DIURNAL AND SEASONAL-VARIATIONS IN VERVET MONKEYS ACTIVITY

This paper analyzed seasonal and diurnal differences in feeding, locom otion, inactivity, and social grooming of adult and subadult free-rang ing vervet monkeys in Natal (38 degrees 35'S and 31 degrees 46'E). Bre aking down hourly activity budgets from the perspective of reproductiv e seasons (birth, premating, and mating seasons) which correspond to e nvironmental conditions in Natal, ive obtained several results. First, there were diurnal Variations for all the behaviours in all seasons s tudied, except for inactivity during the mating season when days were shorter and there was greater food shortage and sexual competition. Se cond, the seasonal influence on the hourly periods of increased activi ty could not be explained solely by the photoperiod or by the other cl imatic factors analyzed. Finally, over-all seasonal differences in act ivity were mainly reflected by the hourly distribution of feeding in t he morning and the pattern of inactivity throughout the day. Therefore , rhythms in activity should be understood in terms of adaptation to b oth climatic constraints and other unrelated metabolic requirements.