Document ID: chunk:federal_register_of_legislation:F2024L00006:reg:3:p23
Version: federal_register_of_legislation:F2024L00006
Segment Type: reg
Provision Reference: reg 3 (pt 23/58)
Character Range: 65643–68856

Medium      High        Medium            Medium
Clearing of habitat               Low      Very High   High              Low
Disease (captive populations)     Low      High        Medium            Low
Pigs *                            Low      Medium      Medium            Low
Overabundant herbivores           Low      Low         Medium            Low
Human disturbance                 Low      Low         Low               Low

 * Threat rating varies among populations (see Appendix 2 for detail)

3.2.3            Inappropriate fire regimes

       3.2.3.1             Wildfire

 A fire regime includes scale, intensity, frequency, seasonality, and patchiness, whether arising from wildfire (this section) or management (section 3.2.3.2). Inappropriate fire regimes (too frequent or infrequent) arising from wildfire or management, and interactions between the two, are a threat to all Eastern Bristlebird populations.

 The Eastern Bristlebird is a cover-dependent and fire-sensitive species (Baker 2000). Ground dwelling and weak fliers, Eastern Bristlebirds are vulnerable to fire. In particular larger and more intense fires which travel quickly may be difficult for birds to escape. Inappropriate fire regimes arising from wildfire may threaten Eastern Bristlebird population viability through direct and indirect impacts and synergisms with other threats, which could ultimately result in localised extinctions (as is thought to have occurred historically, Baker 2003 in Bain et al. 2008).

 Fires that are too infrequent are a major threat to the northern population. Infrequent fires lead to recruitment and/or growth of shrubs and trees resulting in higher canopy cover that has a negative influence on grass cover, reducing habitat quality and ultimately converting suitable habitat to unsuitable habitat. Too frequent or extensive fires are a threat to the central and southern populations, where Eastern Bristlebird density generally increases with time since fire (OEH 2012, DPIE 2018).

 Although Eastern Bristlebirds may be able to avoid fire by moving to unburnt areas and returning when conditions are suitable, the immediate threat of fire may be exacerbated if there is a lack of connecting habitat to enable birds to seek refugia. Therefore, buffer zones, connecting habitat, and unburnt refugia are important for species persistence during and after fire (Bain et al. 2008, Hartley & Kikkawa 1994; Lindenmayer et al. 2009). Rainforest gullies adjacent to grassland are likely to be important for local persistence within the northern population during and after fire.

           The 2019–2020 bushfire season, known as 'Black Summer', was catastrophic. It started in the winter of 2019, which was both Australia's warmest and driest year on record (BOM 2020). These bushfires were unprecedented in the area of land they covered, much of it at high severity (Collins et al 2021), and they are estimated to have burned over 103,000 km² of habitat for native species (Legge at al. 2021; 2022). Bain et al. (2021) estimated 9% of the central and southern Eastern Bristlebird populations are thought to have been killed by the 2019–2020 wildfires; while a separate analysis by Legge et