Ecological and behavioural flexibility of vervet monkeys (Chlorocebus pygerythrus) living in a savanna-woodland fragment near Kigoma, Tanzania

Primates habitats are being increasingly fragmented by human activities worldwide. The behavioural flexibility exhibited by vervet monkeys (Chlorocebus pygerythrus) is assumed to be crucial in the species ability to persist in habitats heavily altered by humans. From July to October 2015 vervet monkeys were studied in a savanna-woodland fragment near Kigoma, Tanzania, to increase our understanding of how primates can survive in anthropogenically altered habitats. Data were obtained on the activity budget, diet, ranging patterns and habitat use of two neighbouring groups living in areas with different degrees of human disturbance: Kitwe (28-33 individuals) and Jakobsen (21-23 individuals). Significant intergroup differences were found in activity budget, ranging patterns and diet. The group occupying the less altered habitat (Kitwe) spent significantly more time moving and had significantly greater day journey length. The group occupying the most heavily altered habitat (Jakobsen) lived in greater population density and spent significantly more time foraging, playing and engaged in sexual activity. Mean home range size (95% KDE) and mean day travel length were greater for Kitwe group (38.8 ha, 2585.2 m) than for Jakobsen group (15.6 ha, 1727.8 m). Comparatively, the group living in the most altered habitat (Jakobsen) included a larger number of food species in their diet (N=42), ate significantly more fruits, flowers, shoots, invertebrates, mature leaves and human processed foods, and included a larger percentage of human derived foods (39% of their diet) while the group living in the less disturbed habitat (Kitwe) included less food species in their diet (N=16), ate a significantly greater amount of seeds, and included a lower percentage of human derived foods (8.6% of their diet). Results show that vervet monkeys use flexible dietary strategies, one of them being the ability to access the human derived food commonly available in their habitat. The data obtained in this study contributes to developing conservation strategies that can ensure the long-term conservation of the vervet monkeys and possibly other species that share this fragmented habitat