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The prairie falcon (''Falco mexicanus'') is a medium-sized falcon of western North America. It is about the size of a peregrine falcon or a crow, with an average length of 40 cm (16 in), wingspan of 1 metre (40 in), and weight of 720 g (1.6 lb). As in all falcons, females are noticeably bigger than males. It breeds from southern Manitoba, Saskatchewan, Alberta and south-central British Columbia south through the western United States–roughly between the eastern edge of the Mountain Time Zone and the Cascade Mountains, as well as the Central Valley of California–to the Mexican states of Baja California, Durango, and northern San Luis Potosí. It is much less migratory than the other North American falcons, but in winter it does withdraw somewhat from the northernmost and highest-elevation parts of its breeding range and spreads west to the deserts and Pacific coast of California, east to about the 100th meridian, and south to Baja California Sur, Jalisco, and Hidalgo. ==Description== Plumage is warm gray-brown (sometimes called "sandy") above and pale with more or less dark mottling below. The darkest part of the upper side is the primary wing feathers; the lightest is the rump and tail, particularly the outer tail feathers. The head has a "moustache" mark like a peregrine falcon's but narrower, and a white line over the eye. A conspicuous character is that the axillars ("wingpits") and underwing coverts are black, except along the leading edge of the wing. This creates an effect of "struts" from the body along each wing. Juveniles resemble adults except that they have dark streaks on the breast and belly and darker, less grayish upperparts. Calls, heard mostly near the nest, are described as repetitive ''kree kree kree…'', ''kik kik kik…'', and the like, similar to the peregrine's but higher-pitched.〔 Experts can separate a distant prairie falcon from a peregrine (generally the only similar species in its range) by its shape and flight style. The prairie falcon has a longer tail in proportion to its size; a more tubular, less stocky body; and the wing joint farther from the body. Its wingbeats are described as strong and shallow like the peregrine's and having the same quick cadence, but stiffer and more mechanical.〔Dunne, Sibley & Sutton (1989)〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Prairie falcon」の詳細全文を読む スポンサード リンク
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