution and pathogenicity of 2 such subtypes of markedly different origins in mallard ducks (anas platyrhynchos): h2n3 isolated from a mallard duck and h13n6 isolated from a ring-billed gull (larus delawarensis). ...	2013	23242805
susceptibility of avian species to north american h13 low pathogenic avian influenza viruses.	gulls are widely recognized reservoirs for low pathogenic avian influenza (lpai) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. although, a wide diversity of influenza viruses have been isolated from gulls, two hemagglutinin subtypes (h13 and h16) are rarely detected in other avian groups, and existing surveillance data suggests they are maintained almost exclusively within gull populations. in order to evaluate t ...	2012	23402121
in vitro biotransformation of decabromodiphenyl ether (bde-209) and dechlorane plus flame retardants: a case study of ring-billed gull breeding in a pollution hotspot in the st. lawrence river, canada.	decabromodiphenyl ether (deca-bde) mixture (~97% of bde-209) is now facing usage restrictions worldwide, which is leading to increased utilization of a series of alternative, replacement flame retardant (fr) products. among these, dechlorane plus (dp) is receiving growing attention as this fr is increasingly being detected in wildlife samples, including birds from north america, europe and asia. recent survey conducted in a known fr hotspot in the st. lawrence river basin near montreal (qc, cana ...	2013	23542572
acute stress during ontogeny suppresses innate, but not acquired immunity in a semi-precocial bird (larus delawarensis).	wild animals often encounter adverse conditions, and in response, activate their hypothalamic-pituitary-adrenal (hpa) axis. to date, work examining the development of the stress response has focused on altricial species, with little work focusing on species with other developmental patterns. additionally, the effects of acute stress on indices of innate and adaptive immunity have been little studied in birds, particularly during development. we examined the ontogeny of the stress response in the ...	2013	23988691
is the bone tissue of ring-billed gulls breeding in a pollution hotspot in the st. lawrence river, canada, impacted by halogenated flame retardant exposure?	bone metabolism is a tightly regulated process that controls bone remodeling and repair in addition to maintaining circulating calcium and phosphate levels. it has been shown that certain organohalogen contaminants may adversely impact bone tissue metabolism and structure in wildlife species. however, exceedingly few studies have addressed the bone-related effects of organohalogen exposure in birds. the objective of the present study was to investigate the associations between markers of bone me ...	2013	24016627
mercury trends in colonial waterbird eggs downstream of the oil sands region of alberta, canada.	mercury levels were measured in colonial waterbird eggs collected from two sites in northern alberta and one site in southern alberta, canada. northern sites in the peace-athabasca delta and lake athabasca were located in receiving waters of the athabasca river which drains the oil sands industrial region north of fort mcmurray, alberta. temporal trends in egg mercury (hg) levels were assessed as were egg stable nitrogen isotope values as an indicator of dietary change. in northern alberta, cali ...	2013	24070029
balancing energy budget in a central-place forager: which habitat to select in a heterogeneous environment?	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 ...	2014	25029498
tracking the sources of polybrominated diphenyl ethers in birds: foraging in waste management facilities results in higher decabde exposure in males.	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 ...	2015	25769125
avian bornaviruses in north american gulls.	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 b ...	2015	25973630
field metabolic rate is dependent on time-activity budget in ring-billed gulls (larus delawarensis) breeding in an anthropogenic environment.	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 del ...	2015	26020626
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
the efficiency of an integrated program using falconry to deter gulls from landfills.	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, conducte ...	2015	26479231
short-term fasts increase levels of halogenated flame retardants in tissues of a wild incubating bird.	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 alter ...	2016	26724461
associations between organohalogen concentrations and transcription of thyroid-related genes in a highly contaminated gull population.	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 ...	2016	26747993
relationships between polybrominated diphenyl ethers and transcription and activity of type 1 deiodinase in a gull highly exposed to flame retardants.	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 ...	2016	27336952
a miniature bird-borne passive air sampler for monitoring halogenated flame retardants.	birds have been used intensively as biomonitors of halogenated flame retardants (hfrs), and several studies have reported elevated tissue concentrations and inter-individual variability for these contaminants. while diet is known to be an important exposure pathway for hfrs in birds, it has been suggested that exposure through air may represent an underestimated source of hfrs for certain species. however, a method was not available for measuring the atmospheric exposure of individual birds to h ...	2017	28545217
the biogeochemical implications of massive gull flocks at landfills.	gulls have long been observed concentrating in flocks of tens to hundreds of thousands at the anthropogenic food sources provided by landfills. yet, the biogeochemical implications of the landfill gull phenomenon have been largely ignored. this study has two goals: 1) to understand the magnitude and geographic extent of landfill gulls in north america, and 2) to quantify the amount of carbon (c), nitrogen (n), and phosphorus (p) transported from landfills to gull roosting sites in order to under ...	2017	28624727
detection of wellfleet bay virus antibodies in sea birds of the northeastern united states.	wellfleet bay virus (wfbv) is a recently described orthomyxovirus isolated from the tissues of common eiders (somateria mollissima) collected during recurrent mortality events on cape cod, massachusetts, usa. coastal massachusetts is the only location where disease or mortality associated with this virus has been detected in wild birds, and a previous seroprevalence study found a significantly higher frequency of viral exposure in eiders from this location than from other areas sampled in north ...	2017	28640712
multiple stressors including contaminant exposure and parasite infection predict spleen mass and energy expenditure in breeding ring-billed gulls.	daily energy expenditure (dee) in animals is influenced by many factors although the impact of stressors remains largely unknown. the objective of this study was to determine how multiple physiological stressors (parasite infection and contaminant exposure) and natural challenges (energy-demanding activities and weather conditions) may affect dee in nesting ring-billed gulls (larus delawarensis) exposed to high concentrations of persistent organic contaminants (pops). physical activity, temperat ...	2017	28647296
mercury speciation and subcellular distribution in experimentally dosed and wild birds.	many bird species are exposed to methylmercury (mehg) at levels shown to cause sublethal effects. although mehg sensitivity and assimilation can vary among species and developmental stages, the underlying reasons (such as mehg toxicokinetics) are poorly understood. we investigated hg distribution at the tissue and cellular levels in birds by examining hg speciation in blood, brain, and liver and hg subcellular distribution in liver. we used mehg egg injection of white leghorn chicken (gallus gal ...	2017	28691779
interaction between deca-bde and hepatic deiodinase in a highly pbde-exposed bird.	studies have shown that debromination of the major component in the deca-brominated diphenyl ether mixture (deca-bde), bde-209, occurs in vivo in birds. recent work from our laboratory on breeding ring-billed gulls (larus delawarensis) exposed to elevated pbde concentrations in the densely-populated metropolis of montreal (canada) further suggests that bde-209 debromination is potentially catalyzed by deiodinases in liver microsomes. the first objective of this study was to determine if type 1 d ...	2018	29433018
spatial trends in a biomagnifying contaminant: application of amino acid compound-specific stable nitrogen isotope analysis to the interpretation of bird mercury levels.	levels of biomagnifying contaminants are greatest in high-trophic level biota (e.g., predatory birds such as gulls). gull eggs have been used to assess contaminant spatial patterns and sources, but such assessments must consider how organism trophic position may influence spatial inferences. stable nitrogen isotopes (δ15 n) in bulk tissue are routinely used in this context. however, bulk δ15 n values are only useful if spatial differences in baseline δ15 n values are considered. amino acid compo ...	2018	29446488
sterols and stanols as novel tracers of waterbird population dynamics in freshwater ponds.	with the expansion of urban centres in the mid-twentieth century and the post-1970 decrease in pesticides, populations of double-crested cormorants (phalacrocorax auritus) and ring-billed gulls (larus delawarensis) around lake ontario (canada and usa) have rapidly rebounded, possibly to unprecedented numbers. along with the use of traditional palaeolimnological methods (e.g. stable isotopes, biological proxies), we now have the capacity to develop specific markers for directly tracking the prese ...	2018	29695442
changes in thyroid axis responses in two ring-billed gull sub-populations differentially exposed to halogenated flame retardants.	developing bird embryos may be affected by a number of thyroid disrupting chemicals through maternal transfer. however, thyroid disruption in developing embryos of wild birds remains largely unstudied, especially with respect to exposure to ubiquitous environmental contaminant classes including halogenated flame retardants (hfrs). the objective of the present study was to investigate responses of the hypothalamic-pituitary-thyroid (hpt) axis of developing birds that are exposed to elevated conce ...	2018	30103139
is the urban-adapted ring-billed gull a biovector for flame retardants?	birds may act as biovectors of nutrients and contaminants at the regional scale and potentially increase the exposure to such substances in ecosystems frequented by these birds. however, no study has estimated biotransport of contaminants by individual birds through their feces (guano). elevated concentrations of halogenated flame retardants (hfrs) have been reported in ring-billed gulls (larus delawarensis) breeding near montreal (qc, canada)- a known hotspot for hfrs. the objective of the pres ...	2019	30321706
west nile virus prevalence in wild birds from mexico.	west nile virus (wnv) emerged in the americas with its introduction in 1999 and now is considered endemic across the continent. in 2002, wnv was detected in mexico, where its occurrence and mortality are considerably lower compared with the us. however, continuous national surveillance programs in mexico are nonexistent. birds are considered the primary hosts and primary geographic dispersers of this pathogen. a total of 200 cloacal and tracheal samples from wild migratory or resident birds were ...	2019	30339087
habitat use strategy influences the tissue signature of trace elements including rare earth elements in an urban-adapted omnivorous bird.	concentrations of trace elements vary naturally between geological environments and as a result of emissions from anthropogenic activities. habitat use strategy is an important determinant of trace element concentrations in tissues and eggs of wild birds. however, a scarcity of studies have documented the relationships between individual bird movements related to foraging activities and exposure to contaminants including trace elements. the objective of the present study was to investigate the i ...	2019	30342322
enigmatic decline of a common fish parasite (diplostomum spp.) in the st. lawrence river: evidence for a dilution effect induced by the invasive round goby.	as they integrate into recipient food webs, invasive exotic species may influence the population dynamics of native parasites. here we assess the potential impact of the eurasian round goby (neogobius melanostomus) on the abundance of eyeflukes of the genus diplostomum, which are common parasites in fishes of the st. lawrence river (canada). analyses of data collected over nearly two decades revealed that the infection levels in three native fish [spottail shiner (notropis hudsonius), golden shi ...	2017	30951571
avian influenza prevalence and viral shedding routes in minnesota ring-billed gulls (larus delawarensis).	birds within the orders charadriiformes (shorebirds, gulls) and anseriformes (waterfowl) are reservoir hosts for avian influenza (ai) viruses, but their role in the transmission dynamics of ai viruses is unclear. to date, waterfowl have been the predominant focal species for most surveillance and epidemiological studies, yet gulls, in particular, have been shown to harbor reassortant ai viruses of both north american and eurasian lineages and are underrepresented in north american surveillance e ...	2019	31131567
effects of external oiling and rehabilitation on hematological, biochemical, and blood gas analytes in ring-billed gulls (larus delawarensis).	avian species experience extensive morbidity and mortality following large-scale oil spills, often resulting in oiled birds being rescued, and admitted to rehabilitation. our objective was to experimentally establish time-specific, descriptive blood analyte data following sublethal oil exposure and subsequent rehabilitation. thirty wild ring-billed gulls (larus delawarensis) were randomly allocated to three treatment groups of 10 birds each. one treatment group served as controls and two treatme ...	2019	31803767
landfills represent significant atmospheric sources of exposure to halogenated flame retardants for urban-adapted gulls.	halogenated flame retardants (hfrs) are contaminants that are abundantly emitted from waste management facilities (wmfs) and that became ubiquitous in air of urbanized regions. urban birds including gulls have adapted to exploiting human food resources (refuse) in wmfs, and have thus experienced population explosions worldwide. however, foraging in wmfs for birds may result in exposure to hfrs that have been shown to be toxic for animals. the objective of this study was to determine the influenc ...	2020	31841804
changes in plasma biochemistry in breeding ring-billed gulls: effects of anthropogenic habitat use and contaminant exposure.	gulls (larids) have become successful at exploiting anthropogenic areas for foraging. however, little is known on the health implications of using anthropogenic habitats and on the associated exposure to environmental contaminants, particularly with respect to plasma biochemistry that is routinely used to diagnose physiological disorders and diseases. the objective of the present study was to investigate the effects of anthropogenic habitat use and exposure to ubiquitous halogenated flame retard ...	2020	31864027
effects of deepwater horizon oil on feather structure and thermoregulation in gulls: does rehabilitation work?	impacts of large-scale oil spills on avian species are far-reaching. while media attention often focuses on lethal impacts, sub-lethal effects and the impacts of rehabilitation receive less attention. the objective of our study was to characterize effects of moderate external oiling and subsequent rehabilitation on feather structure and thermoregulation in gulls. we captured 30 wild ring-billed gulls (larus delawarensis) and randomly assigned each individual to an experimental group: 1) controls ...	2020	32325625
bidirectional transfer of halogenated flame retardants between the gastrointestinal tract and ingested plastics in urban-adapted ring-billed gulls.	the hypothesis that plastics can transfer chemical pollutants to organisms after ingestion has been supported by several lab and field studies. however, models indicate that this transfer could be bidirectional and that whether chemicals move from plastics to the animal or vice versa, depends on several factors, including the relative concentrations of chemicals in both the animal and the plastics ingested. to explore this phenomenon in the field, we examined the relative concentrations of sever ...	2020	32402960
opportunistic predation of birds by breeding herring gulls (larus argentatus).	dietary specialization, exploiting a small fraction of available food resources, is commonly reported for gulls and skuas. predation of birds by these species is usually considered a specialist strategy employed by the minority of the population but non-specialists also predate birds and may actually have a greater impact on the prey species. to date, most studies have focused on predatory bird-specialists, down-playing the possible importance of opportunistic predation by non-specialists. we ad ...	2020	33057336
septic arthritis and osteomyelitis caused by chryseobacterium indologenes in a mute swan (cygnus olor) and a ring-billed gull (larus delawarensis).	a 20-year-old female mute swan (cygnus olor) originally in a flock of free-living swans on a long island, new york, lake, was presented for facial swelling and decreased appetite. an adult male ring-billed gull (larus delawarensis) was also presented to the same wildlife rescue center for bilateral lameness of 1-week duration. once referred for veterinary evaluation and care, both species were diagnosed with septic arthritis and osteomyelitis caused by chryseobacterium indologenes and treated wi ...	2020	33099983