Paul Hobson / Wood warbler (Phylloscopus sibilatrix) singing whilst perched on branch, silhouetted at dawn. Sheffield, England, UK. May.

Paul Hobson / Wood warbler (Phylloscopus sibilatrix) male singing, perched on branch in morning light. Sheffield, England, UK. May.

Bruno D'Amicis / Wood warbler (Phylloscopus sibilatrix) singing on tree branch in old-growth Beech (Fagus sylvatica) forest. UNESCO World Heritage Site. Abruzzo, Lazio and Molise National Park, Italy. June

Dave Bevan / Wood warbler (Phylloscopus sibilatrix) displaying and calling from the branches of an Oak tree (Quercus), Carmarthenshire, Wales, UK, May.

Dave Bevan / Wood warbler (Phylloscopus sibilatrix) displaying, Carmarthenshire, Wales, UK, May.

Andres M. Dominguez / Wood warbler (Phylloscopus sibilatrix) with insect prey, Andalusia, Spain, August.

Fabrice Cahez / Wood warbler (Phylloscopus sibilatrix) singing, silhouetted, Vosges, France, May.

Fabrice Cahez / Wood warbler (Phylloscopus sibilatrix) Vosges, France, May.

Fabrice Cahez / Wood warbler (Phylloscopus sibilatrix) Vosges, France, May.

Paul Hobson / Wood warbler (Phylloscopus sibilatrix) in canopy, Derbyshire, England, UK, May.

Paul Hobson / Wood warbler (Phylloscopus sibilatrix) displaying to a rival in canopy, Derbyshire, England, UK, May.

Paul Hobson / Wood warbler (Phylloscopus sibilatrix) singing male in canopy, Derbyshire, England, UK, May.

Paul Hobson / Wood warbler (Phylloscopus sibilatrix) singing male in canopy, Derbyshire, England, UK, May.

David Tipling / Wood warbler (Phylloscopus sibilatrix) singing, Wood of Cree RSPB Reserve, Dumfries and Galloway, Scotland, May.

David Tipling / Wood warbler (Phylloscopus sibilatrix) singing, Wood of Cree RSPB Reserve, Dumfries and Galloway, Scotland, May.

David Tipling / Wood warbler (Phylloscopus sibilatrix) perched, Wood of Cree RSPB Reserve, Dumfries and Galloway, Scotland, May.

David Tipling / Wood warbler (Phylloscopus sibilatrix) perched, Wood of Cree RSPB Reserve, Dumfries and Galloway, Scotland, May.

Jussi Murtosaari / Wood warbler (Phylloscopus sibilatrix) singing male, central Finland, June.

Robin Chittenden / Wood Warbler (Phylloscopus sibilatrix) singing, Norfolk, May

Robin Chittenden / Wood Warbler (Phylloscopus sibilatrix) singing, Norfolk, May

Ewan Flynn / Wood warbler (Phylloscopus sibilatrix) perched on a branch, singing, Bialowieza forest, Poland. May.

Ewan Flynn / Wood warbler (Phylloscopus sibilatrix) perched on a branch, singing, Bialowieza forest, Poland. May.

Jussi Murtosaari / Wood warbler (Phylloscopus sibilatrix) taking off from flowering willow, Finland. May.

David Tipling / Wood warbler (Phylloscopus sibilatrix) perched on a branch, Pitlochry, Highlands, Scotland, UK. May.

David Tipling / Wood warbler (Phylloscopus sibilatrix) perched on a branch, Pitlochry, Highlands, Scotland, UK. May.

David Tipling / Wood warbler (Phylloscopus sibilatrix) perched on a branch in song, Pitlochry, Highlands, Scotland, UK. May.

David Tipling / Wood warbler (Phylloscopus sibilatrix) perched on a twig, Pitlochry, Highlands, Scotland, UK. May.

Eric Medard / Wood Warbler (Phylloscopus sibilatrix,) perched on branch in forest, Mayenne, France, April.

Jussi Murtosaari / Wood warbler (Phylloscopus sibilatrix) perched on branch amongst blossom. Pargas, Aboland, Finland. May.

Dave Bevan / Wood warbler (Phylloscopus sibilatrix) perched in a tree singing, Carmarthenshire, Wales, UK, May.

Jussi Murtosaari / Wood warbler (Phylloscopus sibilatrix) amongst willow flowers, Finland, May.