Conservation of Romer's tree frogs: Assessment of population status across Lantau and impacts of emerging threats

Romer's tree frog (Liuixalus romeri) is a species of conservation concern in Hong Kong. Recently, two conservation issues have arisen, which we address in this study: population declines detected in two native populations (Chek Lap Kok and Sha Tsui Tau) and shortcomings in long-term population monitoring programme (incomplete coverage resulting in inability to detect declining populations).

For the first issue, we must identify the cause of declines. We will investigate two factors suspected to have contributed to population declines—the introduced greenhouse frog (Eleutherodactylus planirostris) and mosquito larvicides.

For the second issue, given the population monitoring programme only include one population (Ngong Ping) in Lantau, we will carry out population surveys across Lantau to provide fine-scale data on distribution and population status.

The data are crucial to evaluate and mitigate ecological impacts of future urban development in Lantau. Surveys will also be done in Chek Lap Kok to determine if the population has become extirpated. Lastly, we will test and develop guidelines to use automated audio recorders to improve cost-effectiveness and accuracy of population surveys. Overall, the outcomes of this project will contribute to the long-term survival of L. romeri and sustainable development of Lantau.