The Bush Stone-curlew, or Bush Thick-knee, is a large, slim, mainly nocturnal, ground-dwelling bird. It is mostly grey-brown above, streaked with black and rufous. It is whitish below with clear, vertical black streaks. The bill is small and black, and the eye is large and yellow, with a prominent white eyebrow. Both sexes are similar. Young Bush Stone-curlews are similar in appearance to the adults, but are paler, and a little browner in colour. Bush Stone-curlews are nocturnal birds (night birds), doing all their feeding and other activities at night.