300 NORTH AMERICAN BIRDS. 



Archibuteo ferrugineus (Light). 



CALIFORNIA SQUIRREL HAWK. 



Falco ferrugineus. Light, Berl. Trans. 1838, p. 429. Lagopus ferrugineus, Fraser, Proc. 

 Zool. Soc. Loncl. 1844, p. 37. Archibuteo ferrugiiieus, Gray, Gen. B. fol. sp. 3, 1844. 



— Cass. B. of Cal. & Tex. 1854, p. 104; Birds N. Am. 1858, 34. — Bonap. Consp. 

 Av. p. 18. — Strickl. Orn. Syn. I, 41, 1855. — Heerm. P. R. R. Rept. VII, 31, 1857. 



— Coop. & Suck. P. R. R. Rept. XII, ii, 149, 1860. — Coues, Prod. Orn. Ariz. p. 10, 

 1866 (anatomical notes). — Blakist. Ibis, III, 1861, 318 (Saskatchewan; eggs). — 

 Fraser, Pr. Z. S. 1844, 37. — Gray, Hand List, I, 10, 1869. Archibuteo regalis. 

 Gray, List B. Brit. Mus. p. 39, 1844 ; Gen. B. fol. pi. vi. 



Sp.Char. J.r?7/Z<?naZe (41,719, Fort Whipple, Arizona, Dec. 2, 1864; Dr. Coues). Ground- 

 color of head and neck white ; each feather with a medial streak of black, these growing 

 broader posteriorly, and along the upper border of the ear-coverts are so blended as to 

 form an indistinct stripe back from the eye. Entire lower parts (except tibia) and whole 

 under surface of the wing continuous pure white ; breast with a faint tinge of delicate 

 ochraceous ; tibia and tarsus reddish-white, tinged with or inclining to deep ferruginous 

 on upper portion, and with numerous transverse bars of darker ferruginous and blackish ; 

 sides of the breast with a very few hair-like shaft-streaks of black; flanks with a few dis- 

 tant, dark ferruginous bars ; axillars with two or three cordate spots of ferruginous near 

 ends; feathers of the lining next the body, with blended irregularly hastate spots of 

 rufous; under primary coverts shading into cinereous on terminal half, and with obscure 

 broadly hastate spots of a darker shade of the same ; primaries slaty beyond their emargina- 

 tion, deepening gradually toward their tips. Back, scapulars, and lesser and middle wing- 

 coverts fine rufous, each feather with a broad median, longitudinal spot of brownish 

 plumbeous-black, these on the back rather exceeding the rufous; longer wing-coverts and 

 secondaries ashy-umber, with very obsolete transverse bands of darker; primary coverts 

 more ashy, and more distinctly banded ; primaries fine chalky cinereous, this lightest on 

 outer four; shafts pure white. Rump nearly uniform brownish-black, — posterior feathers 

 rufous with medial black blotches ; upper tail-coverts snowy white on outer webs, inner 

 webs more rufous ; a few concealed blackish transverse spots. Tail pale pearly ash, be- 

 coming white basally, and with a wash of dilute rufous along the edge of outer webs; 

 inner webs white, with an ashy tinge thrown in longitudinal washes ; outer feathers 

 nearly white, with faint pale ashy longitudinal mottlings ; shafts of tail-feathers pure white. 

 Fourth qnili longest; third but little shorter; second very much shorter than fifth; first 

 intermediate between seventh and eighth. Wing, 16.75; tail, 9.20; tarsus, 2.95; middle 

 toe, 1.35. 



"Length, 22.50; extent, 54.50. Iris clear light yellow; cere, edges of commissure, and 

 feet bright yellow ; bill very dark l)luish horn ; mouth, purplish flesh-color, livid bluish 

 along edges." 



Adult female (41,720, Fort W^hipple; Dr. Coues). Almost exactly like the male, but 

 black spots on rufous portions of upper parts much restricted, forming oblong spots in 

 the middle of each feather; rump almost entirely rufous, variegated, however, with black. 

 Longitudinal lines on breast more distinct; transverse bars on flanks and abdomen more 

 numerous ; tibial and tarsal feathers wholly deep rufous or ferruginous, the bars more 

 blackish. Third and fourth quills equal and longest ; second intermediate between fifth 

 and sixth ; first equal to eighth. Wing, 17.25 ; tail, 9.75 ; tarsus, 2.95 ; middle toe, 1.40. 

 "Length, 23.25 ; extent, 56.50. Iris light ochraceons-brown." 



Young female (6,883, Los Angelos, California; Dr. Heermann). G-eneral plumage above, 

 grayish-brown ; interscapulars, scapulars, lesser and middle wing-coverts, and feathers of 



