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A History of North American Birds; Land Birds; Vol. 2 of 3 cover

A History of North American Birds; Land Birds; Vol. 2 of 3

Chapter 8: Family CORVIDÆ.—The Crows.
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About This Book

This illustrated volume offers a systematic treatment of North American land birds, presenting family and genus overviews and detailed species accounts. Each entry gives diagnostic characters, measurements, plumage variation by age and sex, vocal and behavioral notes, geographic range, breeding habits, nests and eggs, and comparisons with similar taxa. The text is supported by numerous plates and woodcuts to aid identification and includes technical descriptions and keys for taxonomic clarification. Coverage balances field-identification features with museum-based morphology for naturalists and ornithologists.

Family CORVIDÆ.—The Crows.

Char. Primaries ten; the first short, generally about half as long as the second (or a little more); the outer four sinuated on the inner edge. The nasal fossæ and nostrils usually more or less concealed by narrow, stiffened bristles (or bristly feathers), with short appressed lateral branches extending to the very tip, all directed forwards (these bristles occasionally wanting). Tarsi scutellate anteriorly, the sides undivided (except sometimes below), and separated from the anterior plates by a narrow naked strip, sometimes filled up with small scales. Basal joint of middle toe united about equally to the lateral, generally for about half the length. Bill generally notched.

The preceding characters distinguish the family of Crows quite markedly from all others. The features of the bristles on the bill, and the separation of the lateral and anterior scales by a narrow interval, are worthy of particular attention. The commissure is without the obtusely angular bend near the base, seen in the Icteridæ.

There are two sub-families of Corvidæ represented in America, one embracing the true Crows, the other the Jays. They pass very insensibly into each other, and it is difficult to mark the dividing line. We may, however, distinguish these, as found in the United States, by the following characters:

Corvinæ. Bill as long as the head. Tail short, nearly even; wings long and pointed, longer than tail, and nearly reaching its tip; projecting beyond the under tail-coverts, which reach the middle of tail. Tip of wing formed by the third, fourth, and fifth quills, which are longest.

Garrulinæ. Bill usually shorter than head. Tail lengthened, rounded, and generally longer than the wings, which are short, rounded, and extend scarcely beyond the lower tail-coverts; these not reaching the middle of the tail. Tip of wing formed by the fourth, fifth, and sixth quills, which are longest.

The row of small scales is usually present on both sides of the tarsi in the Corvinæ, but in the Jays is generally restricted to the inner face.