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| [Note Guidelines] Photographer's Note |
The American Kestrel(Falco sparverius) is the smallest falcon in North America—about the size of an American Robin. Like all raptors, the American Kestrel is sexually dimorphic, although there is some overlap within the species. The female ranges in length from 23 to 28 centimeters (9-11 inches) with a wingspan of 53–61 centimeters (21–24 inches) and weighs an average of 120 grams (4.2 ounces). The length of the male varies between 20–25 centimeters (8–10 inches) with a wingspan ranging from 51–56 centimeters (20–22 inches) and weighing an average of 111 grams (3.9 ounces). These subtle differences are often difficult to discern in the field.
American Kestrels are found in a variety of habitats including parks, suburbs, open fields, forest edges and openings, alpine zones, grasslands, marshes, open areas on mountainsides, prairies, plains, deserts with giant cacti, and freeway and highway corridors.
In addition to requiring open space for hunting, American Kestrels seem to need perches for hunting from, cavities for nesting (either natural or man-made), and a sufficient food supply.
The American Kestrel is the only North American falcon to habitually hover with rapid wing beats, keeping its head motionless while scanning the ground for prey. The kestrel commonly perches along fences and powerlines. It glides with flat wings and wingtips curved upward. It occasionally soars in circles with its tail spread and its wings flat.
This falcon species is not long-lived. The oldest banded wild bird was 11 years and seven months old while a captive lived 17 years. A mortality rate average of 57 percent was found. First year mortality rates have declined since 1945 with a decrease in shooting. Major causes of death include collision with traffic, illegal shooting, and predation by other raptors, including the Red-tailed Hawk, Northern Goshawk, Cooper's Hawk, Peregrine Falcon, Barn Owl, and Great Horned Owl.
The American Kestrel's North American population has been estimated at 1.2 million pairs, with the Central and South American populations being as large. It is possible that the clearing of parts of North America for agriculture in the last two hundred years has caused the American kestrel population to increase. The southeastern race, Falco sparverius paulus, is in serious decline (an 82 percent decrease since the early 1940s in north central Florida) possibly due to habitat loss and loss of nest sites, and has been listed in Florida as "threatened." Threats to the species as a whole include loss of nest sites, pesticide poisoning (dieldrin and DDT, among others), and death through collisions with vehicles as well as shooting.
Source:http://en.wikipedia.org/wiki |
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