Mercury Contamination in Idaho Bald Eagles, Haliaeetus leucocephalus
- 191 Downloads
Because mercury contamination is potentially threatening to bald eagle (Haliaeetus leucocephalus) populations, we collected molted feathers at nests to determine the level of contamination in bald eagles in the state of Idaho, USA. Eagle feathers contained measurable amounts of cadmium (Cd), chromium (Cr), selenium (Se), lead (Pb), as well as mercury (Hg). Cadmium, Cr, Se, and Pb levels averaged 0.17, 4.68, 2.02, and 1.29 mg/kg dry weight, respectively, and were at or below concentrations indicated as causing reproductive failure in bald eagles. Mercury contamination was found to be the highest averaging 18.74 mg/kg dry weight. Although a concentration of only 7.5 mg/kg dry weight Hg in bird feathers can cause reduced productivity and even sterility, all of the eagles we sampled bred successfully and the population of bald eagles continues to grow annually throughout the state.
KeywordsBald eagle Haliaeetis leucocephalus Mercury contamination Idaho
This project was funded by the Idaho Department of Fish and Game and Idaho Power Company. We would like to thank the following for their assistance throughout this project: B. Alford, Jon Beals, Blackrock Development Project Manager Kyle Capps, Leslie Carpenter, Kathy and Tom Flint, Toni Holthuijzen, Carrie Hugo, Sonya Knetter, Jeff Knetter, Von Pope, Beth Waterbury, and Mike Whitfield.
- Eisler R (1985a) Cadmium hazards to fish, widlife, and invertebrates: a synoptic review. Biological report 85(1.2), USFWS. Patuxent Wildlife Research Center, Laurel, MDGoogle Scholar
- Eisler R (1985b) Selenium hazards to fish, wildlife, and invertebrates: a synoptic review. Biological report 85(1.10), USFWS. Patuxent Wildlife Research Center, Laurel, MDGoogle Scholar
- Eisler R (1986) Chromium hazards to fish, wildlife, and invertebrates: a synoptic review. Biological report 85(1.6), USFWS. Patuxent Wildlife Research Center, Laurel, MDGoogle Scholar
- Eisler R (1987) Mercury hazards to fish, wildlife and invertebrates: a synoptic review. Biological report 85(1.10), USFWS. Patuxent Wildlife Research Center, Laurel, MDGoogle Scholar
- Harmata AR (1993) Heavy metal and pesticide contamination of bald and golden eagles in the western United States. Unpubl. Rep., US Dept. Interior, EPA. Washington, DCGoogle Scholar
- Jagoe CH, Bryan AL Jr, Brant HA, Murphy TM, Brisbin IL Jr (2002) Mercury in bald eagle nestlings from South Carolina. USA Wildl Dis 38:706–712Google Scholar
- Redig PT, Stove CM, Barnes DM, Aront TD (1983) Lead toxicosis in raptors. Am Vet Med Assoc 177:941–943Google Scholar
- Stout JH, Trust KA (2002) Elemental and organochlorine residues in bald eagles from Adak Island. Alaska Wildl Dis 38:511–517Google Scholar
- Thomas CM, Burch S (2005) Evaluation of inorganic and organic organochlorine contaminants in sediment and biota from Lake Lowell, deer flat national wildlife refuge. Unpubl. Rep. USFWS, Boise, IDGoogle Scholar
- Wiemeyer SN, Frenzel RW, Anthony RG, McClelland BR, Knight RL (1989) Environmental contaminants in blood of western bald eagles. Raptor Res 23:140–146Google Scholar