Mapping the interior of the Dark Cave at Batu Caves, Selangor, Malaysia, using LIDAR laser scanning for its geological structures and the bat roosts

Abstract

Batu Caves is an isolated limestone massif located in the outskirts of north Kuala Lumpur․ Dark Cave supports significant species endemism with its diverse habitats․ Nine reported caverns have been mapped using conventional speleological methods․ The selection of Dark Cave as a Conservation Site was able to limit the number of visitors‚ preventing intrusive surveys and making non-intrusive methods such as Light Detection and Ranging (LIDAR) scanning useful․ In this study‚ the interior of the cave was mapped using LIDAR to produce a 3D model of the caverns․ The results showed that the LIDAR model produced a more accurate representation of Dark Cave than the conventional 2D map․ Features such as cavern’s dimension‚ bat roosting locations‚ and man-made structures revealed in this 3D model are novel from previous conventional maps․ Integration of LIDAR-acoustic-visualisation survey methods further confirms four bat species (Taphozous melanopogon‚ Hipposideros diadema‚ Eonycteris spelaea‚ Rousettus leschenaultii) roosting in the Dark Cave․ T. melanopogon roosts at the brightest part of Dark Cave‚ while colonies of H. diadema were only found in the pitch-dark areas of Dark Cave․ These outcomes produced a more accurate map as reference to scientists and management authority can use it in important conservation decision-making in the future․