《TAIPEI TIMES》 New bat and bird species found on Green Island

A bat is pictured on Green Island in an undated photograph. Photo courtesy of the Ministry of Agriculture’s Taiwan Biodiversity Research Institute

By Esme Yeh / Staff reporter A five-year study conducted by the Ministry of Agriculture’s Taiwan Biodiversity Research Institute has documented 17 new bird species and five new bat species on Taitung County’s Green Island.

The institute conducted the research from 2020 to last year to survey the ecological resources of the island.

The survey found that Green Island has at least 18 wild mammal species and 194 bird species, including 17 new bird species and five new bat species.

The 17 bird species include raptors such as the black eagle and upland buzzard. The five bat species include the yellow-necked sprite, oriental serotine, mountain noctule, oriental free-tailed bat and the Asian bent-winged bat.

Migratory birds are the most often documented bird species on the island, accounting for about 83 percent, the data showed.

Institute Deputy Director Cheng Hsi-chi （鄭錫奇） on Friday said that all five newly documented bat species were identified via ultrasonic detection techniques.

None of the species were captured, seen or photographed, as bats usually fly too fast at night, he said.

Taiwan is home to at least 37 bat species, Cheng said, adding that the institute has been recording their ultrasonic calls to build acoustic signatures for species identification.

The survey showed that fewer than 10 Formosan flying foxes remain on the island.

Cheng said local residents interviewed by researchers said that they knew of a hunter who had captured more than 100 Formosan flying foxes on the island in the last century.

Flying foxes became rare mainly due to habitat destruction and trapping by humans, he said.

There are more than 180 species of flying foxes, mostly found in Asia and Africa. About 1 million people worldwide consume them as food, Cheng said.

Invasive species, such as common mynas, red-bellied squirrels and Asian house shrews, threaten the island through proliferation, he said.

For example, the common myna has become the most dominant bird species on the island and is marginalizing the indigenous species of crested myna, Cheng said.

Island ecosystems are more fragile and less stable than continental ones because of their limited land area, Cheng said.

Species occupying the same ecological niche must compete for scarce resources on islands, he said.

As a result, each ecological niche is often occupied by only one species, making it vulnerable to displacement by invasive species. Cheng urged the public not to bring animals to Green Island.

新聞來源：TAIPEI TIMES

A tundra bean goose is pictured on Green Island in an undated photograph. Photo courtesy of the Ministry of Agriculture’s Taiwan Biodiversity Research Institute