My main research focus is the reproductive ecology of male primates. I have studied the costs of male mating effort in wild chimpanzees in Uganda and, more recently, am investigating life-history trade-offs of reproductive effort in male rhesus macaques in Puerto Rico. My work incorporates behavioral observations with a number of physiological measures of reproductive effort, energy balance, physiological stress, immunocompetence and health.

This study will test the hypothesis that female rhesus macaques show mate choice for males that are better able to cope with oxidative damage and that they identify such males from variation in male facial symmetry and redness. Behavioral observations will be supplemented with assays of oxidative stress markers in urine and blood, and with digital image analyses of male facial traits. This study aims to identify the functional significance of female mate choice in a nonhuman primate that will also illuminate the evolutionary origins of female mating preferences for facial attractiveness among human females.

Food and the competition for food have profound influence on primate sociality, on their reproductive strategies and thus on individual reproductive success. I studied bonobo feeding ecology in the DRC to examine the variation in diet and energy balance and to assess the effects that changes in fruit availability have on this highly gregarious ape species.
Cayo Santiago, off the east coast of Puerto Rico: the site of my current study of rhesus macaques.