Amphibian survey of Ko Pha-gnan in Surat Thani Province, Thailand

Abstract

Insular amphibian species are often overlooked, rendering them vulnerable to habitat encroachment and other anthropogenic threats. The aim of this study was to compile a comprehensive list of amphibian species on Ko Pha-ngan in Surat Thani Province, Thailand. Data were collected via transect surveys and drift line fence traps in three different habitat types from February 2021 to September 2023. Our efforts detected 12 unique amphibian species in each of the three habitat types. The highest number of detections was observed in the Ko Pha-ngan-Than Sadet National Park protected areas. The common tree frog (Polypedates leucomystax) and the common Asian toad (Duttaphrynus melanostictus) were the two most abundantly found species on the island, whereas the Koh Tao caecilian (Ichthyophis kohtaoensis) and the newly described false Doria’s fanged frog (Limnonectes pseudodoriae) where the least commonly found species. In addition, Microhyla heymonsi and Fejervarya limnocharis tadpoles were observed developing in high-salinity water bodies. Many species have shown a high tolerance in human-dominated landscapes. This study sheds light on the need for additional monitoring to better understand the dynamics of endemic species in addition to the impact tourism-driven development and habitat destruction has on a species with an insularly finite habitat.