Food competition in captive female sooty mangabeys ( Cercocebus torquatus atys )

Abstract

We studied the social and foraging behavior of two captive groups of sooty mangabeys under two different spatial food situations. These food conditions were clumped (food was placed in a box) and dispersed (food was dispersed over the entire enclosure). In each group five adult females and two adult males were observed. As a criterion for food competition, individual differences in the relative food intake were used. Adult female mangabeys had a linear, stable, and unidirectional dominance hierarchy. Access to food was rank dependent among females only under clumped food distribution, as current models of the evolution of primate social systems predict. However, feeding success appeared to be mediated not by female but by male agonistic behavior toward females. High-ranking females received relatively less aggression from males and could, therefore, stay and feed longer in the feeding area. Male tolerance of higher-ranking females seems to mediate female feeding success under restricted food resources. The establishment of a special relationship with a high-ranking male might, therefore, be a strategy to get better access to food. This study demonstrates that female competition for access to food should not be analyzed separately from male influences on females and suggests that a more integral role of males in socioecological models of the evolution of primate social systems should be considered.

Sex and age differences in the diet and ingestive behaviors of sooty mangabeys (Cercocebus atys) in the Tai forest, Ivory coast

“…Males consume these hard objects more often, mirroring what is known for Cebus apella (Janson, 1990;Masterson, 1996;Wright, 2005;Gunst et al, 2008) but they also incise and crush these foods more than females for a given ingestive event. What this apparently increased effort means is unclear: it may indicate that females initially process these items simply to get them into their cheek pouches, and that more complete processing is delayed until it can take place under less competitive conditions (e.g., Range and Noe, 2002;Stahl and Kaumanns, 2003). Placing the item within the cheek pouch could also be used to soften the endocarp to facilitate more effective mastication.…”

Familiarity and dominance relations among female sooty mangabeys in the Taï National Park

“…If sooty mangabeys mainly experience scramble competition, no effect of rank on foraging success should have been observed [see van Schaik, 1989]. A study recently conducted on rank-related food benefits among female sooty mangabeys in captivity [Stahl, 1998] did not find an increase in agonistic interactions among females feeding on clumped compared to dispersed food conditions. However, there was a rank-related increase in foraging success when clumped food distributions were provided, as was found in our field study.…”

“…To date, the social system of the sooty mangabey (Cercocebus torquatus atys) has been studied only in captivity [Bernstein, 1971;Ehardt, 1988a, b;Gust & Gordon, 1991, 1994Gust, 1995;Stahl, 1998]. These authors found no particular bonds between related females [Ehardt, 1988a], and no signs of nepotism, such as support for kin or kin occupying adjacent ranks in the hierarchy [Gust & Gordon, 1994].…”

Influence of food dispersion on feeding activity and social interactions in captive Lophocebus albigena and Cercocebus torquatus torquatus

“…The impact of the distribution of food on social interactions has been particularly well studied and throws light on the functioning of social groups of primates, showing for instance that the distribution and the behaviour of males and females are strongly linked (Emlen and Oring 1977;Stahl and Kaumanns 2003;Wrangham 1979). Moreover, social influences on access to food are of critical concern in animal management (Box et al 1995;Redshaw and Mallinson 1991;Price and McGrew 1990).…”