A new analysis of where and when Peregrine Falcons banded in New England have been re-sighted or recovered is providing insights into the continuing recovery of the once-endangered bird.
The raptor was extirpated as a breeding species in New England in the 1960s. A captive-breeding-and-release program was begun in 1974, and as researchers and volunteer nest monitors kept watch, the population expanded rapidly.
Falcons returned not only to traditional nest sites on cliffs in rural areas but also to buildings, bridges, and other structures in urban areas. The species was removed from the federal list of endangered and threatened species in 1999.
According to research published this fall in the Journal of Raptor Research, biologists banded 986 young Peregrine Falcons in Connecticut, Massachusetts, Maine, New Hampshire, Rhode Island, and Vermont between 1990 and 2009. About a quarter of the birds were re-sighted or recovered by December 2009.
Three quarters of the encounters occurred within the study area, write Steven D. Faccio and colleagues, but 57 encounters (24 percent) were in eastern states outside New England, in Ontario, Quebec, or New Brunswick, or far to the south: A male from Vermont was found dead in Nicaragua, while another from Maine was shot in Camagüey, Cuba.
In general, females dispersed farther than males. Falcons in their first year were encountered at greater distances than second-year birds and adults. And the Peregrines showed a strong tendency to settle at nest types similar to those on which they were raised. Over 80 percent of birds that fledged from cliffs returned to nest on cliffs, while 82 percent of falcons from buildings nested on buildings.
A total of 122 individuals either were found dead or died from injuries shortly after being found. Most deaths involved first- and second-year birds.
One of them was a 19-month-old Peregrine from Vermont that flew no farther than New York. According to Faccio, it died after eating a European Starling poisoned with fenthion, an organophosphate pesticide once used to control starlings, Rock Pigeons, and other species that roost on farms, airports, and public buildings.
The chemical was classified as a restricted-use pesticide in 1998. A climber discovered the falcon in the Adirondack Mountains in January 2001.
Read the abstract:
Steven D. Faccio, Michael Amaral, Christian J. Martin, John D. Lloyd, Thomas W. French, and Anthony Tur, 2013, Movement Patterns, Natal Dispersal, and Survival of Peregrine Falcons Banded in New England, Journal of Raptor Research, 47(3): pp. 246-261. Abstract.
A version of this article appeared in the February 2014 issue of BirdWatching Magazine. Subscribe.