to the area. Ecology Scratchbury is within in an area of unimproved grassland on the edge of Salisbury Plain, which is the largest remaining area of calcareous grassland in north-west Europe. The local area supports a rich and diverse grassland flora along with an important associated butterfly fauna, and this led to it being notified as a biological Site of Special Scientific Interest in 1951. Designated as Scratchbury & Cotley Hills SSSI, the site encompasses a total of . The ecology and historical agricultural use of the site is such that regular grazing by sheep is required to maintain the balance of the flora, and to control the growth of shrubs. The grassland is generally dominated by sheep's fescue (Festuca ovina), red fescue (Festuca rubra), and upright brome (Bromus erectus). There are also several varieties of herbs, characteristic to the Wiltshire downland, including for devil's bit scabious (Succisa pratensis), saw-wort (Serratula tinctoria), and chalk milkwort (Polygala calcarea). There are also many other native and site specific plants, including for orchids, meadow grasses, nettles, and other flora. On the steep slopes horseshoe vetch (Hippocrepis comosa), Thymus, and Asperula is plentiful Within the hillfort, a more mesotrophic grassland is present, most probably reflecting past agricultural use and improvement. There are also small areas of hawthorn (Crataegus monogyna), and elder (Sambucus) scrub, particularly along the lower slopes of the downland and on the earthworks. These provide valuable shelter for invertebrates on an otherwise open and exposed site. The site is of high entomological interest, with 29 varieties of resident breeding species of butterfly recorded. The horseshoe vetch (Hippocrepis comosa) is locally plentiful and supports both the chalkhill blue (Lysandra coridon) and the Adonis blue (Lysandra bellargus) butterflies. Other butterfly species to be found on and around the site include for the Duke of Burgundy (Hamearis lucina), the grizzled skipper (Pyrgus malvae), the dark green fritillary (Speyeria aglaja), and the small blue (Cupido minimus). Other insect groups on the site are less well surveyed, but several rare species have been recorded, including for six species of weevil (Curculionoidea), eight species of plant bugs (Hemiptera), and two species of chrysomelid beetle, Aphthona herbigrada and Mantura matthewsii; both of which feed on the rock rose (Helianthemum). Day-flying moths recorded include for the wood tiger (Parasemia plantaginis), and the rare forester moth (Jordanita globulariae). Small mammals such as rabbits (Oryctolagus cuniculus) and badgers (Meles meles) are common