Document ID: chunk:federal_register_of_legislation:F2024L00006:reg:3:p29
Version: federal_register_of_legislation:F2024L00006
Segment Type: reg
Provision Reference: reg 3 (pt 29/58)
Character Range: 83177–86331

Charley pers. comm. cited in Stone et al. 2018). Although Lindenmayer et al. (2017) found a negative relationship between Eastern Bristlebird occurrence and the number of Bitou Bush plants in the Bherwerre Peninsula within Booderee National Park, the species was found to respond positively to increased native vegetation cover following Bitou Bush removal. Despite this relationship, Bitou Bush is generally not a threat to Eastern Bristlebird (D Bain pers. comm. 2021).

 Dieback and invasive weeds interact with other threats to the Eastern Bristlebird.
 For example, Phytophthora cinnamomi may be spread by animal vectors, such as feral predators, or human activity (including fire management and response activities) (OEH 2012). The dominance of Lantana in the mid-storey and overgrowing of native canopy species, combined with (and as a result of) inappropriate fire management regimes (i.e., too infrequent) threatens northern Eastern Bristlebird habitat (DAWE 2021).

 P. cinnamomi is listed as a Key Threatening Process under the EBPC Act, and a threat abatement plan has been prepared (DEE 2018). More information is available elsewhere (DE 2014; DEE 2013).

 Weed infestation impacting the northern population © Copyright, Kelly Roche for NSW Department of
 Planning and Environment

                 3.2.7            Drought

           While droughts are a natural phenomenon in Australia, climate change modelling suggests droughts are likely to be longer and more intense (BOM & CSIRO 2020). Drought episodes may have contributed to Eastern Bristlebird population declines due to resultant loss, modification and/or degradation of habitat (Clarke & Bramwell 1998; Stewart et al. 2004) and reduced food availability (e.g., reduction in invertebrates suitable for feeding nestlings; Hartley & Kikkawa 1994).

           Northern Eastern Bristlebirds have been observed moving into gullies during long hot summers (Stone et al. 2019), highlighting the need for alternative habitat and refugia during temperature extremes. Northern bristlebirds are closely associated with the rainforest margin; all territories are found within 400 m of a dense rainforest edge.
           These margins provide increased humidity for tall, thick tussock grasses and have better quality invertebrate resources for foraging (Stone et al. 2018). An increase in the frequency and duration of drought could have a negative impact on the condition of this ecotone, which will affect the reproductive potential of bristlebirds. Any suppression of reproductive capacity or compromised survivorship in the already small northern population could lead to rapid extinction.

           The Action Plan for Australian Birds 2020 (Charley et al. 2021; Bain et al. 2021) considered an increased frequency or length of droughts in an assessment of threats to the Eastern Bristlebird. Drought impacts may interact with other threats, including climate change, fire, and invasive weeds. For example, the 2019–2020 wildfires were exacerbated by drought (Ward et al. 2020).

           Drought conditions may also impede the implementation of on-ground management actions. For