Taipei Zoo has launched a campaign to hunt down spotted-legged tree frogs in the zoo environs to prevent the alien species from threatening the survival of the endemic white-lipped tree frog, a relative of the invasive species.
In a statement released on Monday, the zoo said a “spot-removing” task force has been formed in cooperation with Yang Yi-ju (楊懿如), a frog expert and associate professor at National Dong Hwa University’s Graduate Institute of Marine Biodiversity and Evolutionary Biology.
The team is tasked with removing several hundred spotted-legged tree frogs and their eggs from inside the zoo before the end of the year, zoo officials said.
According to the zoo, spotted-legged tree frogs were discovered in Taiwan in 2006, when a Taichung resident found clumps of spawn on water plants he had purchased. He originally thought the spawn was from the white-lipped tree frog, but when the tadpoles hatched, discovered the frogs to be of a different species.
Spotted-legged frogs spread fast, but they were not identified as an invasive species until 2010.
Spotted-legged tree frogs and Taiwan’s endemic white-lipped tree frogs are similar in terms of size, color and camouflage. One thing that differentiates them from one another is their croaks: The white-lipped tree frog’s croak sounds like “ta ta ta,” while that of the alien species sounds more like “ga ga ga,” zoo officials said.
The white-and-black patterns of spots on the legs of the two species are also different.
The zoo said the population of spotted-legged tree frogs in the zoo has increased since they were first discovered in 2010.
The frog, which is commonly found in Southeast Asia, has excellent camouflage skills and is an efficient breeder. It lays about 600 eggs at a time — almost double the number produced by its Taiwanese relative, officials said.
They warned that the invader could drive the endemic species to extinction if it is left to build further colonies in Taiwan.