The Peregrine Falcon (Falco peregrinus), also known as the peregrine, and historically as the duck hawk in North America, is a widespread bird of prey in the family Falconidae. It can be found nearly everywhere on Earth, except extreme polar regions, very high mountains, and most tropical rainforests; the only major ice-free landmass from which it is entirely absent is New Zealand.
In animal kingdom, it has the fastest vision speed, and can register nearly 130 frames per second.
The peregrine falcon has a body length of 34 to 58cm and a wingspan from 74 to 120cm. The male and female have similar markings and plumage, but as in many birds of prey the peregrine falcon displays marked sexual dimorphism in size, with the female measuring up to 30% larger than the male. Males weigh 330 to 1.000g and the noticeably larger females weigh 700 to 1.500g.
The back and the long pointed wings of the adult are usually bluish black to slate grey with indistinct darker barring; the wingtips are black. The white to rusty underparts are barred with thin clean bands of dark brown or black. The tail, coloured like the back but with thin clean bars, is long, narrow, and rounded at the end with a black tip and a white band at the very end. The top of the head and a "moustache" along the cheeks are black, contrasting sharply with the pale sides of the neck and white throat. The cere is yellow, as are the feet, an the beaks and and claws are black. The upper beak is notched near the tip, an adaptation which enables falcons to kill prey by severing the spinal column at the neck. The immature bird is much browner with streaked, rather than barred, underparts, and has a pale bluish cere and orbital ring.
The peregrine falcon feeds almost exclusively on medium-sized birds such as, pigeons and doves, waterfowl, songbirds and waders. 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.
The peregrine falcon is sexually mature at one to three years of age, but in larger populations they breed after two to three years of age. During the breeding season, the peregrine falcon is territorial; nesting pairs are usually more than 1km apart, and often much farther, even in areas with large numbers of pairs. The distance between nests ensures sufficient food supply for pairs and their chicks. Within a breeding territory, a pair may have several nesting ledges; the number used by a pair can vary from one or two up to seven in a 16-year period.
According to en.wikipedia