Leaving No Stone Unturned: Delineating the Distribution Range of the White Striped Viper-Gecko (Hemidactylus albofasciatus).

Abstract

Delineating the distribution ranges of a species and understanding factors affecting them is not only a central theme in biogeography but is also important for their conservation. The International Union for the conservation of Nature (IUCN) Red list assess the extinction risk of the species using species range size as one of the criterion. The White-striped viper gecko (Hemidactylus albofasciatus) was categorized as Vulnerable under this criterion. However the assessment was inaccurate and based on literature surveys. Moreover, the distribution range of the species is also unknown. To bridge this gap, we used occurrence data collected from opportunistic surveys and citizen science data to build ecological niche models (ENM) for the gecko. The suitable habitat were later sampled to delineate the accurate range of the species. We found, two rivers acting as geographical barriers, marking the northern and southern extent of the species distribution, although there was suitable habitats, for a several kilometre on either side of the barriers. We calculated the area of occupancy and extent of occurrence as 480 km2 and 1,609 km2, respectively, suggesting that the IUCN status of the species should be further elevated to Endangered.