A Cardinal Measure of Competitive Ability in Barbary Macaque Males (Macaca sylvanus)

Abstract

71, 2006, 585) as a cardinal measure of male competitive ability in a group of Barbary macaques living under semi-free ranging conditions. To derive competitive ability scores, we used a semi-experimental protocol where two males had to compete over access to a prized food resource (i.e. a nut) within the natural group setting. This protocol was used because it allowed the exclusion of three factors other than competitive ability (i.e. respect of ownership, social tolerance and motivation) which may influence the outcome of dyadic encounters in group-living primates. We expected that a measure of competitive ability excluding the three above-mentioned influences would correlate with some intrinsic features of males. Male competitive ability scores were calculated based on 357 nut tests. As expected, male competitive ability shows a curvilinear relationship with age (used as a proxy for male general physical condition), with young, 'athletic' males having the highest scores. However, we also found that male competitive ability scores were highly correlated with the dominance scores derived from naturally occurring agonistic interactions, which suggest that observations of spontaneous interactions may suffice to estimate the competitive abilities of individuals. We conclude that despite its limitation, the normalized David score is often preferred to ordinal ranking as an estimate of resource holding potential as originally defined (Parker G.

Models of coalition or alliance formation

“…During that time, primatologists and other field biologists have amassed a vast amount of detailed and high-quality data on coalition and alliance formation (Barrett and Henzi, 2006;Bissonnette et al, 2009b;Bissonnette, 2009;Harcourt and Stewart, 2007;Mitani, 2006;Perry, 2008). But models have not kept pace.…”

Coalitions in theory and reality: a review of pertinent variables and processes

“…For group-living animals, an individual RHP may be partially reflected in his place in a rank order based on dyadic dominance relationships (Noë, 1989). Indeed, several studies have shown that ordinal ranks (de Vries, 1998;de Vries & Appleby, 2000) and cardinal ranks (Boyd & Silk, 1983;Adams, 2005;Romero & Castellanos, 2010) correlate with some RHP components, such as body mass, body size, or age (e.g., Dittus, 1977;Packer, 1979;Jones, 1980;Clutton-Brock et al, 1982;Zucker & Clarke, 1998;Alberts et al, 2003;Setchell et al, 2006;Bissonnette et al, 2009b), but this is far from universal. For example, Fedigan (1992) reported that in wild capuchin monkeys, small, young and even incapacitated males have occupied alpha male positions, suggesting that social variables, instead of physical attributes of age and size, determine the dominance rankings of the males.…”

“…For example, Bissonnette et al (2009a) used a cardinal measure of competitive ability in Barbary macaque males (Bissonnette et al, 2009b), based on normalized David's scores derived from dyadic winner-loser matrices, to test the assumption that a coalition is successful if the strength of the coalition members is greater than the strength of the target. They found that asymmetry in strength was a significant predictor of coalition success, and this factor alone could explain up to 78.6% of coalition outcomes in the study group.…”

Age-dependent change of coalitionary strategy in male Barbary macaques

“…In this paper, we focus on age as an intrinsic factor to explain intraspecific variation in male coalition formation in one semi-free-ranging population of Barbary macaques (Macaca sylvanus). It has previously been shown that age can act as a good proxy for the physical condition (Bissonnette et al, 2009a). Older males may be forced to start behaving cooperatively as they age to maintain their access to females (Bissonnette et al, 2009b).…”

“…In the current study, we took age as a proxy for the male's intrinsic power (Berghänel et al, 2011) and investigated whether it is an important factor influencing coalition formation in Barbary macaque males using a combined cross-sectional and longitudinal approach comparing three study years (2006, 2008, and 2014). Inspection of the relationship between age and competitive ability (Bissonnette et al, 2009a) suggested a steady decrease after age 14 (see below). Thus, we predicted first that post-prime phase males ( ≥ 14 years) form coalitions more often than prime males (5-13) in the same group year (in 2006, 2008, or 2014 respectively).…”