Wildfire in rainforest margins is associated with variation in mammal diversity and habitat use

Context Rainforests typically evolved without the influence of fire or with only low-intensity fires, making them vulnerable to contemporary increases in fire frequency and intensity. Rainforest-associated species are predicted to be less adaptable than generalist species, but little is known about how fire in rainforest margins affects their habitat use and behaviour.Aims We investigated how mammal community composition, diversity, probability of habitat use and probability of movement were affected by wildfires that occurred in rainforest margins in South East Queensland, Australia, in 2019-20.Methods We deployed camera traps at 23 sites spanning the following three fire-habitat categories: unburnt rainforest (UR), burnt rainforest (BR) and surrounding burnt sclerophyll forest (BS), and used passive detection to analyse habitat use and behaviour.Key results Fire-habitat category had little influence on community composition. Species diversity was highest in unburnt rainforest compared with burnt rainforest and surrounding burnt sclerophyll forest. The probability of habitat use was highest in unburnt rainforest for both the long-nosed bandicoot (Perameles nasuta, estimated mean probability (95% CI): UR = 57.1% (22.98, 85.6), BR = 0%, BS = 0%) and the fawn-footed melomys (Melomys cervinipes: UR = 100%, BR = 87.5% (46.3, 98.3), BS = 50% (20.0, 80.0)). Probability of movement for the bush rat (Rattus fuscipes) increased with increasing elevation in burnt sclerophyll and was unaffected by elevation in unburnt and burnt rainforest.Conclusions Rainforest margins that experienced wildfire had reduced species diversity, most likely owing to a reduction in habitat use by rainforest-associated species. Movement patterns of mammal species were complex and not consistently related to recent fire history.Implications Rainforest margins and associated species are likely to be negatively affected by increasing wildfire intensity and frequency. In addition to urgent climate-change mitigation, land management that prevents wildfire incursion is likely to benefit rainforest communities in future.