Large-tailed Nightjar’s enormous gape

Jeremiha Loei’s two video clips of an adult Large-tailed Nightjar (Caprimulgus macrurus) in an open nest on the ground with two young chicks were documented in 2014. The chicks were more than a week older in the second clip.

Being nocturnal, nightjars naturally hunt at night. They are mainly insectivorous, catching insects while in flight and swallowing them whole. Having an extra wide gape is a great advantage in capturing their prey. The image above, a videograb from the video clip below, shows the chick gaping widely at around 0:45 minutes

Note that the two fluffy chicks are covered with down feathers with the wing feathers just developing.

The image above is a videograb from the second video clip shown below. It shows the equally large gape of the adult at 0:50 minutes. Note that the chicks are now about more than a week older and covered with feathers.

The nightjar’s enormous gape is due to its ability to open its mouth both vertically and horizontally LINK. The gape is aided by a lining of long, tactile bristles that helps to funnel insects into the mouth when the nightjar is feeding on the wing LINK.

Jeremiah Loei
Singapore
31st July 2017

This post is a cooperative effort between Birds, Insects N Creatures Of Asia and BESG to bring the study of birds and their behavior through photography and videography to a wider audience.