It was a fairly poor year for the butterfly locally. Though it persisted at all those surveyed Upper Thames colonies where it was seen last year, it is still absent from some historic sites.

Numbers at all sites were lower than in 2007.

Chalkhill Blues (m. & f.)
Photo © Malcolm Brownsword

Amounts of Horseshoe Vetch (the sole foodplant of this species) appeared unchanged at all sites, so it is presumed that the cool, wet weather leading to taller growth of vegetation around the Horseshoe Vetch stalled the development of the immature forms of the butterfly. Larval feeding is curtailed in wet conditions. Longer vegetation extends drying times near ground level where the larvae feed (crepuscularly).

The 2007 distribution of Chalkhill Blue
Lysandra coridon

Records via Levana (nb: this map, based on data sent to Levana, is an incomplete picture - it shows the need for record submission more clearly than the distribution of Chalkhill Blue!)

Contact has been maintained at some key sites, though there is a need to identify the owners and establish contact at various other sites, so that management advice can be passed on. This will stress the need for Horseshoe Vetch growing in short, sparse turf in full sun.