Australia

Australian Owlet Nightjar (Aegotheles chrisoptus)

The Australian owlet nightjar Aegotheles chrisoptus (Family: Aegothelidae) is a nocturnal bird found in woodland across Australia and in southern New Guinea. On summer nights in woodland areas, above the din of crickets comes the occasional distinctive, churring call of the owlet nightjar (which can be found here: Owlet Nightjar Call). They are more likely to be seen in summer because being a nocturnal feeder, their activity increases as we move into warmer weather.

The Australian owlet nightjar is both the most common of all the owlet nightjar, and the only species of this secretive family to occur in Australia. Australian owlet nightjar are widespread, occurring across Australia as well as in Papua New Guinea and the Australian Islands. Although most common in arid habitats, they can be found throughout Australia in any habitat with suitable tree hollows for nesting and daytime roosts.

Superficially similar to the nightjars (Family: Caprimulgidae), owlet nightjars are a monotypic family (Aegothelidae) more closely related to hummingbirds and swifts (Class: Apodiformes). Like swifts, owlet nightjars are insectivorous, hunting during the night within defined territories both in-flight and diving from perches.

Australian owlet nightjars are the smallest of the Australian night birds, with adults between 21 and 25cms – about the same length as a noisy miner. These night birds form permanent pair bonds, and pairs establish and maintain a territory throughout the year. Their breeding season usually begins in late winter, normally extending from October to January, and pairs raise one brood of up to four young each year. Although the Australian owlet nightjar is probably the most abundant and one of the most widespread nocturnal birds in Australia, the majority of information published about its ecology, behaviour and especially reproductive biology is anecdotal. Both sexes construct the nest, but it appears that only one individual, presumably the female, incubates the eggs, and cares for the chicks.  Another little known fact about Aegotheles cristatus is that during cold periods in the Winter (between May and September), individuals often go into Torpor (What is Torpor?) to save energy during the coldest part of the day!

Although common, they can be difficult to find, and unlike Australia’s other nocturnal birds they only have weak eye-shine. In more open or arid habitat, they are often to be found roosting in the hollows of low trees during the day or sitting on roads at night. Whilst in forested habitat, your best chance is to listen carefully at night for their call, and look for movement between gaps in the canopy.

(c) Jeremy Ringma: http://www.flickr.com/photos/jeremyringma/

by Megan Barnes