Birds of America
By John James Audubon, F. R. SS. L. & E.
VOLUME IV.
FAMILY XXVI.--PICINAE. WOODPECKERS.
Bill long or of moderate length, straight, stout, angulate, tapering,
compressed toward the tip, which is generally wedge-shaped and abrupt; mandibles
nearly equal, outline of the upper slightly convex, the ridge narrow, sides
sloping, with a lateral ridge, edges straight; lower with the angle short and
narrow, the dorsal line nearly straight, the ridge narrow, the sides with a
faint ridge. Nostrils basal, elliptical or oblong, concealed by reversed
bristly feathers. Head of moderate size, oblong; neck of moderate length; body
stout. Legs short; tarsus short, moderately stout, anteriorly scutellate, scaly
behind; toes usually four, first short, rudimentary, or sometimes wanting,
fourth very long and reversed, equalling or exceeding the third. Claws large,
strong, much curved, much compressed, very acute. Plumage soft, blended, rather
compact on the back; wings of moderate length or long, with the first quill very
small, the third, fourth, and fifth longest. Tail of moderate length, much
rounded or cuneate, of twelve feathers, of which the lateral are extremely
small, and placed above the next, the rest, but especially the three middle
pairs, with the shafts exceedingly large and strong, the webs narrowed toward
the end, with their filaments deflected and stiff, the tip pointed or emarginate
from being worn. Tongue slender, with the tip horny and furnished with reversed
prickles or bristles, capable of being protruded to a great length by the
elongation of the hyoid bones, which curve over the head to between the right
eye and nostril, or even extend round a great part of that eye. OEsophagus of
uniform width; proventriculus extremely large; stomach of moderate size, or
rather small, broadly elliptical or roundish, moderately muscular; epithelium
thin, dense, and longitudinally rugous; intestine of moderate length, rather
wide; no coeca; cloaca very large, globular, or elliptical. Trachea simple,
with a single pair of inferior laryngeal muscles. Nest, a cavity dug in a tree;
eggs from four to six, elliptical, white.
The groups present characters which are so undecided, and exhibit such
gradual approximations, that I think it better here to consider all our
Woodpeckers as of one genus.