Jerdon's Nightjar

Jerdon's nightjar is a medium-sized nightjar native to southern India and Sri Lanka, best recognised by its call, like a wooden plank being beaten, each note ending in a quaver. It was formerly treated as a subspecies of the long-tailed nightjar; vocalisation studies support it as a full species. The Sri Lankan subspecies is aequabilis (Wikipedia, general species account).

It is 26 cm long, almost a head's length bigger than the Indian nightjar, and differs in its barred tail, rufous rear neck and wing bars. Plumage is variegated buff and brown, the collar is blackish, and the male has a white patch on each wing. Like other nightjars it is nocturnal. Nationally Least Concern (Sri Lanka National Red List 2012).