Yellow-rumped Thornbill

The Yellow-rumped Thornbill, Acanthiza chrysorrhoa, presents as a small, brownish avian with a striking yellow rump that captures the eye. This species, the largest of the thornbills, measures between 9.5 to 12 cm in length and tips the scales at a mere 9 grams. It boasts a short tail and a long, slender bill, ideal for its insectivorous diet. The bird's plumage is a tapestry of nature's hues, with a black forehead speckled with white, a grey head and neck, and a white line above the eye that contrasts with its white throat. The belly is a canvas of white with a light buff under the wings, while the wings themselves are grey and the tail, black. Subspecies exhibit slight variations in plumage.

Identification Tips

When observing the Yellow-rumped Thornbill, look for the distinctive yellow rump that stands out against its otherwise muted tones. The black forehead with white spots, grey upperparts, and white underparts with light buff on the flanks are key identification markers. The bird's long, slender bill and short tail are also characteristic features to note.

Habitat

This adaptable bird can be found across a variety of landscapes, including open forests, woodlands, grasslands, savannahs, and scrublands. It thrives in these environments across much of Australia.

Distribution

The Yellow-rumped Thornbill has a broad range across western, southern, and eastern Australia, including Tasmania. However, it is notably absent from the north coast of Western Australia, parts of central Australia, northern Queensland, and central and northern Northern Territory.

Behaviour

This species is known for its cooperative breeding habits and is often seen foraging in small groups. It may also join mixed-species flocks with other small insectivorous passerines.

Song & Calls

The song of the Yellow-rumped Thornbill is a delightful symphony of twittering, musical, sweet, and high-pitched notes. Additionally, this species is an adept mimic, particularly known for imitating the alarm calls of the Noisy Miner.

Breeding

Breeding season spans from July to December, with the possibility of multiple broods within a year. Nests are dome-shaped structures, cleverly designed with a false top nest to deceive predators, while the true nest lies concealed within. Clutch size typically consists of three to four eggs, which are incubated for about 16 to 18 days. Both parents are involved in feeding the young, which fledge after approximately 19 days.

Similar Species

While the Yellow-rumped Thornbill is the largest of its genus, it may be confused with other thornbill species. However, its distinctive yellow rump and the specific pattern of its plumage set it apart.

Diet and Feeding

Insectivorous by nature, the Yellow-rumped Thornbill feeds primarily on ants, beetles, bugs, and lerps. It also consumes spiders, flies, and occasionally seeds. Foraging typically occurs in small groups.

Conservation status

The IUCN Red List classifies the Yellow-rumped Thornbill as Least Concern, indicating a stable population without significant threats to its survival at this time.