Can wing morphology inform conservation priorities for Southeast Asian cave bats?

Abstract

Adaptations for foraging in the complex airspaces of forest interiors may make bat species in the Asian tropics particularly susceptible to forest loss. However, ecomorphological analysis of Vietnamese bat assemblages challenges the hypothesis that, due to their greater vagility, cave-roosting bats are less vulnerable to habitat fragmentation than foliage-roosting species. Of the 13 most highly adapted forest-interior species in our study, eight were cave-roosting members of the Rhinolophidae and Hipposideridae and had wing morphologies closely resembling five foliage-roosting members of the Murininae and Kerivoulinae-species typically thought to have low vagility. Overall, both cave-roosting and foliage-roosting bats exhibited a wide range of flight indices and species' wing designs corresponded with preferred foraging habitats, suggesting that foraging strategy may outweigh roost preference as a determinant of bat wing morphology and flight performance. Consequently, where such variation occurs, cave-roosting bat ensembles are likely to include species with low vagility and similar sensitivity to habitat fragmentation. This could have important conservation implications as Asian karst formations support high cave densities and important bat diversity yet increasingly represent forest refugia in anthropogenic landscapes. We, therefore, advocate greater consideration of species vagility in determining conservation priorities for the region's bat fauna.Abstract in Vietnamese is available with online material.

Assemblage and Species Threshold Responses to Environmental and Disturbance Gradients Shape Bat Diversity in Disturbed Cave Landscapes

“…However, these adaptations (e.g., low wing loading and high-frequency echolocation calls) greatly constrain foraging success in the more open habitats that occur when forests are cleared [22]. Consequently, forest-adapted species may be differentially susceptible to land-use change around caves [23]. Similarly, hunters typically target large-bodied species that roost colonially in large aggregations [24], conferring greater risk to species that share those traits and behaviors.…”

Echolocation and roosting ecology determine sensitivity of forest‐dependent bats to coffee agriculture

“…Given the decline of species richness and abundance of Kerivoulinae and Murininae in other agricultural types (Furey et al., ; Phommexay et al., ) and disturbed habitats (Struebig et al., ), a directional shift of phylogenetic diversity of bats in SE Asia as landscapes are modified is to be expected (Kingston, ). Despite the phylogenetic component to vulnerability in our samples, our finding of trait convergence—to small size and high frequencies—across families precludes reliance on phylogeny alone and highlights the importance of trait‐based analyses for studying responses of bats to disturbances, particularly if predictive frameworks are to be developed (Furey & Racey, ).…”

“…The high‐frequency calls used rapidly attenuate in air (Denzinger & Schnitzler, ) and disfavor targeting prey in more open microhabitats. Flight constraints might also preclude these species from hunting fast‐flying insects in open habitats because their wing morphologies are more suitable for slow and maneuverable flight in cluttered environments (Furey & Racey, ; Senawi, ).…”

<b>First record of Bourret’s Horseshoe Bat <I>Rhinolophus paradoxolophus</I> (Mammalia: Chiroptera: Rhinolophidae) from Myanmar with a review of the taxonomy, distribution and ecology of the species</b>

“…Based on its wing morphology, which is characterised by a short wingspan, low aspect ratio and wing loading and high tip shape values, it can be predicted that R. paradoxolophus primarily forages in forest interiors (Furey & Racey 2016). Data from Kim Hy Nature Reserve, Vietnam suggests it especially favours primary forest over disturbed forest or degraded forest and agricultural land .…”