Butastur Hodgs., J. A. S. B., xii, p. 311,(1843).
Type, Circa teesa Frankl.
The genus Butastur is in many ways intermediate between the Buzzards and true Eagles but differs from both in certain important characters. In the characters of the tarsus they approach Cuncuma and seem to have been rightly placed by Blanford between this genus and Spilornis, though they might equally well be interleaved between the Kites and Buzzards.
In this genus the tarsus is naked, without transverse shields, covered with imbricate shields which are rather larger in front; the toes are short; the bill is compressed and the culmen curved from the base; there is generally a festoon, sometimes well marked, on the edge of the upper mandible; the nostrils are oval and oblique ; the wings are long, the third quill longest, the fourth nearly equal to it, the second and fourth about equal and much shorter ; the first four primaries emarginate inside; the size is rather small and the measurements of the two sexes much the same.
The genus is represented in Africa and the Oriental Region.
Key to Species.
A.Tail tinged rufous, with narrow or no cross-hands.
A.Quills chiefly brown above......................B. teesa, p. 104.
B.Quills chiefly rufous above.....................B. liventer, p. 106.
B.Tail not tinged rufous, with broad dark bands.,...............B. indicus, p. 107.