New Bird Species Found in Japan for 1st Time in 45 Years

Tokyo, March 18 (Jiji Press)–An international research team including Japan’s Yamashina Institute for Ornithology said Wednesday that it has discovered a new bird species in the Tokara Islands of Kagoshima Prefecture, southwestern Japan. The new bird, named the Tokara Leaf Warbler, or Phylloscopus tokaraensis, is the first bird species to be given a scientific name in Japan since 1981, when the Okinawa rail was named Gallirallus okinawae. The team, which also included researchers from Japan’s Forestry and Forest Products Research Institute and the University of Gothenburg in Sweden, found that the Tokara Leaf Warbler is genetically and morphologically distinct from the Iijima’s Leaf Warbler, which has long been considered the same species. The Iijima’s Leaf Warbler, or Phylloscopus ijimae, a migratory bird of the Passeriformes order, is about 12 centimeters long and has been known to breed in Tokyo’s Izu Islands. Breeding by a similar bird was confirmed in the Tokara Islands in 1988, but that bird was classified as the same species as the Iijima’s Leaf Warbler in a paper published the following year. Researcher Takema Saito of the Yamashina Institute for Ornithology began studying the birds out of skepticism that the two populations of birds had been considered the same species despite the island groups being located about 1,000 kilometers apart. The research team conducted a detailed analysis of genetic information, morphological differences and variations in calls. The research revealed that the Iijima’s Leaf Warbler and the Tokara Leaf Warbler populations diverged from a common ancestor approximately 2.8 million to 3.2 million years ago, with no genetic exchanges since. The study also found that the Tokara population has slightly shorter legs and heads, and that the male singing patterns differ between the two groups. The findings led to the conclusion that the Tokara Leaf Warbler is a new species. “I’m glad we had the rare opportunity (to discover a new species),” Saito said. “I hope we will be able to find similar cases of ‘hidden diversity’ in the future.” The findings were published Tuesday in the U.S. scientific journal PNAS Nexus. END [Copyright The Jiji Press, Ltd.]