Its hard to beat the inspiration of watching a falcon in flight. One of the many spectacular birds that migrates back to Alaska in the spring to nest and rear their young is the Peregrine falcon (Falco peregririus). The name comes from the Latin adjective pereginus, meaning “coming from foreign parts” or “wanderer”. The peregrine was so named as a result of the lengthy migrations of some populations, and, surely, the ones which arrive here have come a long ways and will not remain long in this area. A North American name for the peregrine was “duck hawk” and the naturalist Audubon aptly called the bird the “great-footed hawk” but these names are no longer used.
The falcon group, with four species in Alaska, is distinguished from other birds of prey by a tooth-like projectiion near the tip of the upper half of the bill. Falcons are generally smaller and more streamlined than the hawks, with small heads, firm compact plumage, and long pointed wings, adaptations which allow them to fly at great speed. In flight they have quick, powerful wing strokes. Their strong, hooked bill and powerful, taloned feet mark falcons as highly specialized predators.
The falcon female (called the “falcon” by falconers) is larger than the male (called the “tiercel”). Adult males are 15 to 18 inches long and weigh about 1 1/4 pounds, while the females are 18 to 21 inches long and weigh about 2 pounds. Some birds of prey soar or hover in the sky and others have evolved short wings for quick, darting flights in forested country. But the long winged peregrine specializes in direct pursuit in the open. Its usual quarry are birds. The speed of its dives (stoops) at prey are estimated at well over 200 mph. At such speeds it delivers a fierce blow to the prey with a half-closed foot, the usual method of disabling or killing medium-sized and large prey. Small prey such as swallows or sandpipers are snatched in mid-flight.
The peregrine nests mostly on precipitous cliffs. These birds are very territorial during the breeding season and the nests are usually at least a mile, or often much farther, apart. This ensures adequate food for all nesting pairs and their offspring. During spring courtship ritual the male courts his larger mate with awesome aerobatics and a “wichew” call. Three or four mottled eggs are laid, one every other day and incubation is by both adults. Renesting following loss of the first clutch (complement of eggs) is rare in the Arctic or subarctic due to the short summer season, but is a regular occurrence farther south. Nestlings (called eyases) spend 35 to 45 days in the nest and sexual maturity is not reached until at least two years of age. Some exceptional individuals have been known to live 18 to 20 years, but the average falcon’s lifespan is probably much shorter.
Peregrines, like other predators, are at the top of the food chain, an advantageous position with few enemies and a longer lifespan, but disadvantageous because pesticides become more concentrated at each link of the food chain, exposing them to higher levels. Populations of the peregrine falcon have been re- established in areas where it had been exterminated by DDT-induced breeding failures. As with the entire extinction problem, long-term solutions depend on changing attitudes toward our fellow creatures and the reduction of the appropriation of Earth’s resources by Homo sapiens. One can not see these amazing falcons without considering habitat destruction and all the various impacts that continue to accelerate the loss of species, both spectacular ones and the more obscure.