The Relative Importance of Size of Food and Interfood Distance in Eliciting Aggression in Captive Rhesus Macaques (Macaca mulatta)

Abstract

We conducted an experiment on a group of captive rhesus macaques (Macaca mulatta) in which we manipulated both food size and interfood distance independently to examine which factor was more important in causing aggressive competition. For each of 254 trials, the monkeys were offered simultaneously two apple pieces ranging in size from 1 to 40 g at interfood distances ranging from 1 to 5 m. In contrast to other studies, food size and interfood distance were not conflated in this study. Multiple regression analyses revealed that food size was a better predictor of aggression whereas interfood distance was a better predictor of the ability to monopolize foods. Growing evidence suggests that factors such as food size, quality and depletion time are more important than interfood distance in influencing aggression within groups.

Ecological models of female social relationships in primates: similarities, disparities, and some directions for future clarity

“…In an experimental study, Schaub (1995) found that subordinate longtailed macaques (Macaca fascicularis) were less likely to obtain foods when the dominant animals were closer to them, but he could only test them at distances of 30 cm and 100 cm. A recent study of captive rhesus macaques (Mathy & Isbell, 2001) suggests that 100 cm is well within the zone of monopolizabilit y of higher-ranking animals when there is no physical barrier between the animals, as was the case in Schaub's experiment. In Mathy and Isbell's study, group-living individual s were provided with two apple pieces simultaneously.…”

“…The models make arguments about patch sizes across a wide range of spatial scales, but it is not clear what scale is appropriate for different kinds of competition. Recognizing this, Isbell and colleagues have attempted to examine more speci cally the operational aspects of food distributio n as they affect competition (Isbell & Pruetz, 1998;Isbell et al, 1998;Pruetz & Isbell, 2000;Mathy & Isbell, 2001). It appears that the patchiness of foods per se is not what matters.…”

Within‐group female–female agonistic interactions in Taiwanese macaques (Macaca cyclopis)

“…Therefore, it is predicted that higher-quality foods [Koenig et al, 1998;Range & Nöe, 2002] or food items in clumped distribution [Mathy & Isbell, 2001] are more likely to be monopolized. Defending higher-quality foods is rewarded by gaining a higher intake of energy and nutrition.…”

Behavioural and Glucocorticoid Responses of a Captive Group of Spider Monkeys to Short-Term Variation in Food Presentation

“…The interaction between the spatial and the temporal availability of food resources will determine the possibility of monopolizing food patches [Goss-Custard et al, 1984;Grenier et al, 1999;Weir and Grant, 2004]. For instance, when food occurs in discrete patches, spatial clumping and temporal dispersion of patches may promote resource monopolization, whereas spatial dispersal and high abundance of food reduces the defensibility of food patches [Goldberg et al, 2001;Mathy and Isbell, 2001]. When food monopolization occurs, within-group feeding competition may emerge, either directly, through the expression of ritualized or aggressive behaviours, or indirectly, through dominance relationships [Goss-Custard et al, 1984;Grenier et al, 1999;Mathy and Isbell, 2001;Weir and Grant, 2004].…”

“…For instance, when food occurs in discrete patches, spatial clumping and temporal dispersion of patches may promote resource monopolization, whereas spatial dispersal and high abundance of food reduces the defensibility of food patches [Goldberg et al, 2001;Mathy and Isbell, 2001]. When food monopolization occurs, within-group feeding competition may emerge, either directly, through the expression of ritualized or aggressive behaviours, or indirectly, through dominance relationships [Goss-Custard et al, 1984;Grenier et al, 1999;Mathy and Isbell, 2001;Weir and Grant, 2004]. In addition to its influence on the establishment and maintenance of social relationships among group members, feeding competition represents a stressor to many animal species, as attested by changes in the secretion of glucocorticoids (e.g.…”