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 ( ...200515827210
identification and characterization of avihepadnaviruses isolated from exotic anseriformes maintained in captivity.five new hepadnaviruses were cloned from exotic ducks and geese, including the chiloe wigeon, mandarin duck, puna teal, orinoco sheldgoose, and ashy-headed sheldgoose. sequence comparisons revealed that all but the mandarin duck viruses were closely related to existing isolates of duck hepatitis b virus (dhbv), while mandarin duck virus clones were closely related to ross goose hepatitis b virus. nonetheless, the s protein, core protein, and functional domains of the pol protein were highly cons ...200515708992
new hepatitis b virus of cranes that has an unexpected broad host range.all hepadnaviruses known so far have a very limited host range, restricted to their natural hosts and a few closely related species. this is thought to be due mainly to sequence divergence in the large envelope protein and species-specific differences in host components essential for virus propagation. here we report an infection of cranes with a novel hepadnavirus, designated chbv, that has an unexpectedly broad host range and is only distantly evolutionarily related to avihepadnaviruses of rel ...200312525630
characteristics of pasteurella multocida isolated from waterfowl and associated avian species in california.characteristics of pasteurella multocida isolated from tissues of dead waterfowl and associated avian species found at 23 sites located in northern and central california, from january 1986 through january 1988 are reported. two hundred ninety five isolates of p. multocida were obtained from 23 avian species. most of the isolates belonged to the subspecies p. multocida multocida (63%), followed by p. multocida gallicida (37%), and by p. multocida septica (less than 1%). there appeared to be a hi ...19902338724
avian cholera in waterfowl in saskatchewan, spring 1977.avian cholera was diagnosed in lesser snow geese (anser c. caerulescens), ross' geese (anser rossii) and individuals of several other waterfowl species in a small area of south-western saskatchewan over a 1 month period during the 1977 spring migration. approximately 250 dead birds were found. this is apparently the first time avian cholera has been reported in migrating waterfowl in canada. the site of the mortality was midway between the wintering and nesting areas of the two principal species ...1979459043
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 ...201627155329
possible origins and evolution of the hepatitis b virus (hbv).all members of the family hepadnaviridae are primarily viruses which contain double-stranded dna genomes that are replicated via reverse transcription of a pregenomic rna template. there are two subgroups within this family: mammalian and avian. the avian member's include the duck hepatitis b virus (dhbv), heron hepatitis b virus, ross goose hepatitis b virus, stork hepatitis b virus and the recently identified parrot hepatitis b virus. more recently, the detection of endogenous avian hepadnavir ...201324013024
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 ...201121506868
forced copulation results in few extrapair fertilizations in ross's and lesser snow geese.extrapair paternity varies from 0 to over 70% of young among various populations of birds. comparative studies have suggested that this variation is related to nesting density, breeding synchrony and the proportion of extrapair copulations. we used minisatellite dna fingerprinting to examine levels of extrapair paternity in ross's geese, chen rossi, and lesser snow geese, c. caerulescens c. (hereafter snow geese) nesting in the largest known goose colony in the world. these geese have one of the ...199910328793
opening the black box: using process evaluation measures to assess implementation and theory building.the past decade has seen increasing recognition in prevention science of the need to move away from a black box approach to intervention evaluation and toward an approach that can elaborate on the mechanisms through which changes in the outcomes operate (chen & rossi, 1989; durlak & wells, 1997; spoth et al., 1995). an approach that examines issues of program implementation is particularly critical in the design of efficacy studies of school-based preventive interventions. numerous preventive in ...199910676545
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 ...201324312520
the genetics of polymorphism in the ross' goose (anser rossii). 197128565027
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 ...201728403519
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 ...200128547172
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