Adults are 16–18 cm (6.3–7.1 in) long with short finch
-like bills. They weigh about 1 oz (28 g).
Adult males are mostly black with creamy napes and white scapulars, lower backs, and rumps. Adult females are mostly light brown, although their coloring includes black streaks on the back and flanks, and dark stripes on the head; their wings and tails are darker. The collective name for a group of bobolinks is a chain