Spot-legged Tree Frog (Polypedates megacephalus)

Themes

Invasive species

PSBR model type

Pressure (P)

Corresponding targets

SDGs

15.8 By 2020, introduce measures to prevent the introduction and significantly reduce the impact of invasive alien species on land and water ecosystems and control or eradicate the priority species.

Aichi Biodiversity Targets

Target 9: By 2020, invasive alien species and pathways are identified and prioritized, priority species are controlled or eradicated, and measures are in place to manage pathways to prevent their introduction and establishment.

Biodiversity Action Plan

D41050 Prevention of invasive species:

1. Develop an emergency eradication plan for new invasive species and conduct regular drills with local governments.

2. Establish a long-term control plan for invasive species to minimize the economic loss and ecological impact caused by invasive species.

Key performance indicator of the action plan:

• Number of existing invasive species, affected areas, and eradication cases handled/executed in the invasive species control plan.

• The reduction rate of distribution range/number of existing invasive species. The reduction in the number of individuals of existing invasive species.

Background

The tadpoles of the spot-legged tree frog (Polypedates megacephalus) will prey on the tadpoles of the native frogs, and will also compete the habitats with the Brauer's tree frog (Polypedates braueri) and other native tree frogs, which causes the ecological imbalance of native tree frogs. Therefore it's necessary to control and monitor the distribution and number of spot-legged tree frog populations.

Definition and Calculation

Changes in the distribution and number of spot-legged tree frogs. The location and number of spot-legged tree frogs are mainly surveyed by volunteer teams, and then the data are compiled by the Lab of Amphibian Conservation at National Dong Hwa University and further analyzed using GIS layers to demonstrate the distribution change of spot-legged tree frog.

The data and temporal range

The locations and number of spot-legged tree frog (Polypedates megacephalus) (2010–2018)

The uncounted data is combined with the number of frogs and the number of observation is treated as "1". If the data is a range, such as 10-19, or <50, the lowest number (10 or 50) is used as the number of observations.

Updates

From November 13, 2017 to November 12, 2018, a total of 11,572 spot-legged tree frogs were recorded in Taiwan.

Trends

The results of the indicator clearly demonstrate that the distribution of the spot-legged tree frog and the number of observations have increased year by year from 2010–2018. Although the number of observations slightly decreased in 2014, it has increased again from 2015 to 2018, and it has spread to Hengchun, Hualien, etc. Prof. Y.-R. Yang at National Dong Hwa University said that the spot-legged tree frog has entered the fourth stage of invasion—the population is too large to eradicate and contain. It is necessary to consider how to carry out long-term management and evaluate the measures adopted to protect native species.

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. (2018) Gone through the four stages within seven years—controlling the invasive spot-legged tree frog is a task without turning back.