Bald eagle

Abstract: Thirty-seven bald eagles found sick or dead in 18 States during 1971-72 were analyzed for organochlorine pesticides and polychlorinated biphenyls (PCB's). DDE and PCB's were detected in all bald eagle carcasses; 30 carcasses contained DDD and 28 contained dieldrin. Four eagles contained possibly lethal levels of dieldrin and nine eagles had been poisoned by thallium. Autopsies revealed that illegal shooting was the most common cause of mortality. Since 1964 when data were first collected, 8 of the 17 eagles obtained from Maryland, Virginia, South Carolina, and Florida possibly died from dieldrin poisoning; all four specimens from Maryland and Virginia were from the Chesapeake Bay Tidewater area.

Abstract: The bald eagle (Haliaeetus leucocephalus) population in North America declined greatly after World War II due primarily to the eggshell thinning effects of p,p'-DDE, a biodegradation product of DDT...

Abstract: genus commonly found in the western hemisphere. In the eastern U.S., the bald eagle is the largest raptor and is commonly associated with large bodies of water. Bald eagles are considered common in South Florida and are known to breed throughout the state. Nest sites are usually located near large rivers, lakes, or estuaries where the eagle feeds primarily on fish and water-dependant birds. This large raptor was adversely affected by the bioaccumulation of pesticides, principally DDT. These organochlorines interfered with calcium metabolism, which resulted in eggshell thinning. Reduced productivity resulted in population declines and jeopardized the existence of this species. Banning of DDT and other organochlorines during the early 1970s reversed the decline in bald eagle numbers throughout its range. In Florida, overall bald eagle nesting has increased from a few hundred nesting territories in 1973 to 831 in 1995. Similar increases in nesting activity have been documented throughout the remainder of its range. Current threats to the bald eagle include: habitat fragmentation and loss, collisions with cars and powerlines, and shooting. In recognition of increases in the eagle population, efforts are currently underway to reevaluate the management of bald eagles in the southeastern U.S. and to refine conservation recommendations to reduce eaglehuman conflict. This account represents South Florida’s contribution to the range-wide recovery plan for the bald eagle (FWS 1989).