Falco sparverius

Pointed wings, reddish back and tail, two black stripes on each side of white sides of head; male has blue-gray wings; averages 27 cm long, 58 cm in wingspan (NGS 1983).

Differs from peregrine falcon, merlin, and aplomado falcon in having a reddish back and tail and double black marks on sides of head; peregrine falcon is much larger. Smaller than the Eurasian kestrel (averages 34 cm long), which has only a single black mark on each side of the head.

BREEDING: Open or partly open habitat; prairies, deserts, wooded streams, burned forest, cultivated lands and farmland with scattered trees, open woodland, along roads, sometimes in cities.

Nests in natural holes in trees, abandoned woodpecker holes, holes in buildings or cliffs, abandoned magpie nests, and similar sites. Readily uses nest-boxes, which may dramatically increase density of nesting pairs in some areas (may use boxes put up for wood duck or goldeneye). In western Venezuela, nest cavities tend to face into prevailing winds (Balgooyen 1990). Rarely returns to breed in vicinity where reared, but breeders tend to return to their previous territories (Palmer 1988).

NON-BREEDING: Various open and semi-open habitats. In winter, males use less open habitats than do females (Smallwood 1987, Palmer 1988, Ardia and Bildstein 2001).

Average territory size was 109.4 ha and 129.6 ha in two western U.S. studies (Cade 1982); home range diameter during the breeding season ranged from about 0.5 to 2.4 km in different regions; see Palmer (1988) for further data.

See Palmer (1988) for egg dates. Clutch size is 3-7 (usually 4-5). Incubation mainly by female, lasts usually 29-31 days. Two broods a year may be raised in some areas (e.g., central North America [Toland 1985], Chile). Young are tended by both parents, leave nest in about 29-31 days, may stay with parents for 2-4 weeks or more (no later than late summer in U.S.). Readily lays replacement clutch if first clutch is lost. Most first breed at 1 year. Monogamy through successive breeding seasons seems to prevail (Palmer 1988). Nesting density varies greatly throughout range, depending on nest-site availability and probably food supply; may tolerate close nesting by other pairs in some regions.