The spotless crake (Zapornia tabuensis) is a species of bird in the rail family, Rallidae. It is widely distributed species occurring from the Philippines, New Guinea and Australia, across the southern Pacific Ocean to the Marquesas Islands and south to New Zealand.
As an adult the spotless crake can reach a length of 17 – 20 cm; a wingspan of 26 – 29 cm; and can weigh between 40 – 50g. The head, and neck of the spotless crake is a bluish–grey slate colour. Some also have an occasional light grey or whitish patch on the chin, which can extend down the throat. The back, the outer wings, and inner wings have a dark reddish–brown which then fades into a dark blackish – brown on the tail feathers. The underside of the spotless crake is also a bluish–grey which then transitions to a blackish–grey on the underside of the tail feathers. Its bill is black, and its eyes are a deep red which contrast sharply with the head. The legs and feet are a reddish–pink colour. Spotless crake lack any obvious sexual dimorphism, making it difficult to distinguish between male and female.
The juvenile is similar to the adult, but its colouring is duller over the whole body, and is paler and browner than the mature crake. Its chin and throat have a white patch on it. The back is a dull brown, and the head and underside is a dull grey–brown. The eyes are a brownish-orange which then begin to turn red as it matures. The colour of the legs and feet can vary from an olive–brown, brownish–grey, or a brownish–flesh colour which also turn red as it matures.
The spotless crake has a variety of calls, although little is known about the meaning of each. Originally, seven separate calls of the spotless crake were detected, including a bubbling sound, a sharp, high pitched ‘pit-pit’, a ‘mook’ sound which varies in loudness and pitch, and a loud ‘purring’ call. The high-pitched ‘purr’ sound is believed to be its song. This call is made up of a rapid series of notes which are roughly 25 per second, making it its loudest call. More calls were detected at the time but since then only four have been described.