Attempted re-introduction of the western bristlebird in south-western Australia

Summary

The western bristlebird (Dasyornis longirostris), Vulnerable and confined to a narrow stretch of southwestern Australia's south coast, had declined from about 620 pairs in 2001 to roughly 320 following extensive wildfires. Western Australia's Department of Environment and Conservation attempted to establish a new subpopulation near Walpole, within the species' historic range but west of its remaining strongholds, adapting techniques developed for the related noisy scrub-bird. In spring 1999 and 2000, 15 bristlebirds were captured from Two Peoples Bay Nature Reserve, briefly held in aviaries where they settled and fed readily, and released into the Nuyts Wilderness of Walpole-Nornalup National Park; three more birds were translocated to nearby D'Entrecasteaux National Park in 2007. Radio-tracked birds began singing territorial songs within a day of release, and some pairs began dueting within 24 hours, evidence they were finding adequate food. A major lightning-caused wildfire in March 2001 burned about 2,800 hectares of the release area, yet at least seven bristlebirds were still calling in late 2001, and one bird persisted for at least five years. However, surveys from October 2003 found only one calling bird, and none were detected from October 2005 onward, while the 2007 release group showed no evidence of persistence beyond four months. Major difficulties included a skewed sex ratio among captured birds, difficulty catching birds in 2007, wildfire habitat loss, and feral cat predation despite control efforts. The project rates itself a Failure, though it demonstrated the translocation methods themselves were sound even as long-term establishment did not succeed.