Niche partitioning explains the difference between widespread and restricted distributions, and detection rarity of arboreal mammals from north Kimberley savannas

Context Conservation managers often have little information on distribution ranges and ecological characteristics of rare species, thereby hindering effective decision-making. This challenge is evident for arboreal mammals of northern Australia where species vary widely in abundance, are nocturnal and cryptic, and exhibit regionally divergent patterns of rarity and decline. Aims We compare (1) trapping niche, (2) denning and foraging niche and (3) vegetation habitat preferences to test for links between niche and rarity among arboreal species. Methods Survey data obtained using a variety of terrestrial and arboreal methods are used to define trapping niche, vegetation habitat preferences and abundance/distribution of arboreal mammal species in Western Australia’s northern Kimberley. Denning and foraging niche is defined based on available literature. Key results Based on combined niche observations, we suggest that arboreal denning species with a preference for open forest vegetation are the most prone to rarity, restricted distributions and decline in the Kimberley. Very restricted extent of suitable open forest vegetation in the Kimberley may locally exacerbate threats to forest specialists. Generalist, terrestrial denning species preferring savanna woodlands/shrublands and rugged rocky habitats were more abundant and less restricted in their distributions than forest specialists. Conclusions These results highlight the local importance of small areas of open forest for threatened arboreal mammals in the Kimberley. Implications We suggest that targeted adaptive management interventions to preserve and enhance open forest vegetation and arboreal habitat including den hollows, through application of low intensity prescribed burning for protection from damaging wildfires, would benefit specialist arboreal species.