Animals often have a limited time to perform different fitness-enhancing activities,
such as the trade-off between socializing versus foraging in group-living species.
Many previous studies have focused on how ecological and social factors influence
activity budget at the individual or group level in various species. However, few primate
studies have focused on multiple study groups living within a similar habitat.
Here, we analyse group, season and sex effects on the individual activity budget
of wild vervet monkeys (Chlorocebus pygerythrus) living in four groups with overlapping
home ranges. Generally, our findings support previous studies on primates.
Our results indicate that intragroup competition may force larger groups to spend
more time feeding and less time resting. We also found that seasonal variation, and
therefore food availability, has a strong influence on the monkeys’ activity budget.
Females, which are the philopatric sex in vervet monkeys, spent more time socializing
while, in general, males spent more time resting. However, we did not find any
difference on the time spent socializing between groups. Since there is evidence that
not only time constraints and habitat quality but also group size influence individual
behaviours and ultimately group living, we advise that future studies should focus
on multiple groups of the same species living in the same habitat in order to better
understand how all these variables are interlinked.