Indian Roller - Behaviour and Ecology

Behaviour and Ecology

These birds are usually seen perched on prominent bare trees or wires. They descend to the ground to capture their prey which may include insects, arachnids, small reptiles (including Calotes versicolor and small snakes) and amphibians. Fires attract them and they will also follow tractors for disturbed invertebrates. In agricultural habitats in southern India, they have been found at densities of about 50 birds per km2. They perch mainly on 3—10 metre high perches and feed mostly on ground insects. Nearly 50% of their prey are beetles and 25% made up by grasshoppers and crickets. The feeding behaviour of this roller and habitat usage are very similar to that of the Black Drongo. During summer, they may also feed late in the evening and make use of artificial lights and feed on insects attracted to them. They are attracted to swarms of winged termites and as many as 40 birds have been seen to perch on a 70 metre stretch of electric wires. Their habit of feeding near roadsides sometimes results in collisions with traffic. A decline in the numbers of these birds seen along roadsides in northern India has been noted.

The display of this bird is an aerobatic display, with the twists and turns that give this species its English name. The breeding season is March to June, slightly earlier in southern India. Displays when perched include bill-up displays, bowing, allopreening, wing drooping and tail fanning. Holes created by woodpeckers or wood boring insects in palms are favoured for nesting in some areas. Nest cavities may also be made by tearing open rotten tree trunks or in cavities in building. The cavity is usually unlined and is made up mainly of debris from the wood. The normal clutch consists of about 3-5 eggs. The eggs are white and broad oval or nearly spherical. Both sexes incubate the eggs for about 17 to 19 days. The young fledge and leave the nest after about a month. Nearly 80% of the eggs hatch and fledge.

The call of the Indian Roller is a harsh crow-like chack sound. It also makes a variety of other sounds, including metallic boink calls. It is especially vociferous during the breeding season.

The bird bathes in open water by plunge-diving into it, a behaviour often interpreted as fishing but may occasionally attempt fishing from water.

Blood parasites Leucocytozoon of the family Plasmodiidae have been noted in the lung tissues as also parasitic helminth worms Hadjelia truncata and Synhimantus spiralis.