Photo: M Carter
Plains-wanderer
Maher, Philip N. 1997
Introduction in: 'A survey of Plains-wanderers Pedionomus torquatus and native grasslands on the Riverine Plain', New South Wales, Birds Australia, Hawthorn, Vic.The Plains-wanderer Pedionomus torquatus is an Australian endemic species that has long evoked interest from the world ornithological community. It is the sole member of the family Pedionomide (Olsen and Steadman 1981), having no known living relatives. Plains-wanderers superficially resemble button-quail (Turnix spp) in that females are larger and more brightly coloured than males and have bright yellow legs and bill and give a low ooming call. However, they are more closely related to plovers and dotterels (Olsen and Steadman 1981). Like button-quail, the male Plains-wanderer does most of the incubation and chick rearing (Baker-Gabb et al 1990) if not all of it. The disparity in size and role reversal of the sexes during breeding is unusual among birds.
Plains-wanderers' prime habitat on the Riverine Plain is the hard, red-brown earths with a sparse covering of native herbs and grasses. Red-brown earths are irregularly distributed across the Plain (primarily brown, red and grey clays) and are found mainly on elevated plains or along levees of prior streams and their associated swamps.
Optimal Plains-wanderer habitat contains around 50% bare ground (Baker-Gabb et al 1990) and two levels in the structure of the grassland: a lower layer of 8cm or less which is important for concealment from aerial predators and a sparser layer of 10 -40cm. Plains-wanderers can sometimes be found in grassland with almost no upper layer but are rarely found if there is no lower layer.
Plants of the genera Stipa, Danthonia, Helipterum, Helichrysum, Chrysocephalum and Calocephalus are usually present in grasslands where Plains-wanderers are located. Chrysocephalum apiculatum (formerly Helichrysum apiculatum) together with Stipa are good indicator species of Plains-wanderer habitat.
Plains-wanderers, living in such an open environment, are vulnerable to predators such as Black Falcons Falco subniger, Brown Falcons Falco berigora and Spotted Harriers Circus assimilis. Their camouflage and cryptic daylight behaviour are their main safeguard. When disturbed at night Plains-wanderers are less secretive. They rarely fly during the day, however, when they do, their flight is more dipping and uneven than at night, presumedly as a defence against raptors. Their flight pattern at night is slow and direct, resembling a crake's (Porzana spp) with rapid, shallow wingbeats and legs trailing out behind. They are diurnal, feeding on a wide variety of seeds and ground dwelling insects (Baker-Gabb 1988).
In years of average rainfall Plains-wanderers pair up in July, have eggs in August and young in September. However if conditions are wet in August and September they are more likely to successfully produce young in October and November. On two occassions during wet conditions Plains-wanderers have been recorded on raised grass nests about 30 mm off the ground. They will continue to breed through the summer if there have been good rains. Breeding can also occur in autumn, particularly if there has been little success in the spring and summer. Plains-wanderers breed best in years of average rainfall rather than excessively wet or dry years. Since 1981, in the southern Riverina, they appear to have failed to breed in the spring and summer of the drought years (1982-83 and 1994) and bred with little success in the wet years (1990-92).
Approximately 1200 Plains-wanderers, including those recorded in the current surveys, have been recorded on 31 properties in the Riverina by the author to the end of 1997.
