Verdon, S. | bioRxiv Science

bioRxiv2026

Rainfall immediately before and after fire promotes long-term occurrence of a rare, fire-sensitive passerine.

Attributes of fire regimes are known to drive habitat suitability for many species in fire-prone environments. Comparatively little is known about how abiotic conditions (e.g. rainfall events, cumulative rainfall, drought) at the time of fire may affect long-term (>2-years) post-fire occurrence. We sought to a) establish whether the post-fire development of heathland habitat for the endangered mallee emu-wren is influenced by rainfall within 12-months before or after the most-recent fire, b) identify the preferred fire-age of heathland vegetation for the mallee emu-wren, and c) map those habitats most likely to support the species across a large reserve ([~]271,000 ha), Ngarkat Conservation Park, from which it has been extirpated. Using historical presence records, collected prior to the extirpation of mallee emu-wrens from the study area, we implemented a random-forest modelling approach to predict relative likelihood of occurrence (considered a proxy for probability of suitable habitat). Rainfall in the 12-months before and after fire had a positive effect on relative likelihood of mallee emu-wren occurrence. The development of high-quality mallee emu-wren habitat required at least 420 mm of rainfall in the 12-months prior to the most recent fire. Only 35% of Ngarkat received rainfall above this threshold prior to the most recent fire. Rainfall in the 12-months after fire positively influenced relative likelihood of mallee emu-wren occurrence, though the effect was less pronounced than pre-fire rainfall. Relative likelihood of mallee emu-wren occurrence peaked 15 years after fire, with an [~]10-year peak time window of relative occurrence (10-20-years). This study highlights that abiotic conditions at the time of fire, particularly rainfall in the 12-months preceding fire, have long-lasting impacts on relative probability of occurrence for this fire-sensitive species. Targeting fire management in ways that maximise post-fire occurrence of the mallee emu-wren - particularly by burning senesced habitat following periods of elevated rainfall - has potential to enhance conservation outcomes. Given the substantial and long-term impact of rainfall around the time of a fire identified in this study, short-term climatic conditions deserve greater attention in a range of ecosystems where managers aim to use fire to manipulate habitat for the benefit of fire-sensitive species.

ecology↗

bioRxiv2025

A typology of Australian terrestrial bird communities

AimIncreasing interest in holistic measurement of the response of fauna communities to interventions requires suitable community condition metrics. However, the development of such metrics is hindered by the absence of broad-scale typologies at suitable spatial and ecological resolutions. We aimed to derive a preliminary typology of terrestrial bird communities for Australia, based on bird co-occurrence data, and describe and map the likely distribution of each community type across the continent. LocationMainland Australia, continental islands Time period1973-2022 Major taxa studiedAves MethodsWe used fine-scale co-occurrence data from standard 2-ha surveys in BirdLife Australias citizen-science database. After filtering to reduce bias, we used hierarchical clustering followed by iterative consultation with experts to identify reliably distinct and recognisable terrestrial bird communities across Australia. We used Maxent to model the likely distributions of each community, and developed community descriptions based on each communitys composition and distribution. ResultsThe resultant typology included 29 reliably distinct and recognisable bird communities with major clusters corresponding with seven broad geographical regions. The distributions of bird communities did not correspond tightly to the boundaries of major vegetation groups, with most communities occurring across multiple vegetation types. Main ConclusionsOur preliminary typology of bird communities provides a standard classification at a continental scale. It newly defines distinct bird communities as entities for which condition benchmarks can be established to allow assessment of their conservation status and monitoring of change over time. Refinement will enable cryptic communities in areas with sparse data to be identified. The method could be translated to other regions where adequate coverage of data in the form of standardised surveys of fauna are available. Vast biodiversity datasets delivered through citizen science programs provide the opportunity to develop such typologies for fauna communities, as a precursor to developing targeted and informative community condition metrics.

ecology↗