The Bobolink invariably builds its nest upon the ground, usually in a meadow, and conceals it so well among the standing grass that it is very difficult of discovery until the grass is cut. The female is very wary in leaving or in returning to her nest, always alighting upon the ground, or rising from it, at a distance from her nest. The male bird, too, if the nest is approached, seeks to decoy off the intruder by his anxiety over a spot remote from the object of his solicitude. The nest is of the simplest description, made usually of a few flexible stems of grasses carefully interwoven into a shallow and compact nest. The eggs, five or six in number, have a dull white ground, in some tinged with a light drab, in others with olive. They are generally spotted and blotched over the entire egg with a rufous-brown, intermingled with lavender. They are pointed at one end, and measure .90 by .70 of an inch. They have but one brood in a season.
In some eggs, especially those found in more northern localities, the ground-color is drab, with a strong tinge of purple. Over this is diffused a series of obscure lavender-color, and then overlying these are larger and bolder blotches of wine-colored brown. In a few eggs long and irregular lines of dark purple, so deep as to be undistinguishable from black, are added. These eggs are quite pointed at one end.
Genus MOLOTHRUS, Swainson.
Molothrus, Swainson, F. Bor.-Am. II, 1831, 277; supposed by Cabanis to be meant for Molobrus. (Type, Fringilla pecoris, Gm.)
Molothrus pecoris.
32446
Gen. Char. Bill short, stout, about two thirds the length of head; the commissure straight, culmen and gonys slightly curved, convex, the former broad, rounded, convex, and running back on the head in a point. Lateral toes nearly equal, reaching the base of the middle one, which is shorter than tarsus; claws rather small. Tail nearly even; wings long, pointed, the first quill longest. As far as known, the species make no nest, but deposit the eggs in the nests of other, usually smaller, birds.
The genus Molothrus has the bill intermediate between Dolichonyx and Agelaius. It has the culmen unusually broad between the nostrils, and it extends back some distance into the forehead. The difference in the structure of the feet from Dolichonyx is very great.
Molothrus pecoris.