The effect of social and ecological factors on the time budget of wild vervet monkeys

Abstract

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.

The consistency of individual centrality across time and networks in wild vervet monkeys

“…Alternatively, resident males could groom more with females to strengthen their bonds and to encourage the females to mate with them rather than with the new males. The high centrality of high-ranking individuals and females in affiliative networks has been reported in numerous primate species (Lehmann & Ross, 2011;Sosa, 2016;Wooddell et al, 2019) including vervet monkeys (Blaszczyk, 2018;Borgeaud et al, 2017;Canteloup et al, 2019;Seyfarth, 1980). High-ranking individuals may provide benefits to others, such as tolerance or agonistic support, in exchange for grooming (Borgeaud & Bshary, 2015;Schino, 2006;Seyfarth, 1977), and others learn to solve novel tasks from them (Canteloup et al, 2020a).…”

Vervet monkeys socialize more when time budget constraints are experimentally reduced

“…We suggest that this makes sense in an environment where seasonal variation has a strong impact on food availability (Canteloup et al, 2019). Generally, vervet monkeys in our study seem to be able to find the right balance between their physiological and social needs.…”

“…Our findings show that vervets are highly flexible in their behaviour and can adapt their activity budget as a function of the availability of time and food. We suggest that this makes sense in an environment where seasonal variation has a strong impact on food availability (Canteloup et al, 2019). Generally, vervet monkeys in our study seem to be able to find the right balance between their physiological and social needs.…”

“…First, we asked whether our three study groups of monkeys would respond in a similar or different way to the food supplementation in their activity budget adjustment. This question is pertinent as previous studies (Borgeaud & Bshary, 2015;Borgeaud et al, 2016;van de Waal, 2018;Canteloup et al, 2019) indicated that vervet groups of the study site behave differently in multiple contexts. Such variation is apparently driven by factors linked to group identity (social interaction patterns, traditions and/or home range characteristics) rather than group size (van de Waal, 2018).…”

Field data confirm the ability of a biophysical model to predict wild primate body temperature

“…McFarland et al 2014; see alsoCantaloup et al 2019). 337During nocturnal hours the hot model was allowed to use the most heat-conservative 338 nocturnal body posture of huddling between other monkeys.…”