This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Naturgeschichte der Vgel Mitteleuropas vol plate Naumann colorcorrected. en Males of Greenish Warbler Phylloscopus trochiloides Sundevall syn Phylloscopus viridanus Blyth Green LeafWarbler Phylloscopus nitidus Blyth Arctic Warbler Phylloscopus borealis Blasius de Mnnchen von Grnlaubsnger Phylloscopus trochiloides Sundevall