Part 61

=1750=, ♀. ½ =1750=, ♀. =10571=, ♀. ½ =10571=, ♀. ¼

Buteo borealis (1750; 10571).]

Buteo zonocercus (52763).]

Buteo swainsoni (58505).]

The species of this genus are very numerous, especially within the tropics, and are found all over the world, except in Australia. About thirty nominal species are known, of which about fifteen distinct species, not including geographical races, belong to America. A single species, B. solitarius (Pandion solitarius, Peale), (Gray’s Hand List, I, 15, No. 136,) belongs to the Sandwich Islands. The genus seems to be wanting in the Australian and East Indian regions.

The following species and races belong to the North American fauna.

Species and Races.

=A.= Three outer primaries with their inner webs cut or emarginated.

1. =B. pennsylvanicus.= Wing, 9.85–11.40; tail, 6.30–8.00; culmen, .70–.80; tarsus, 2.15–2.80; middle toe, 1.20–1.40. Third to fourth quill longest; first shorter than seventh. Adult. Tail dull black, paler at the tip, crossed by two to four bands of dilute umber, or brownish-white, varying in width, but the last always broadest. Upper tail-coverts tipped and barred with white. Lower parts dull rufous-brown, nearly unbroken on the breast, but posteriorly much variegated with roundish transverse spots of white, forming broad transverse bars, interrupted by the dusky shaft. Upper parts dark umber, darker on the back. Young. Tail dull grayish-umber, growing darker terminally, narrowly tipped with whitish, and crossed by about six narrow and indistinct bands of dusky; these gradually becoming obsolete basally, the last much broader. Lower parts white, or light ochraceous, with longitudinal spots of dark brown or blackish on the sides of the breast and abdomen, and roundish or transversely cordate ones on the sides, flanks, and tibiæ. A conspicuous “mustache” on the cheeks, from the rictus down. Upper parts much as in the adult. Hab. Eastern North America, and Middle America, south to Bogota and Caraccas.

2. =B. swainsoni.= Wing, 12.00–17.00; tail, 6.50–9.00; culmen, .80–.95; tarsus, 2.95–2.70; middle toe, 1.50–1.70. Third to fourth (usually third) quills longest; first usually longer than seventh. Adult. Tail dark grayish-brown, sometimes with a hoary cast, crossed by five to seven, or more, narrow bands of dusky, usually very obscure, and becoming obsolete basally. Colors of other portions extremely variable; the upper parts, however, continuous, unvariegated, dark brown, or blackish; the lower parts sometimes also entirely dusky, except the tail-coverts, which are always (?) barred with white. Normal plumage. A dark area covering the jugulum and breast, dull rufous in the ♂, and dark grayish-brown in the ♀. Other lower parts whitish, sometimes pure, and nearly immaculate, but usually more or less tinged with ochraceous and rufous, and transversely barred with various shades of brown. Young. Tail hoary brownish-gray, crossed by numerous, very indistinct, narrow bands of darker, and faintly tipped with whitish. Ground-color of the head, neck, and lower parts, light ochraceous, or cream-color (sometimes nearly white), the anterior upper parts with large longitudinally ovate spots of black; these assuming the form of streaks on the head and neck. Sides of the breast with an aggregation of larger spots of the same, and sides with sparser hastate or deltoid spots. Upper parts purplish-black, more or less variegated with ochraceous; the relative proportion of the two colors varying with the individual.

Wing, 14.40–17.00; tail, 8.00–9.50; culmen, .80–.95; tarsus, 2.30–2.70; middle toe, 1.50–1.70. Weight 1½–3½ lbs. Hab. Western Province of North America, from the Mississippi Valley, and the region of the Great Lakes (Michigan, Wisconsin, Iowa, to Arkansas, also Canada and Massachusetts) to the Pacific …

var. swainsoni.

Wing, 12.00–15.30; tail, 6.50–9.00; culmen, .85–.90; tarsus, 1.95–2.60; middle toe, 1.50–1.60. Colors similar, but the young paler than that of var. swainsoni. Adult unknown. Hab. Middle and South America, and southern border of the western United States, from New Mexico to Buenos Ayres (two specimens, Costa Rica, and Buenos Ayres, Mus. S. I.) …

var. oxypterus.

=B.= Four outer primaries with their inner webs cut.

a. Form light, the legs slender; tail of adult without a subterminal band of black more distinct than the others.

3. =B. zonocercus.= Wing, 15.50–17.40; tail, 8.50–10.75; culmen, .90; tarsus, 2.50–2.80; middle toe, 1.60–1.85. Entirely deep black, with more or less concealed pure white spotting. Adult. Tail carbonaceous-black, with three very broad zones, of pure white on inner webs and ash on the outer webs. Young. Tail dark brown, the inner webs more or less, sometimes entirely, white, crossed by numerous oblique bands of black. Hab. Mexico (chiefly western?) and adjacent southwestern portions of the United States (Arizona, COUES; Southern California, San Diego, COOPER).

4. =B. lineatus.= Wing, 11.25–14.25; tail, 8.00–10.00; culmen, .75–.90; tarsus, 2.70–3.25; middle toe, 1.30–1.50. Fourth to fifth quill longest; first shorter than seventh. Outer webs of the primaries with quadrate spots of whitish; lesser wing-coverts dark rufous; lower parts rufous more or less barred with whitish, or whitish spotted longitudinally with dusky. Adult. Head, neck, lesser wing-coverts, and lower parts deep rufous, the lower parts more or less barred posteriorly with whitish. Primaries and tail black; the former with quadrate spots of pure white on the outer webs, and the latter crossed by six narrow bands of pure white, and tipped with the same. Young. Head, neck, and lower parts whitish, usually more or less tinged with ochraceous, and with longitudinal markings of dusky. Primaries and tail dusky; the former mostly ochraceous anterior to the sinuation of their outer webs, the latter crossed by numerous narrow bands of pale grayish-brown, these becoming paler and more ochraceous toward the base. Lesser wing-coverts more or less tinged with dark rufous.

Adult. Lower parts light rufous barred with white. Young. White prevailing on the lower parts. Hab. Eastern Province of the United States …

var. lineatus.

Adult. Lower parts deep dark rufous, almost free from bars, except posteriorly. Young. Dark spotting on the lower parts predominating. Hab. Pacific Province, and southern Western Province, of the United States …

var. elegans.

b. Form robust and heavy, the tarsus stout; tail of the adult with a subterminal band of black broader than the other.

5. =B. borealis.= Wing, 13.25–17.75; tail, 8.50–11.30; culmen, .90–1.15; tarsus, 2.70–3.40; middle toe, 1.60–1.95. Weight, 2½ to 4 lbs. Third to fifth quill longest; first shorter than seventh and shorter than tenth. Colors extremely variable, ranging from entirely pure white beneath, through various shades of ochraceous and rusty, and greater or less amount of darker spots and bars, to an entirely uniform brownish-black. Adult. Tail deep rufous, generally paler at the tip; with or without black bars. Young. Tail grayish-brown, crossed by nine or ten bands of black, much narrower than the gray ones. Lower parts always with white predominating.

Tibiæ and lower tail-coverts without transverse bars, at any age. Lower parts with white always predominating. Tail never with more than one bar of black.

Feathers of the head and neck edged laterally with rufous; scapulars and wing-coverts much variegated with whitish; upper tail-coverts white, barred with rufous. Throat with blended streaks of blackish, this usually predominating; tibiæ and lower tail-coverts plain yellowish-white. Hab. Eastern Province of North America, to the Missouri plains …

var. borealis.

Similar, but colors much paler, the lower parts entirely pure white, with little or no spotting on the abdomen. Tail usually destitute of the black subterminal band. Hab. Plains, from Texas to Minnesota …