Black-tailed Skimmer or Scarce Chaser?

Another warm day sun and some cloud. Went to do weekly shopping, some gardening and then out to meet my cousin and his wife for lunch which was very good. Back home C went to give blood and I did lollipopping, made some cheese scones and lemon squares then went out for a walk late afternoon. It was brilliant as I saw quite a few different butterflies, the Skimmer or Chaser and two Green Woodpeckers along with rabbits and various wildflowers. If anyone can say for certain which of the two the blip is of would love to know! Best Large. Also put the Green Woodpecker on blipfolio/Swans etc.