(European) Green Woodpecker
Picus viridis

Often, the first sign of one of these birds is a very loud 'hyup-hyup-hyup' as it flies away, showing its bright yellow rump as it goes. They spend a lot of time on the ground and feed primarily on ants and can be seen in fields, parks and gardens. This bird is a female - females have black moustaches, while males have had a red centre to theirs. The last shot is the same bird (she often visits the patch of grass outside our house) as a juvenile.
 

  

  

1-3: Frogmore, Hampshire, 12/12/2006.
4: Frogmore, Hampshire, 06/09/2006.