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 Continental (anatum) - Perched
Note: male and female plumages are very similar. Differences are subtle, and where applicable, are listed below.
HEAD
- upper portions and part of sides blackish and sometimes with narrow whitish band across the forehead
- sides of face blackish below the eye (malar patch)
- the chin and throat are white
- the beak is bluish-gray with a dark tip and yellowish base
- the cere and eyering are yellow
- the eye is very dark
- in females the soft part coloring may be more muted and the whitish-buff of the nape may be more visible
BODY
- the upper breast is plain white
- the lower breast and belly varies from a tawny
- buff to grayish with black streaks in the center and transverse bars, chevrons and spots lower down. The barring is heaviest on the flanks and thighs.
- the back is variably dark bluish-gray or slatey with slightly paler rump
- in females the underparts may be more buffy and more heavily marked black and the sides, flanks and thighs may be more grayish with wider barring
WINGS
- the upper surface is the same as the back with some darker barring evident on the greater coverts
- the primaries are black towards the tips which reach the tip of the tail
TAIL
- the upper side is light bluish gray or may be darker and is tipped whitish and has up to 12 black cross bars
- the under surface is paler with less evident patterning
- the undertail coverts are pale with black spots or barring
LEGS
- the legs and feet are yellowish with black talons
Immmature Continental (anatum) - Perched
HEAD
- the crown and nape are variably dark brownish chestnut
- variations of buffy-rufous streaking, buffy forehead, pale eyestreak.
- a dark brown cheek patch is evident
- the beak is bluish-gray with a dark tip as in the adults
- the cere and eye ring, or orbital skin, may be bluish, greenish or muted yellow
- the eye is very dark brown
BODY
- the background color of the underparts is a rufous-buff with heavy dark brown streaks broadening to chevrons on the flanks and undertail coverts
- immatures are streaked as opposed to barred as in adults
- the upperparts are variably darkish brown with the buffy margin of the feathers limited
WINGS
- the upper parts are similar to the back and the primaries are also dark brown as opposed to black in the adults
- the tips do not quite reach the tip of the tail
TAIL
- the upper surface is the same as the back or darker with discontinuous pale tawny barring
- the underside is paler and the undertail coverts are rufous-buff with heavy dark streaking
LEGS
- the legs and feet are variably bluish to yellowish with black talons
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.
MYTHOLOGY
None is known for North America.
VOICE
There is much variation in the descriptions of the Peregrine Falcon's voice but all might be thought of in terms of variations of several basic calls. The voice of the male is higher than that of the female. "Cacking" is the most commonly described call and is used in nest defense or as a rapid fire scream during an attack. When perched high during courtship or when the female is ready to copulate, either sex may give the "waik" call. "Eeechip" is used during mutual courtship and breeding displays as well as during some aggressive and fighting circumstances. When making the nest scrape, "chuckles" are uttered and when begging for food a "treble-whine" is given. "Eep-eep-eep" is used during aggressive chase, "upchip" when the female is ready to copulate and "chitter" for copulation readiness. When she is not ready for copulation, the female utters a "chup-chup" and when mounting for copulation, the male gives the "chutter" call. When being threatened with attack, the "treble-whine", and "chitter" are used. Most calls are used in various contexts and relate to advertising, display, copulation, feeding and territorial defense.
