The Bush Stone-curlew or Bush Thick-knee (Burhinus grallarius), is a large (55 to 60cm wingspan), ground-dwelling bird endemic to Australia. Although it looks rather like a wader and is related to the oystercatchers, avocets and plovers, it is a terrestrial predator filling an ecological niche similar to that of the roadrunners of North America.
Bush stone-curlews remain reasonably common in the north of Australia but have become rare in the less fertile south.
The bush stone-curlew has a broad habitat preference, it can be found in open forest, eucalyptus woodland, rainforest edges, grassy plains, arid scrub land and along inland watercourses. It is still abundant in the tropical and sub-tropical north, however numbers have declined in southern parts of its range.
Like most stone-curlews, it is mainly nocturnal and specialises in hunting small grassland animals. Gleaning or probing soft soil or rotting wood as well as snatching visible prey. Birds usually forage individually or in pairs over a large home range.
During the day, bush stone-curlews tend to remain inactive, sheltering amongst tall grass or low shrubs and relying on their cryptic plumage to protect them from predators. When disturbed, they freeze motionless, often in odd-looking postures. For visual predators like raptors (and humans), this works well, but it serves little purpose with animals that hunt by scent such as foxes, dingoes or goannas.
Extra fun facts
Despite their ungainly appearance and habit of freezing motionless, they are sure-footed, fast and agile on the ground, and although they seldom fly during daylight hours, they are far from clumsy in the air; flight is rapid and direct on long, broad wings.
The bush stone-curlew is probably heard more than it is seen. Its call sounds like a wail or a scream in the night. When scared, it screeches - a sound similar to the screech of a possum. When threatened (presumably in the presence of a nest), they may raise their wings wide and high in an impressive threat posture and emit a loud, hoarse hissing noise.