quality:correction, quality:corruption, structural:scholar_edition, structural:expansion, information:classification
Feeding

The peregrine falcon's diet varies greatly and is adapted to available prey in different regions. However, it typically feeds on medium-sized birds such as pigeons and doves, waterfowl, gamebirds, songbirds, parrots, seabirds, and waders. Worldwide, it is estimated that between 1,500 and 2,000 bird species, or roughly a fifth of the world's bird species, are predated somewhere by these falcons. The peregrine falcon preys on the most diverse range of bird species of any raptor in North America, with over 300 species and including nearly 100 shorebirds. Its prey can range from 3 g (0.11 oz) hummingbirds (Selasphorus and Archilochus ssp.) to the 3.1 kg (6.8 lb) sandhill crane, although most prey taken by peregrines weigh between 20 g (0.71 oz) (small passerines) and 1,100 g (2.4 lb) (ducks, geese, loons, gulls, capercaillies, ptarmigans and other grouse). Smaller hawks (such as sharp-shinned hawks) and owls are regularly predated, as well as smaller falcons such as the American kestrel, merlin and, rarely, other peregrines.

In urban areas, where it tends to nest on tall buildings or bridges, it subsists mostly on a variety of pigeons. Among pigeons, the rock dove or feral pigeon comprises 80% or more of the dietary intake of peregrines. Other common city birds are also taken regularly, including mourning doves, common wood pigeons, common swifts, northern flickers, eurasian collared doves, common starlings, American robins, common blackbirds, and corvids such as magpies, jays or carrion, house, and American crows. Coastal populations of the large subspecies pealei feed almost exclusively on seabirds. In the Brazilian mangrove swamp of Cubatão, a wintering falcon of the subspecies tundrius was observed successfully hunting a juvenile scarlet ibis.

Among mammalian prey species, bats in the genera Eptesicus, Myotis, Pipistrellus and Tadarida are the most common prey taken at night. Though peregrines generally do not prefer terrestrial mammalian prey, in Rankin Inlet, peregrines largely take northern collared lemmings (Dicrostonyx groenlandicus) along with a few Arctic ground squirrels (Urocitellus parryii). Other small mammals including shrews, mice, rats, voles, and squirrels are more seldom taken. Peregrines occasionally take rabbits, mainly young individuals and juvenile hares. Additionally, remains of red fox kits and adult female American marten were found among prey remains. Insects and reptiles such as small snakes make up a small proportion of the diet, and salmonid fish have been taken by peregrines.

The peregrine falcon hunts most often at dawn and dusk, when prey are most active, but also nocturnally in cities, particularly during migration periods when hunting at night may become prevalent. Nocturnal migrants taken by peregrines include species as diverse as yellow-billed cuckoo, black-necked grebe, virginia rail, and common quail. The peregrine requires open space in order to hunt, and therefore often hunts over open water, marshes, valleys, fields, and tundra, searching for prey either from a high perch or from the air. Large congregations of migrants, especially species that gather in the open like shorebirds, can be quite attractive to a hunting peregrine. Once prey is spotted, it begins its stoop, folding back the tail and wings, with feet tucked. Prey is typically struck and captured in mid-air; the peregrine falcon strikes its prey with a clenched foot, stunning or killing it with the impact, then turns to catch it in mid-air. If its prey is too heavy to carry, a peregrine will drop it to the ground and eat it there. If they miss the initial strike, peregrines will chase their prey in a twisting flight.

Although previously thought rare, several cases of peregrines contour-hunting, i.e., using natural contours to surprise and ambush prey on the ground, have been reported and even rare cases of prey being pursued on foot. In addition, peregrines have been documented preying on chicks in nests, from birds such as kittiwakes. Prey is plucked before consumption. A 2016 study showed that the presence of peregrines benefits non-preferred species while at the same time causing a decline in its preferred prey. As of 2018, the fastest recorded falcon was at 242 mph (nearly 390 km/h). Researchers at the University of Groningen in the Netherlands and at Oxford University used 3D computer simulations in 2018 to show that the high speed allows peregrines to gain better maneuverability and precision in strikes.