Home The Butterflies of Gloucestershire Species Habitats Conservation

Chalk-hill Blue

Lysandra coridon
Male, 16 August 1980 Female, 29 August 1992


Chalk-hill Blue colonies are found on unimproved Cotswold grasslands where Horseshoe Vetch (Hippocrepis comosa) grows. Unlike some grassland species which can survive on very small areas of habitat, Chalk-hill Blue colonies are mostly on quite large areas of suitable grassland.

Female, 5 August 1978

Conservation Issues

Population sizes fluctuate from year to year and site to site. Heavy grazing during the summer seems to be very detrimental, but total lack of grazing for several years can eliminate a colony because the foodplant becomes scarce in the long grass.

One year, Horseshoe vetch on one site seemed to disappear almost completely, although seedling growth restored the habitat in subsequent years. The cause of this event was uncertain, and the effect was only observed because the site was being monitored following an Adonis Blue reintroduction.

Flight Period

Mainly late July to late August.


Throughout the Cotswolds on suitable sites. There are a few records of the species at some distance from its nearest colony.