DIETS AND FOOD PREFERENCES OF 2 SOUTH-AFRICAN TORTOISES GEOCHELONE-PARDALIS AND PSAMMOBATES-OCULIFER

The diet and plant species preferences of two sympatric tortoises, the mountain tortoise Geochelone pardalis and serrated tortoise Psammobat es oculifer, were studied in the northern Cape Province, South Africa. Owing to the difference in rainfall patterns during the two years of study, differing results were obtained between study periods and betwe en tortoise species. During the dry year both tortoises used the veget ation in relation to its availability; grass was used extensively as w ere succulents. In the higher rainfall study period a greater variety of ephemerals was available. The mountain tortoise extended its use of available species but continued to use grass; this component disappea red completely from the diet of the serrated tortoise and they concent rated on herbs and succulents. Preference in both species is for succu lents and species of the Fabaceae. Tribulus terrestris also featured i n both diets in both periods. It is suggested that the patterns shown reflect the climatic affinities of the two species.