| effect of trh, tsh, and lh-rh on plasma thyroxine and triiodothyronine in the lesser snow goose (anser caerulescens caerulescens) and plasma thyroxine in the rouen duck (anas platyrhynchos). | | 1979 | 117891 |
| epizootic necrotic enteritis in wild geese. | outbreaks of a disease characterized by severe necrotic enteritis occurred among canada geese (branta canadensis), lesser snow geese (anser caerulescens), ross' geese (a. rossi), and white-fronted geese (a. albifrons) on lakes in saskatchewan and manitoba during the autumn of 1983, 1984 and 1985. ducks using the lakes were apparently not affected. lesions in the geese closely resembled those described in enteritides in other species associated with the proliferation of clostridium perfringens in ... | 1987 | 3625893 |
| description of the goose coccidium eimeria stigmosa (klimes, 1963), with evidence of intranuclear development. | oocysts of eimeria stigmosa isolated from a wild juvenile lesser snow goose (anser caerulescens caerulescens) were used in experimental infections of laboratory-reared geese. the structure of oocysts is described; a peculiar bumpy surface and a calyx-like thickening around the micropyle are illustrated by scanning electron microscopy. experimentally infected geese had reduced feed intake and passed blood in their feces. six days post-inoculation (p.i.) oocysts were passed for about 24 hr. oocyst ... | 1986 | 3783353 |
| waterfowl mortality caused by aflatoxicosis in texas. | waterfowl mortality caused by aflatoxicosis occurred in two separate areas in texas during the 1977-78 wintering season. the first outbreak occurred in snow geese (anser caerulescens) on the gulf coast prairies, followed by an outbreak in mallards (anas platyrhynchos) in the north-central portion of the state. aflatoxin b1 levels in geese were 500 ng/g (dry weight). aflatoxin b1 levels in the second mortality were 10-250 ng/g (dry weight). the exact source of the toxin was not demonstrated in th ... | 1982 | 6813512 |
| [hemoglobins, xlvii. hemoglobins of the bar-headed goose (anser indicus): primary structure and physiology of respiration, systematic and evolution]. | the primary structures of the alpha- and beta-chains of the main component of bar-headed goose (anser indicus) are given. by homologous comparison with the hemoglobin of the grey-lag goose (anser anser) 3 differences were found in the alpha-chains, 1 difference in the beta-chains. in position alpha 119 h2ala and beta 125 h3asp alpha 1 beta 2-contact points are changed. the mutation alpha 63 e12val brings a drastic change in tertiary structure of the alpha-chains of bar-headed goose: the helices ... | 1982 | 7106705 |
| dynamics of parasitic infections at four sites within lesser snow geese (chen caerulescens caerulescens) from the breeding colony at la pérouse bay, manitoba, canada. | we enumerated parasite burdens within the blood, gizzard, ceca, and kidneys of adult female lesser snow geese chen caerulescens caerulescens collected from the breeding colony at la pérouse bay, manitoba, canada, in 1989. we observed 5 species of nematodes, 1 species of digenean, 1 species of protozoan, and an unidentified microfilaria in these geese. we compared parasite burdens between geese collected during the incubation (2-14 june) and brood-rearing (1-5 august) periods. there was a signifi ... | 1994 | 8064540 |
| lead concentrations in liver and kidneys of snow geese during an avian cholera epizootic in california. | during an avian cholera epornitic, between december 1982 and january 1983, 58 dead, 23 sick, and 106 hunter-killed lesser snow geese (chen caerulescens caerulescens) were collected at delevan national wildlife refuge, colusa county, california, usa. fifty-one of the dead and sick geese were infected with pasteurella multocida. lead concentrations in the livers ranged from < 1 to 253 parts per million (ppm) (dry weight). lead concentrations in the kidneys ranged from < 1 ppm to 547 ppm (dry weigh ... | 1993 | 8258858 |
| pasteurella multocida serotype 1 isolated from a lesser snow goose: evidence of a carrier state. | pharyngeal swabs were collected from 298 lesser snow geese (chen caerulescens caerulescens) at banks island (northwest territories. canada) in the summer of 1994. pasteurella multocida serotype 1 was isolated from an adult male bird and p. multocida serotype 3 was isolated from an adult female goose. pathogenicity of the serotype 1 isolate was confirmed by inoculation in pekin ducks (anas platyrhynchos). the serotype 3 isolate was non-pathogenic in pekin ducks. this is the first documented isola ... | 1997 | 9131570 |
| helminths of wintering geese in texas. | ten canada geese (branta canadensis), 24 snow geese (chen caerulescens) and 22 white-fronted geese (anser albifrons) from coastal texas (usa) were examined for helminths. three cestode, seven nematode, and three trematode species were collected. gizzard nematodes (amidostomum anseris, a. spatulatum and epomidiostomum crami) infected 53 of 54 birds. gross lesions were not attributed to helminth infections and the host population does not appear to be impaired by them. | 1997 | 9249720 |
| antibodies against pasteurella multocida in snow geese in the western arctic. | to determine if lesser snow geese (chen caerulescens caerulescens) are a potential reservoir for the pasteurella multocida bacterium that causes avian cholera, serum samples and/or pharyngeal swabs were collected from > 3,400 adult geese breeding on wrangel island (russia) and banks island (canada) during 1993-1996. pharyngeal swab sampling rarely (> 0.1%) detected birds that were exposed to p. multocida in these populations. geese with serum antibody levels indicating recent infection with p. m ... | 1999 | 10479077 |
| a new avian hepadnavirus infecting snow geese (anser caerulescens) produces a significant fraction of virions containing single-stranded dna. | we describe the identification and functional analysis of an evolutionary distinct new avian hepadnavirus. infection of snow geese (anser caerulescens) with a duck hepatitis b virus (dhbv)-related virus, designated sghbv, was demonstrated by detection of envelope proteins in sera with anti-dhbv pres and s antibodies. comparative sequence analysis of the pcr-amplified sghbv genomes revealed unique sghbv sequence features compared with other avian hepadnaviruses. unlike dhbv, sghbv shows an open r ... | 1999 | 10489339 |
| avian cholera in waterfowl: the role of lesser snow and ross's geese as disease carriers in the playa lakes region. | we collected samples from apparently healthy geese in the playa lakes region (usa) during the winters of 2000-01 and 2001-02 to determine whether carriers of pasteurella multocida, the bacterium that causes avian cholera, were present in wild populations. with the use of methods developed in laboratory challenge trials (samuel et al., 2003a) and a serotype-specific polymerase chain reaction method for identification of p. multocida serotype 1, we found that a small proportion of 322 wild birds ( ... | 2005 | 15827210 |
| a recent chicken repeat 1 retrotransposition confirms the coscoroba-cape barren goose clade. | chicken repeat 1 (cr1) is a member of the non-long terminal repeat class of retrotransposons. we have isolated a truncated cr1 element within the third intron of the lactate dehydrogenase b gene of the coscoroba and the cape barren goose (anseriformes; coscoroba coscoroba, cereopsis novaehollandiae). because the element was absent in orthologous loci within mallard (anas platyrhynchos), snow goose (anser caerulescens), and tundra swan (cygnus columbianus), it provides strong support to the recen ... | 2005 | 16182151 |
| multi-species patterns of avian cholera mortality in nebraska's rainwater basin. | nebraska's rainwater basin (rwb) is a key spring migration area for millions of waterfowl and other avian species. avian cholera has been endemic in the rwb since the 1970s and in some years tens of thousands of waterfowl have died from the disease. we evaluated patterns of avian cholera mortality in waterfowl species using the rwb during the last quarter of the 20th century. mortality patterns changed between the years before (1976-1988) and coincident with (1989-1999) the dramatic increases in ... | 2006 | 16699151 |
| spring-harvested game birds from the western james bay region of northern ontario, canada: organochlorine concentrations in breast muscle. | although studies have assessed organochlorine concentration in breast tissue (pectoral muscle) of fall-harvested game birds in canada, data for spring-harvested game birds are limited, especially for remote sub-arctic areas. taking into account that most traditional aboriginal diets include a large number of spring-harvested game birds, there is a need to assess organochlorine concentration in spring-harvested water birds with respect to suitability for human consumption. we examined organochlor ... | 2007 | 17675140 |
| description of the larva of ceratophyllus vagabundus vagabundus (siphonaptera: ceratophyllidae) from nests of ross's and lesser snow geese in nunavut, canada. | abstract adults of the flea, ceratophyllus vagabundus vagabundus , were present in the hundreds in nests of ross's ( chen rossii ) and lesser snow ( chen caerulescens caerulescens ) geese in the arctic goose colony at karrak lake, nunavut, canada. ceratophyllus v. vagabundus had not been previously recorded in association with ross's or snow geese. large numbers of c. v. vagabundus adults and larvae were collected and a description of the larva is provided for the first time. on the basis of ext ... | 2011 | 21506868 |
| determining the background levels of bismuth in tissues of wild game birds: a first step in addressing the environmental consequences of using bismuth shotshells. | bismuth shotshells have been approved as a "nontoxic" alternative to lead in north america. approval was based on a limited number of studies; even background levels of bismuth in wildfowl were unknown. we report on the concentration of bismuth (and lead) in muscle and liver tissues of wildfowl (anas platyrhynchos, anas acuta, anas crecca, branta canadensis, chen caerulescens) harvested with lead shotshell. average liver-bismuth levels detected in the present study (e.g., teal, 0.05 microg/g dw; ... | 2004 | 15276269 |
| [helminth fauna anseriformes (aves) in the lodz zoological garden]. | in the years 1959-1990 429 birds on 30 species of anseriformes were examined post mortem at zoo lódź. the helminths were found in 108 birds (25.17%) of 19 species. in infected birds there were found 4 species of trematodes: one of them, catatropis verrucosa is in poland new for cygnus olor; 9 species of cestodes--7 of them are in poland new for examined hosts; namely: drepanidotaenia lanceolata for dendrocygna viduata, cygnus atratus, branta bernicla, and anas platyrhynchos; microsomacanthus par ... | 1997 | 9424942 |
| renal coccidiosis and other parasitologic conditions in lesser snow goose goslings at tha-anne river, west coast hudson bay. | lesser snow goose (chen caerulescens caerulescens) goslings, approximately 5 weeks of age, were collected near the mouth of tha-anne river, northwest territories, canada, during mid-august 1991. many dead goslings had been observed in the area from 1988 to 1990. goslings from near the coast, where habitat degradation by grazing geese was severe, were smaller, weighed less, and had a greater prevalence of renal coccidiosis (eimeria truncata) and cecal nematode (trichostrongylus spp.) infection th ... | 1996 | 8827676 |
| trophic mismatch and its effects on the growth of young in an arctic herbivore. | in highly seasonal environments, timing of breeding of organisms is typically set to coincide with the period of highest resource availability. however, breeding phenology may not change at a rate sufficient to keep up with rapid changes in the environment in the wake of climate change. the lack of synchrony between the phenology of consumers and that of their resources can lead to a phenomenon called trophic mismatch, which may have important consequences on the reproductive success of herbivor ... | 2015 | 26235037 |
| population growth in snow geese: a modeling approach integrating demographic and survey information. | there are few analytic tools available to formally integrate information coming from population surveys and demographic studies. the kalman filter is a procedure that facilitates such integration. based on a state-space model, we can obtain a likelihood function for the survey data using a kalman filter, which we may then combine with a likelihood for the demographic data. in this paper, we used this combined approach to analyze the population dynamics of a hunted species, the greater snow goose ... | 2007 | 17601135 |
| assortative mating in lesser snow geese (anser caerulescens). | assortative mating occurs in the dimorphic lesser snow geese in the wild. mixed matings between the blue and white phases are much less frequent than would be expected by chance. evidence from marked birds in field conditions indicated that mate choice was correlated with familial color. birds from white families usually chose white mates, birds from blue families usually chose blue mates, and birds from mixed families chose mates of either color. similar results were obtained under captive cond ... | 1976 | 1267737 |
| isoenzyme status and genetic variability of serum esterases in the lesser snow goose, anser caerulescens caerulescens. | a maximum of 22 bands comprising four esterase subgroups--acetylesterase, carboxylesterase, cholinesterase, and acetylcholinesterase--were detected following electrophoresis of lesser snow goose sera on polyacrylamide gels. a minimum of seven structural genes was surmised to be involved in the biosynthesis of these enzymes following physiochemical characterizations. the genetic variability of these loci was calculated to be 1.25% average heterozygosity, while 14.3% of the loci were polymorphic. ... | 1977 | 921742 |
| seasonal changes in plasma concentrations of lh in the lesser snow goose (anser caerulescens caerulescens). | | 1978 | 418826 |
| seasonal changes in thyroid activity in the lesser snow goose (anser caerulescens caerulescens) including reference to embryonic thyroid activity. | | 1980 | 7427809 |
| life history studies of the lesser snow goose (anser caerulescens caerulescens) : i. the influence of age and time on fecundity. | in many species, fecundity is dependent on age. for some populations - particularly those exploiting temporally variable environments - these age-specific fecundities may themselves vary with time. in this report, we investigate the general effects of age and time on clutch size in a wild population of lesser snow geese (anser caerulescens caerulescens). we show that both factors affect clutch size independently. age effects are confined almost exclusively to the two, three and four year old age ... | 1983 | 28310210 |
| identification of restriction-fragment-length polymorphisms in genomic dna of the lesser snow goose (anser caerulescens caerulescens). | a genomic library of partially ecori-digested dna from the lesser snow goose, anser caerulescens caerulescens, was constructed in the phage vector charon 4. phage containing only unique sequences were identified by screening plaques with 32p-labeled genomic dna. restriction-fragment-length polymorphisms (rflps) were identified by probing dna from 11-13 male birds from the breeding colony at la perouse bay. of the 17 probes examined, all detected rflps with at least one of ecori, hindiii, msp1, a ... | 1987 | 2895887 |
| intra-seasonal decline of clutch size in lesser snow geese. | different mechanisms proposed to explain the intra-seasonal decline in clutch size of lesser snow geese (anser caerulescens caerulescens) were tested at the la perouse bay colony, manitoba, canada. ovary examination of females collected after laying revealed that the actual number of eggs produced per female decreased over the laying period. this finding eliminates nest-parasitism, partial clutch predation and renesting attempts as sufficient explanations for seasonal clutch size decline. follic ... | 1989 | 28312816 |
| breeding dispersal in a heterogeneous landscape: the influence of habitat and nesting success in greater snow geese. | despite numerous studies on breeding dispersal, it is still unclear how habitat heterogeneity and previous nesting success interact to determine nest-site fidelity at various spatial scales. in this context, we investigated factors affecting breeding dispersal in greater snow geese (anser caerulescens atlanticus), an arctic breeding species nesting in two contrasting habitats (wetlands and mesic tundra) with variable pattern of snowmelt at the time of settlement in spring. from 1994 to 2005, we ... | 2008 | 17938972 |
| predator behaviour and predation risk in the heterogeneous arctic environment. | 1. habitat heterogeneity and predator behaviour can strongly affect predator-prey interactions but these factors are rarely considered simultaneously, especially when systems encompass multiple predators and prey. 2. in the arctic, greater snow geese anser caerulescens atlanticus l. nest in two structurally different habitats: wetlands that form intricate networks of water channels, and mesic tundra where such obstacles are absent. in this heterogeneous environment, goose eggs are exposed to two ... | 2008 | 18248387 |
| manipulating individual state during migration provides evidence for carry-over effects modulated by environmental conditions. | despite observational evidence of carry-over effects (coes, events occurring in one season that produce residual effects on individuals the following seasons), to our knowledge no experimental studies have been carried out to explore how coes might affect reproductive output. we simulated an environmental perturbation affecting spring-staging migrants to investigate coes in greater snow geese (anser caerulescens atlanticus). during three consecutive years, 2037 females captured during spring sta ... | 2012 | 21865256 |
| benefiting from a migratory prey: spatio-temporal patterns in allochthonous subsidization of an arctic predator. | 1. flows of nutrients and energy across ecosystem boundaries have the potential to subsidize consumer populations and modify the dynamics of food webs, but how spatio-temporal variations in autochthonous and allochthonous resources affect consumers' subsidization remains largely unexplored. 2. we studied spatio-temporal patterns in the allochthonous subsidization of a predator living in a relatively simple ecosystem. we worked on bylot island (nunavut, canada), where arctic foxes (vulpes lagopus ... | 2012 | 22268371 |
| the greater snow goose anser caerulescens atlanticus: managing an overabundant population. | between the early 1900s and the 1990s, the greater snow goose anser caerulescens atlanticus population grew from 3000 individuals to more than 700 000. because of concerns about arctic degradation of natural habitats through overgrazing, a working group recommended the stabilization of the population. declared overabundant in 1998, special management actions were then implemented in canada and the united states. meanwhile, a cost-benefit socioeconomic analysis was performed to set a target popul ... | 2017 | 28215008 |
| associations between body composition and helminths of lesser snow geese during winter and spring migration. | costs of parasitism are predicted to be higher with greater parasite intensities and higher inter-parasite competition (diversity). we tested whether greater helminth intensities and diversity were associated with poorer body composition (whole-body fat, protein, mineral and true body mass) in lesser snow geese, chen caerulescens caerulescens. as part of a larger study on nutritional ecology, 828 wintering or migrating geese were shot between january and may 1983 in 27 different date-locations ( ... | 2012 | 22713759 |
| decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the arctic. | a full understanding of population dynamics depends not only on estimation of mechanistic contributions of recruitment and survival, but also knowledge about the ecological processes that drive each of these vital rates. the process of recruitment in particular may be protracted over several years, and can depend on numerous ecological complexities until sexually mature adulthood is attained. we addressed long-term declines (23 breeding seasons, 1992-2014) in the per capita production of young b ... | 2017 | 28403519 |
| what to eat now? shifts in polar bear diet during the ice-free season in western hudson bay. | under current climate trends, spring ice breakup in hudson bay is advancing rapidly, leaving polar bears (ursus maritimus) less time to hunt seals during the spring when they accumulate the majority of their annual fat reserves. for this reason, foods that polar bears consume during the ice-free season may become increasingly important in alleviating nutritional stress from lost seal hunting opportunities. defining how the terrestrial diet might have changed since the onset of rapid climate chan ... | 2013 | 24223286 |
| multi-scale occupancy approach to estimate toxoplasma gondii prevalence and detection probability in tissues: an application and guide for field sampling. | increasingly, birds are recognised as important hosts for the ubiquitous parasite toxoplasma gondii, although little experimental evidence exists to determine which tissues should be tested to maximise the detection probability of t. gondii. also, arctic-nesting geese are suspected to be important sources of t. gondii in terrestrial arctic ecosystems, but the parasite has not previously been reported in the tissues of these geese. using a domestic goose model, we applied a multi-scale occupancy ... | 2016 | 27155329 |
| antibodies to influenza a viruses in wintering snow geese (chen caerulescens) in texas. | wild waterfowl in the order anseriformes are recognized reservoirs for influenza a viruses (iavs); however, prevalence of infection can vary greatly by species. few isolates of iavs have been reported from snow geese (chen caerulescens), and generally they have not been regarded as an important component of this reservoir. in february 2013, 151 combined cloacal and oropharangeal swabs and 147 serum samples were collected from snow geese wintering on the gulf coast of texas. none of the swab samp ... | 2016 | 27309076 |
| identification of type a influenza viruses from wild birds on the delmarva peninsula, 2007-10. | wild waterfowl and shorebirds in the delaware-maryland-virginia (delmarva) peninsula region within the atlantic flyway were sampled as part of the early detection of highly pathogenic h5n1 avian influenza (ai) in wild migratory birds program. the u.s. department of agriculture (usda) and state wildlife agencies submitted 7858 samples for ai virus (aiv) testing by real-time reverse transcription pcr (rrt-pcr) to the university of delaware poultry health system from april 2007 to march 2011. virus ... | 2017 | 28301233 |
| a link between water availability and nesting success mediated by predator-prey interactions in the arctic. | although water availability is primarily seen as a factor affecting food availability (a bottom-up process), we examined its effect on predator-prey interactions through an influence on prey behavior (a top-down process). we documented a link between water availability, predation risk, and reproductive success in a goose species (chen caerulescens atlantica) inhabiting an arctic environment where water is not considered a limited commodity. to reach water sources during incubation recesses, gees ... | 2009 | 19323230 |
| do geese fully develop brood patches? a histological analysis of lesser snow geese (chen caerulescens caerulescens) and ross's geese (c. rossii). | most birds develop brood patches before incubation; epidermis and dermis in the brood patch region thicken, and the dermal connective tissue becomes increasingly vascularized and infiltrated by leukocytes. however, current dogma states that waterfowl incubate without modifications of skin within the brood patch region. the incubation periods of lesser snow geese (chen caerulescens caerulescens; hereafter called snow geese) and ross's geese (c. rossii) are 2-6 days shorter than those of other goo ... | 2006 | 16432729 |
| spring-harvested game birds in the western james bay region of northern ontario, canada: the amount of organochlorines in matched samples of breast muscle, skin, and abdominal fat. | we examined matched-tissue samples (the right pectoral muscle plus the associated skin and fat was considered a breast portion) of 81 spring-harvested waterfowl and 19 summer-harvested godwits (limosa spp.) to assess the potential of these water birds contributing to the body burden of pcbs and ddt noted in first nation people of the western james bay region, northern ontario, canada. in general, the dabbling ducks (mallard duck, anas platyrhynchos; and northern pintail, a. acuta) had significan ... | 2008 | 18058032 |
| body condition, migration, and timing of reproduction in snow geese: a test of the condition-dependent model of optimal clutch size. | the seasonal decline of avian clutch size may result from the conflict between the advantage of early breeding (greater offspring value) and the advantage of a delay in lay date (improved body condition and hence clutch size). we tested predictions of a condition-dependent individual optimization model based on this trade-off (rowe et al. 1994) in a long-distance migrant, the greater snow goose (chen caerulescens atlantica), using data on condition, migration, and reproductive decisions of indiv ... | 2003 | 12856240 |
| energetics of reproduction in female and male greater snow geese. | arctic-nesting geese are classified as "capital" breeders (i.e., birds that rely largely on endogenous reserves to meet the high nutrient requirement of clutch formation) as opposed to "income" breeders (those that rely directly on ingested food). however, some evidence has suggested that energy reserves of greater snow geese (chen caerulescens atlantica) are not sufficient to meet these costs. we tested whether greater snow geese were capital breeders and examined the consequences on their repr ... | 1995 | 28306833 |
| lesser snow goose helminths show recurring and positive parasite infection-diversity relations. | the patterns and mechanisms by which biological diversity is associated with parasite infection risk are important to study because of their potential implications for wildlife population's conservation and management. almost all research in this area has focused on host species diversity and has neglected parasite diversity, despite evidence that parasites are important drivers of community structure and ecosystem processes. here, we assessed whether presence or abundance of each of nine helmin ... | 2017 | 28229044 |
| limnological regime shifts caused by climate warming and lesser snow goose population expansion in the western hudson bay lowlands (manitoba, canada). | shallow lakes are dominant features in subarctic and arctic landscapes and are responsive to multiple stressors, which can lead to rapid changes in limnological regimes with consequences for aquatic resources. we address this theme in the coastal tundra region of wapusk national park, western hudson bay lowlands (canada), where climate has warmed during the past century and the lesser snow goose (lsg; chen caerulescens caerulescens) population has grown rapidly during the past ∽40 years. integra ... | 2015 | 25750718 |
| ecological implications of reduced forage quality on growth and survival of sympatric geese. | allometric constraints associated with digesting leaves require relatively small avian herbivores to consume high-quality forage. how such constraints are overcome during ontogeny when energy and nutrient requirements are relatively high has not been adequately explored. we compared growth trajectories of canada and lesser snow goose goslings raised on grass-based diets that differed in protein (10%, 14% or 18%) and fibre (30% or 45%) with those of free-living goslings on akimiski island, canada ... | 2015 | 25081822 |
| evidence of territoriality and species interactions from spatial point-pattern analyses of subarctic-nesting geese. | quantifying spatial patterns of bird nests and nest fate provides insights into processes influencing a species' distribution. at cape churchill, manitoba, canada, recent declines in breeding eastern prairie population canada geese (branta canadensis interior) has coincided with increasing populations of nesting lesser snow geese (chen caerulescens caerulescens) and ross's geese (chen rossii). we conducted a spatial analysis of point patterns using canada goose nest locations and nest fate, and ... | 2013 | 24312520 |
| effects of exploitation on an overabundant species: the lesser snow goose predicament. | invasive and overabundant species are an increasing threat to biodiversity and ecosystem functioning world-wide. as such, large amounts of money are spent each year on attempts to control them. these efforts can, however, be thwarted if exploitation is compensated demographically or if populations simply become too numerous for management to elicit an effective and rapid functional response. we examined the influence of these mechanisms on cause-specific mortality in lesser snow geese using mult ... | 2014 | 24111581 |
| rapid environmental degradation in a subarctic ecosystem influences resource use of a keystone avian herbivore. | 1. environmental degradation can change resource use strategies of animals and thereby affect survival and fitness. arctic herbivores may be especially susceptible to the effects of such environmental change because their rapid growth rates demand high-quality forage, which may be limited as environmental conditions deteriorate. we studied the consequences of a trophic cascade, driven by lesser snow goose (chen caerulescens caerulescens) overgrazing on the south-west coast of hudson bay, canada, ... | 2012 | 22471734 |
| environmental change and the cost of philopatry: an example in the lesser snow goose. | the consequences of philopatric and dispersal behaviours under changing environmental conditions were examined using data from the colony of lesser snow geese (anser caerulescens caerulescens) breeding at la pérouse bay, manitoba, canada. in response to increased population size and decreased food abundance over time, increasing numbers of family groups have been dispersing from the traditional feeding areas. goslings from dispersed broods were significantly heavier (7.3%), and had longer culmen ... | 1993 | 28313785 |
| fitness consequences of egg-size variation in the lesser snow goose. | we investigated the relationship between eggsize variation and (a) egg hatching success, (b) chick survival to fledging and recruitment, and (c) adult female survival, over 12 years in the lesser snow goose (anser caerulescens caerulescens). by comparing the means and variances of egg size for successful and unsuccessful eggs, our aim was to assess the relative fitness of eggs of different sizes and to determine the type of selection operating on egg size in this species. as both egg size and re ... | 1993 | 28313647 |
| pre-incubation feeding activities and energy budgets of snow geese: can food on the breeding grounds influence fecundity? | the potential contribution of early spring feeding conditions in the arctic to clutch size variation was examined in a population of lesser snow geese anser caerulescens caerulescens. behavioural observations were combined with energetic analyses of food material to derive an estimate of the energy budgets of pre-laying and laying females. food intake of females between arrival on the breeding grounds and incubation was considerable; estimated energy gains in this period were in the same magnitu ... | 1996 | 28307639 |
| genetic and environmental components of clutch size variance in a wild population of lesser snow geese (anser caerulescens caerulescens). | | 1983 | 28568123 |
| synchrony in the lesser snow goose (anser caerulescens caerulescens). ii. the adaptive value of reproductive synchrony. | | 1982 | 28568240 |
| breeding synchrony in the lesser snow goose (anser caerulescens caerulescens): i. genetic and environmental components of hatch date variability and their effects on hatch synchrony. | | 1982 | 28563155 |
| the use of nutrient reserves by breeding male lesser snow geese chen caerulescens caerulescens. | | 1977 | 606348 |
| the genetics of polymorphism in the goose anser caerulescens. | | 1968 | 28564811 |
| mortality of geese as a result of collision with the ground. | two incidents are reported in which groups of migrating wild geese were found dead in agricultural fields in southern manitoba during spring. in each case, the birds died overnight and poisoning was suspected; however, the birds had lesions of severe traumatic injury. the first incident, in 1985, involved about 150 lesser snow geese (anser caerulescens caerulescens); the second, in 2003, involved 62 canada geese (branta canadensis). both incidents occurred on dark, moonless nights. one possible ... | 2005 | 16107686 |
| the genetic legacy of mother goose--phylogeographic patterns of lesser snow goose chen caerulescens caerulescens maternal lineages. | by using the polymerase chain reaction to amplify and sequence 178 bp of a rapidly evolving region of the mtdna genome (segment i of the control region) from 81 individuals, approximately 11% of the variation present in the lesser snow goose chen caerulescens caerulescens l. mitochondrial genome was surveyed. the 26 types of mtdna detected formed two distinct mitochondrial clades that differ by an average of 6.7% and are distributed across the species range. restriction analysis of amplified fra ... | 1992 | 1344986 |
| agriculture and herbivorous waterfowl: a review of the scientific basis for improved management. | swans, geese and some ducks (anatidae) are obligate herbivores, many are important quarry species and all contribute to a variety of ecosystem services. population growth and shifting ranges have led to increasing proximity to man and thus increasing conflicts. we review and synthesize the role of these birds as herbivores on agricultural land (cropland, rotational grassland and pasture) and other terrestrial habitats where conflict with human interests may occur. a bibliographic analysis of pee ... | 2017 | 26946181 |
| relationships between graminoid growth form and levels of grazing by caribou (rangifer tarandus) in alaska. | herbivores and their forage interact in many ways, in some instances to the benefit or detriment of herbivore and vegetation. studies of wildebeest (connochaetes taurinus) in africa and snow geese (chen caerulescens) in the arctic have suggested that these grazers enhance graminoid production in certain sites by repeatedly using them. other studies have concluded that herbivores are sensitive to local variation in forage quality and quantity, and preferentially use those sites that are intrinsic ... | 1996 | 28307265 |
| the dynamics of avian influenza in lesser snow geese: implications for annual and migratory infection patterns. | wild water birds are the natural reservoir for low-pathogenic avian influenza viruses (aiv). however, our ability to investigate the epizootiology of aiv in these migratory populations is challenging and, despite intensive worldwide surveillance, remains poorly understood. we conducted a cross-sectional, retrospective analysis in pacific flyway lesser snow geese, chen caerulescens, to investigate aiv serology and infection patterns. we collected nearly 3000 sera samples from snow geese at two br ... | 2015 | 26591451 |
| hepatic microsomal metabolism of bde-47 and bde-99 by lesser snow geese and japanese quail. | in the present study, we investigated the oxidative biotransformation of 2,2',4,4'-tetrabromodiphenyl ether (bde-47) and 2,2',4,4',5-pentabromodiphenyl ether (bde-99) by liver microsomes from wild lesser snow geese (chen caerulescens caerulescens) and domesticated japanese quail (coturnix japonica). formation of hydroxy-metabolites was analyzed using an ultra-high performance liquid chromatography-tandem mass spectrometry-based method. incubation of bde-47 with avian liver microsomes produced si ... | 2017 | 28525869 |
| isolation and characterization of brachyspira spp. including "brachyspira hampsonii" from lesser snow geese (chen caerulescens caerulescens) in the canadian arctic. | brachyspira is associated with diarrhea and colitis in pigs, and control of these pathogens is complicated by their complex ecology. identification of wildlife reservoirs of brachyspira requires the discrimination of colonized animals and those simply contaminated through environmental exposure. lesser snow geese (chen caerulescens caerulescens) were sampled in the canadian arctic during the summer of 2011, and cloacal swabs were cultured on selective media. brachyspira isolates were obtained fr ... | 2013 | 23933825 |
| do glucocorticoids in droppings reflect baseline level in birds captured in the wild? a case study in snow geese. | baseline glucocorticoid (cort) levels in plasma are increasingly used as physiological indices of the relative condition or health of individuals and populations. the major limitation is that cort production is stimulated by the stress associated with capture and handling. measuring fecal cort is one way to solve this problem because elevation of fecal cort usually does not occur before 1-12h after a stressful event in captive animals. however, the effect of capture and handling on fecal cort le ... | 2011 | 21510949 |
| correlations between sequential timing decisions do not necessarily indicate strategic behavior: a comment on bêty et al. | using correlation analysis, bêty, gauthier, and giroux confirmed that individuals of the migrating snow geese (chen caerulescens atlantica) arriving earlier on their breeding grounds experienced longer prelaying periods but laid earlier than late-arriving birds. they concluded that these birds strategically adjusted timing to optimize fitness. this test is, however, not sufficient to indicate strategic behavior. we show analytically that, without assuming strategic behavior, arrival date, prelay ... | 2010 | 20961222 |
| year-round effects of climate on demographic parameters of an arctic-nesting goose species. | understanding how climate change will affect animal population dynamics remains a major challenge, especially in long-distant migrants exposed to different climatic regimes throughout their annual cycle. we evaluated the effect of temperature throughout the annual cycle on demographic parameters (age-specific survival and recruitment, breeding propensity and fecundity) of the greater snow goose (chen caerulescens atlantica l.), an arctic-nesting species. as this is a hunted species, we used the ... | 2014 | 24724860 |
| temporal variation of juvenile survival in a long-lived species: the role of parasites and body condition. | studies of population dynamics of long-lived species have generally focused on adult survival because population growth should be most sensitive to this parameter. however, actual variations in population size can often be driven by other demographic parameters, such as juvenile survival, when they show high temporal variability. we used capture-recapture data from a long-term study of a hunted, migratory species, the greater snow goose (chen caerulescens atlantica), to assess temporal variabili ... | 2013 | 23456200 |
| tug of war between continental gene flow and rearing site philopatry in a migratory bird: the sex-biased dispersal paradigm reconsidered. | nonrandom dispersal has been recently advanced as a mechanism promoting fine-scale genetic differentiation in resident populations, yet how this applies to species with high rates of dispersal is still unclear. using a migratory species considered a classical example of male-biased dispersal (the greater snow goose, chen caerulescens atlantica), we documented a temporally stable fine-scale genetic clustering between spatially distinct rearing sites (5-30 km apart), where family aggregates shortl ... | 2009 | 19207261 |
| a general model for the analysis of mark-resight, mark-recapture, and band-recovery data under tag loss. | estimates of waterfowl demographic parameters often come from resighting studies where birds fit with individually identifiable neck collars are resighted at a distance. concerns have been raised about the effects of collar loss on parameter estimates, and the reliability of extrapolating from collared individuals to the population. models previously proposed to account for collar loss do not allow survival or harvest parameters to depend on neck collar presence or absence. also, few models have ... | 2004 | 15606410 |
| trophic interactions in a high arctic snow goose colony. | we examined the role of trophic interactions in structuring a high arctic tundra community characterized by a large breeding colony of greater snow geese (chen caerulescens atlantica). according to the exploitation ecosystem hypothesis of oksanen et al. (1981), food chains are controlled by top-down interactions. however, because the arctic primary productivity is low, herbivore populations are too small to support functional predator populations and these communities should thus be dominated by ... | 2004 | 21680492 |
| nitrogen dynamics in an alaskan salt marsh following spring use by geese. | lesser snow geese (anser caerulescens caerulescens) and canada geese (branta canadensis) use several salt marshes in cook inlet, alaska, as stopover areas for brief periods during spring migration. we investigated the effects of geese on nitrogen cycling processes in susitna flats, one of the marshes. we compared net nitrogen mineralization, organic nitrogen pools and production in buried bags, nitrogen fixation by cyanobacteria, and soil and litter characteristics on grazed plots versus paired ... | 2002 | 28547263 |
| foraging time and dietary intake by breeding ross's and lesser snow geese. | we compared foraging times of female ross's (chen rossii) and lesser snow geese (chen caerulescens caerulescens) breeding at karrak lake, nt, canada and examined variation due to time of day and reproductive stage. we subsequently collected female geese that had foraged for known duration and we estimated mass of foods consumed during foraging bouts. female ross's geese spent more time foraging (mean % ± se =28.4±1.3%; p=0.0002), on average, than did female lesser snow geese (21.5 ± 1.4%). forag ... | 2001 | 28547172 |
| explaining co-occurrence among helminth species of lesser snow geese (chen caerulescens) during their winter and spring migration. | the digestive tracts of 771 lesser snow geese (chen caerulescens) collected from january to may 1983 from 12 locations (27 samples) were examined for helminth parasites to determine whether parasite species present in wintering geese or in spring migrants occurred independently of each other. nine helminth species were identified. seven had mean prevalences >5% and were the focus of this study. six of those species were waterfowl generalists, one was a goose specialist. our primary objective was ... | 1999 | 28308313 |
| forage digestibility and intake by lesser snow geese: effects of dominance and resource heterogeneity. | we measured forage intake, digestibility, and retention time for 11 free-ranging, human-imprinted lesser snow geese (chen caerulescens caerulescens) as they consumed underground stembases of tall cotton-grass (eriophorum angustifolium) on an arctic staging area in northeastern alaska. geese fed in small patches ([formula: see text]=21.5 m(2)) of forage that made up ≤3% of the study area and consisted of high-quality "aquatic graminoid" and intermediate-quality "wet sedge" vegetation types. domin ... | 1996 | 28307834 |
| matriarchal population genetic structure in an avian species with female natal philopatry. | we employ mitochondrial (mt) dna markers to examine the matrilineal component of population genetic structure in the snow goose chen caerulescens. from banding returns, it is known that females typically nest at their natal or prior nest site, whereas males pair with females on mixed wintering grounds and mediate considerable nuclear gene flow between geographically separate breeding colonies. despite site philopatry documented for females, mtdna markers show no clear distinctions between nestin ... | 1992 | 28564392 |
| frequency-dependent fitness consequences of intraspecific nest parasitism in snow geese. | the reproductive efficiency, defined as the number of breeding recruits produced per egg laid; of intraspecific nest parasites; of hosts in parasitized nests; and of unparasitized nesting females, was measured for 14 years for lesser snow geese anser caerulescens caerulescens nesting near churchill, manitoba, canada. relative efficiencies were 0.71-0.88, 0.91, and 1.0 for eggs of parasites, hosts, and unparasitized birds, respectively. differences in the hatching probabilities of the three class ... | 1990 | 28564307 |
| effects of simulated feeding by snow geese on scirpus americanus rhizomes. | we simulated the feeding of greater snow geese (chen caerulescens atlantica) on the rhizomes of three-square bulrush (scirpus americanus) in a tidal marsh along the st. lawrence river estuary in québec. during the spring staging period, aboveground biomass is unavailable and geese feed solely on rhizomes and overwintering buds. an experiment was designed to test the effect of three factors on subsequent growth of scirpus: the intensity of removal (3 to 77% removal of belowground biomass), the nu ... | 1987 | 28310427 |
| life history studies of the lesser snow goose (anser caerulescens caerulescens). vi. plumage polymorphism, assortative mating and fitness. | the investigated the hypothesis that positive assortative mating for plumage coloration observed in populations of the dichromatic lesser snow goose (anser caerulescens caerulescens) evolved and persists due to selective advantages accruing to individuals choosing mates phenotypically similar to themselves. we examined potential differences between pure (white × white, blue × blue) and mixed (white × blue, blue × white) pairs for an array of fitness components related to both fecundity and viabi ... | 1985 | 28561360 |
| life history studies of the lesser snow goose (anser caerulescens caerulescens). iii. the selective value of plumage polymorphism: net fecundity. | between 1969 and 1977 the frequency of the blue phenotype of the dimorphic lesser snow goose (anser caerulescens caerulescens) showed a steady increase at the la pérouse bay colony near churchill, manitoba. cooch (1961, 1963) suggested the global increase resulted from selection pressures favoring blue individuals. the selection hypothesis was evaluated by examining phenotypic differences in net fecundity. we partitioned the reproductive cycle into a series of stages, each defined by a particula ... | 1985 | 28563650 |
| life history studies of the lesser snow goose (anser caerulescens caerulescens). iv. the selective value of plumage polymorphism: net viability, the timing of maturation, and breeding propensity. | cooch (1961, 1963) suggested that changes in the genotypic composition of snow goose colonies comprising the hudson bay-foxe basin population could be attributed to selection favoring the blue phenotype. in the preceding paper (cooke et al., 1985), we examined potential differences in net fecundity between the two phenotypes at la pérouse bay in northern manitoba. no substantial differences in any component of fecundity were detected. in the present paper, we examined potential differences in pr ... | 1985 | 28563631 |
| serological and molecular detection of toxoplasma gondii in terrestrial and marine wildlife harvested for food in nunavik, canada. | toxoplasma gondii, a zoonotic protozoan parasite, infects mammals and birds worldwide. infection in humans is often asymptomatic, though illnesses can occur in immunocompromised hosts and the fetuses of susceptible women infected during pregnancy. in nunavik, canada, 60% of the inuit population has measurable antibodies against t. gondii. handling and consumption of wildlife have been identified as risk factors for exposure. serological evidence of exposure has been reported for wildlife in nuna ... | 2019 | 30944016 |
| assessing bias in demographic estimates from joint live and dead encounter models. | joint encounter (je) models estimate demographic rates using live recapture and dead recovery data. the extent to which limited recapture or recovery data can hinder estimation in je models is not completely understood. yet limited data are common in ecological research. we designed a series of simulations using bayesian multistate je models that spanned a large range of potential recapture probabilities (0.01-0.90) and two reported mortality probabilities (0.10, 0.19). we calculated bias by com ... | 2020 | 32612891 |
| a comparison of drone imagery and ground-based methods for estimating the extent of habitat destruction by lesser snow geese (anser caerulescens caerulescens) in la pérouse bay. | lesser snow goose (anser caerulescens caerulescens) populations have dramatically altered vegetation communities through increased foraging pressure. in remote regions, regular habitat assessments are logistically challenging and time consuming. drones are increasingly being used by ecologists to conduct habitat assessments, but reliance on georeferenced data as ground truth may not always be feasible. we estimated goose habitat degradation using photointerpretation of drone imagery and compared ... | 2019 | 31398201 |
| quantification of avian hazards to military aircraft and implications for wildlife management. | collisions between birds and military aircraft are common and can have catastrophic effects. knowledge of relative wildlife hazards to aircraft (the likelihood of aircraft damage when a species is struck) is needed before estimating wildlife strike risk (combined frequency and severity component) at military airfields. despite annual reviews of wildlife strike trends with civil aviation since the 1990s, little is known about wildlife strike trends for military aircraft. we hypothesized that spec ... | 2018 | 30383828 |
| a multi-isotope (δ13c, δ15n, δ34s, δ2h) approach to establishing migratory connectivity in lesser snow geese: tracking an overabundant species. | expanding populations of north american midcontinent lesser snow geese (anser caerulescens caerulescens) have potential to alter ecosystems throughout the arctic and subarctic where they breed. efforts to understand origins of harvested lesser snow geese to better inform management decisions have traditionally required mark-recapture approaches, while aerial photographic surveys have typically been used to identify breeding distributions. as a potential alternative, isotopic patterns that are me ... | 2018 | 30142189 |
| spring temperature, migration chronology, and nutrient allocation to eggs in three species of arctic-nesting geese: implications for resilience to climate warming. | the macronutrients that arctic herbivores invest in their offspring are derived from endogenous reserves of fat and protein (capital) that females build prior to the period of investment or from foods they consume concurrently with investment (income). the relative contribution from each source can be influenced by temporal and environmental constraints on a female's ability to forage on arctic breeding areas. warming temperatures and advancing arctic phenology may alter those constraints. from ... | 2018 | 30092605 |
| reproductive success of a keystone herbivore is more variable and responsive to climate in habitats with lower resource diversity. | the effects of climate on wild populations are often channelled through species interactions. population responses to climate variation can therefore differ across habitats, owing to variation in the biotic community. theory predicts that consumer demography should be less variable and less responsive to climate in habitats with greater resource diversity. we tested these predictions using a long-term study of breeding lesser snow geese along the western coast of hudson bay, manitoba, canada. re ... | 2018 | 29676509 |
| evaluating behavioral responses of nesting lesser snow geese to unmanned aircraft surveys. | unmanned aircraft systems (uas) are relatively new technologies gaining popularity among wildlife biologists. as with any new tool in wildlife science, operating protocols must be developed through rigorous protocol testing. few studies have been conducted that quantify the impacts uas may have on unhabituated individuals in the wild using standard aerial survey protocols. we evaluated impacts of unmanned surveys by measuring uas-induced behavioral responses during the nesting phase of lesser sn ... | 2018 | 29375801 |
| do foraging methods in winter affect morphology during growth in juvenile snow geese? | physical exertion during growth can affect ultimate size and density of skeletal structures. such changes from different exercise regimes may explain morphological differences between groups, such as those exhibited by lesser snow geese (chen caerulescens caerulescens; hereafter snow geese) foraging in southwest louisiana. in rice-prairie habitats (hereafter rice-prairies), snow geese bite off or graze aboveground vegetation, whereas they dig or grub for subterranean plant parts in adjacent coas ... | 2016 | 30128119 |
| influenza a virus surveillance, infection and antibody persistence in snow geese (anser caerulescens). | some snow geese (anser caerulescens) migrate between eurasia and north america and exhibit high seroprevalence for influenza a viruses (iavs). hence, these birds might be expected to play a role in intercontinental dispersal of iavs. our objective in this manuscript was to characterize basic incidence and infection characteristics for snow geese to assess whether these birds are likely to significantly contribute to circulation of iavs. thus, we 1) estimated snow goose infection prevalence by su ... | 2021 | 33621417 |