Researchers have identified a new bird species, the Tokara leaf warbler (Phylloscopus tokaraensis), in Japan. The discovery stems from studies showing that populations previously classified as the Izu leaf warbler (Phylloscopus ijimae) on the Tokara Islands differ significantly in genetics and song from those on the Izu Islands. The Izu leaf warbler is a rare migratory bird found only in these two island groups south of Tokyo.
Analysis of whole genomes confirmed the distinctiveness of the Tokara population, leading to its recognition as a separate species.