ich in turn are eaten by birds of prey. When DDT is introduced into the environment it produces DDE, which accumulates in eggshells causing them to break in the nest (2). The Environmental Protection Agency banned the pesticide in 1972. One of the major driving forces behind the banning of DDT was the book "Silent Spring" by Rachel Carson, who was a former U.S. Fish and Wildlife employee (3).Peregrines are often brought into shelters after being wounded by hunters. In past years they were killed because they feed off of game birds such as quail. The Migratory Bird Treaty Act states that it is illegal to trap, kill, or otherwise disturb the Peregrine and it's nests. DDT and its effects decimated a once healthy peregrine falcon population. Populations in the western states dropped more than 90% (3). In 1970 there were only two pairs in all of California, down from an estimated 300 in 1960 (2). The population was helped along the road to recovery by the banning of DDT. Despite this action large amounts of the chemical lingered in the environment for years to come. The peregrine was put on the endangered species list in 1973(2). This is one of the reasons for its rapid increase. There was a massive captive breeding effort and over 6,200 pairs were released into the wild (4). Mostly volunteers and zoos hand raised these falcons. This breeding effort was instrumental in repopulating the Peregrine to the wild. One problem with a captive breeding program is the possibility of a founding effect and population bottleneck. Also many non-innate behaviors, normally taught by the parents, captive hatchlings do not know. Often times eggs from captive breed birds would be placed in wild Peregrine nests. The success of the Peregrine has become an important symbol for the Endangered Species List and the US Fish and Wildlife. Its success means that it is possible to repopulate a species into the wild. Controversy still surrounds th...
