What factors influence rapid post-fire site re-occupancy? A case study of the endangered Eastern Bristlebird in eastern Australia

Abstract

We quantified the post-fire recovery of the endangered Eastern Bristlebird (Dasyornis brachypterus) at Booderee National Park, south-eastern Australia. Occurrence was recorded on 110 sites a year before, and for 3 years after a major unplanned fire in 2003. Although the Eastern Bristlebird is thought to be sensitive to wildfire, data indicated that the species either persisted continuously on burned sites or returned to previously occupied sites within 2 years. Post-fire site occupancy was associated with several factors: (1) pre-fire site occupancy; (2) vegetation type; (3) spatial heterogeneity in fire and the amount of unburned vegetation surrounding a site; and (4) site-level vegetation structure (e.g. diversity of understorey and midstorey plants). The most likely mechanism underpinning rapid re-occupancy was movement by resident birds to unburned parts elsewhere within their territories. The addition of intensive feral predator baiting within the present study suggests that predation may have a more important effect on populations after unplanned fires than formerly recognised. Our results have significant implications for fire management in areas where the Eastern Bristlebird occurs. Care should be taken with back-burning during unplanned fires and the spatial and temporal arrangement of prescribed fires to ensure unburned vegetation remains as refugia to facilitate bird persistence.

Limited Population Structure, Genetic Drift and Bottlenecks Characterise an Endangered Bird Species in a Dynamic, Fire-Prone Ecosystem

“…In-situ survivorship in unburnt refuges has been attributed to the rapid demographic recovery in birds (e.g. the fire-sensitive Eastern Bristlebird Dasyornis bachypterus [92]) and the persistence of species diversity and genetic diversity in invertebrates following large fires [5], [26], [93].…”

Characterizing Spatial Neighborhoods of Refugia Following Large Fires in Northern New Mexico USA

“…Stressors including drought [83] and fire [73] limit the distribution of vulnerable species to refugial environments [80,84]. Identifying the regional context of refugia within burn mosaics is important to gaining a broader view of places protected from changing climate and disturbance regimes [76,85].…”

Population genetic structure of the endangered Eastern Bristlebird, Dasyornis brachypterus; implications for conservation

“…Habitat refugia seem likely to have ensured both the persistence and continuing reproduction (Bain et al 2008;Lindenmayer et al 2009), and hence recovery of population size thereby limiting the erosion of genetic diversity. Indeed, standing genetic variation within these populations is within the range reported for or greater than, a number of similarly threatened, sedentary or habitat specialist birds, with comparable life histories (Hudson et al 2000;Brown et al 2004;Boessenkool et al 2007).…”