Three
subspecies are generally recognized. However the nominate form can be found
from West Asia (Iraq, Arabia) east across the Indian Subcontinent, and within
India north of the Vindhyas mountain ranges. The subspecies “indicus” is mainly
found in peninsular India and Sri Lanka. The southern bird form has a darker
reddish collar on the hind neck which is missing in the nominate form. The race
“affinis” of northeastern India and Southeast Asia (Thailand, Myanmar,
Indo-china) is sometimes considered a full species, but within the Indian
region, it is seen to intergrade with benghalensis.
The form “affinis” is
darker, larger and has a purplish brown and un-streaked face and breast.
Moreover it has underwing coverts in a deeper shade of blue. The Indian roller
is widely distributed across Asia, from West Asia (Iraq), through the Indian
Subcontinent (including Pakistan, Sri Lanka and the islands of Lakshadweep and
“Maldive Islands” into Southeast Asia. The bird main habitat is cultivation,
thin forest and grassland. They’re frequently seen perched on roadside electric
wires. 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, little reptiles including “Calotes versicolor” & little snakes
and amphibians. Therefore fires attract them and they’ll also follow tractors
for disturbed invertebrates. In agricultural habitats in southern India, they
have been seen at densities of about 50 birds per km2. They perch mainly on 3
to 10 meter high perches and feed mostly on ground insects. Approximately 50%
of their prey is beetles and twenty five per cent made up by grasshoppers and
crickets.
The Indian Roller feeding behavior is 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’re attracted to swarms of winged termites and as many as 40 birds
have been seen to perch on a 70 meter 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.
This is an
aerobatic display bird, with the twists and turns that give this species its
English name. The breeding season starts from March to June, to some extent
earlier in southern India. The bird displays when perched include bill-up
displays, bowing, “allopreening”, wing drooping and tail fanning. The holes
created by woodpeckers or wood boring insects in palms are favored for nesting
in few areas. Moreover nest cavities may also be made by tearing open rotten
tree trunks or in cavities in building. The cavity is typically unlined and is
made up mostly of debris from the wood. The normal clutch contains 3 to 5 eggs,
which is normally in white and broad oval or nearly spherical.
The both male
and female incubate the eggs for about 17 to 19 days. The young bird fledges
and leaves the nest after near 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 particularly
vociferous during the breeding season and the bird bathes in open water by
plunge-diving into it, a behavior often interpreted as fishing. But it may
sporadically attempt fishing from water. Moreover adding its chopped feathers
to grass and feeding them to cows was supposed to increase their milk yield.
The Indian roller has been selected as the state bird by the Indian states of
Bihar, Andhra Pradesh, Telangana, Karnataka and Odisha.
