About Caprimulgus atripennis Jerdon, 1845
Shared Nightjar Traits
Like other nightjars, Caprimulgus atripennis has a wide gape, long wings, soft downy plumage, and is nocturnal in habits. It reaches an overall length of 26 cm, which is almost a full head length larger than the Indian nightjar (C. asiaticus).
Distinguishing Field Marks
It can be distinguished from the Indian nightjar by its barred tail, rufous rear neck, and wing bars. Vermiculations on the crown are fine, giving the crown a nearly uniform shade, and the collar is blackish.
Plumage Details
Males have a white patch on each wing. Like other dark tropical woodland nightjars, this species has cryptic plumage that is mainly variegated buff and brown.
Subspecies Variation
It has an unbroken white gorget similar to the long-tailed nightjar, but its tail is shorter. The Sri Lankan subspecies aequabilis is slightly smaller and darker than the nominate form.
Vocalizations
Its typical call is a fast repetitive ch-woo-woo; a second, frog-like croaking call has also been reported.
Habitat Range
This nocturnal bird inhabits open woodland, scrub, and cultivated land.
Flight Characteristics
It flies after sundown with an easy, silent fluttering flight that can look like a large moth at a casual glance.
Diurnal Roosting
During the day, Jerdon's nightjar rests silently on the ground, hidden by its camouflaged plumage, and is difficult to detect as it blends into the surrounding soil.
Diet
It feeds on nocturnal insects such as moths.
Nocturnal Perching Habits
Unlike the Indian nightjar (C. asiaticus), this species rarely rests on roads at night, and prefers to alight on bushes, making it harder to spot in vehicle headlights. Despite this nocturnal preference for perching on bushes, it roosts on the ground, though it calls from trees.
Breeding Season
The breeding season runs from March to July in India, and from February to May in Sri Lanka.
Nesting Behavior
This species does not build a nest; instead, it lays two marbled eggs directly on bare ground. The brooding bird provides the best protection for the eggs by covering them closely with its camouflage plumage.
Chick Behavior
Chicks are able to crawl away from the nesting site soon after hatching, and will hide among leaves when alarmed.