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Heavy metals in tissues of waterfowl from the Chesapeake Bay, USA.
1984
Guilo R.T. di | Scanlon P.F.
Effects of dietary selenium on the health and survival of captive wintering lesser scaup
2013
Brady, Caroline | Petrie, Scott | Schummer, Michael | Badzinski, Shannon | Belzile, Nelson | Chen, Yu-Wei
Accumulation of selenium (Se) by lesser and greater scaup (Aythya affinis, A. marila) at staging and wintering areas could have contributed to the decline in their continental population. We exposed lesser scaup to background (0.8 μg/g), moderate (8.1 μg/g) and high (20.7 μg/g) levels of dietary Se in captivity and measured survival rates and indices of health in relation to hepatic Se concentrations. There was 100% survival in scaup exposed to Se for 10-weeks (average staging duration at Great Lakes), but ducks in the high treatment group had less lipids. There was 93% survival after 23-weeks (average wintering duration at Great Lakes), but no differences among treatment groups in body composition. There were no effects of Se on oxidative stress and cell-mediated immunity; rather we recorded immuno-stimulatory effects on antibody production. Results from our captive study suggest Se alone did not cause the continental decline in scaup populations.
Mostrar más [+] Menos [-]Is selenium affecting body condition and reproduction in boreal breeding scaup, scoters, and ring-necked ducks
2008
DeVink, J.M.A. | Clark, R.G. | Slattery, S.M. | Wayland, M.
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, respectively. Only scoter livers (66%) were above 33 mg/kg dw Se. Scaup and ringneck Se levels were unrelated to breeding status or lipid and protein levels; breeding scoters and females with greater lipid mass had higher Se than non-breeders. Egg and follicle concentrations in scaup and scoters were normal (mean [95%CI] = 2.3 [1.9-2.6] and 2.4 [2.1-2.7] mg/kg dw, respectively). Overall, we found no support for a relationship between selenium and boreal scaup and scoter declines, and discuss current Se threshold concentrations. Selenium is not affecting boreal scaup, ring-necked duck, or scoter body condition or reproduction.
Mostrar más [+] Menos [-]Accumulation in and effects of lead and cadmium on waterfowl and passerines in northern Idaho
1995
Blus, L.J. | Henny, C.J. | Hoffman, D.J. | Grove, R.A. (National Biological Service, Patuxent Wildlife Research Center, 3080 SE Clearwater Drive, Corvallis, Oregon 97333 (USA))