This bird has been recently recognized as a distinct species and added to the Sri Lankan endemic list. Sparrow sized and stockier than our other swallows, it is unmistakable with purple-blue glossed upperparts and rusty underparts and rump. Both sexes are alike. Young are duller.
The species is well distributed throughout the island up to about 1500 metres elevation. The birds associate in pairs or more often in scattered groups and spend their time flying after the insect prey they feed on. The usual habitat is open areas such as paddy fields, roadsides, grasslands, grass covered hillsides etc. The flight is typical swallow type with the wings being open and shut at the wrist joint. The birds flutter the wings rapidly and then glide gracefully before fluttering the wings again. The flight is however not as fast as the other swallows’. This species commonly associates with other swallows as well as swifts. They fly high as well as within a few feet from ground level. When not flying the birds sit in an open perch like a bare twig or power cable and preen themselves. The call is a pleasant muffled t’lee easily recognized when once heard. The birds also utter a loud twitter accompanied by a shuffling of wings.
The Sri Lanka swallow (Cecropis hyperythra) is a resident breeder endemic to Sri Lanka. It is closely related to the red-rumped swallow, and was formerly considered a subspecies.
It is a large swallow with a tail which forks deeply, and the combination of deep rufous underside and navy blue rump without any marks is a unique feature of this species. Its rufous underside can be used to tell it apart from the red-rumped swallow. It is a passerine, which means it has three toes pointing forward and one pointing backward, allowing it to perch.
It is found in a variety of open country habitats in both the lowlands and foothills in Sri Lanka, including farm fields and lightly wooded areas.
