University of Wollongong Research Online Faculty of Science - Papers (Archive) Faculty of Science, Medicine and Health 1-1-2008 Post-fire recovery of eastern bristlebirds (Dasyornis brachypterus) is context-dependent D W. Bain University of Wollongong, [email protected] J R. Baker NSW Department of Environment and Climate Change, [email protected] K O. French University of Wollongong, [email protected] R J. Whelan University of Wollongong, [email protected] Follow this and additional works at: https://ro.uow.edu.au/scipapers Part of the Life Sciences Commons, Physical Sciences and Mathematics Commons, and the Social and Behavioral Sciences Commons Recommended Citation Bain, D W.; Baker, J R.; French, K O.; and Whelan, R J.: Post-fire recovery of eastern bristlebirds (Dasyornis brachypterus) is context-dependent 2008, 44-49. https://ro.uow.edu.au/scipapers/3089 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] Post-fire recovery of eastern bristlebirds (Dasyornis brachypterus) is context- dependent Abstract In late December 2003, a wildfire in the Jervis Bay region of New South Wales burned through an area that previously supported a large population of the endangered eastern bristlebird (Dasyornis brachypterus). The eastern bristlebird has been described as fire-sensitive, and fire is implicated in the decline of the species. The frequency of occurrence of bristlebirds was investigated in the second week after the fire in a range of sites varying in fire intensity. Bristlebirds were found in burned habitats but were less common in the sites that were more intensely burnt. Bristlebirds had been surveyed along transects in this area two months before this fire and were surveyed again 1, 9 and 13 months after the fire. Compared with prefire numbers, bristlebird numbers decreased in burnt areas after the fire and increased in unburnt areas. This pattern was evident for up to nine months after the fire, after which bristlebird numbers returned towards prefire levels in both burnt and unburnt vegetation. This is in contrast to some previous research on bristlebirds and fire. We suggest that bristlebirds avoided the fire by moving to unburnt areas and returned later when conditions were more suitable. We consider that the apparently slight impact of this fire on bristlebirds was due to the close proximity of unburnt habitat and other refuges. The response of bristlebirds and presumably other birds to fire is likely to be strongly context-dependent, so fire management may be able to be designed so as to be compatible with the conservation of local bristlebird populations. Keywords Post, fire, recovery, eastern, bristlebirds, Dasyornis, brachypterus, context, dependent Disciplines Life Sciences | Physical Sciences and Mathematics | Social and Behavioral Sciences Publication Details Bain, D., Baker, J. R., French, K. O. & Whelan, R. J. (2008). Post-fire recovery of eastern bristlebirds (Dasyornis brachypterus) is context-dependent. Wildlife Research, 35 (1), 44-49. This journal article is available at Research Online: https://ro.uow.edu.au/scipapers/3089 Post-fire recovery of eastern bristlebirds (Dasyornis brachypterus) is context- dependent Wildlife Research, 2008, 35: 44-49 D.W. BainA, J.R. BakerB, K.O. FrenchA and R.J. WhelanAC A Institute for Conservation Biology and Law, University of Wollongong, Wollongong, NSW 2522, Australia. B Biodiversity Conservation Science Section, NSW Department of Environment and Climate Change, PO Box 1967, Hurstville, NSW 2220, Australia. C Corresponding author. Email: [email protected] Key Words: fire, eastern bristlebird, recolonisation, habitat, Running Head: Eastern Bristlebird Response to Fire. 1 Abstract In late December 2003, a wildfire in the Jervis Bay region of NSW burned through an area that previously supported a large population of the endangered eastern bristlebird (Dasyornis brachypterus). The eastern bristlebird has been described as fire-sensitive, and fire is implicated in the decline of the species. The frequency of occurrence of bristlebirds was investigated in the second week after the fire in a range of sites varying in fire intensity. Bristlebirds were found in burned habitats but were less common in the sites that were more intensely burned. Bristlebirds had been surveyed along transects in this area two months prior to this fire and were surveyed again 1, 9 and 13 months post- fire. Compared with pre-fire numbers, bristlebird numbers decreased in burnt areas after the fire and increased in unburnt areas. This pattern was evident for up to nine months post-fire, after which bristlebird numbers returned towards pre-fire levels in both burnt and unburnt vegetation. This is in contrast to some previous research on bristlebirds and fire. We suggest that bristlebirds avoided the fire by moving to unburnt areas and returned later when conditions were more suitable. We consider that the apparently slight impact of this fire on bristlebirds was due to the close proximity of unburnt habitat and other refuges. The response of bristlebirds and presumably other birds to fire is likely to be strongly context-dependent, so fire management may be able to be designed so as to be compatible with the conservation of local bristlebird populations. 2 Post-fire recovery in Dasyornis brachypterus 1 Introduction 2 3 Fire has been present in Australia since the Tertiary Period (Kemp 1981) and much of the 4 flora of Australia has evolved characteristics that allow survival after this disturbance 5 (Gill 1981). Much of Australia’s fauna has also evolved with the influence of fire, 6 resulting in a range of responses from avoidance to exploitation (Keith et al. 2002; 7 Whelan et al. 2002). The variation in response to fire among Australia’s fauna can be 8 explained by a combination of life history, biology and fire regime (Whelan et al. 2002), 9 and escape behaviours are expected to become less effective as the size, frequency or 10 intensity of fire increases. 11 12 Many species, including some bird species, take advantage of post-fire conditions. Loyn 13 (1997) found that birds that feed in open ground, such as the flame robin (Petroica 14 phoenicea), scarlet robin (Petroica multicolor), buff-rumped thornbill (Acanthiza 15 reguloides) and superb fairy-wren (Malurus cyaneus), thrived for three years post-fire by 16 exploiting low shrub regrowth. Some insectivores and raptors respond immediately, to 17 take advantage of easy hunting of prey disturbed by fire (Woinarski and Recher 1997). 18 19 The change in population size after a single fire cannot be viewed as indicating a ‘typical’ 20 response, because response will depend on specific fire characteristics such as intensity 21 and extent, the time since the previous fire and on long-term fire histories (Bradstock et 22 al. 2005). For example, variation in response to fires was recorded in the splendid fairy- 23 wren; there was no direct mortality as a result of a fire after a six-year fire-free period 24 (Rowley and Brooker 1987), but two more fires in the ensuing three years each caused a 25 decline in numbers (Russell and Rowley 1993). 26 27 There are species that are fire-sensitive because they are unable to avoid the direct effects 28 or they depend on resources that are removed by fire, such as dense vegetation. For 29 example, the rufous bristlebird (Dasyornis broadbenti) was not recorded in the area of a 30 single large fire in eastern Victoria until two years post-fire (Reilly 1991). Western 31 bristlebirds (Dasyornis longirostris) took 2 - 6 years to recolonise moister areas after a 3 Post-fire recovery in Dasyornis brachypterus 1 fire, and up to 14 years to recolonise some drier areas (Smith 1987; Burbidge 2003). 2 Another fire-sensitive species, the noisy scrub-bird (Atrichornis clamosus) took 4 - 10 3 years to begin recolonising burnt areas (Danks 1997). 4 5 Both individual wildfires and altered fire regimes have been identified as threats facing 6 many species in Australian birds (Garnett and Crowley 2000). Of Australia’s 155 7 threatened bird species, 47% have wildfire and/or inappropriate fire regimes identified as 8 current threats to their long-term survival (Garnett and Crowley 2000). The eastern 9 bristlebird (Dasyornis brachypterus) is listed as threatened in all jurisdictions of its range: 10 nationally endangered under the Environment Protection and Biodiversity Conservation 11 Act 1999, endangered in New South Wales under the Threatened Species Conservation 12 Act 1995, endangered in Queensland under the Queensland Nature Conservation Act 13 1992 and threatened in Victoria under the Victorian Flora and Fauna Guarantee Act 14 1988. The main threats have been identified as habitat loss and fragmentation, introduced 15 predators, and inappropriate fire regimes (Garnett and Crowley 2000; DEC 2004). 16 17 The eastern bristlebird is a cryptic, ground-dwelling, insectivorous and semi-flightless 18 passerine. It is described as fire-sensitive, based primarily on the work of Baker (1997; 19 2000; 2003). From various studies, Baker (2003) concluded that fire was implicated in 20 the extinction of at least 12 populations of eastern bristlebirds in the last three decades. 21 Fire temporarily removes dense understorey vegetation, which is a critical component of 22 the preferred habitat of the eastern bristlebird. Being semi-flightless and cover-dependent, 23 the eastern bristlebird is not expected to be able to colonise new areas readily or to 24 recolonise areas after disturbances (Smith 1977; Baker 2000). Being semi-flightless may 25 also expose the species to higher mortality during fires. 26 27 Various studies of fire responses of eastern bristlebird populations have shown an array 28 of results. Eastern bristlelbirds were known from 11 sites in 1978 near Mallacoota in 29 Victoria but by 1994, as a result of fires, eastern bristlebirds were only found at 1 of those 30 11 sites (Clarke and Bramwell 1998).