Figure 1.

DNA sampling localities (coloured circles and triangles) and the approximate breeding distributions of the eight Phylloscopus species in the present study. The circles and triangles represent sampling sites. The dashed box in the bottom left of the map represents the study area. The breeding maps are based on BirdLife (https://www.birdlife.org/) and Birds of the World (https://birdsoftheworld.org). Up to four species are sympatric at several localities in China, exceptionally up to five species.