Field Guide/Birds/Falco peregrinus

The Peregrine Falcon or, formerly, in North America, Duck Hawk (Falco peregrinus) is a medium-sized falcon about the size of a large crow: 38-53 cm (15 to 21 inches) long. It has a wingspan of about 1 metre (40 inches). Males weigh 570-710 grams; the noticeably larger females weigh 910-1190 grams.

Range, habitat and subspecies

Peregrine Falcons live mostly along mountain ranges, river valleys, and coastlines and increasingly, in cities. They are widespread throughout the entire world and are found on all continents except Antarctica.

There are many subspecies of Peregrine Falcons, including:

• Falco peregrinus tundrius breeds in the Arctic tundra of North America but is migratory and travels as far as South America.
• F.p. pealei is found in the Pacific Northwest of North America, and is non-migratory.
• F.p. anatum is mostly found in the Rocky Mountains. Although it used to be common throughout eastern North America, and is currently being re-introduced in the region, it remains uncommon in much of its former range. Most mature anatums, except those that breed in more northern areas, winter in their breeding range.

The Barbary Falcon, Falco (peregrinus) pelegrinoides, is often considered to be a subspecies of the peregrine.

Peregrines in mild winter regions are usually permanent residents. Other populations migrate; for instance, birds from Alaska, northern Canada and Greenland migrate to Central and South America. Similarly, many birds from northern Eurasia move further south or to coasts in winter, but in milder areas, some birds, especially adult males, will remain on the breeding territory. Migrating birds may travel far out over open ocean.

Threats

The Peregrine Falcon became endangered because of the overuse of pesticides, in particular DDT, during the 1950s and 1960s. Pesticide build-up interfered with reproduction, thinning eggshells and severely restricting the ability of birds to reproduce. In several parts of the world, this species was wiped out by pesticides.

Peregrine eggs and chicks are often targeted by thieves and collectors, so the location of their nest should not be revealed, unless they are protected.

The Peregrine, (formerly known as the Duck Hawk in the US), along with the Red-tailed Hawk and the Barn Owl, is considered an avian pest in many rural areas of the United States.

Recovery efforts

This Peregrine Falcon was found injured and survived in Olomouc Zoological Garden, the Czech Republic. One of activities of the zoological garden is a programme of helping injured birds of prey.

Wildlife services around the world organized Peregrine Falcon recovery teams to breed them in captivity, at Cornell University and the renowned World Center for Birds of Prey located in Boise, Idaho, among other places.

The birds were fed through a chute so they could not see the human trainers. Then, when they were old enough, the box was opened. This allowed the bird to test its wings. As the bird got stronger, the food was reduced because the bird could hunt its own food. This procedure is called hacking. To release a captive-bred falcon, the bird was placed in a special box at the top of a tower or cliff ledge.

Worldwide recovery efforts have been remarkably successful. In the United States, the banning of DDT, over time, made it possible for released birds to breed successfully. There are now dozens of breeding pairs of peregrine falcons in the northeastern USA. Many have settled in large cities, including London Ontario, where they nest on skyscraper window ledges and the towers of suspension bridges. These structures typically closely resemble the natural elevated cliff ledges which the species prefers for nesting locations. During daytime the falcons have been observed swooping down to catch common city birds such as pigeons and starlings. In many cities, the falcons have been credited with controlling the numbers of such birds, which have often become pests, without resort to more controversial methods such as poisoning or hunting.

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Successful efforts at saving endangered species like the Peregrine were recognized by a U.S. postal stamp.

In Virginia, state officials working with students from the Center for Conservation Biology of the College of William and Mary in Williamsburg successfully established nesting boxes high atop the George P. Coleman Memorial Bridge on the York River, the Benjamin Harrison Memorial Bridge and Varina-Enon Bridge on the James River, and at other similar locations. 13 new chicks were hatched in this Virginia program during a recent year. Over 250 falcons have been released through the Virginia program.

The peregrine falcon was removed from the U.S. Threatened and Endangered Species list on August 25, 1999. Although still on the North Carolina Endangered Species list, the falcon seems to be making a comeback in western Northern Carolina, namely the Chimney Rock Park, which huge rock faces serve as ideal nesting ledges for the peregrine falcon. Attempts to set up nests for the birds have proved successful, but the birds always seemed to disappear or move further west. But in April 2005, bird watchers and a local ornithologist spotted a peregrine falcon defending its nest site.

In the UK, there has been a good recovery of populations since the crash of the 1960s. This has been greatly assisted by conservation and protection work led by the RSPB. Peregrines now breed in many mountainous and coastal areas especially in the west and north. They are also using some city buildings for nesting, capitalizing on the urban pigeon populations for food.

Trivia

The Mediterranean Peregrine Falcon, in this context known as the Maltese Falcon, was the annual rent required by Roman Emperor Charles V when he donated the Island of Malta to the Knights Hospitaller in 1530.

A nesting pair of peregrine falcons reside atop the Cathedral of Learning, on the main campus of the University of Pittsburgh.