WILLIAM OSBORN / Green woodpecker (Picus viridis) at nest hole. UK, England

Mike Wilkes / Green Woodpecker feeding young at nest in tree, England, UK

Mike Wilkes / Green Woodpecker feeding young at nest in tree, England, UK

Hermann Brehm / Green woodpecker (Picus viridis) juvenile, Hungary. June

Andy Rouse / Green woodpecker (Picus viridis) feeding on ground. UK. July.

Paul Hobson / Green woodpecker (Picus viridis) female on tree stump. May.

Paul Hobson / Green woodpecker (Picus viridis) female on tree stump in woodland. May.

Brian Bevan / Green woodpecker (Picus viridis) chick begging for food from parent at nest hole, Bedfordshire, England, UK, June.

Brian Bevan / Male Green woodpecker (Picus viridis) feeding young at nest hole, Bedfordshire, England, UK, June.

Brian Bevan / Male Green woodpecker (Picus viridis) feeding young at nest hole, Bedfordshire, England, UK, June.

Hermann Brehm / Green Woodpecker (Picus viridis ) male, Germany, December.

Hermann Brehm / Green woodpecker (Picus viridis ) male, Germany, December.