Use of space by the African Striped Ground Squirrel Xerus erythropus

Five Striped Ground Squirrels Xerus erythropus were radio-tracked at Katumani, Kenya, for periods of up to 10 days. The results were used to explore their short-term use of space. Definitions of the terms 'home range' and 'core', and some aspects of the methodology of home-range analysis are discussed. In an area of low-productivity bushland, subject to intermittent drought, where their food supply was patchy and unpredictable, the squirrels travelled about 1.5 km per day, and occupied rather large home ranges averaging 12.4 ha. Levels of aggression between conspecifics was low, home ranges were not defended, and there was considerable range overlap. Nights were spent in burrows which were commonly shared with conspecifics. On most days a single relatively long exploratory excursion was made outside the home range, extending the average area of the total range to some 40 ha. Despite the presence of major environmental features which might have been expected to affect the squirrels' foraging behaviour, such as cultivated fields, home range use was very symmetrical, suggesting that essential resources (food, shade, burrows) were widely dispersed throughout the range. Squirrels foraged alone, harvesting small, scattered, high-quality food items, mainly vegetable. Activity was interrupted from time to time to retire to the shade to lose heat, and a midday rest was taken. Only part of the home range was used each day. A variable degree of central concentration of activity could be observed. The squirrels' use of space enabled them to exploit available food resources opportunistically and efficiently, and made them difficult to control effectively.