Document Type


Date of Degree Completion

Spring 2017

Degree Name

Master of Science (MS)


Primate Behavior

Committee Chair

Lori K. Sheeran

Second Committee Member

Mary Radeke

Third Committee Member

Nadine Ruppert


The Southern pigtail macaque (Macaca nemestrina) is an understudied species in the Cercopithecidae family distributed in Southeast Asia. In this field study, I focused on interactions of Southern pigtail macaques to better understand mother-infant relationships. I observed five to six mother-infant dyads from April 2016 to September 2016 in the Segari Melintang Forest Reserve, Perak, Peninsular Malaysia. I used focal sampling methods to score mother and infant behaviors from two ethograms. I hypothesized that as infant age increased, mother and infant behaviors seen to be important in pigtail macaque mother-infant captive studies, would change over time. As infant age increased, mother permissive behaviors and mother-infant contact duration showed significant negative correlations. A GLMM of mother permissive behavior as the outcome variable only showed infant age as a significant predictor variable. From the infant’s perspective, as infants increased in age, mother-infant contact duration showed a significant negative correlation, while mother-directed vocalizations showed no association. A GLMM of mother-infant contact duration as the outcome variable showed only infant age as a significant predictor variable. Infants made more breaks in the mother-infant dyad between 100-350 days of age. Adult females and juveniles were significantly more likely to be within 1-5 m proximity of mothers as infants aged. These data show that mother permissive behavior, mother-infant contact duration and proximity are crucial elements to consider when examining wild pigtail macaque mother-infant relationships and infant independence.