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Last Call

Bird Loss and the Threat of Extinction

Peregrine Falcon

(Falco peregrinus)

The return of a once-lost aerial speedster

Sepia photograph of a female perching on a branch and her nestlings huddled in a cliff-side nest. Photo taken by Arthur Allen, the founder of the Lab of Ornithology at Cornell University, sometime in the late 1920s or early 1930s.
Photograph of female Peregrine Falcon and her nestlings at Taughannock Falls.
Photo by Arthur Allen
Color illustration of a Peregrine Falcon with its steely blue, white and black plumage.
Illustration of a Peregrine Falcon by Jane Kim.
Illustration by Jane Kim

In the first decades of the 20th century, early Cornell ornithologists regularly observed and photographed Peregrine Falcons in the Taughannock gorge. Then they were gone.

The main cause was simple but lethal: the pesticide DDT, introduced after World War II, accumulated through food webs and weakened raptor eggshells so severely that nests failed repeatedly. By the late 1960s, peregrines had vanished from much of the eastern United States, including New York. The precipitous decline of peregrines was also mirrored by losses of other raptors such as Bald Eagles and Ospreys.

Rachel Carson’s Silent Spring (1962) helped catalyze public awareness of the dangers of pesticides, and policy caught up with science. DDT was banned in the United States in 1972, and peregrines, listed as endangered in 1970 under the Endangered Species Conservation Act, remained listed as it morphed into the Endangered Species Act (ESA) at the end of 1973. The Peregrine Fund launched critical raptor conservation and recovery efforts.

With cleaner environments and thousands of young falcons released across the continent, Peregrine Falcon populations slowly rebuilt. Birds began nesting again, not only on natural cliffs but also on bridges and skyscrapers—urban stand-ins for their traditional rocky ledges.

Photograph of a Peregrine Falcon flying in front of a dark background of shale cliffs.
Peregrine Falcon at Taughannock
Photo by Andrew Johnson

By 1999, the Peregrine Falcon had recovered so fully that it was removed from the U.S. Endangered Species List, although recovery at a continental scale did not reach every place at the same time.

Now, if you visit Taughannock Falls State Park on an early spring morning, you might again spot two Peregrine Falcons swooping in unison over the gorge, their swift arcs and plunges tracing an airborne courtship ritual known as “sky dancing.” Taughannock’s resident Peregrine Falcons are a conservation success that has converted a historical record into a living one.

Photo of Cornell Professor Tom Cade and a Peregrine Falcon in an indoor office setting at the at Ornithology Lab.
Professor Tom Cade and a Peregrine Falcon at the Ornithology Lab at Cornell University

The Peregrine Fund

The successful recovery of Peregrine Falcons has deep local links in Ithaca. In 1970, Cornell professor Tom Cade and colleagues co-founded The Peregrine Fund, an organization that has become the linchpin of raptor conservation and recovery efforts worldwide. A bold strategy underpinned their success: breeding peregrines in captivity, raising young birds to independence using a technique borrowed from falconry called “hacking,” then releasing them into the wild. Following their success, this method has since also been adapted to help preserve other vulnerable raptor populations such as ospreys and eagles.

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