Prairie falcon

The prairie falcon (Falco mexicanus) is a medium-large 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 approximately 1 meter (40 in), and average weight of 720 g (1.6 lb). As in all falcons, females are noticeably bigger than males. Though a separate species from the peregrine, the prairie falcon is basically an arid environment adaptation of the early peregrine falcon lineage, able to subsist on less food than the peregrine, and generally lighter in weight than a peregrine of similar wing span. Having evolved in a harsh desert environment with low prey density, the prairie falcon has developed into an aggressive and opportunistic hunter of a wide range of both mammal and bird prey. It will regularly take prey from the size of sparrows to approximately its own weight, and occasionally much larger. It is the only larger falcon native only to North America. It is resident from southern Canada, through western United States, and into northern Mexico. The prairie falcon is popular as a falconry bird, where with proper training it is regarded as being as effective as the more well known peregrine falcon. Male prairie falcons are usually 37 to 38 cm in length (~15 inches) and weigh 500 to 635g (1.1 to 1.4 lbs). Females are about 45 cm in length (17.7 inches) and weigh 762 to 970g (1.7 to 2.1 lbs). A large female can be nearly twice the size of a small male, with wingspan reaching to 1.1 meters (3.5 feet), and tends to hunt significantly larger prey. 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.