Australasian Treecreepers

Australasian treecreepers are a group of medium-small, oscine songbirds found mainly in Australia, with one species native to New Guinea. With seven species in total, they are characterized by their mostly brown plumage with patterns on their underparts, long tails, short legs, and slightly down-curved bills. While there is some sexual dimorphism, all species exhibit strong feet and a relatively stout body, which aids them in foraging for insects under tree bark, especially eucalypts, and on the ground in various habitats including mid-montane forests, woodlands, and rainforests. These birds, which measure 14-19 cm in length and weigh 17-44 g, are generally poor fliers and are considered non-migratory. Treecreepers use their beaks and specialized tongues to glean insects from bark, but unlike their distant Holarctic relatives, they do not use their tails for support when climbing. They are cooperative breeders; with some species forming groups where helpers aid in nest construction and chick-rearing. They nest in tree holes and defend breeding territories with varying degrees of intensity. The brown treecreeper can also adapt to more open woodland environments but is sensitive to habitat loss. The family's closest relatives are believed to be the large lyrebirds, as supported by molecular studies.