Peregrine Falcon (Falco Peregrinus) Ron Joseph
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STATE ENDANGERED Peregrine Falcon (Falco peregrinus) Ron Joseph Description the East and bred in Maine. Breeding peregrines The peregrine falcon is a sleek, rapid-flying bird were reported in all mountainous and coastal of prey. Its wingspan measures 35-46 inches, body headland regions of the state. length ranges from 13-19 inches, and weight is 20- Breeding habitat requires cliffs for nesting and 35 ounces. Females are about 30 percent larger than perching and an adequate prey base of small to males; otherwise the sexes are similar in appearance. medium-sized birds. Open water in proximity to Adults have uniform blue-gray upperparts that cliffs may enhance foraging opportunities. Nests, or extend as a “helmet” onto the head and face; light eyries, are located on ledges or overhangs that are barring on the belly; white on the chest and throat; inaccessible to mammalian predators and provide and a rufous wash on the lower chest and belly. The protection from the elements. More recently, bold, distinct mustache mark is obvious on both peregrines have adapted to nesting on bridges and adults and immatures. Immature birds have brown buildings in urban environments. Peregrines are upperparts, heavy streaking on the underparts, and coastal migrants. In September and October, many buff on the chest and throat. Wings are long and Canadian birds (tundrius and anatum subspecies taper to a point. The tundra peregrine (subspecies from the North) are seen throughout Maine, par- tundrius), which typically is seen during migration ticularly near offshore islands. in the East, is paler than the anatum subspecies. Maine’s reintroduced peregrines are a genetic blend Life History and Ecology of many subspecies and races from around the world Peregrine falcons generally reach sexual maturity and vary in plumage characteristics. at two years of age. They form permanent pair bonds and remain mated for life. Peregrines breed- Range and Habitat ing in Maine return from wintering areas and Peregrine falcons establish territories in March or April. Courtship are found worldwide displays include high circling, undulating flights, and breed on all conti- and figure-eight flights. Both members of the pair nents except Antarc- engage in high circling and “flight play.” tica. Although once The nest is a scrape or slight depression in gravel broadly distributed in or debris on a cliff ledge. Eggs are laid at 2-3 day North America, they intervals, with completed clutches containing 3-4 were extirpated eggs. Incubation begins with the laying of the last throughout much of egg and lasts 30-36 days. Both sexes share incuba- their historic range. tion duties, although the female does the majority. Three subspecies occur Hatching in Maine occurs in May or early June. The in North America. young remain in the nest for about six weeks and fledge in late June or July. Fledglings remain at the Range in Maine Falco peregrinus Known locations anatum was native to nest through August. Both adults feed the young. Maines Endangered and Threatened Wildlife ©2003 Maine Department of Inland Fisheries & Wildlife • Peregrines attack and kill their prey in flight by a endangered species list in 1999, but its breeding sharp blow from a vertical dive. Diving speeds have population remains listed as endangered on the been estimated at 200 miles per hour. Primary prey Maine list, as its numbers here are still low. items include shorebirds, seabirds, rock doves, and a variety of other small birds. Peregrines migrate in Recommendations: the fall, primarily to coastal areas in the Southeast or ✔ Prior to land development near peregrine falcon Central and South America. However, some adults eyries, consult with a biologist from MDIFW to breeding in the Northeast may remain year-round. assist with planning. ✔ Use voluntary agreements, conservation ease- Threats ments, conservation tax abatements and incentives, Shooting and collection of peregrines or their and acquisition to protect important habitat for eggs were infrequently documented in Maine during threatened and endangered species. the early 1900s. Increased use of pesticides after ✔ Prohibit climbing on the cliff and hiking near World War II, especially DDT, caused drastic the cliff rim within ¼ mile of peregrine eyries declines in peregrine populations worldwide. Orga- during the March 15 to August 15 nesting season. nochlorine compounds like DDE, a by-product of Falcons are especially disturbed by nearby activity DDT, resulted in shell thinning, egg breakage, and on the cliff or on trails that are line-of-sight from reproductive failure. After peregrines were com- the nest or perches. (Where falcon nests are already pletely extirpated from the eastern United States by established in proximity to humans, these recom- the early 1960s, DDT was banned in the U.S. in mendations can be relaxed, unless the birds show 1972. Although no longer used here, this chemical evidence of disturbance from human activity.) persists in our environment and is still used in South ✔ Maintain trail closures until five weeks after the America where peregrines winter. Habitat is not last bird has fledged (usually late July to mid- limiting in Maine, where cliffs adjacent to large August). open areas are in good supply. Human disturbance ✔ Avoid construction of permanent roads within (e.g., hiking and rock climbing) during the nesting 660 feet of a known peregrine site. season can cause nest failure. ✔ Avoid logging within ¼ mile of an active eyrie during the nesting season. Conservation and Management ✔ Aircraft should not approach closer than 1,500 There is little information on past populations of feet above a nest. Closer approaches may cause the eastern peregrine (subspecies anatum) in Maine. peregrines to attack planes or may cause a frantic Only 16 eyries are referenced in the historic litera- departure from the nest. Falcons startled from the ture, but this likely is an underestimate. An eyrie eyrie have been known to damage eggs or injure occupied by peregrines during 1962 in Acadia nestlings. ✔ National Park was among the last known active Route powerlines and other wires away from nests in the East. eyries to avoid collisions and electrocution hazards. ✔ Maine joined other states in a large-scale reintro- Avoid applications of pesticides around occupied duction program. Young, captive-reared peregrines eyries during the breeding season. ✔ were slowly released at former nest sites in a process Wetlands, especially intertidal mudflats, estuar- called “hacking.” A total of 144 birds were success- ies, and coastal marshes, are key feeding areas. fully released at eight different locations in Maine Protect wetlands used regularly by peregrine falcons from 1984-1997. Peregrines began to nest in Maine at any time of the year from filling, development, or in 1987. The first successful nesting of reestablished other disturbances that could alter prey abundance peregrines in Maine occurred in Oxford County. In and habitat quality. ✔ 1988, the last site occupied by eastern peregrines in Maintain large trees and snags in areas where Acadia National Park was reoccupied. From 1988- peregrines nest and feed. These perches are impor- 2001, 5-8 pairs nested in the state at 13 different tant for roosting and hunting. Leave snags and sites. Young have been produced at normal rates. debris on mud flats for perching and roosting. The population dramatically increased to 15 pairs in 2002. Reintroduced peregrines have been successful in New Hampshire, Vermont, and New York, and undoubtedly young produced there have established eyries in Maine. With recovery of the species nation- wide, the peregrine falcon was taken off the federal • For more information: MDIFW Endangered Species Program • 207-941-4466 • www.mefishwildlife.com •.