Limestone karst ecology and anthropogenic activities associated with cave-dwelling bats of Southern Shan State, Myanmar

Limestone cave systems constitute an important ecological niche supporting numerous bat species in Southeast Asia, with Myanmar, having a particular high number of understudied caves. Investigating the natural and anthropogenic ecological drivers that influence higher densities and species diversity of bats co-roosting in these natural caverns is therefore vital for identifying regions of heightened conservation need. We examine characteristics of limestone caves and alternative sites of bat congregation / roosting associated with cave-dwelling bat abundance at 41 sites in Pinlaung Township, Southern Shan State, Myanmar. The characteristics evaluated included cave surface area and complexity, microclimate conditions, seasonality, and a modified biotic vulnerability (BV) index. Larger caves and caves with warmer temperatures were significantly more likely to support higher total numbers of bats. Further distance from the road was also associated with higher bat abundance; as the distance increased, human disturbance decreased, resulting in larger bat populations. The majority (63.2%) of caves were classified as moderately vulnerable (BV class B), 18.4% highly vulnerable (BV class A), and 18.4% vulnerable (BV class C), indicating that environmental protections are essential to ensuring the long-term sustainability of cave-dwelling bat habitat within limestone karsts. Most cave sites evaluated faced multiple threats to bat populations, including bat hunting, guano harvesting, and cave development, which are known threats to cave-dwelling bats in other parts of Southeast Asia. This study identifies Southern Shan State, Myanmar as a critical habitat for limestone karst cave-dwelling bat species habitat that is in urgent need of conservation.