This and the next two genera contain the typical Hawks, which are distinguished from Falcons, Eagles, Buzzards, Harriers, and Kites by having proportionally shorter and more rounded wings, and from all except the Harriers by having the tibia and tarsus nearly equal in length.
The true Hawks are chiefly found in forest or well-wooded tracts, and they always breed on trees. The sexes are very different in size. " Their flight is often near the ground and is performed by a few rapid strokes of the wings, alternating with a sailing with outspread wings. They are more arboreal in their habits than the Falcons, hunting in woods or on the skirts of woods, or along avenues and hedgerows, and they generally seize their prey by a sudden pounce during their flight, not following the quarry to any distance as the Falcons do." (Jerdon.)
Although the group is here divided into three genera, the generic distinctions are not very marked, and all the species are by some naturalists referred to a single genus, whilst Kaup and Gurney refer each of the six Indian kinds to a different generic section.
The genus Astur as here admitted has a short stout bill curving sharply from the cere, with a large festoon ; the nostril is moderate in size and oval. The wing is short and rounded, extending to about the middle of the long tail. Usually the 4th quill is longest, occasionally the 3rd or 5th, the three not differing greatly in length. Tarsus long, stout, scutellate in front and behind, reticulate on the sides, only the upper part covered with feathers; toes and claws moderate, the bill from the gape measuring 1/2 to 2/5 the length of the tarsus and about § the length of the outer toe. The plumage is grey or brown above, spotted beneath in the young, transversely barred in adults.
Besides the true Goshawks, the present genus contains a number of smaller Hawks, two of which are Indian, the others being very widely distributed. Of the Indian species A. badius has been distinguished as Scelospiza or Scelospizias, A. soloensis as Tachyspiza. The generic name Micronisus employed by Jerdon really belongs to an African group known as Melierax.
Key to the Species.
a. Fourth quill longest.
a1. Size large wing 12 to 15………………………A. palumbarius, p. 397.
b1. Size small, wing 7 to 9………………………A. badius, p. 398.
b. Third quill longest, wing about 7.5………………………A. soloensis, p. 400.