One late June afternoon I was watching the sunset from the cliffs at Rock Point, when a piercing KAK KAK KAK wrenched me from my rapture. An adult Peregrine falcon dove at me before alighting on the cliffside. She was guarding her nest. While the encounter took me by surprise, Peregrines have nested here, and in other places in Burlington, for years. People have spotted breeding pairs at Lone Rock Point, Red Rocks Park, Mallets Bay, and the Whitcomb Quarry in Colchester. However, if I had been walking along this cliff in the 1970s my Peregrine sighting would have been astonishing. From the mid-1960s to the late-1970s Peregrines were completely extinct east of the Mississippi.
Peregrines are crow-sized falcons with a blue-grey back, a barred white chest, and a dark brown head. Renowned for their flight speed, a Peregrine can exceed 200 mph in its hunting stoop. While their diet consists almost exclusively of medium-sized birds, the Peregrine will occasionally hunt small mammals, small reptiles, or even insects. It was Peregrines’ diet that got them entangled with DDT. In the 1940s, DDT, an insecticide used both agriculturally and in urban areas, quickly permeated the food chain. Apex birds of prey like Osprey, Bald Eagles, and Peregrines were subjected to especially high levels of the toxin. Female Peregrines that were exposed to DDT laid eggs with shells too fragile to protect the embryo inside and populations plummeted.
The efforts of the Cornell University Peregrine Fund, founded in 1970, to revive the U.S. Peregrine population is one of the biggest success stories in U.S. conservation. The driving force of this success was the Eastern Peregrine Falcon Reintroduction Program, which sought to reestablish a breeding population of Peregrines at “hack sites” around the Eastern U.S. The young falcons and tiercels (male Peregrines) that Cornell released at these sites were the offspring of captive Peregrines, but the scientists raised them with little to no human contact. After the birds were about a month old, the scientists brought them to the hack site and placed them on a cliffside in a hack box, a unique container that opens on one side with bars blocking the Peregrines from escaping. The birds spent a week in the box getting oriented to their surroundings, after which it was time for fledging. The scientists removed the bars, and the young birds took their first flights. Providing they did not get snatched up by a red-tailed hawk, the fledglings would stick around for another month or two getting free meals from the hack box before dispersing. These birds were almost certainly the ancestors of the falcon that scolded me at Rock Point.
Three of the reintroduction program’s hack sites were on cliff bands in Vermont. In 1983, the Peregrine Fund recorded the progress of the young birds at these hack sites and disseminated a summary report. Most of the report was written in the terse and objective tone of a lab notebook. The report refers to the birds by number, and the descriptions are factual. However, the sections written by Mike Mauer, the full-time attendant at a remote granite cliff band somewhere in central Vermont (the location has been requested to be kept a secret) depart from the dry tone of the rest of the report. In his site description, he describes the geology, ecology, and aesthetics of the place in a tone that wavers between factual and poetic.
A fantastic view stretches 180 degrees from east to West and includes Camel’s Hump and the Green Mountains to the West, and the White Mountains of New Hampshire to the East. Between the two horizons are endless, rolling, tree-covered hills and mountains.
As the report continues his love for both the project and the individual fledglings is clear. He refers to the birds by the names that he and the other volunteers gave them: P.F Flyer, Nuphar, Captain Nemo, Linnaea, Calypso, Andromeda, and Chamaedaphne.
Calypso- She was this year’s miss Piggy. She loved to eat and then perch in the White Pine.
Jeffrey Allen, a local Birder and frequent visitor to this particular site in the 80s fondly remembers lugging frozen chickens up the mountain to feed the fledglings, sitting with Mauer in the observation blind, and watching the fledglings “helicoptering” in the hack box. Although he may not have stuck to pure convention in his reporting, Mauer was a passionate advocate for a struggling species. It’s clear from everyone I talk to that the sentiment among the attendants was optimistic. The Peregrine problem seemed like one they could actually solve.
In light of the convolution that accompanies most ecological and environmental problems, it is easy to be jealous of the Peregrine project in its heyday. The ecological problem that the organization was combatting had a clear cause, DDT, and a clear answer, reintroduction. Seems pretty straight forward, right? Margaret Fowle, a wildlife biologist for the Audubon Society who has been working with Peregrines since 1997, corrects me. The Peregrine problem may have been clearer than some, but the solution was not easy. The Peregrine Fund was immensely successful in fundraising and the project they embarked on was expensive. In 1999, the Peregrine Fund estimated that over 4 million dollars of expenses had been put into the project in over the course of the year (including donated land and building materials). Hundreds of volunteers donated countless hours to the cause, and it took decades of hard work.
Fowle says that the Peregrine Project was a learning experience for conservationists. Ecologists realized that they needed to set thresholds and have consistent monitoring data so that when a species declines it is noticed before they are nearly extinct. “It’s not enough to fight for endangered species,” she says, “we need to keep common species common.”
Nowadays, Peregrines are one of those “common species.” If you spend much time around cliffsides, or elsewhere around skyscrapers, you are likely to encounter one. Their presence is a living reminder of the ability for conservation to make a real and lasting impact on the biology and beauty of our Burlington landscapes.
Written by Gabriel Allen