Common Frogs

Themes

Population of selected taxa

PSBR model type

State (S)

Corresponding targets

Aichi Biodiversity Targets

Target 19: By 2020, knowledge, the science base and technologies relating to biodiversity, its values, functioning, status and trends, and the consequences of its loss, are improved, widely shared and transferred, and applied.

Biodiversity Action Plan

D12030 Strengthen the research on population changes of indicator animals, plants, and micro organisms. Action plan key performance indicator:

• Research projects on the change of indicator species

Background

Recently, the massive reduction of regional frog populations has become an important global topic. Influenced by climate change, environmental destruction, human disturbance, and invasion of alien species, the number of frogs has decreased rapidly, and over 30% of frog species are endangered or extinct. Through the participation of citizen scientists, this indicator monitors the populations of common frogs in Taiwan with the same standardized survey methods. The temporal and spatial changes of common frog populations will help to understand the influence of climate chagne and environmental disturbance on frog populations and provide important information for management and decision-making.

Definition and Calculation

Calculate the number of native, endemic, and alien species in common frogs of Taiwan based on the data of amphibians resources survey, and calculate the individual percentage of total number of these three categories each year to understand the composition trends.

Updates

A total of 109,214 frogs were recorded in Taiwan from November 13th, 2017 to November 12th, 2018. Among them, LaTouchte's frog (Hylarana latouchii) has the largest population, with a total of 12,295. The second largest population is alien Spot-legged tree frog (Polypedates megacephalus), with a total number of 11,572. Alien species account for 10.76%, native species 54.22%, and endemic species 35.03%.

Trends

The biodiversity indicator trend diagram shows that the population of alien Spot-legged tree frog (Polypedates megacephalus) has expanded. The proportion of alien species has increased and the proportion of native species has decreased year by year. The research by Prof. Y.-R. Yang (2015) at National Dong Hua University reveals that the Spot-legged tree frog might compete with the native Brauer's tree frog (Polypedates braueri) and affect its population.

Data Management Authorities

Lab of Amphibian Conservation, Department of Natural Resources and Environmental Studies, National Dong Hwa University

Data sources/URL

• Lab of Amphibian Conservation, Department of Natural Resources and Environmental Studies, National Dong Hwa University—Amphibians resource survey network

• Yang, Y.-R. (2015) Monitoring and controlling alien treefrog—Polypedates megacephalus project. pdf