Chalk Hill Blue at non-calcareous site

[JimB]

During the last couple of weeks I have been fortunate to be able to survey a private nature reserve, used primarily for bird ringing, on the Isle of Wight. To my surprise I have recorded Chalk Hill Blue on both occasions with Thursday's count being c.50 and consisting of both sexes. The nearest colony to the Haseley Nature Reserve is Arreton Down, c. 1-km to the north west.

Unlike Arreton Down, Haseley is a non-calcareous site although it does have Birdsfoot, various clover and Bird's Foot Trefoil. Emmet and Heath mention that this species does occasionally colonise a non-calcareous area although it does not appear to be sustainable long-term presumably due to the lack of its chief food plant.

I noted and photographed a lot of the males present were taking salt at the edge of the lakes in the reserve. I will watch with interest to see if they do breed here or whether it is a weather-induced movement.

Has anyone else recorded Chalk Hill breeding at a non-calcareous site ?.

[Tony Moore]

In the fifties, I caught a fresh male CHB in an abandoned field in Shirley, near Birmingham. It was the only one I ever saw and must have been 40/50 miles away from any calcareous sites. I doubt if it was a release, but have no idea how it got there.

Tony M.