Raptors commonly referred to as "birds of prey," include hawks, owls, eagles, falcons and vultures. Many people are fascinated with these creatures, especially the majestic bald eagle. Fortunately, after some frightening declines in some of the species, raptors represent one of New Jersey's greatest success stories.
The bald eagle, osprey and peregrine falcon have made impressive comebacks from the brink of extinction, in large part thanks to the efforts of biologists from the NJ Division of Fish and Wildlife. Unfortunately, not all species of raptors are thriving. The American kestrel, for instance, has experienced a sharp decline in recent years, and the work of biologists in the Endangered and Nongame Species Program continues.
The bald eagle is a shining example of recovery in New Jersey. In 1973, when the Endangered and Nongame Species Conservation Act was passed, there was just one nesting pair, in a remote forest in Cumberland County.
Today there are more than 100 nesting pairs of eagles in the state. Most are in the Delaware Bay counties of Cumberland and Salem, but eagles can now be found statewide. Additionally, numbers of wintering eagles along the Delaware have increased dramatically. They remain on the state endangered species list (threatened federally), however, due to their sensitivity to environmental contaminants, habitat loss and human disturbance.
The statewide population increased to 148 territorial pairs in 2013, up from 135 in 2012. One hundred-nineteen pairs were known active (meaning they laid eggs). Ninety-six nests were known to be successful in producing 176 young. Nine eagle pairs maintained territories but did not lay eggs. The nest activity of twenty pairs was unknown due to lack of observations or searches.
Long before the introduction of the pesticide DDT, habitat destruction, shootings, and poisonings had greatly reduced the nation's eagle population. Just as persecution of eagles and other birds of prey was fading, post-war chemical introductions began, threatening these same top-tier birds.
DDT was used heavily in New Jersey, in part for mosquito control, and by 1970, only one nest at Bear Swamp in Cumberland County remained. Consequently, the bald eagle was listed as endangered under New Jersey's new Endangered and Nongame Species Conservation Act in 1973, and as federally endangered throughout the lower 48 states, under the Endangered Species Act in 1978.
Thanks to the banning of DDT, habitat protection afforded by the Endangered Species Act and intensive conservation work by many partners, the bald eagle was deemed nationally recovered in August 2007.
Peregrine falcons, known as the fastest bird in the skies, had their populations decline due to the effects of DDT which caused their eggs to fail, and they became extinct east of the Mississippi by 1964. They were one of the first birds to be the focus of conservation, however, and through an intensive reintroduction program, returned to the skies in New Jersey and other eastern states in the 1980's.
The population in New Jersey has been about 20-24 pairs annually since 2000. In 2003 peregrine falcons returned to their historic cliff nesting habitat on the Hudson River Palisades; a huge milestone in the peregrine's recovery in the state and the region.
Ospreys, formerly known as the fish hawk, rely almost exclusively on fish for their diet. They have taken well to human structures, such as duck blinds and channel markers, for nest structures. They, like eagles and falcons, succumbed to the effects of DDT and their population dropped to about 60 pairs by the early 1970’s.
With the help of biologists and more recently volunteers who put up nest structures, they have recovered to more than 500 nesting pairs. The Endangered and Nongame Species Program monitors their health as an indicator of many coastal species, as they are sensitive to contaminants and the viability of the aquatic food chain.
The American kestrel, a once-common inhabitant of uncultivated fields and pastures has declined in recent years, and the reasons are largely unknown. In February, 2012, the American kestrel became listed as a State Threatened species. Studies are under way, but the declining numbers of American kestrel habitat loss seems to be the main culprit.
The bald eagle story in Pennsylvania has also been one of success. Just 30 years ago, there were only three nests left in the state. With the help of the Canadian government, the Pennsylvania Game Commission brought bald eagle chicks to the state. Today, Pennsylvania boasts more than 250 nests.