The Picidæ are found all over the world with the exception of Madagascar, Australia, the Moluccas, and Polynesia. America is well provided with them, more than half of the described species belonging to the New World.
The subfamilies of the Picidæ may be most easily distinguished as follows, although other characters could readily be given:—
Picinæ. Tail-feathers pointed, and lanceolate at end; the shafts very rigid, thickened and elastic.
Picumninæ. Tail soft and short, about half the length of wing; the feathers without stiffened shafts, rather narrow, linear, and rounded at end.
Yunginæ. Tail soft and rather long, about three fourths the length of wing; the feathers broad, and obtusely rounded at end.
Of these subfamilies the Picinæ alone occur north of Mexico. The Yunginæ, to which the well-known Wryneck of England (Jynx torquilla) belongs, are exclusively Old World; the Picumninæ belong principally to the tropical regions of America, although a few species occur in Africa and India. One species, Picumnus micromegas, Sundevall, belongs to St. Domingo, although erroneously assigned to Brazil. This is the giant of the group, being about the size of the White-bellied Nuthatch (Sitta carolinensis) the other species being mostly very diminutive, varying from three to four inches in length.
Subfamily PICINÆ.
The diagnosis on the preceding page will serve to distinguish this group from its allies, without the necessity of going into greater detail. It includes by far the largest percentage of the Picidæ, and in the great variations of form has been variously subdivided by authors into sections. Professor Sundevall, in his able monograph,[124] establishes the following four series, referring all to the single genus Picus:—
I. Angusticolles. Neck slender, elongated. Nostrils concealed by bristles. Tail-feathers black or brownish, immaculate.