This is the text of my audio piece on the yellow-rumped thornbill for the Bimblebox 153 Birds Art Project, which is touring around Queensland to raise awareness of the Bimblebox Nature Refuge, which is threatened by coal mining. 153 species of birds have been spotted in the reserve.
Yellow-rumped thornbills (Acanthiza chrysorrhoa) are endemic to Australia and widespread, particularly across southern Australia.
These lively little little brown birds with the bright yellow rump and spotty forehead have a couple of interesting features—they build a decoy nest and they sometimes breed cooperatively.
After building a dome-shaped nest, where the eggs are laid, they carry on construction—adding a second storey like a classic cup-shaped nest. Being empty, it discourages the attention of potential predators on the eggs and chicks, which are in the real nest below. Experimental studies have shown that the decoy nest does indeed reduce predation.
The trick nest may also help hide the real one from cuckoos.
Occasionally, young yellow-rumped thornbills hang around with their parents after fledging, and help raise the chicks of subsequent broods. These helpers work on the nest, and bring food to the chicks. This reproductive strategy, called cooperative breeding, is more common among Australian bird species than elsewhere. It’s seen in quite of few, but not all, species of thornbill.
A published account of a young yellow-rumped thornbill helping its parents describes its nestbuilding and chick-feeding skills improving immensely with the practice it got as a helper at the nest.
A short bio:
Margie Beilharz is a Melbourne writer and editor with over six years’ experience in science communication. She followed a PhD in Zoology with work in environmental policy in the Victorian National Parks Service and then as a lecturer at Deakin University. After studying technical communication to get back into the workforce after a family break, which included two years living in London, Margie joined science PR firm Science in Public, working on a communication projects for a wide range of clients. Now she’s added freelance writing and editing at The Open Desk into the mix, and is newsletter editor for Editors Victoria.