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 16 in, a wingspan of approximately 40 in, and an average weight of 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 the similar wingspan. 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 the western United States, and into northern Mexico. The prairie falcon is popular as a falconry bird, wherewith proper training it is regarded as being as effective as the more well-known peregrine falcon.