Breeding bald eagles depend on aquatic ecosystems for breeding and wintering. They usually nest in tall trees in remote areas near large bodies of open water. Bald eagle nests can be built in a variety of trees, but in the north, they tend to prefer tall, sturdy white pines with unobstructed views of the water. Adults show strong ties to their nests, returning year after year. According to the U.S. Fish and Wildlife Service, breeding habitat requires at least 640 acres of undeveloped land and water with little human disturbance. The USFWS recommends keeping at least a 660-foot distance from nests, more than 1,300 feet during breeding season. In winter, bald eagle habitat must include open water, so they often congregate around dams, where fast-moving water keeps ice from developing. Threats Humans present the greatest threat to bald eagles. Despite state and federal protections, bald eagles continue to be shot, poisoned and trapped, and environmental damage wrought by humans continues to adversely affect them. Toxic chemicals like DDT decimated eagles decades ago, and continues to adversely affect them today. DDE, a metabolite of DDT, and PCBs are found in high concentrations in bald eagle eggs in the Delaware Bay area, and PCBs have hurt eagle reproduction in the Great Lakes region. Oil spills, pesticides and other toxins also continue to present threats to the birds' recovery. Other threats include lead poisoning, vehicular collisions, mercury poisoning from fish, human disturbance and habitat loss. Lead is believed to be introduced into eagles in a variety of ways, including leaded hooks, lines and sinkers, as well as contaminated or poisoned waterfowl and deer carcasses. The greatest threat to bald eagles remains destruction and loss of habitat due to human activity. This is perhaps the gravest threat to the long-term survival of eagles. To learn more about the characteristics of the bald eagle, click on any of the photos or links below. Gender differences || Eyesight || Wings, flight & migration Life stages || Why "bald" eagles? || Nesting & breeding Habitat & Threats || Predators & Predation Terms of Use - Copyright 2007 Central Vermont Public Service Copyright photos CVPS, Floyd Scholz U.S. Fish & Wildlife Service and Vermont Department of Fish & Wildlife Web related issues || Site developed by Interactive Media Advertising