Feeding ecology and social organization of wildcats (Felis silvestris) and domestic cats (Felis catus) in Scotland
This thesis describes and compares the feeding ecology and social organization of felids, especially the Scottish wildcat and the domestic cat, with the aim of understanding the adaptive significance of interand intro-specific differences in social behaviour. The field work was conducted over three years from November 1975. Wildcats were studied at Glen Tanar Estate, Aberdeenshire. Domestic cats were studied in two areas; they were either 'free-ranging' when living unrestrained in farmland in the Outer Hebrides or 'feral' on the uninhabited Monach islands.The main food of wildcats and domestic cats was rabbits, especially young rabbits and rabbits with myxomatosis, which were taken in proportion to their availability. These rabbits showed different anti-predator behaviour than adult rabbits. Rabbits occurred in patches in particular habitats and fewer were present in winter than insummer. Cats hunted-by-themselves and they were more successful in finding and catching rabbits by moving around and stalking (mobile strategy) than by lying in wait at rabbit holes (stationery strategy). Differences in hunting success between cats were related to differences in social status; by excluding subordinate cats from good hunting areas, dominant cats had more opportunities to catch rabbits.Radio-tracking revealed that wildcats were solitary and territorial;they also used faeces as scant marks within their territories. Adults had larger ranges than young wildcats but all were centred on forestscrub habitats which provided most food, cover for stalking and refugefrom bad weather in winter. Ranges of males sometifes partly overlapped the ranges of females, but the ranges of females never overlapped.Free-ranging domestic cats had overlapping hunting ranges but each cat hunted alone. Most litters were born in the fields and breeding pairs were more aggressive, urine-sprayed more frequently and excluded othercats from an area surrounding their dens. In winter, these cats relied on food handouts and scavenging from the farms and lived more communally to exploit this highly clumped food.The feral cats on the island were solitary and dominant cats defended territories centred on rabbit stronghold areas. Faeces were used as scent posts, as in wildcats, but unlike subordinate and free-ranging domestic cats who usually buried faeces. Litters were born at any time of year but during the years of study, all kittens died of starvation in winter,These results were compared with other studies of felids. Most felids are solitary but lions and domestic cats may live in groups, or alone, or a mixture of these life styles, and this intraspecific variation is at least as large as the interspecific variation shown between felids. I concluded that the availability, dispersion and acquisition of food is an important selective force acting on social organization. The basic hunting technique of all felids is solitary stalking but where prey is abundant, relatively large sized or easy to acquire, andpatchily distributed, cats may live in groups. In contrast, where prey is lose abundant, smaller and more dispersed, cats live and hunt solitarily in larger defended territories.