Photo: American Kestrel, Mick Thompson/Audubon Photography Awards
Evelyn Novins
The American Kestrel, Falco sparverius, sometimes erroneously called a sparrowhawk, is found throughout North America. The misnomer likely arises from confusion with the Eurasian Sparrowhawk, another bird that likes open hunting grounds with high perches from which to spot prey. But the sparrowhawk is an Accipitor, and the kestrel is not a hawk but a falcon, as evidenced by its flight profile, with its characteristic pointed wings and long, narrow tail. American Kestrels are often seen perching on utility wires alongside farm fields, or hovering with rapid wingbeats, until dropping to snatch prey from the ground or mid-air. This robin-sized falcon is speedy and fun to watch.
American Kestrel female, Christopher Ciccone/Audubon Phtography Awards
American Kestrel male, Mick Thompson/Audubon Photography Awards
The Audubon Field Guide identifies black, blue, gray, red, brown, white and yellow on the body of the American Kestrel. The male’s blue/gray-colored wings distinguish it from the slightly larger female, which has red/brown wings. Both sexes have brownish backs and buffy-white, or off-white, undersides with a black flecking, as well as two dramatic, black slashes running down from the eye. The female has black barring on the wings and back with a red/brown cap. The male’s cap is dark grey. It is a colorful bird with noticeably yellow feet.
The American Kestrel generally inhabits any kind of open area from farmland and forest clearings to deserts -- wherever it can find abundant prey and some raised perches. In breeding season, it must be near places with appropriate nesting sites. The kestrel is a cavity nester; however, it does not make its own cavity, relying on abandoned woodpecker holes, natural cavities in trees, or rock cervices. The good news is that these secondary cavity nesters will readily nest in man-made boxes with unobstructed entrances.
Fairfax County has maintained several capped mounds at the I-95 Landfill Complex as grasslands and meadows, attracting Eastern Meadowlarks, Bobolinks, and other grassland-loving birds and insects to the area. The American Kestrel, which favors this kind of open space for hunting, is frequently seen in this area. To further conservation efforts, landfill managers also recently set aside a portion of the 500-acre landfill as a “no mow” area, with the aim of increasing high-quality meadow habitat that should attract a variety of grassland birds. To encourage American Kestrels to nest in the area, NVBA has contributed several nest boxes, which the County has erected at the landfill.
The last 10 years have seen a steady decline in the numbers of this species. Habitat alteration, pesticides, and predation by Cooper’s Hawks all have been cited as contributors to the decline. But there is increasing recognition that to understand the decline in population of the American Kestrel and other birds over the last decade scientists must look at the species’ total life cycle. The growth of information on species’ migration, available through the free, interactive, online Bird Migration Explorer, is evidence of that focus.
The Kestrel is a migratory bird, but with only a short, southern migration. Breeding birds from Canada and some northern states migrate to southern states during the winter season. Scientists are now paying attention to its migration stops and wintering habitat in addition to its breeding habitat to understand its population decline. The Clifton Institute's research gathers this whole life cycle information. Together with the Smithsonian Conservation Biology Institute, the Clifton Institute has tagged 19 kestrels with GPS transmitters to assess what type of grassland areas the birds prefer while breeding and while migrating. This project produces results which landowners, land managers, and conservationists can use to support declining species.
So, despite the decline in Kestrel numbers in the past decade, there is some hope that both local and global conservation initiatives will allow our continued enjoyment in observing the lovely and lively American Kestrel.