Falco Sparverius
The American Kestrel is the smallest falcon in North America – about the size of a large thrush, such as the American Robin, on average. The American Kestrel is sexually dimorphic, although there is some overlap within the species. The female ranges in length from 9-11 in (23-28 cm) with a wingspan of 21-24 in (53-61 cm) and weighs an average of 4.2 oz (120 g). The length of the male varies between 8-10 in (20-25 cm) with a wingspan ranging from 20-22 in (51-56 cm) and weighing an average of 3.9 oz (111 g). These subtle differences are often difficult to discern in the field. Diet: They feed on insects, small birds, reptiles, and rodents, and they often hover over their prey before plunging and capturing it on the ground. Habitat: They can been seen in open desert and along edges of woodlands. They nest in tree cavities, and abandoned woodpecker holes. Vocalizations: The American Kestrel has three basic vocalizations – the "klee" or "killy", the "whine", and the "chitter." The "klee" or "killy" is usually delivered as a rapid series – killy, killy, killy, killy when the kestrel is upset or excited. It is used at the apex of the dive display, during fights with other kestrels, and after unsuccessful hunting attempts. The "whine" may last as long as one to two minutes and may be single or treble. The more intense the situation, the more likely the "whine" will move toward the treble extreme. "Whines" are given during courtship feeding and copulation. The treble whine is heard from breeding females and fledged hungry young. The "chitter" is the most frequent vocalization in male-female interactions. Its volume and duration depends upon the stress or excitement of the situation. It is associated with friendly approaches and bodily contact between the sexes during breeding season. Occasionally a "chitter" follows a "whine." Calling occurs throughout the day. Nestlings at two weeks can produce all three vocalizations. Female kestrels tend to have slightly lower pitched and harsher voices than males.
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