How Peregrine Falcons Connect Four National Parks

Birds live almost everywhere, from roadrunners in the Arizona desert to house sparrows in city parking lots, and no bird shows how connected the natural world is better than the peregrine falcon. Once prized by kings for hunting, it can reach 180 mph chasing prey, making it the fastest animal in the world. Usually just a speck high overhead, it grows to 36 to 49 cm (14.2 to 19.3 inches) long, about the length of an adult's forearm. It is one of the few raptors that nests on every continent except Antarctica, and its name means "wandering." Here are its stories from four very different national parks.

Acadia National Park, Maine

Peregrines' history at Acadia shows people's power both to harm and to help. From at least the 1930s they nested on the cliffs of Champlain Mountain and Valley Cove, where the eastern subspecies — sometimes called the "big-footed falcon" — used steep, high rock faces to protect its eyries (nests). Both were among the 500 nest sites the U.S. Fish and Wildlife Service identified across the eastern United States in the 1930s.

Then came DDT. Heavy use of the pesticide from the 1940s on washed and blew into soil, water and the ocean, far from the fields where it was sprayed. Small animals such as fish absorbed it, and predators that ate many of them built up ever more poison — bioaccumulation. The falcons laid eggs with shells too thin to hatch. By a 1964 survey, there were no active nests left in the eastern United States; the peregrine had been extirpated there.

Captive breeding and reintroduction brought it back. Acadia's Jordan Cliffs became Maine's first reintroduction site, where 23 captive-bred falcons were released between 1984 and 1986. In 1988 Ganesh, one of the young from the site two years before, turned up at the Precipice Cliffs, returning every summer; in 1991 nesting there finally succeeded, with 3 chicks fledged — Acadia's first successful wild nest since 1956. Ganesh came back to the same site each year until 1999, and falcons returned to Jordan Cliffs and Valley Cove too. By 2021 the three sites had fledged well over 100 young, a success built by nonprofits, state and federal agencies, universities and private falconers together. Biologists band the chicks so they can be identified even after migrating thousands of miles.

Big Bend National Park, Texas

The peregrine came off the federal endangered species list in 1999, but with fewer than a dozen known nesting pairs in Texas it remains endangered under state law, and most of the state's peregrines live in the Big Bend region. The park's 801,000 acres of desert, river and mountain are broken by the Chisos Mountains, about 6,000 feet above the river at the highest peak. Peregrines breed on riverside bluffs and high cliffs and feed on doves, ducks, swallows and plentiful insects.

A peregrine above the Rio Grande at Big Bend. NPS.

Peregrines were first recorded in the Chisos in 1901. Big Bend's birds are the subspecies Falco peregrinus anatum, and the mild climate at this southern edge of their range may let them live here year-round without migrating.

Park Service policy protects every state-listed endangered species and species of concern, so the park has monitored peregrines every year since 1971, even after federal delisting. Loud, erratic noise can make nests fail, so the East Rim of the Chisos is closed during the breeding season (February 1 through May 31) and motorboats are banned in all three river canyons. Since the falcon's federal listing in 1970, federal, state and private efforts in Texas have brought a remarkable recovery; Superintendent Bob Krumenaker noted that the small population in the park and along the Rio Grande Wild and Scenic River is most of the peregrines in Texas. A life-size bronze falcon outside the Chisos Mountains Visitor Center, donated by Friends of Big Bend (now Big Bend Conservancy), marks that success.

Sequoia National Park

In a park of superlatives — the General Sherman Tree is the world's largest tree by volume — the fastest animal fits right in. Peregrines have historically nested on Moro Rock, a 6,725-foot granite dome, and despite DDT's toll they have come back, nesting there from roughly April to August. They mate for life and return to the same nest year after year. Visitors can climb the rock's 350 carved granite steps for the view and a chance to spot them, though it isn't easy: many other birds flock over the foothills below, and summer smog limits visibility — air pollution is another hazard for the falcons.

Some climbing routes on Moro Rock close during breeding season to protect nesting falcons. Image from the National Park Service's page.

Statue of Liberty National Monument, New York

Peregrines use skyscrapers and big bridges all over New York City, and the Statue of Liberty is one of their sites despite the crowds — around 20,000 visitors a summer day, 4.5 million a year. The tall metal-and-stone statue mimics the high cliffs the birds evolved on, and they perch where people cannot go: the torch flame, the rays of the crown, the top of her head, her left shoulder, the tablet's numerals, her left index finger, the folds of her robe and the ledges of the pedestal. They are most active from January, when they claim territory, through April; breeding runs from February to early April.

The island also sits in a migratory corridor full of prey — insects, anadromous and catadromous fish, birds, and marine and airborne mammals. Peregrines here mostly hunt rock doves, mourning doves, American woodcocks and northern flickers, plus bats drawn by insects swarming around the lights that illuminate the statue at night. Park Ranger Jim Elkin, who has worked there for nearly three decades, recalls one summer afternoon when a red bat was circling the island's main mall and a falcon dove from the statue's head, snatched the bat inches from his own head — he felt the gust from its wings — and carried it back up beside its mate to eat it in six quick bites.

A peregrine perched on the Statue of Liberty. Image from the National Park Service's page.

Sources

Rewritten from the National Park Service article "'Wandering' Through Park Skies: How Peregrine Falcons Connect National Parks" (public domain), in hubnx's own words. The article derives "peregrine" from a Spanish word; the page leaves the language out. Photographs credited to Friends of Acadia, and one of a modern bronze sculpture, are not reproduced.