Effect of supplementary feeding on the social behaviour and distribution patterns of free-ranging southern white rhinoceros

An increasing number of free-ranging southern white rhinos (Ceratotherium simum Burchell 1817) live in fenced and intensively managed reserves. They are often kept in small populations and depend on supplementary feeding in the dry season, which can influence their behaviour and distribution. We studied the distribution and social behaviour of free-ranging southern white rhinos in two smaller reserves in South Africa. In the first reserve, the rhinos (n = 13) were supplementary-fed while in the second one, the rhinos (n = 8) depended on natural grazing. Following the start of supplementary feeding in the first reserve, the rhinos changed their distribution and concentrated in areas around the feeding places. We observed (79 h of observation) the social behaviour of rhinos at places, where they frequently gathered and the agonistic interactions between them were significantly more frequent at the feeding places (in the first reserve) than at the natural grazing and resting area (in the second reserve). A sufficient number of feeding places and especially their good dispersion could help decrease the agonistic behaviour. Knowledge of the social behaviour of free-ranging rhinos at potentially competitive places in smaller reserves can also be very valuable for better understanding of behaviour of captive animals.