32974, ♀. ½
32974, ♀. ½
32974, ♀. ¼
I. plumbea.
Gen. Char. Form falcon-like; the neck short, wings long, and pointed, the primaries and rectrices strong and stiff, and the organization robust. Bill short and deep, the commissure irregularly toothed, and notched; gonys very convex, ascending terminally; cere narrow; nostril very small, nearly circular; feet small, but robust; tarsus about equal to middle toe, with a distinct frontal series of broad transverse scutellæ; claws rather short, but strongly curved, slightly grooved beneath, their edges sharp. Third quill longest; first of variable proportion with the rest. Tail moderate, the feathers wide, broader terminally, and emarginated.
This genus is peculiar to America, the two most closely related genera being Elanus on the one hand and Harpagus on the other. Its species belong to the tropical and subtropical regions, one of them (I. plumbea) generally distributed throughout the intertropical portions, the other (I. mississippiensis) peculiar to Mexico and the southern United States.
In their habits, they are very aerial, like the genus Nauclerus, sailing for the greater time in broad circles overhead, occasionally performing graceful evolutions as they gyrate about. Like Nauclerus, they are also partially gregarious, and, like it, feed chiefly on insects and small reptiles, which they eat while flying.