Population size and microhabitat features of the crocodile newt Tylototriton pasmansi Bernardes et al., 2020 in northern Vietnam

Abstract

Pasman's Crocodile Newt (Tylototriton pasmansi) is endemic to tropical broadleaf forests in northern Vietnam. Information regarding its population size, distribution, and habitat characteristics remains extremely limited, and its IUCN Red List status is Data Deficient. This study was conducted in Xuan Son National Park and Phu Canh Nature Reserve, Phu Tho Province, to estimate population sizes and identify relevant habitat features of the species. We found newt habitats based on community interviews and then conducted capture-mark-recapture surveys. The results showed that the population size of these newts was quite small, with only an estimated 70 and 236 individuals at the examined sites in Xuan Son National Park and Phu Canh Nature Reserve, respectively. The microhabitat of T. pasmansi primarily comprises small, shallow ponds with minimal water flow and muddy bottoms at elevations of around 1000 m, characterized by a wide pH range. This is the first study estimating the population size of a newt species in Vietnam. As climate change intensifies, habitat monitoring and improvements, such as the establishment of breeding pools, along with education of local residents are needed to prevent local extinctions of this interesting species.