Robin Chittenden / Birdwatchers and twitchers observing Arctic warbler (Phylloscopus borealis) Wells, Norfolk, England, UK. September 2017.

Jussi Murtosaari / Arctic warbler (Phylloscopus borealis), adult male, Finland, July.

Claudio Contreras / Fumarole, Evermann Volcano, Socorro Island, Revillagigedo Archipelago Biosphere Reserve / Archipielago de Revillagigedo UNESCO Natural World Heritage Site (Socorro Islands), Pacific Ocean, Western Mex...

Roger Powell / Arctic warbler (Phylloscopus borealis) singing over territory while perched on a willow stem in bud. Varanger Fjord, Finmark, Norway

Roger Powell / Arctic warbler (Phylloscopus borealis) perched on a willow stem in bud. Varanger fjord, Finmark, Norway