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The Return of Charismatic Megafauna
by Laura Heady; photo by Allan Bowdery

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In shape they described the elliptical orbit of a planet; in color they were cream based but so liberally splattered with burnt reds and browns that the overlying colors coalesced and eclipsed it. They had the luster of polished stone, the texture of a lover’s touch, and a warm glow that recalled life itself.

In a word, they were beautiful;
among the most beautiful eggs in the world of birds.

—Pete Dunne, The Wind Masters

For peregrine falcons trying to survive in a changing world, their “beautiful eggs,” became somewhat of an Achilles heel for the species. Vulnerable to the likes of English egg collectors in the Victorian era, and later to the far more devastating effects of ddt in the twentieth century, peregrine falcon populations suffered at the hands of man. This revered bird, the fastest in the world with a cruising speed of 55mph, has been celebrated for its aerial prowess and powerful feet. Peregrines dive—or “stoop”—at their prey at up to180mph, knock their victim down in mid-air with their large feet, and then swoop below to catch the falling prey in their talons. The peregrine falcon is exquisitely designed for the challenges the natural world might present—but not for the chemical threats introduced into the environment by humans.
Peregrine falcons (Falco peregrinus) are the most cosmopolitan of all birds, occurring on all continents but Antarctica. In the northeastern United States, there were as many as 350 breeding pairs at one time, with 40 to 50 historic eyries (nest sites) in New York alone. But introduction of dichloro-diphenyl-trichloroethane (ddt) in the 1940s sent toxic shock waves up the food chain. Insects exposed to ddt were eaten by song birds, where the poison bioaccumulated. The levels of ddt further magnified in peregrines as they preyed upon contaminated songbirds. No longer able to distribute calcium properly, the ddt-accumulated female peregrines were laying eggs that were thinner-shelled than nature intended, and were crushed by the weight of the incubating adults. Widespread reproductive failure almost wiped out the species, and by 1965 all nesting pairs in New York were gone and populations in other parts of the country were in similar decline.

Conservation Success Story
In 1969 the us Fish and Wildlife Service added the peregrine falcon to the endangered species list. And in 1972, 10 years after Rachel Carson addressed the misuse of pesticides in her classic Silent Spring, the link between ddt and reproductive failure in bird species was identified and the use of ddt was banned. The effects of pesticide exposure lingered, and still do today (particularly since ddt may be used illegally in the us and is still used legally in tropical countries where many migrating birds overwinter); however, the numbers of peregrines slowly began to rebound.

Dr. Heinz Meng, Professor of Biology at suny New Paltz, made a tremendous contribution to the recovery of the species. His research led to the very first captive-bred peregrine falcons, which were “hacked” back to the wild in 1974 from the top of a 10-story building on the campus. (Hacking involves caring for young raptors at an artificial nest until they are able to fly and hunt on their own.) Eventually, successful hacking programs supported by The Peregrine Fund, New York State Department of Environmental Conservation (nysdec), and volunteers enabled over 150 captive-bred peregrines to be released at various locations from New York City to the Adirondacks, including Hudson River bridges, the top of Empire State Plaza in Albany, and the Shawangunk Mountains in New Paltz.

The peregrine falcon returned to New York as a breeding bird in 1983 when two nests were discovered on New York City bridges. Next they were found in the Adirondacks. And by the early 1990s, peregrines had started establishing territories in the mid-Hudson Valley, and are now actively building nests on the Tappan Zee, Bear Mountain, Newburgh-Beacon, Mid-Hudson, and Kingston-Rhinecliff Bridges. Community residents have shared in the excitement via the Internet, which provides live Web camera footage of nesting peregrines on the Mid-Hudson Bridge in Poughkeepsie, the Dunn Memorial Bridge in Albany, and at 55 Water Street, a 54-story building in southern Manhattan where a pair settled on the 14th floor after moving from the Bank of New York building in 1999. (For Web footage, visit www.dec.state.ny.us and follow the links for peregrine falcons.)

“Start checking the dec’s Web site around late March,” said Ted Kerpez, Regional Wildlife Manager with nysdec Region 3. “The cameras will go live once there’s a peregrine in the nest.” The peregrines are thought to begin selecting nesting ledges in January or February, with mating behavior occurring during the following spring months. The young typically fledge by early summer and then remain in the vicinity of the nest for a couple of months. But it’s uncertain where the mid-Hudson Valley peregrines go after that. “Nobody is really sure what they do over the winter,” said Kerpez. “They might head south, but maybe they stick around. Some think they go to New York City for the winter. There have been winter sightings in Poughkeepsie, but the reports have been spotty.”

High Exposure Balancing Act
While the return of peregrines to urban areas is promising, the urban nest sites are often on man-made structures and are therefore more vulnerable to disturbance during periods of maintenance or repair. A full recovery of the species will depend on the establishment of a nesting population in natural areas, such as the Shawangunk Mountains. Daniel Smiley of Mohonk Preserve and Dr. Meng observed the last peregrines in the Shawangunks in 1957. With the species returning to other sites in the region, however, it seemed their return to the tall cliffs was imminent. After many years of watching and waiting, a pair of peregrines appeared in the Shawangunks in 1998, after an absence of over forty years, and have been nesting each year since.

“As the population of peregrines expands from their urban locations and along bridges, it is only natural for them to return to their ancestral sites—providing those sites offer adequate nesting opportunities devoid of human disturbance,” said Dr. Tom Sarro, Professor of Biology at Mount Saint Mary College in Newburgh.

Dr. Sarro has been working with John Thompson, Natural Resource Specialist at Mohonk Preserve, to monitor the pair of nesting peregrines on Millbrook Mountain, and a second pair that was just discovered last year at the Trapps area of the preserve. Thompson indeed has a challenge in protecting the peregrines from human disturbance while balancing recreational use of the Trapps, a popular rock climbing area.
“In the 1950s, preserve rangers considered 50 climbers on the cliff a busy day. Now it’s ten times that,” said Thompson. “Our goal is to protect habitat so peregrines can return, and to educate climbers and hikers why the cliffs need to be closed during breeding.” Peregrines mate for life, and generally return to the same nesting areas. In natural environments, they lay three to four eggs in scrapes, shallow depressions scratched into the soil. Sensitive to disturbance above and below the eyrie, breeding pairs nest on high cliff ledges, and thereby avoid threats of most four-legged predators.

In theory, these high nests should also prevent disturbance from most two-legged creatures, but the vertical playground provided by the Trapps cliffs at Mohonk Preserve means the peregrines are sharing their territories with rock climbers. Audible and visual disturbances may cause the peregrines to abandon their nests; so climbing routes in close proximity are being restricted during the breeding season. This shouldn’t come as a surprise to the climbing community, according to Andrew Zalewski, rock climber and salesperson at Rock and Snow in New Paltz. “There are route closures all over the country for raptor conservation, and there’s still plenty of rock left to climb on.” And at Mohonk, rock climbers have played a “vital role” in assisting with research efforts by climbing to eyrie ledges after the young have fledged and collecting prey remains and any unhatched eggs. “Prey remains indicate what the adults are feeding their young,” said Thompson, “and unhatched eggs are analyzed [for contaminants like pesticide residue] to determine why they didn’t hatch.”

Volunteer Monitoring Efforts
Although removed from the federal list in 1999, peregrine falcons are still listed as an endangered species in New York. Since the number of breeding pairs has grown steadily to over 40 known pairs in the state, conservation efforts have shifted from captive breeding programs to locating, monitoring, and protecting breeding pairs. The success of Mohonk’s monitoring program is largely to the credit of volunteers. With patience, field journals, and spotting scopes, volunteers are providing the many pairs of eyes and ears needed to observe the peregrine’s behavior at the confirmed eyries. Sarro and Thompson hope to expand the core group of volunteers, to “explore other areas on the ridge for the possible presence of ‘new’ breeding pairs.”

To qualify as a volunteer, you should be patient, observant, dependable, and enjoy witnessing such feats as nuptial flights, aerial exchanges of food, and vigilant nest defense. “I’ve watched a fledgling take its first flying lessons from its parents, and seen a female fly upside down to take a meal from her mate,” said Sarro. And Allan Bowdery, a volunteer from New Paltz, shared in Sarro’s enthusiasm on being close enough to hear a peregrine in full stoop. “With speeds upward of 150mph, it sounded just like a fighter jet,” said Bowdery. “Just spectacular.”

Monitoring begins this month and continues through the fledgling season in early summer. For a truly spectacular volunteer opportunity and bird’s eye view of this conservation success story, contact the Mohonk Preserve at 255-5969.