About Caprimulgus indicus Latham, 1790
The jungle nightjar (Caprimulgus indicus Latham, 1790) measures roughly 21 to 24 centimeters in total length, while the Sri Lankan subspecies kelaarti is smaller in size. Its overall plumage is mostly grey, with black streaks running across its crown. It does not have a prominent wing patch; any wing patch present is rufous in color. The tail is greyish, marked with clearly separated, narrow black bars. Males of the species have a white throat patch that is split in the middle. Females have a rufous throat patch and visible submoustachial streaks. The most common call of the jungle nightjar is a sequence of thacoo or chuck notes, produced at a rate of 5 notes every 2 seconds, and it sounds like a distant engine. Its song is a slow, regular series of FWik-m notes, which can be repeated continuously for up to 10 seconds. This song sometimes ends in quick whistling foo-foo notes that match the sound made when air is blown over the opening of an open bottle. A call identified as uk-krukroo and attributed to this species by Ali and Ripley in their Handbook is incorrect; this call actually belongs to the Oriental scops owl (Otus sunia).
