The Peregrine Falcon is a cosmopolitan species and one of only four living species that has achieved a worldwide distribution without the help of humans. In North America, the population is comprised of three races, all fairly similar in appearance, but with clinal variations that result in differences in plumage and size between the races that are often distinguishable in the field. Other individuals are not safely assignable to races from field observations.
The race Falco peregrinus anatum is commonly referred to as the "Continental" Peregrine Falcon, Falco peregrinus pealei as "Peale's" Peregrine Falcon, and Falco peregrinus tundrius as "Tundra" Peregrine Falcon.
The Peregrine Falcon is a medium to large falcon that is generally darkly hooded in appearance with a dark back and upper tail and light, heavily barred and spotted underparts. The side of the face has a prominent dark mustache patch set beside a variably white cheek. Juveniles are generally dark brown, heavily streaked birds with some variations between races. More than any other falcon, this is a bird of many habitats including coastal marine environments, temperate forests, arctic tundra, arid deserts and open country of all descriptions with suitable tall cliffs for nesting.
SIZE
Of all of the North American falcons, only the Gyrfalcon exceeds this medium-sized raptor in size. It is about the same size as the Prairie Falcon or a large American Crow. The males and females are similar in size with females averaging perhaps 15 percent larger. Females vary from 18 to 21 inches (46 to 53 centimeters) in length with wingspans from 38 to 44 inches (97 to 112 centimeters). Weights vary from 1.5 to 2.7 pounds (680 to 1,225 grams). Males vary in length from 15 to 18 inches (38 to 46 centimeters) with wingspans from 34 to 39 inches (86 to 99 centimeters). Male weights range from 1.1 to 1.8 pounds (499 to 816 grams).
MORPHS AND MOLTS
There are no distinctive colour morphs of the Peregrine Falcon but each race differs somewhat from the other. Further, individuals of the same race can show some variation within a range. If the F. p. anatum race were taken as the standard, F. p. pealei tends to be larger and darker overall whereas F. p. tundrius is similar in size but generally lighter. Variations within races can make field separation uncertain. The timing of the molt varies with the breeding cycle and happens earlier at southern latitudes. The female begins molting during egg laying but the males not for sometime afterwards. Completion of the molt takes from 4.5 to six months such that the final changes may be completed on the wintering grounds. By day 40, nestlings have attained the full juvenal plumage. The molt towards the first basic plumage is quite variable but generally starts during the summer of the second calendar year and lasts late into that year or January of the third year. Once the basic plumage has been attained, this is the first definitive (adult) plumage.
SPECIFIC DESCRIPTION
Adult Tundra (tundrius) - Flight
- a medium to large, dark-backed falcon but the upper surface may appear to be less contrasty between the back and the lighter rump as in anatum
- the underparts appear light and less-heavily barred, the malar patch less extensive and the white cheek patch more extensive than in anatum
- female is generally similar but somewhat darker with heavier barring on undersides
Immature Tundra (tundrius) - Flight
- more variable than other forms and often with a "blonde"-headed look
- back may appear more buffy and occasional "red-tailed" individuals have been noted
- the undersides appear lighter and more finely streaked than the other races
SIMILAR SPECIES
The Peregrine Falcon is closest in size and weight to the Prairie Falcon but has a darker back and more prominent mustache mark with overall markings being more contrasty and less brownish. Large female Peregrine Falcons overlap small male Gyrfalcons in size but the latter species although highly variable, tends to be more evenly colored and lacking the boldness in the mustache mark. Juveniles are more similar and Peregrine Falcons and Gyrfalcons are easily confused at greater distances. Both gray-morph and dark-morph Gyrfalcons have two-toned underwings whereas the underwing of the Peregrine Falcon is uniform.
Soaring Peregrine Falcons have similarities to soaring Broad-winged Hawks and not infrequently, Northern Harriers and Mississippi Kites are mistaken for Peregrines.
OTHER NAMES
The Peregrine Falcon is commonly known as the "Duck Hawk" but also as "Peale's Peregrine" (pealei race), "Tundra Peregrine" (tundrius race), "Big-footed Falcon", "Bullet Hawk", "Pinnacle Hawk", and "Sea Hawk."
ETYMOLGY
The genus Falco is of Latin origins and means "sickle." This may be in reference to the shape of the beak or more likely the talons of all falcons. The specie name peregrinus is Latin for "wandering" or "foreign." The components of the word are per for through and ager meaning field or land. Thus, we can infer "across country" from the complete word or the falcon that wanders from place to place across the land.
