Peregrine Falcon

Identification

A compact, deep-chested falcon with long pointed wings and a relatively short tail. Females are noticeably larger than males — the size gap is so wide that the sexes were once described as different species. Adults are slate grey above with a fine dark barring on the underparts, a crisp black helmet and a broad black cheek stripe that hangs below the eye like a drooping moustache. The eye ring, cere and feet are yellow. Juveniles are brown above and heavily streaked below, with a paler, less crisp face pattern.

Almost everything it eats is taken on the wing: pigeons, ducks, shorebirds, starlings. The classic attack is the stoop — a folded-wing dive from high above that ranks as the fastest recorded movement of any animal, exceeding 320 km/h in level flight measurements. It does not build a nest, but scrapes a shallow depression into a cliff ledge, a quarry face, or increasingly a skyscraper balcony, bridge girder or church tower, where city birds hunt the local pigeon flock. The alarm call is a hard, chattering series of kek notes.

The species was nearly erased from eastern North America by DDT and has recovered so completely that urban pairs are now routine. Look for it in fall and winter at coastal migration points and estuaries, where it flushes shorebird flocks, and scan tall city buildings and cathedral towers in spring for ledge-nesting pairs. Its level, stiff-winged flight — deep, quick beats followed by a glide — is a reliable cue even at a distance.