Date of Award


Degree Type


Degree Name

Master of Philosophy (MPHIL)


Environmental Science

First Advisor

Prof. SUNG Yik Hei


Globally, 28% of the reptiles are fossorial. Fossorial reptiles, which perform important ecological functions, such as being ecosystem engineers, top predators and bioindicators, are indispensable members of the soil ecosystem. However, the ecology of fossorial reptiles is relatively little known because of their cryptic behavior and rarity. In Hong Kong, there are four species of fossorial reptile, three of which are rare and of potential conservation concern. Among the four fossorial reptile species that occur in Hong Kong, Indotyphlops lazelli and Dibamus bogadeki, are endemic to Hong Kong and are globally threatened species. On the other hand, the distribution of Indotyphlops albiceps is disjunct with no record between Myanmar and Hong Kong, necessitating a study to clarify the taxonomy status of different populations. Besides anecdotal sighting records, no systematic ecological studies have been conducted on fossorial reptiles—basic information, including distribution, population status and basic ecology, is largely lacking.

In view of the conservation concern of fossorial reptiles, existence of knowledge gap and potential threats, a study on the distribution and population status of local fossorial reptiles is essential. In this study, firstly, systematic field surveys using three sampling techniques (quadrat search, artificial refuges and opportunistic search) were conducted in four sites (Pok Fu Lam, Lung Fu Shan, Lady Clementi’s Ride and Sunshine Island) to evaluate the effectiveness of sampling methods for detecting fossorial reptiles. Only Indotyphlops braminus and I. albiceps were detected in the field surveys. I found that artificial refuge is suitable for longer-term study with sufficient manpower, while active search is cost-effective method for detection of fossorial reptiles and suitable for both long-term and short-term studies. The encounter correlates significantly with a set of environmental factors, including ambient humidity, gradient and canopy cover. Secondly, phylogenetic analysis was carried out to clarify the taxonomic status and phylogenetic relationship among the three target blind snake species. My results consolidated that I. lazelli is a genetically valid species, and suggested that I. albiceps is a potential new species.

This study provides insights into optimising surveys on fossorial reptiles in ecological impact assessment and ecological studies, advices to inform conservation actions for the threatened species (including D. bogadeki and I. lazelli), and suggestions on further studies to fill the vast knowledge gaps of the ecology of fossorial reptiles.



Recommended Citation

Chan, M. H. (2023). Uncover the underground: Distribution and population status of blind snakes and Bogadek’s burrowing lizards (Master's thesis, Lingnan University, Hong Kong). Retrieved from