Six decades ago, conservation authorities recorded an alarming drop in the population of the animal that became our national symbol. There were only 487 nesting pairs of bald eagles in 1963 throughout the country â 417 of them in the continental United States â according to the U.S. Fish & Wildlife Service. This raised concerns that we could lose the bald eagle for good. âWhen America adopted the bald eagle as the national symbol in 1782, the country may have had as many as 100,000 nesting eagles. The first major decline of the species probably began in the mid- to late 1800s, coinciding with the decline of waterfowl, shorebirds and other prey. Although they primarily eat fish and carrion, bald eagles used to be considered marauders that preyed on chickens, lambs, and domestic livestock. Consequently, the large raptors were shot in an effort to eliminate a perceived threat,â the government agency wrote. âCoupled with the loss of nesting habitat, bald eagle populations declined. In 1940, noting that the species was âthreatened with extinction,â Congress passed the Bald Eagle Protection Act, which prohibited killing, selling or possessing the species. A 1962 amendment added the golden eagle, and the law became the Bald and Golden Eagle Protection Act. Shortly after World War II, DDT was hailed as a new pesticide to control mosquitoes and other insects. However, DDT and its residues washed into nearby waterways, where aquatic plants and fish absorbed it. Bald eagles, in turn, were poisoned with DDT when they ate the contaminated fish. The chemical interfered with the ability of the birds to produce strong eggshells. As a result, their eggs had shells so thin that they often broke during incubation or otherwise failed to hatch. DDT also affected other species such as peregrine falcons and brown pelicans. In addition to the adverse effects of DDT, some bald eagles have died from lead poisoning after feeding on waterfowl containing lead shot, either as a result of hunting or from inadvertent ingestion. ⦠Loss of habitat, shooting, and DDT poisoning contributed to the near demise of our national symbol.â