Peregrine Falcons: Immigration and Subsequent Adaptation in

the Manhattan Area:Julián Rojo

Molly Malar

John O.

www.freefunflies.com

Life of a Falcon

Young usually fledge about 35 to 45 days after hatching.

Falcons live as long as twenty years.

Sexual maturity occurs at between one and two years of age.

Falcons may stay in the area for some time after fledging but eventually go off to find their own sites.

Natural Habitat

To hunt, these falcons dive from high cliffs and grab their prey, usually small birds, out of the air with their strong claw-like beaks

Peregrines usually inhabit rocky mountainous regions near water

http://www.nwf.org/peregrinefalcon/

Hunting Style:Anatomy:

Their anatomy is fit for diving at high speeds that reach over 160 kilometers per hour (Cornell).

Peregrine falcons lurk about high in the sky for minutes on end, eventually they before swoop down at high speeds towards its unsuspecting prey. They smash their claws against their target, delivering a devastating blow that either kills or cripples them on impact ( De Candido ). Such methods of predation have been hard-wired into peregrine falcons over time

Recovery Efforts: The Peregrine Fund

The successful reintroduction of the Peregrines into the wild after their endangerment in 1970 was achieved through the efforts of The Peregrine Fund, an international organization dedicated to the restoration of populations of birds of prey.

The fund focused on reestablishing viable populations of the species throughout its historic North American range.

After breeding Peregrines in captivity, The Peregrine Fund released nearly 160 captive-raised birds from 1974-1988 at a dozen sites from New York City to the Adirondacks.

Peregrines Find New Homes in Urban Environments

Urban environments serve as opportune habitats for Peregrines because: City bridges or skyscrapers provide a

great deal of open air space and a unique perch for hunting

Predators are virtually eliminated and food sources

Recently Peregrines have been beginning to develop additional adaptations to take advantage of their urban habitats while they hunt mostly in the daytime

outside the city, urban falcons are beginning to become nocturnal hunters.

Skyscrapers provide hunting perches at altitudes often flown by nocturnal prey & birds sometimes become disoriented from the lights of the city and circle skyscrapers, which makes them an easy target for Peregrines

Nesting

Statistics indicate that male and female peregrine falcons show a moderate discrepancy regarding hunting “success”, as male falcons bring up to five times more food to the nest than females (Cade, 33). This statistic however, is somewhat inaccurate, as it does not take into account the effect of gender roles. Males tend ‘hunt and gather” more often than females because females have a “sedentary role as guardians of the nest and the young that might inhabit it” (Cade, 33).

Nesting (continued)

Peregrines nest on tall buildings and bridges, with ledges similar to those found on cliffs in the wild.

Ledges provide protection from the elements and predators.

Mating pairs are territorial, generally keeping at least half a mile between one another.

Scouting for new hospitable locations

Studies have shown that the peregrine falcons’ feeding patterns peak twice in the morning (Schenieder).

In order for hunting and gathering to take place, peregrine falcons must first find suitable nesting ground. Males go about exploring the terrain, looking for potential areas that can serve as a new home.

:http://www.flickr.com/photos/nylocations/457651694/

Their search takes about ten days, which coincidently, appears to be the maximum amount of time in which they can retain their memory (Schneider). On the final days of the ten-day period the falcons will return to one of the sites that they had committed to memory and claim it as their own (Cade 43).

Peregrine Falcons in NYC

As of April 26, 2009, there were 16 mating pairs living in New York City.

Peregrines generally mate for life, returning to the same nest site in consecutive years to hatch young.

Falcons hatch 3 -5 eggs at a time.

Man-made falcon nest on the New York Hospital. Another example of the advantages of living in the city for the falcons.

Here is **The Video** that perfectly encapsulates the high points of the peregrine falcon’s sublime hunting style

Life Science Wiki Project: Peregrine Falcons

Works Cited:

Bildstein, Keith L. “Return of The Peregrine.” Journal of Wildlife Management Vol.

68, Iss. 2 (April 2004)

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index=33&did=758867441&SrchMode=1&sid=10&Fmt=3&VInst=PROD&VType

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BirdWeb. “Peregrine Falcon” http://birdweb.org/birdweb/bird_details.aspx?

id=114 (accessed March 8, 2009)

Chace, Jameson F. and Walsh, John J. “Urban effects on native avifauna: a

review.” Landscape and Urban Planning 74, no.1 (5 December 2003),

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V91-

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2aae5369635c22683a5

Cohen, Fiona. “Birds of Prey Adapt Their Habits to the Urban Landscape.” Seattle

PI, November 28 2007,

http://seattlepi.nwsource.com/getaways/341299_falcons29.html

DeCandido, Robert and Allen, Deborah. “Nocturnal Hunting By Peregrine Falcons

At Empire State Building, New York City” The Wilson Journal of Ornithology. Vol.

118, Iss. 1. (March 2006), http://proquest.umi.com/pqdweb?

index=2&did=1012798211&SrchMode=1&sid=1&Fmt=4&VInst=PROD&VType=

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Environmental Graffiti. “Peregrine Falcons Thriving After Going Urban”

http://www.environmentalgraffiti.com/ecology/peregrine-falcons-thriving-after-going-urban/773 (accessed March 6, 2009).

Loucks, Barabra A. and Nadareski, Christopher A. “Back From the Brink” New

York State Conservationist. Vol. 59, Iss. 5. (April 2005).

Niemi, Gerald J and Michael, McDonald E. “Application of Ecological Indicators.”

Annual Review of Ecology, Evolution, and Systematics Vol. 35 (2004)

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The Peregrine Fund. “Peregrine Falcon.”

http://www.peregrinefund.org/explore_raptors/falcons/peregrin.html (accessed

March 6, 2009).