Leucosticte, Swainson, Fauna Bor. Am. II, 1831, 265. (Type, Linaria tephrocotis, Sw.)
Leucosticte tephrocotis.
19255 ♂
Gen. Char. Bill conical, rounded, rather blunt at the tip; the culmen slightly convex; the commissure slightly concave; the nostrils and base of commissure concealed by depressed bristly feathers; a depressed ridge extending about parallel with the culmen above the middle of the bill. Another more conspicuously angulated one extending
forward from the lower posterior angle of the side of the lower mandible, nearly parallel with the gonys. Tarsus about equal to the middle toe and claw. Inner toe almost the longer, its claw not reaching beyond the base of the middle one. Hind toe rather longer, its claw longer than the digital portion. Wings very long; first quill longest; all the primaries longer than the secondaries. Tail forked.
This genus differs from Ægiothus in the more obtuse and curved bill, the less development of bristly feathers at the base, the ridge on the lower mandible, the lateral toe not reaching beyond the base of the middle one, and possibly a longer hind toe. Its relationship to the other allies will be found expressed in the synoptical table of Coccothraustinæ.
Leucosticte tephrocotis.
The number of American species, or at least races, of this genus has been increased considerably since the publication of Birds of North America, five now belonging to the American fauna, instead of the three there mentioned. Of the species usually assigned to the genus, one, L. arctoa, is quite different in form, lacking the ridge of the mandible, etc., and in having the ends of the secondaries graduated in the closed wing, instead of being all on the same line. The colors, too, are normally different; in arctoa being dusky, with silvery-gray wings and tail, without rose tips to the feathers of the posterior part of body; and in Leucosticte proper, the wings and tail being dark-brown narrowly edged with whitish, or more broadly, like the ends of the feathers of the body behind, with rose-color. For the present, however, we shall combine the species, not having before us any American specimens of L. arctoa.
From the regular gradation of each form into the other—the extremes being thus connected by an unbroken chain of intermediate forms—it seems reasonable to consider all the North American forms as referable to one species (L. tephrocotis, Sw., 1831) as geographical races. They may be distinguished as follows:—