The Eastern Bristlebird: Cover-dependent and Fire-sensitive

Abstract

The Eastern Bristlebird Dasyornis brachypterus inhabits a wide range of vegetation communities including rainforest, eucalypt forest, woodland, mallee, shrubland, swamp, heathland and sedgeland. At Barren Grounds, East-ern Bristlebirds mostly occurred in habitat with the characteristic layers of ground cover (≤ 0.25 m), low cover (0.25-1.0 m) and tall shrub cover (≥ 1 m). Using the point-frequency method, the ground cover measure averaged 91% and consisted of herbs, coral ferns and litter; the low cover averaged 92% and consisted of a tangle of herbs, coral ferns, litter and/or small shrubs; and the tall shrub cover averaged 74% and consisted of larger shrubs but also included mallee and tree cover. At Barren Grounds, in 1992 and 1995, respectively, the density of Eastern Bristlebirds in old fire-age habitat (9-15 years) was 2.5-times and 5-times the density in young fire-age habitat (three years). In the recently burnt areas, Eastern Bristlebirds generally avoided regenerating low vegetation in favour of unburnt clumps, rapidly regenerating mallee or shrubs, particularly Melaleuca squarrosa in wet areas, and patchily burnt areas some of which were associated with escarpment edges. In old fire-age habitat at Barren Grounds-Budderoo, Jervis Bay and Nadgee, Eastern Bristlebirds breed and occur at relatively high densities. Fire has been implicated in the local extinction of numerous Eastern Bristlebird populations. However, the two populations which are currently the largest, Barren Grounds-Budderoo and Jervis Bay, are characterised by a three decade recent history of relatively small-area burns and long periods between fires over much of the available habitat. The Eastern Bristlebird is a cover-dependent and fire-sensitive species. Areas of known Eastern Bristlebird habitat and adjacent potential habitat should be managed to enhance the growth of dense low vegetation and to exclude fire.

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