Spizella, Bonap. Geog. and Comp. List, 1838. (Type, Fringilla canadensis, Lath.)
Spinites, Cabanis, Mus. Hein. 1851, 133. (Type, Fringilla socialis, Wils.)
Spizella monticola.
871 ♂
Gen. Char. Bill conical, the outlines slightly curved; the lower mandible decidedly larger than the upper; the commissure gently sinuated; the roof of the mouth not knobbed. Feet slender; tarsus rather longer than the middle toe; the hinder toe a little longer than the outer lateral, which slightly exceeds the inner; the outer claw reaching the base of the middle one, and half as long as its toe. Claws moderately curved. Tertiaries and secondaries nearly equal; wing somewhat pointed, reaching not quite to the middle of the tail. First quill a little shorter than the second and equal to the fifth; third longest. Tail rather long, moderately forked, and divaricated at the tip; the feathers rather narrow. Back streaked; rump and beneath immaculate. Young streaked beneath.
This genus differs from Zonotrichia principally in the smaller size and longer and forked, instead of rounded tail.
Birds of the year of this genus are very difficult to distinguish, even by size, except in monticola. The more immature birds are also very closely related. In these the entire absence of streaks on a plumbeous head point to atrigularis; the same character in a reddish cap, and a reddish upper mandible to pusilla; a dusky loral spot with dark streaks and generally a rufous shade on top of head, to socialis. S. breweri, with a streaked head, lacks the dusky lore and chestnut shade of feathers. S. pallida generally has a median light stripe in the cap, and a dusky mandibular line.
Common Characters. Interscapular region with black streaks. Rump and lower parts without streaks (except in young). Wing with two narrow light bands (indistinct in atrigularis).
A. Crown different from the sides of the head, a plain light superciliary stripe. Young with crown and breast streaked.
a. Crown rufous and plain in adult; in young, grayish and with streaks.