Fire‐mediated habitat change regulates woodland bird species and functional group occurrence

Abstract

In an era characterized by recurrent large wildfires in many parts of the globe, there is a critical need to understand how animal species respond to fires, the rates at which populations can recover, and the functional changes fires may cause. Using quantified changes in habitat parameters over a~400-yr post-fire chronosequence in an obligate-seeding Australian eucalypt woodland, we build and test predictions of how birds, as individual species and aggregated into functional groups according to their use of specific habitat resources, respond to time since fire. Individual bird species exhibited four generalized response types to time since fire: incline, decline, delayed, and bell. All significant relationships between bird functional group richness or abundance and time since fire were consistent with predictions based on known time-since-fire-associated changes in habitat features putatively important for these bird groups. Consequently, we argue that the bird community is responding to post-fire successional changes in habitat as per the habitat accommodation model, rather than to time since fire per se, and that our functional framework will be of value in predicting bird responses to future disturbances in this and other obligate-seeder forest and woodland ecosystems. Most bird species and functional groups that were affected by time since fire were associated with long-unburned woodlands. In the context of recent large, stand-replacement wildfires that have affected a substantial proportion of obligate-seeder eucalypt woodlands, and the multi-century timescales over which post-fire succession occurs, it would appear preferable from a bird conservation perspective if fires initiating loss of currently long-unburned woodlands were minimized. Once long-unburned woodlands are transformed by fire into recently burned woodlands, there is limited scope for alternative management interventions to accelerate the rate of habitat development after fire, or supplement the resources formerly provided to birds by long-unburned woodlands, with the limited exception of augmenting hollow availability for key hollow-nesting species.

Fire and functional traits: Using functional groups of birds and plants to guide management in a fire‐prone, heathy woodland ecosystem

“…Neither the richness nor abundance of hollow-nesting birds was related to time since fire in this study. This result contrasts with a study in a semi-arid Eucalyptus woodland dominated by obligate-seeding trees (Gosper et al, 2019) that showed a strong influence of time since fire on the abundance of hollow-nesting birds.…”

A seven‐year study of the response of woodland birds to a large‐scale wildfire and the role of proximity to unburnt habitat

“…Guild-level responses to fire disturbance have been reported in other studies in Australia (Turner 1992;Loyn 1997;Davis et al 2016;Gosper et al 2019b) and elsewhere (Barlow & Peres 2004). The apparent negative fire response shown by the insectivore and frugivore/granivore guilds in the present study probably reflects loss and successional recovery of foraging habitat and is similar to the findings of Davis et al Overall difference probability value (chi-squared goodness of fit -7 years pooled) and temporal difference probability value (chi-squared contingencyyears 1, 4 and 7): *P < 0.05, **P < 0.01, ***P < 0.001.…”

Faunal responses to fire in Australian tropical savannas: Insights from field experiments and their lessons for conservation management

“…First, the primary effects of fire are indirect through habitat change, which is caused by both individual fires and by different fire regimes. This has been shown for many biomes for a wide range of animal taxa, including ants (Andersen, 2019), reptiles (Costa et al, 2020;Dixon et al, 2018), birds (Gosper et al, 2019;Woinarski & Recher, 1997) and small mammals (Griffiths & Brook, 2014). In particular, fire has a pervasive effect on fauna through its impact on habitat openness (Andersen, 2019).…”

“…However, severe fire causes major habitat transformation, initiating a long-term series of habitat changes that successively favour different animal species (Fox, 1990;Gosper et al, 2019;Lindenmayer et al, 2016Lindenmayer et al, , 2019. A feature of such forests is the occurrence of old-growth specialists that are often under conservation threat because of habitat fragmentation and inappropriate burning or logging (Chalmandrieret al, 2013;Dixon et al, 2018Dixon et al, , 2019Lindenmayer et al, 2017;Taylor et al, 2012).…”