Birds of America
By John James Audubon, F. R. SS. L. & E.
FAMILY XVIII.--CORVINAE. CROWS.
Bill about the length of the head, robust, nearly straight, compressed;
upper mandible with the dorsal line more or less arched, its tip slightly
deflected, the edges sharp, with a slight notch or sinus. Nostrils basal,
roundish, concealed by reversed slender stiff feathers. Head rather large,
ovate; neck of moderate length, body compact. Feet of ordinary length, rather
stout; tarsus compressed, with about eight large scutella; toes four, first
stronger, but about the same length as the second and fourth, which latter is
adherent at the base. Claws rather large, arched, compressed, acute. Plumage
various; wings long or of moderate length, much rounded, the first quill about
half the length of the fourth or fifth, which are longest; tail of twelve broad
feathers. Upper mandible concave, with several longitudinal ridges; tongue
oblong, flat above, horny, thin edged, with the tip slit and lacerated;
oesophagus of moderate width, without dilatation; proventriculus bulbiform;
stomach, a gizzard of moderate power, with a rugous dense epithelium; intestine
of moderate length and width; coeca small, cylindrical, adnate. Trachea with
four pairs of inferior laryngeal muscles. Nest in high places, or in cavities,
rudely constructed; eggs from four to six, ovate or oblong.