The Orthonychidae is a family of birds with a single genus, Orthonyx, which comprises of two species of passerine birds endemic to Australia and New Guinea, the Logrunner and the Chowchilla. Some authorities consider the Australian family Cinclosomatidae to be part of the Orthonychidae. Both species use stiffened tails to brace themselves when feeding.
The Logrunner, Orthonyx temminckii, is from south-eastern Australia, where it is very local in its distribution, and strictly terrestrial in its habits. The wings are, however, barred with white, and the chin, throat and breast are in the male pure white, but of a bright reddish-orange in the female. The remiges are very short, rounded and much incurved, showing a bird of weak flight. The rectrices are very broad, the shafts stiff, and towards the tip divested of barbs. The northern subspecies, found locally in New Guinea, was formerly considered its own species, Orthonyx novaeguineae.
The Chowchilla, Orthonyx spaldingii from Queensland is of much greater size than the Logrunner, and with a jet-black plumage, the throat being white in the male and orange-rufous in the female.
Both are semi-terrestrial birds of weak flight, and build a domed nest on or near the ground. Insects and larvae are their chief food, and the males are described as performing dancing antics like those of the lyrebird.
The fossil record does not much help to determine the affiliations of the Orthonychidae. Three prehistoric species are known to science. The very large Orthonyx hypsilophus from Green Waterhole Cave and an undescribed species found in Pyramids Cave which was a bit smaller than the logrunner are probably of Late Pleistocene age. Orthonyx kaldowinyeri is known from Middle or Late Miocene deposits of Riversleigh; it is the oldest and smallest species known to date (Boles, 1993).
- This article incorporates text from the Encyclopędia Britannica Eleventh Edition, a publication now in the public domain.
- Boles, Walter E. (1993): A Logrunner Orthonyx (Passeriformes: Orthonychidae) from the Miocene of Riversleigh, North-western Queensland. Emu 93: 44-49. DOI:10.1071/MU9930044 (HTML abstract)
- ^ Etymology: kaldowinyeri is the Yaralde (Ngarrindjeri) word for "a very long time ago"; this species is the oldest record of the family found to date. Like the bird, the language is nowadays extinct.
- Orthonychidae videos on the Internet Bird Collection