| some metazoan parasites of ring-necked ducks, aythya collaris (donovan), from canada. | | 1978 | 641683 |
| migratory birds of central washington as reservoirs of campylobacter jejuni. | migratory ducks, canada geese, and sandhill crane from the pacific north american flyway have been screened for campylobacter spp. samples (298) from these birds were examined and the incidence of campylobacter spp. in the samples were as follows: sandhill crane (grus canadensis tabida), 81%; ducks (aythya collaris, anas carolinensis, aythya americana, and anas platyrhynchos), 73%; and canada geese (branta canadensis), 5%. all isolates were identified as campylobacter jejuni. to our knowledge th ... | 1988 | 3378202 |
| experimental lead toxicity in the ring-necked duck. | ring-necked ducks (aythya collaris) were administered a single lead shot by gastric intubation. at weekly intervals over a 7-week period, the birds were weighed and blood samples obtained for measurement of hematocrit, free erythrocyte protoporphyrin (fep), blood lead and delta-aminolevulinic acid dehydratase (delta-alad) activity. the birds were fluoroscoped weekly to ensure that the pellets had been retained. blood lead concentrations peaked 1 week after dosing at a concentration of 7.75 micro ... | 1986 | 3780650 |
| blood parasitemia in a south texas wintering waterfowl population. | eleven species of wintering waterfowl were trapped on the welder wildlife foundation, san patricio county, texas, between october, 1976 and may, 1977. blood films were made from 580 ducks. leucocytozoon simondi, haemoproteus nettionis, plasmodium circumflexum, and a microfilaria were found in three species. these blood parasites occurred in 70 lesser scaups (aythya affinis), 12 blue-winged teals (anas discors), and 3 ring-necked ducks (aythya collaris). there was no difference in the rates of i ... | 1980 | 6768901 |
| blood lead concentrations of waterfowl from unhunted and heavily hunted marshes of nova scotia and prince edward island, canada. | blood lead concentrations of juvenile american black ducks (anas rubripes) sampled in unhunted sanctuaries of nova scotia (ns) and prince edward island (pei), canada, usually were < 30 parts per billion (ppb). based on gizzard content analyses of juvenile american black ducks from hunted areas, eight (24%) of 33 flightless birds contained ingested lead shot. blood lead concentrations were > or = 100 ppb in seven of eight juveniles with ingested shot; thus we adopted blood lead concentrations 100 ... | 1993 | 8258857 |
| vacuolar myelinopathy in waterfowl from a north carolina impoundment. | vacuolar myelinopathy was confirmed by light and electron microscopic examination of mallards (anas platyrhynchos), ring-necked ducks (aythya collaris), and buffleheads (bucephala albeola) collected during an epizootic at lake surf in central north carolina (usa) between november 1998 and february 1999. clinical signs of affected birds were consistent with central nervous system impairment of motor function (incoordination, abnormal movement and posture, weakness, paralysis). this is the first r ... | 2003 | 12910770 |
| effects of nontoxic shot regulations on lead accumulation in ducks and american woodcock in canada. | prior to the first nontoxic shot zones being established in canada, a nationwide survey of lead (pb) concentrations in wing bones of hatch year (hy) dabbling and diving ducks determined the incidence of elevated pb exposure in waterfowl in different parts of the country (scheuhammer and dickson 1996). the main objectives of the present study were (1) to compare these previously collected data with the incidence of elevated pb accumulation in the same species several years after the establishment ... | 2005 | 15719196 |
| is selenium affecting body condition and reproduction in boreal breeding scaup, scoters, and ring-necked ducks? | elevated levels of selenium (se) have been detected in wintering and spring-staging lesser scaup. here, we compared spring scaup se and mercury (hg) levels to those of ring-necked ducks and white-winged scoters, species exhibiting increasing and decreasing boreal populations, respectively. mercury concentrations were low in all three species. geometric mean (95%ci) liver se concentrations were 6.2 (5.5-7.0), 4.6 (4.0-5.4), and 32.6 (28.4-37.3)mg/kg dry weight (dw) in scaup, ringnecks and scoters ... | 2008 | 17583399 |
| influenza a viruses in wild birds of the pacific flyway, 2005-2008. | avian influenza viruses (aivs) pose a significant threat to public health, and viral subtypes circulating in natural avian reservoirs can contribute to the emergence of pathogenic influenza viruses in humans. we investigated the prevalence and distribution of aivs in 8826 migratory and resident wild birds in north america along the pacific flyway, which is a major north-south migration pathway that overlaps with four other flyways in alaska providing opportunities for mixing of eurasian and amer ... | 2010 | 20059316 |
| waterfowl ecology and avian influenza in california: do host traits inform us about viral occurrence? | we examined whether host traits influenced the occurrence of avian influenza virus (aiv) in anatidae (ducks, geese, swans) at wintering sites in california's central valley. in total, 3487 individuals were sampled at sacramento national wildlife refuge and conaway ranch duck club during the hunting season of 2007-08. of the 19 anatidae species sampled, prevalence was highest in the northern shoveler (5.09%), followed by the ring-necked duck (2.63%), american wigeon (2.57%), bufflehead (2.50%), g ... | 2010 | 20521673 |
| 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 |
| fire, humans, and climate: modeling distribution dynamics of boreal forest waterbirds. | understanding the effects of landscape change and environmental variability on ecological processes is important for evaluating resource management policies, such as the emulation of natural forest disturbances. we analyzed time series of detection/nondetection data using hierarchical models in a bayesian multi-model inference framework to decompose the dynamics of species distributions into responses to environmental variability, spatial variation in habitat conditions, and population dynamics ... | 2014 | 24640539 |
| winter waterbird community composition and use at created wetlands in west virginia, usa. | information on nonbreeding waterbirds using created wetlands in the central appalachian region of the united states is limited. we compared waterbird communities of two managed wetlands, created in 2013 and 2001, in west virginia. we observed 27 species of waterbirds. species richness and diversity were generally similar between the wetlands, but species composition and use differed. branta canadensis (canada geese), anas strepera (gadwall), bucephala albeola (buffleheads), aythya affinis (lesse ... | 2017 | 28386513 |
| radiocesium in migratory aquatic game birds using contaminated u.s. department of energy reactor-cooling reservoirs: a long-term perspective. | low-level releases of radiocesium into former nuclear reactor cooling-reservoirs on the u.s. department of energy's savannah river site (srs) in south carolina, usa, dating primarily to the late 1950s and early 1960s, have allowed examination of long-term contaminant attenuation in biota occupying these habitats. periodic collections of migratory game birds since the 1970s have documented (137)cs (radiocesium) activity concentrations in birds of srs reservoirs, including mainly par pond and pond ... | 2017 | 28273599 |
| thinking like a duck: fall lake use and movement patterns of juvenile ring-necked ducks before migration. | the post-fledging period is one of the least studied portions of the annual cycle in waterfowl. yet, recruitment into the breeding population requires that young birds have sufficient resources to survive this period. we used radio-telemetry and generalized estimating equations to examine support for four hypotheses regarding the drivers of landscape scale habitat use and movements made by juvenile ring-necked ducks between the pre-fledging period and departure for migration. our response variab ... | 2014 | 24551123 |
| avian metapneumovirus subtype c in wild waterfowl in ontario, canada. | avian metapneumovirus (ampv) is an emerging poultry pathogen that has a significant economic impact on poultry production worldwide. the geographic range of the virus continues to expand, and wild birds have been implicated as reservoirs of ampv that have the potential to spread the virus over long distances. our objective was to determine the apparent prevalence of ampv subtype c in wild waterfowl in ontario, canada. wild waterfowl were captured in august and september, 2016 as part of routine ... | 2018 | 29457370 |
| patterns of trace element accumulation in waterfowl restricted to impoundments holding coal combustion waste. | waterfowl are often exposed to and readily accumulate anthropogenic contaminants when foraging in polluted environments. settling impoundments containing coal combustion waste (ccw) enriched in trace elements such as arsenic (as), selenium (se), and mercury (hg) are often used by free-ranging migratory and resident waterfowl and represent potential sources for contaminant uptake. to assess accumulation of ccw contaminants, we experimentally restricted waterfowl to a ccw-contaminated impoundment ... | 2020 | 32096287 |