Ecological specialisation and conservation of Australia's Large-footed Myotis: a review of trawling bat behaviour

Increasing exploitation of natural systems by humans is the driving force behind global devastation of biodiversity. Extinction risk is however not apportioned evenly across all taxa and specialist species are inherently more vulnerable compared to generalists. World-wide, 16 species of microchiropterans exhibit adaptations for specialist trawling foraging behaviours. Approximately half of these species are relatively well represented in the literature. Amongst these, the Large-footed Myotis, Myotis macropus, exhibits typical trawling bat behaviour; spending the majority (~88%) of foraging time over water, feeding predominantly on aquatic prey items and selecting roosts close (<500m) to permanent water. These traits are broadly representative of all trawling bats and reflect convergence of the group on common, specialised behaviours. Such convergence places trawling bats at risk of very similar conservation threats, primarily disruptions to water-ways used for foraging, disturbance at cave roost sites and the possible reduction of suitable foraging habitat associated with aspects of human-enhanced climate change. These overarching conservation issues are highlighted by several studies of just a few species, but likely represent the same threats faced by all trawling bats, including those for which there is currently little published research available. Conservation of trawling bats world-wide will therefore benefit from actions that, in the least, address the common threats identified throughout this review.