Some countries and companies are spending extra money to bury power-lines or to build safe nesting platforms on transmission towers. Increasing pressure to clean up our water and air is forcing needed changes. We have made progress. We must make more.
As recovery and reintroduction programs were begun, as the US Fish & Wildlife Service assembled the largest colony of breeding bald eagles in captivity at its Patuxent Wildlife Research Center near Laurel, Maryland, in an effort to return healthy eagles to the wild. After taking the nesting bald eagles' first clutch of eggs and incubating them artificially, the bald eagles usually laid a second clutch, which the birds were allowed to incubate. In all, 124 bald eagles were hatched at Patuxent.
These captive-hatched bald eagles were an important source for restocking wild populations, and helped to reestablish a broader distribution. Patuxent's program came to an end in 1988, as bald eagles began to reproduce more successfully in the wild, and the center turned its efforts toward other, more critically endangered, species.
Some states continue reintroduction efforts, and two methods are generally used. Eaglets used for reintroduction may be captive-hatched, or, since usually only two young per nest survive, they may be transferred from a bald eagle nest with a clutch of more than two. These "extra" eaglets are placed in the nest of an adult pair whose own eggs are infertile or fail to hatch.
The "foster parents" readily adopt the eaglets and raise them as their own. Another method, called hacking, is a procedure adapted from the sport of falconry, and it was particularly successful in New York State, where only one unproductive pair of eagles was nesting in 1970. At eight weeks of age, nestling eaglets, many flown in from nests in Alaska, were placed on man-made towers located in remote areas. Biologists stayed hidden while providing them with food, and released them when they became able to fly. By the 1990s, there were 20 nesting pairs in New York, many of them around New York City's reservoir system in the Catskills.
The most spectacular recovery, however, took place in the Chesapeake Bay area, where only 32 pairs were nesting in 1977 to produce 18 young, and in 1993, 151 pairs contributed 172 fledglings to the expanding populations.
With these and other recovery methods, as well as habitat improvement and the banning of DDT, bald eagle populations have steadily increased. Indeed, the number of nesting pairs in the lower 48 United States increased 10-fold, from less than 450 in the early 1960s, to more than 4,500 adult bald eagle nesting pairs in the 1990s. In the Southeast, for example, there were about 980 breeding pairs in 1993, up from about 400 in 1981. The largest concentrations were in the states of Florida and Louisiana.
During an April 2007 survey taken by U.S. Fish & Wildlife Service, there were an estimated 9,789 nesting pairs of bald eagles. In the lower 48 states, MN, FL, and WI have the largest population of nesting bald eagles.