The American kestrel prefers to hunt from an exposed perch, which offers a vantage point over open areas, from which it spots its prey using its acute eyesight (2). Once its prey has been targeted, this sit-and-wait predator swoops down towards the ground to catch it in its talons, and kills the prey with bites to the head or neck (2) (4). It feeds mainly on large insects and small rodents in North America, but may feed more upon lizards in tropical regions. The American kestrel is also equally adept at catching flying prey out in the air and, like most other kestrels, also commonly hovers above the ground (2). Once captured, its prey may be eaten straight away, taken back to its perch and consumed, or cached for periods of unfavourable weather when hunting opportunities are limited (2) (4).
Solitary for most of the year, the monogamous American kestrel forms breeding pairs between March and July in North America, with the timing of breeding varying across its range (2) (4). Like other true falcons (genus Falco), nests are not built, but old holes in trees, banks or cliffs or old magpie stick-nests are reused. In the northern hemisphere four to six white eggs with dense brown spots are laid, while in the Caribbean two to four are laid (2) (4). The eggs are incubated for around 28 to 32 days and the chicks will fledge after some 30 to 38 days in the nest. The young adults may breed from a year old, and this species has a life expectancy of almost ten years (2).
It is after the breeding season that many American kestrels migrate to spend winter in areas with higher food abundance. Birds at northern latitudes and juveniles tend to migrate significant distances, while birds in more tropical regions may remain fairly resident in the same area year-round (4). Populations in Alaska and Canada may migrate as far as Panama and the Caribbean islands, and those birds breeding on Tierra del Fuego may migrate northwards to the South American mainland (4) (5).