Birds of America
By John James Audubon, F. R. SS. L. & E.
FAMILY XVI.--AGELAINAE. MARSH BLACK-BIRDS.
Bill of moderate length, sometimes short, seldom longer than the head,
stout, straight, conical, compressed, tapering, pointed; upper mandible with the
dorsal line nearly straight, the nasal sinus short and very wide, the ridge thus
appearing to encroach on the forehead, the sides rounded, the edges without
notch; lower mandible with the angle short and rounded, the dorsal line
straight, the edges involute. Nostrils basal, roundish or oblong. Head rather
large, ovate; neck short; body moderately full. Legs of moderate length, stout,
rather slender; tarsus compressed, with eight anterior scutella; hind toe large,
lateral toes equal, the outer adherent at the base. Claws generally long,
arched, compressed, acute. Plumage soft, blended, in the males usually glossy.
Wings of moderate length, with the outer three or four quills longest, the first
being very little shorter than the second, or sometimes even exceeding it; tail
of twelve feathers, of moderate length, or elongated. The roof of the upper
mandible concave, with three longitudinal ridges, of which the middle is larger,
and at the base forms a hard prominence; tongue sagittate and papillate at the
base, narrow, deep, pointed. OEsophagus wide, dilated about the middle;
proventriculus oblong; stomach roundish or elliptical, with the lateral muscles
distinct and well developed; the epithelium dense and longitudinally rugous;
intestine short and rather wide; coeca very small, cylindrical; cloaca oblong.
Trachea simple, with four pairs of inferior laryngeal muscles. Female much
smaller. Nest various, on trees or bushes, or on the ground, generally
elaborate. Eggs about five, ovate, spotted and streaked.