Crested Serpent Eagle - Behaviour and Ecology

Behaviour and Ecology

The Crested Serpent Eagle, as its English name suggests, is a specialist reptile eater which hunts over forests, often close to wet grassland, for snakes and lizards. It is placed along with the snake eagles of the genus Circaetus in the subfamily Circaetinae. It is found mainly over areas with thick vegetation both on the low hills and the plains. This species is a resident species, but in some parts of their range they are found only in summer.

The call is a distinctive Kluee-wip-wip with the first note being high and rising. They call a lot in the late mornings from their perches where they spend a lot of time and they rise on thermals in the mornings. When alarmed, they erect the crest and the head appears large and framed by the ruff. They will sometimes follow snakes on the ground. They roost in the interiors of trees with dense foliage. A radio-telemetric study of the species in Taiwan found that the birds spend 98% of the day perched and usually finding food in the morning hours. They appear to use a sit and wait foraging strategy.

The breeding season is mainly in winter to spring. The nest is a large platform built high on a tree. Both birds in a pair build the nest but the female alone incubates. In central India, the Terminalia tomentosa is often used. The nests are lined with green leaves from the tree on which it is placed. The usual clutch is one egg but two are sometimes laid and only a single chick is successfully raised in a season. Nests are defended by the parents.

Several species of endoparasitic nematodes have been recovered from the intestines of Crested Serpent Eagles including Madelinema angelae Avian pox virus infections which cause warts on the face have been observed in a wild bird living in Taiwan. A number of ectoparasitic bird lice have been described from the species including Kurodaia cheelae.