Western Bristlebird Dasyornis longirostris: Response to fire and persistence of home range in the Fitzgerald River National Park, Western Australia

Abstract

We investigated the response of the Western Bristlebird Dasyornis longirostris to fire in the Fitzgerald River National Park (FRNP), Western Australia, over a 34-year period. This species is a threatened Western Australian endemic restricted to a highly fire-prone habitat. Commencing in 1985, we surveyed for occurrence of Western Bristlebirds within the FRNP. Monitoring that was specifically focused on fire impacts began at Fitzgerald Track in November 1994 following a fire the previous month. That site had been surveyed in June and August 1994 before the fire. Fires in other recently surveyed locations in 1997–1998, 2000, 2008 and 2019 allowed for comparisons to be made following further monitoring of these sites. Many Bristlebirds survived a fire then relocated along or near the fire edge, usually in clusters of home ranges where suitable habitat was available. Bristlebirds gradually re-occupied burnt areas when these became suitable, often to home ranges occupied before the fire. There was a tendency for a home range to be occupied for >1 year. A change independent of fire could occur. Areas of vegetation of different fire ages were used by Bristlebirds for differing time periods. Sites in the lower-rainfall areas required longer periods of time for habitat to be recolonised by Bristlebirds and the maximum age of vegetation occupied by Bristlebirds varied between sites. For these reasons, generalised prescriptions are not appropriate, but fire management of individual patches of Bristlebird habitat in the FRNP can be guided by these findings, ensuring that unburnt refuge areas are both protected and retained, with the timing of management actions informed by knowledge of population response and habitat condition.