IPS title
 
 
     
 

Empirical Work - Tests of the Socioecological Model

 
 
Javan Langur Stumptailed macaques
Javan Langur Stumptailed macaques
 
 
 
 
 
 

Assamese macaqueSocial relationships in macaques vary from the despotic-nepotistic dominance style of rhesus macaques with frequent conflicts and barely existing reconciliatory behavior to the egalitarian societies of Sulawesi macaques (e.g. Macaca nigra, M. tonkeana) where aggressors often receive counter-attacks and most conflicts are reconciled. This marked variation among species of the same genus made macaques focus of comparative tests of the socioecological model. Lack of support elicited the formulation of an alternative hypothesis that social relationships are independent of ecology but vary along phylogenetic lines. To date few studies (especially on macaques) provide all the necessary data from resource abundance to energy intake, quantified social behavior and reproductive performance to test predictions of the socioecological model. Thus, the empirical work complements our theoretical and conceptual aims by providing new comparative field data on macaques living in Phu Khieo Wildlife Sanctuary (PKWS), Northeastern Thailand (more about the fieldsite). Members of the IPSE group gather information on patterns of resource exploitation and differential physical condition/reproduction that captive studies cannot provide and investigate social relationships among un-provisioned males and females in the light of resource competition and sexual conflict.

 
 
 
 
 
 

Mitred langurThe major alternative explanation fort he evolution of social relationships ist he phylogenetic hypothesis (Matsamura 1999, Thiery 2000) developed for macaques. We started to compile data for an independent test of this idea with Asian leaf monkeys. We cooperate with zoos that keep large groups of leaf monkeys from different species groups feeding on a leaf-based diet. Using a combination of behavioral data with non-invasive hormone analysis from feces samples we investigate the individual and species-specific stress response of animals of different rank classes and with different dominance styles. Thus, the captive work stands on its own while at the same time providing important reference points for the interpretation of our field data.