When Keith visited Portland on 1/08/19 he tells us:
One of many tens, probably hundreds, of Chalkhill Blues at Tout Quarry Park, Portland this morning. They were literally everywhere with occasional Gatekeepers and Wall Browns. Very enjoyable!
Amazing to think at Cerne Abbas, Giant’s Hill only a single male specimen was found last year, the first appearance for more than five years, yet on Portland you are falling over them.