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At least 883 records · Page 49Linked to original sources
USGS1990

Western grebe, Aechmophorus occidentalis, wintering biology and contaminant accumulation in Commencement Bay, Puget Sound, Washington

Western Grebes wintering at the head of Commencement Bay (bordering the waterways) accumulated significant amounts of mercury, arsenic, DDE, PCBs, chlordanes, and perhaps cadmium and HCB between 17 October 1985 and 6 February 1986. No change in selenium or lead was detected, but copper declined significantly. Western Grebes were likely to accumulate even higher levels of certain contaminants because they remained in Commencement Bay for an additional 3 months after the final collection. Remige moult and bursa length were used to separate five individuals believed to represent one age class, from the remainder of the October collection. These birds, perhaps nonbreeders spending one continuous year in Puget Sound, contained the 5 highest PCB, 5 of the 8 highest DDE, and 2 of the 3 highest mercury concentrations. No evidence was found in the literature to suggest the contaminant concentrations we reported would adversely impact the Western Grebe population. As expected, lipid content of carcasses increased significantly from October (15.5%) to February (28.8%).

Canadian Field-Naturalist↗
USGS1989

Breeding biology and habitat use of black ducks

Forested wetlands are Important habitats for black ducks nesting in the Northeast. Invertebrates, with their high protein content, are primary foods of females during egg laying and for rapidly growing ducklings. Beaver-created and modified wetlands provide excellent habitat for feeding as well as protective cover. As these wetlands age, their quality declines after 7-10 years, and waterfowl use diminishes. Wetland availability and quality should be considered when managing beaver.

Maine Agricultural Experiment Station Miscellaneou↗