American Kestrel

Falco sparverius

American Kestrels are adaptable in their choice of nesting habitats. Their requirements-moderately short grass in which to find prey and secure cavities in which to raise their young-are usually met in open, rural areas. However, these small falcons occasionally nest in towns and even city centers. Breeding pairs may be found in all types of habitat except deep woods (Palmer 1988). Nest sites are often situated in tree cavities, but they can also occur in utility poles excavated by woodpeckers, in the walls of buildings, and in specially-designed kestrel boxes (Nagy 1972).

Code Frequency

Because American Kestrels are relatively conspicuous while hunting and perching, the blocks in which they were found may accurately represent their true breeding distribution in Missouri. Evidence of probable breeding, such as pairs and territoriality, were more detectable for kestrels than most species. Because kestrels nest in cavities in open country, Atlasers were frequently able to confirm breeding. Nonbreeding individuals may have been observed in blocks where kestrels were recorded as possible breeders.

Distribution

The most obvious characteristic of the American Kestrel's breeding distribution was its general avoidance of the most forested parts of the state. Kestrels were recorded in greatest density from west central Missouri north to the Iowa line. Overall, their distribution appeared to reflect the occurrence of open agricultural land. In north central and northeastern Missouri, there were fewer blocks where the species was recorded despite a prevalence of seemingly appropriate habitat. Although the Mississippi Lowlands appeared more suitable for kestrels than for most bird species, the number of blocks in which this species was reported appeared low considering the abundance of agricultural land in this natural division. Additionally, there were only two blocks in this division where breeding was confirmed. Perhaps nest site availability or appropriate foraging habitat limits the kestrel's breeding distribution in the Mississippi Lowlands. Confirmed breeding was recorded for most blocks in the Kansas City and St. Louis areas.

Average Number of Birds / 100 stops

Phenology

The earliest confirmation of breeding for American Kestrels was on April 22 when a bird was seen entering a nest cavity in circumstances indicating nesting. According to Toland (1983) Missouri kestrels often raise two broods during a season. He observed double broods in 14 of 53 nest boxes and reported the first brood was initiated in March and the young typically fledged in early June. The second nesting began in mid- to late June and fledging occurred in mid- to late August, Toland said. The only definitive evidence of a second brood obtained from the Atlas Project was a nest with Eggs: that was observed July 12.

Breeding Evidence

Reported in 483 (40.0%) of 1,207 blocks

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