The chief environmental threat to the eagles, the pesticide DDT, which made the eagle's eggshells brittle and doomed generations of young birds before birth, was banned by the Environmental Protection Agency when it was new in 1972.
Listed as endangered in most of the country in 1967 under a law that preceded the 1973 Endangered Species Act, the eagle has been afforded some kind of federal protection since 1918.
What had been the concern of developers, which the new guidelines are designed to help address, was described by Christopher Galik, environmental policy analyst of the National Association of Homebuilders. "The main idea for us was: when we're delisting something, it shouldn't result in a higher regulatory burden than before," Mr. Galik said.
The Endangered Species Act prohibits killing the birds, either directly or by interfering with their habitat: areas where they nested, bred and fed. It takes precedence over the older laws, like the Bald and Golden Eagle Protection Act, which prohibits activities that would "disturb" the birds but does not specifically protect habitat.
Once the bird is no longer protected by the Endangered Species Act, these other protections will come to the fore, along with the new voluntary guidelines and whatever protections are imposed by states or local communities. The Fish and Wildlife Service proposed that "disturb" would be defined as activities that would disrupt the eagles' feeding and breeding or that would directly kill or injure the birds or cause them to abandon their nests.
The bird's populations have recovered unevenly across the country, with the slowest recovery coming in the Southwest, which was the least hospitable area for the birds originally. Recovery has also been slow in Vermont despite aggressive recent efforts. But in the upper Northwest and the Southeast, the bird has thrived. Alaska and Canada, the fish and wildlife service estimates, have about 50,000 birds.
The environmental representatives said that some of the protections afforded by the Endangered Species Act were crucial to restoring the bird's populations and warned that they would be blunted or eliminated in legislation under consideration in the House of Representatives. That legislation revises and narrows the current law's requirements for habitat protections.
David P. Smith, the Interior Department's deputy assistant secretary for Fish, Wildlife and Parks, said yesterday that the fish and wildlife service "is confident that existing protections both at the federal level and the state and local levels for habitat are sufficient."
Jamie Rappaport Clark, the executive vice president of the environmental group Defenders of Wildlife, who headed the Fish and Wildlife Service when delisting was first proposed in the Clinton administration, said Monday that she was "pleased to see this process back on track."
