Bat diversity (Mammalia, Chiroptera) in and around Gomantong and Madai caves, Sabah: insights from field surveys and published records from other Malaysian Bornean caves.

Gomantong and Madai caves are two of the largest limestone formations with intricate cave systems located in the Lower Kinabatangan and Kunak areas, respectively, in Sabah, Malaysia, Borneo. Despite their ecological and economic significance, limited published information exists on the bat species inhabiting these caves. This study aims to analyze bat diversity at both caves and compare their species richness and diversity to other cave inventories in Sabah and Sarawak. Two bat surveys were conducted around Gomantong caves with a combined trapping effort of 56 trap nights deployed in the surrounding forest. A bat survey at Madai cave utilized 16 trap nights deployed within the caves. A total of 974 and 264 bats were captured from Gomantong and Madai caves, representing 14 and 8 bat species, respectively. A compilation of bat species records from previous studies shows that Gomantong and Madai caves host at least 26 and 30 bat species, respectively. Comparisons with other caves across Malaysian Borneo reveal that Mulu cave and Wind cave in Sarawak, each with 29 species, rank just below Madai cave in bat diversity. Gomantong and Madai caves serve as critical roosting habitats for diverse bat species, including Borneo-endemic and rare species (e.g., , ), highlighting their ecological importance and the urgent need for conservation and sustainable management to mitigate anthropogenic threats. This survey provides an updated checklist of bats in the Gomantong caves and the Madai cave from Sabah, Malaysia. This study also compiles the bat species diversity of other selected caves across Malaysian Borneo.