THE DISTRIBUTION AND STATUS OF THE ADDER (VIPERA-BERUS L) IN SCOTLANDDETERMINED FROM QUESTIONNAIRE SURVEYS

During 1992 two questionnaire surveys, aimed at farmers and sections o f the general public, were conducted to determine the distribution and status of the adder (Vipera berus L.) in Scotland. In total, 94% of t he Scottish mainland and inner isles were covered by the two surveys. The adder appears to be widespread throughout Scotland, although it is absent from much of the Central Valley, the Outer Hebrides and Northe rn Isles, and from much of the mountainous region between Inverness an d Glasgow. The distribution of the adder in Scotland was compared with the distributions of different habitat types defined in the ITE Land Class survey. Adders were strongly associated with areas of heterogene ous land use and negatively associated with intensively arable areas a nd rugged mountainous areas. Strong evidence was found to suggest that perceived adder abundance had declined during the last 10 years. Alth ough the evidence suggesting that the distribution of adders in Scotla nd had changed was less strong, the results of the Farm Survey did ind icate that it had contracted. The perceived change in status of the ad der in Scotland during the last 10 years was compared with the observe d changes in land use over the same period.