More numerous in species, and also natives of the Oriental region, are the Serpent Eagles (Spilornis), which differ from those last considered ” by having a broad nuchal crest covering the whole nape, and by the peculiar coloration, being brown above and below in adults, all but one or two with rounded white spots or ocelli on the lower parts.” Their wings are short and rounded, the 4th or 5th quill being longest, while the tarsus, toes, and claws are the same as in the Harrier-Eagles.
The Serpent Eagles, a name, by the way, which is sometimes applied to the last group, but which is best restricted to the present, take their common name from the character of their food, which consists largely of snakes and other reptiles. They are more sedentary and arboreal in their habits than their relatives, and are less often seen on the wing, preferring to watch from some vantage point for their prey. Of the fifteen species recognized, the Indian Serpent Eagle (S. Cheela), of the Himalayas and the Indian peninsula, is the largest and perhaps best known. In this the male is about twenty-eight inches and the female thirty inches long. The upper parts are dark brown with a rich purple or ruddy gloss, the crown and the crest black, the basal. half of the feathers being white, while the lower parts are brown of various shades, more or less spotted and barred. The smaller wing-coverts are blackish with small white spots; the tail is also blackish, mottled with whitish and crossed by brown bars. This bird, according to Blanford, is ” usually found on trees near water, especially the trees along irrigation channels and canals in upper India, and along stream-beds in the lower Himalayas and in the central provinces and southern India.” It may be known by the strongly marked bars on the wings and tail and above all by its loud, plaintive cry. The nest is built in trees, and on the shallow lining of green leaves one, or at most two, eggs are laid, these being more or less streaked and spotted with brownish red and purple. This species, besides feeding on snakes, frogs, and lizards, sometimes captures small mammals, birds, and large insects. Intimately related to this are three or four other species which have practically the same type of coloration but differ in size, and there is a single species that has the abdomen barred instead of spotted, thus departing from the typical color pattern of the genus. Quite a number of species are confined to single, often small, islands.