Peregrine Falcons

The Peregrine Falcon is a large bird measuring 13 to 20 inches in length with a wingspan of 2 ½ to 4 feet. The back and wings of the adult are a bluish black or dark grey and its head is black. The chest and belly are white to buff colored and is broken by horizontal bars.

The tail is long and narrow, but rounded at the tip with a distinct white band at the very end. The top of the head and the 'mustache' are black and contrast sharply with the pale coloring of the throat and neck. It is often said to be 'wearing' a helmet. Its feet, beak and claws are black. Its beak is notched on the top. This is an adaptation which enables the falcon to kill its prey by severing the spinal column.

The male and female have similar markings, but the species demonstrates sexual dimorphism. The female is close to 30 % larger than the male.

Juveniles are more brown than black and have streaks rather than distinct bars on their chest and belly.

The Peregrine Falcon is a familiar bird of prey. Except for Antarctica, it is a familiar sight on every continent. They prefer wide-open spaces such as mountain ranges, river valleys, deserts, and coastlines. It is an adaptable bird. It has even adapted to life in the city, building its nest on the top of bridges and tall buildings. In mild-winter regions, the Peregrine Falcon is a year-round resident, but populations that breed in the arctic climes typically migrate.

Their name means 'wanderer' and outside of the breeding season, they will travel vast distances in search of prey. They have incredible homing instincts and will return to the same site, often the same nest year after year. Some nesting sites have been in continuous use for hundreds of years, with one generation after another making use of it.

The Peregrine Falcon reaches sexual maturity by the end of its first year but doesn't usually mate until the second or third year. The pair mates for life and use the same nesting site every year.

The courtship flight includes a series of aerial acrobatics, steep dives, and spirals. Part of the ritual includes the passing of prey from the male to the female while in flight. It is a difficult maneuver requiring the female to fly upside-down. The food is then passed from the male's talons to the female.

The Peregrine Falcon is territorial during nesting season. Nest sites are at least a half mile apart, often farther. This assures enough prey for the mating pairs. The female chooses the nest site. She will scrape a shallow hollow in loose soil or dead vegetation but does not add any material to the nest. The nest site may be on a cliff ledge, or the top of a tall building or bridge. When choosing a ledge, she prefers a one on the south side with some vegetation.

Sometime between February and March 1 to 5 white eggs with brown markings are laid in the scrape. They are incubated by the female for 29 to 33 days. The male may incubate the eggs for a time during the day but never at night. If the clutch is lost early in the season, the female will try again.

The male which is called the 'tiercel' provides food for the female and the chicks, but care for the hatchlings is exclusively the female's domain. The chicks fledge at 42 to 46 days but remain dependent on their parents for up to 2 months.

The Peregrine Falcons are carnivores feeding almost exclusively on medium sized birds, such as waterfowl, songbirds, pigeons, and doves. It will hunt bats at night, but rarely hunts small mammals. Its diet varies greatly depending on what prey is available. They will eat insects and reptiles when the need arises.

They hunt from dawn to dusk, when prey is the most active, but Peregrine Falcon living in urban environments may be nocturnal.

The Peregrine Falcon searches for prey from a high perch or from the air. Once prey is spotted, it folds back its tail and wings, tucks its feet in, and dives. It strikes its prey with its foot, either killing or stunning it and then turns and catches it before dropping to the ground. It will pluck the feathers before consuming its prey.

There was a sharp decline in the population of the Peregrine Falcon in the 1950's, 60's, and 70's. The decline was attributed to the use of DDT. Since the ban of DDT in the United States and Canada, the Peregrine Falcon has made a comeback. It was removed from the U.S. Endangered Species list in 1999.