Nationally important area of limestone habitat including grassland, woodland and limestone pavement, supporting some of Britain’s rarest butterflies, including Peal Bordered Fritillary and High Brown Fritillary, as well as an array of other rare invertebrates and plants
Warton Crag is part of the network of nationally important wildlife conservation sites that occupy limestone areas around Morecambe Bay. The nature reserve includes important habitats such as limestone grassland and limestone pavement, as well as ancient semi-natural woodland.
The thin, free-draining soils and rocky outcrops on Westfield support areas of limestone grassland where notable species include Bird’s-foot Trefoil, Horseshoe Vetch and Kidney Vetch, providing a blaze of colour in May and June. Common Rock Rose and Thyme occupy similar habitats and flower a little later. The rock outcrops also support one of the most important lichen assemblages in Lancashire.
Limestone pavement is an internationally important habitat supporting rare plants such as Rigid Buckler Fern and Juniper, Pale St. John's Wort and Angular Solomon's-seal. In Potts Wood and Strickland Wood the groundflora includes Wood Anemone, Bluebell and Primrose as well as Early Purple Orchid, Violets and Pignut; woodland types are typical of moist, calcareous soils, with Ash and Hazel predominating, alongside Yew, Birch and Rowan. Spindle and Lancaster Whitebeam are also present while older stands of Goat Willow and Sessile Oak occupy patches of deeper soil. The moist, shady conditions beneath the canopy support a range of ferns including Hart's-tongue, Male Fern and Broad Buckler-fern.
The reserve is of national importance for its butterflies, supporting some of Britain’s rarest species including Pearl Bordered Fritillary, Small Pearl Bordered Fritillary and High Brown Fritillary, the larvae of which feed on Violets in woodland clearings and along bracken edges. Other notable butterflies include Northern Brown Argus, Wall Brown and Dingy Skipper, while rare moths include Least Minor, Barred Tooth-Striped and White-Spotted Sable moth. Recent surveys recorded an additional 32 Red Data Book or Nationally Notable species of invertebrate, including Lacewings, Beetles and Sawflies. The reserve also supports Common Lizard and Slow Worm.
Woodland is managed by coppicing, which provides patches of open, sunlit ground vital to Fritillaries and a range of other woodland species. The areas of limestone grassland and bracken are managed by conservation grazing using hardy, native breed cattle, which help maintain a mosaic of important habitats.
Species and habitats