Northern brown argus  (Aricia artaxerxes)

There has been a serious decline in this species around the Durham area, and reductions have also occurred in southern Scotland. More surveys are needed to ascertain the species' status in this area, however (3).

Sheltered unimproved grassland with low grazing levels has been greatly reduced, and persists in fragmented patches. Loss and degradation of this habitat has greatly contributed to the decline of this species. In some cases inappropriate grazing regimes result in otherwise suitable habitat becoming degraded (4); a lack of grazing results in scrub invasion, and overgrazing excludes the species even if the food plant is abundant (3).

Many colonies in the north of England occur in nature reserves where management has successfully been altered for this species. A good example occurred at St Abb's Head National Nature Reserve, where in 1992 there was a switch from heavy grazing to selective spring and autumn grazing. The population of the northern brown argus subsequently increased dramatically (3). The Countryside Stewardship Scheme includes management prescriptions aimed at this species; private landowners receive grants for managing their land in these ways (3). The northern brown argus is a priority species under the UK Biodiversity Action Plan (4).