Critter of the week January 4, 2013: American Kestrel

The American kestrel (Falco sparverius) is the smallest of North America's falcons. This widespread species uses a wide range of habitats from deserts and grasslands up to alpine meadows. However they do favor areas with short ground vegetation and sparse trees. Typically you see them perched on power lines and utility poles along roadways. In more natural areas, they often are seen atop snags.When perched, they will often pump their tails.

These pretty raptors actually nest in cavities but can't excavate their own. They take over old woodpeckers holes and natural tree cavities as well as rock crevices and man-made structures. They even take to nest boxes. Inside the cavity there aren't any nesting materials. The males are the scouts that find possible nesting sites that eh shows his mate, but it is the female who has the final word. Kestrels nest from mid-March to early June. Clutch sizes range from 4-5 eggs. Incubation lasts 26-32 days and nestling stage ranges from 28-31 days.

These tiny raptors are diurnal hunters that scan for prey such as insects, invertebrates, small rodents,  and small birds. A common prey item is a vole. Since birds can see ultraviolet light, trails of urine left by voles are trackable and probably lead them right to their quarry. But these small and graceful birds are also prey for other larger raptors (Northern Goshawks, barn owls, Cooper's hawks, red-tailed hawks, and sharp-shinned hawks). They can also become victims of rat snakes and in the nest...fire ants!

There are two subspecies of Kestrel. A migrant northern subspecies (Falco sparverius sparverius) winters here from September through April. The southeastern American kestrel (Falco sparverius paulus) is a year-round resident throughout Florida and is the subspecies you are seeing during the summer months. The southeastern American kestrel is currently listed as threatened in the state of Florida. The decline in their numbers in recent years is likely due to the loss of appropriate nesting snags. To help combat this, you can put up American kestrel nesting boxes (but if you have bird feeders be wary b/c small birds are also kestrel prey!). For more kestrel nesting box information visit: http://myfwc.org/wildlifehabitats/profiles/birds/raptors-and-vultures/american-kestrel/