Social Structure of the Squirrel Monkey (Saimiri sciureu s, Iquitos): Relationships among Behavior, Heartrate, and Physical Distance

Abstract

The relationships between heartrate, behavior, and physical distance were assessed in squirrel monkeys forming a stable colony. For many specific behaviors, heartrate is elevated from baseline 2 min before the behavior and depressed afterwards. Heartrate during a specific behavior is often related to rank by either a U or inverted U: high and low ranking animals show similar heartrates but those of midranking animals are depressed or elevated. The findings are interpreted in terms of the possible evolutional effects on endocrine output of long- and short-term stress.