MORPHOLOGICAL AND PELAGE CHARACTERISTICS OF WILD LIVING CATS IN SCOTLAND - IMPLICATIONS FOR DEFINING THE WILDCAT

The indigenous wildcat, Felis silvestris Schreber, 1775, and the intro duced domestic cat, F. catus L., have been sympatric in Britain for mo re than 2000 years. As a result of interbreeding, any distinction betw een these two forms has become obscured, although a range of morpholog ical criteria (pelage patterns, body measurements, gut lengths, skull morphometrics) and genetic techniques (immunological distances, electr ophoresis, DNA hybridization) have been used previously to distinguish between them. A sample of 333 wild-living cats in Scotland was assess ed for coloration and markings of pelage, standard body measurements a nd weights, and (for carcasses only) limb bone lengths, intestine leng ths, and skull measurements. These cats were also classified as wildca t, hybrid, or domestic cat according to traditional pelage criteria. M ultivariate analyses on these variables, for adult cats, failed to sho w any clearly distinct groups. When each of the variables was analysed separately, only the distribution of limb bone and intestine length m easurements suggested the possibility that two groups might exist. Gro up 1 cats had short intestines and long limb bones. Group 2 consisted of cats with long intestines and short limb bones. Although the charac teristics defining cats in Group 1 were similar to those traditionally associated with wildcats, they exhibited a much broader range of pela ge and coloration than traditionally described. The groups exhibited a degree of geographical separation. The distribution of Group 1 cats w as found to be related to certain environmental variables, namely mean annual temperature and land with poor potential for forestry and agri culture, suggesting that there may be a biological basis for the separ ation. The implications of these results on the identification and tax onomy of the wildcat are significant. The concept of the wildcat and t he domestic cat as separate species can be challenged. The paper highl ights the complexity and difficulties for conventional taxonomy when u sed as a means for distinguishing between a wild type and its domestic ated form where there is interbreeding.