[3] It will regularly take prey from the size of sparrows or finches to birds approximately its own weight, and occasionally much larger.

The prairie falcon is resident from Canada (mainly Alberta, British Columbia and Saskatchewan) through the Western United States (west of the Mississippi) and south into Northern Mexico.

Like many raptors and falconiformes, the prairie falcon is popular in falconry; with proper training and care, it is regarded as being equally as skilled as the more well-known peregrine, among others.

[4] 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.

Exposed portions of shoulder and back feathers tend to be more uniformly colored in juveniles and barred with light and dark horizontal stripes in adults.

Skin around eyes, above beak (cere) and on legs and talons tends to be more yellow and sometimes with tinges of orange or green in adults.

Factor one can be mistakenly observed because a Prairie Falcon's crop expands and distends upon feeding exposing the white under feathers of the upper breast so that a juvenile Prairie Falcon which just fed can appear from a distance to have a very bright white upper breast like an adult.

Also, factor 3 varies so that sometimes a Prairie Falcon's feet begin to turn yellow while juvenile and some individuals have gray skin as adults.

It was previously often considered the only New World member of the hierofalcon subgenus, but in recent decades this assumption has been disproven by genetic analysis.

[7][8] It now is considered an early aridland offshoot of the peregrine falcon lineage, much as the hierofalcons represent a later[9] separate divergence that similarly adapted to arid habitat.

The karyological data of Schmutz and Oliphant[11] provided early scientific evidence of the unexpectedly close relationship between the peregrine and prairie falcons.

This process has led to the prairie falcon having enhanced survivability in the sparse arid environment that dominates the interior of the American west.

[16] The male offspring of these crossings may be fertile, and provide an avenue for at least some gene flow to possibly still occur between the species.

It breeds from southern 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.

The majority of prey is 150g or less, a weight that even the smaller tiercel (male) can carry long distances back to the nest.

[17] In keeping with the needs of a predator living in a prey-sparse desert environment, the prairie falcon has developed a wide range of hunting and flight styles.

[19] Like the Merlin, it often hunts by flying fast and low, at a height of only a few meters or so, hoping to find surprised prey as it comes over the terrain or around bushes.

The large, powerful, and surprisingly agile golden eagle is the apex avian predator in this range, and is generally willing and able to attack and kill any of these other raptors.

However, the prairie falcon will aggressively defend its territory against any of them, with male and female often mounting a coordinated attack, and often turns the tables on these larger raptors.

Wildlife biologists report numerous observations of prairie falcons successfully driving away and sometimes killing raptors larger than themselves.

[33] It is thought the prairie falcon mostly avoided the population loss suffered by the peregrine from DDT induced egg shell thinning due to its more remote environment partly insulating it from pesticide contamination.

[35] However, these reintroduced peregrines are little threat to prairie falcon populations within their natural range, as the prairie falcon with its greater heat tolerance, lower daily food requirement, and wider prey base has the survival advantage in the harsh high desert environment in which it has evolved to prosper.

It is the most popular falcon captured from the wild for falconry purposes in the United States, due to its abundance and relative ease to acquire.

"[36] The smaller and more agile males are particularly effective in the taking of small game birds such as dove, quail, and smaller ducks, while the larger and more powerful females reliably take larger game up through the size of large ducks and even pheasants.

[38][39] The sage-grouse in particular is difficult game, with the males weighing as much as 8 lbs, and being so hard-muscled that inexperienced falcons can easily be injured in striking them in a high-speed stoop.

It takes a skilled falcon that knows how to forcefully but carefully and accurately strike them in the head or wing to bring them down cleanly.

[1] However, it has experienced some local declines in Texas, California, British Columbia and Alberta as grasslands are developed for agriculture, suburbs, highways, and other automobile uses.

[44] A major contributor to mortality has been the Great horned owl (Bubo virginianus) but to a lesser extent, it has been observed that infestations of Haematosiphon inodorus and in some cases Oeciacus vicarius may be a cause of fledgling morbidity.