New One on Me!

This is a Green Hairstreak butterfly. I've never knowingly seen one before.
I was back at Burbage Valley this afternoon in a return quest to find Ring Ouzels. 
I did hear one and I may have seen the back end of one as it disappeared!
I did get a very good view of a male cuckoo as it was chased off - but no pictures. The stonechats were very photogenic again and I enjoyed seeing this attractive butterfly in the sun and warmth.