What kind of bird species is this?
Almost definitely (I'm not a regular birder) European Green Woodpecker (latin name: Picus viridis) and it is native to your area according to its species distribution map.


  "Green woodpeckers are the largest and most colourful woodpeckers
  native to Britain. They are easily recognised by their laughing
  ‘yaffle’ call, which they use to demarcate their territory. They also
  drum on trees, though the sound is not as resonant as that made by the
  other two British species (the greater and lesser spotted
  woodpeckers). Green woodpeckers survive on a diet of insects and have
  a particular fondness for ants. They return day after day to their
  favourite ant hill to feed." - BBC nature