Yellow-rumped Thornbill

The Yellow-rumped Thornbill is the largest and probably the best-known thornbill, with a striking yellow rump. It is mainly grey-olive to grey-brown above to cream below, with a white-spotted black crown and a dark eye stripe. The tail is black, with white tips. The sexes are similar. Young birds have softer, fluffier plumage on the body, but are otherwise similar. Often seen in small flocks feeding on the ground, often with other thornbills and ground-feeding birds.

The Yellow-rumped Thornbill is separated from the smaller Buff-rumped Thornbill, A. reguloides, by its bright yellow rump, paler underbody and distinctive dark eye stripe and spotted head.

The Yellow-rumped Thornbill is found throughout eastern and south-eastern Australia, including Tasmania, as well in southern parts of the Northern Territory and on the Nullarbor Plain in Western Australia.

The Yellow-rumped Thornbill is found on the ground in open habitats, such as woodlands, forests, shrublands and grasslands with some trees. It is also common in agricultural lands, along watercourses, beside roads and in parks and gardens. It is found in most climatic zones, but only sparse in tropics, arid zone and east of the Great Dividing Range.

The Yellow-rumped Thornbill feeds mainly on insects, but may sometimes eat seeds. It is primarily a ground-feeding bird, more so than most other thornbills, but stays near tree cover and will sometimes feed in shrubs or trees. Often seen in mixed flocks with other thornbills and birds such as Speckled Warblers and Weebills.

Yellow-rumped Thornbills sometimes breed co-operatively, with a pair being assisted by one or two helpers, which help to build the nest and feed the young. The nest is a large and untidy structure of grass and bark with two parts: an upper 'false' cup-shaped nest and a lower, domed, nest-chamber with a hooded entrance. The function of the false nest is not clearly understood, with many theories being put forward, such as: deterring predators or parasitic cuckoos, a roosting place for male or fledglings, a 'practice' nest for the helpers or as a 'displacement' activity for males. The nest is usually in the dense foliage of trees, near the end of branches or in vines or mistletoe. The female incubates the eggs alone, but is assisted by the male and any helpers with feeding and protecting the young.

Urban development around large cities has caused Yellow-rumped Thornbill populations to decline. However, it has adapted well to urban and agricultural habitats, where native vegetation remains, except in Western Australia where extensive clearing has occurred. Eaten by cats and sometimes hit by cars on roads.