Adonis blue  (Lysandra bellargus)

Many areas of suitable grassland have been removed by agricultural intensification, other sites have become degraded following abandonment or a decline in grazing, which maintains the short sward required by this species. In many sites a short sward was maintained solely by rabbit grazing, but the introduction of myxomatosis in the 1950s and the subsequent crash in rabbit populations led to a loss of short sward grasslands and a decline in the Adonis blue. After 1981, as rabbit populations have recovered and conservation measures have been put into action, the Adonis blue has made a partial recovery in some areas (5).

Many important sites for the Adonis blue have been designated as nature reserves, other sites have been targeted by agri-environment schemes such as Countryside Stewardship and Environmentally Sensitive Areas (ESAs) which have paid farmers grants to restore or increase livestock grazing. Despite these promising steps, in many areas the Adonis blue is still dependent on rabbit grazing, which can be unpredictable, to maintain a suitable sward height. Some sites are too small and isolated to support viable populations; horseshoe vetch is a poor coloniser and has been lost entirely from some former sites where there has been scrub invasion. The Adonis blue is a priority species under the UK Biodiversity Action Plan (UK BAP)(5).