Northern Hawk Owl Biology
A Reference for North and Central American Owls
Name: Northern Hawk Owl – Surnia ulula
Other Common Names: Hawk Owl; American Hawk Owl; Hudsonian Hawk Owl; Canadian Owl.
Subspecies: There is one race of Hawk Owl in North America and one race widespread across Northern Eurasia (S. u. ulula) that may be found as an accidental in Western Alaska although this race will not be discussed further.
S. u. caparoch is distributed across Canada, Central and Eastern Alaska. During winter months there is some southward movement in which it will usually cross into at least a few of the northern states of the U. S. (and several states during invasion years).
Measurements and Weights:
Wingspan: 31 – 35 in.
Length: 14.5 – 17.5 in.
Tail: 6.25 – 7.5 in.
Average Weight: Male: 10.7 oz.
Average Weight: Female: 12.3 oz.
Description: The Hawk Owl has more of a falcon shape to it than typical owl shape. This is a strictly diurnal owl, medium sized, tame, earless, and has habits that resemble some of the smaller hawks (hence its name). It has a long rounded tail, relatively pointed wings, and fast flight with bursts of wing beats and glides. The owl is rich dark brown on the backside with large white spots on the outer wings and scapulars and some thin white bars on the tail feathers, the crown thickly spotted. A black line starts at the middle top of each eye, curves up and around the sides of the grayish-white facial disk. There is white around the tops and sides of the bill and a white line extending up the eyebrows and bordering the black line to its highest point at the top if the facial disk. At this point the black line encircling the facial disk splits into a second line, on each side, that curves over the head down the back of the neck dividing the sides and back of the head into three areas. The sides are spotted almost to solid white. The chin is deep brown completing the facial disk. The underside (chest, flanks, and belly) has heavy, short brown, broken bars on a white base. The underside of the tail is also barred brown and white and the underside of the wings are like the rest of the underside (broken brown bars). The bill is light yellow and the iris is lemon yellow. Legs and feet are feathered.
Young: The upper parts are deep brown with fewer white markings. Crown and nape mostly dull grayish-buff. Facial disk whitish with brownish-black border along the top and sides. The underside is whitish, the barring is less distinct, with the chest and flanks shaded brown.