A bird long thought to be a single rare species in Japan has turned out to be two. Scientists discovered that the elusive Ijima’s Leaf Warbler and a newly identified Tokara Leaf Warbler look almost identical, but their DNA and songs reveal they are distinct species. The finding marks Japan’s first new bird species discovery in more than 40 years and highlights how modern genetic tools are uncovering hidden biodiversity that would otherwise go unnoticed.