Invasive toads are close to but absent from Komodo National Park

Abstract

The islands of Komodo National Park in the Wallacea region are the habitats of Komodo dragon (Varanus komodoensis). Although the Wallacea islands have lower species richness compared to the other large islands in Indonesia, they are rich in endemics, and the occurrence of invasive species would therefore threatened the ecological, economic and social balance of the regions. Several papers have hinted at the possibility of the invasion of Komodo National Parks by Asian toads, a situation which would potentially affect the survival of the Komodo dragon. To detect the presence of the invansive toad Duttaphrynus melanostictus in Komodo National Park and its surroundings areas we carried out an amphibian survey using a Visual Encounter Survey method during February to April 2018. The surveyed location consisted of two main islands within Komodo National Park (Rinca island and Komodo island), Flores island (Labuan Bajo and Cumbi village) and Sumbawa island (Sape). Two species of amphibians were found in Komodo National Park (Rinca island and Komodo island), while seven species of amphibians were found across all four locations. No D. melanostictus toads were found in Flores (including in Komodo National Park), however the toad was found to be abundant in Sape (Sumbawa island).