Meeting Abstract

P1.45  Jan. 4  Ontogenetic patterns of locomotion in white-faced capuchins (Cebus capucinus) and mantled howlers ( Alouatta palliata ) BEZANSON, M; Santa Clara University bezanson@email.arizona.edu

Across primates, the degree to which coordination and increases in body mass during ontogeny are limiting factors in the development of adult-like locomotor competence is unclear. Wild white-faced capuchins (Cebus capucinus) are characterized by long juvenile periods where males reach reproductive maturity at ten years and females reach reproductive maturity at approximately seven years of age. In mantled howlers (Alouatta palliata), reproductive maturity is attained by approximately four years of age. I collected 955.7 hours of data (57,344 individual activity records) on locomotion and posture, activity, branch size, branch angle, and crown location during a 12 month period at Estaci�n Biol�gica La Suerte in northeastern Costa Rica. Life history timing and differences in rates of growth did not predictably influence the development of adult-like positional behaviors in capuchins and howlers. Young capuchins resembled the adult pattern of locomotion and posture by six months of age while howlers exhibited significant differences in several postural and locomotor categories through 24 months of age. These results indicate that ontogenetic changes in body mass and morphology appear to have a minimal effect on locomotor behavior and habitat use in juvenile capuchins while in howlers, coordination and increases in body mass may limit feeding, foraging, and travel activities. Data presented here suggest that the environment exerts different pressures on growing capuchins and howlers that may relate to diet, energy expenditure, foraging skill, and/or social learning.