A comparative study of positional behavior in three species of tamarin monkeys

Abstract

Tamarins of the genusSaguinus are small-bodied New World monkeys that exhibit clawlike or modified nails. Patterns of positional behavior and habitat utilization are presented for three species,Saguinus fuscicollis, S. geoffroy, andS. mystax. These data were collected on free-ranging tamarin populations in Panama and Peru. Despite considerable differences in body weight, all three species exhibited very similar patterns of positional behavior, with quadrupedal bounding and running accounting for 43 – 52% of travel time. Leaping was the second most common locomotor activity and accounted for 31 – 41% of travel. Although each species leaped principally on small supports in the perimeter of the tree crown, approximately 20% of all leaps inS. fuscicollis involved moderate to large sized vertical trunks located in the undercanopy. Leaping between trunks was rare in the two larger tamarin species. Measurements taken on live wild-trapped adults reveal that compared toSaguinus geoffroyi andS. mystax, S. fuscicollis is characterized by a long legspan and an especially long armspan. It is proposed that inS. fuscicollis, elongated forelimbs play an important role in maneuvering and rotating the body during the in-air phase of trunk-to-trunk leaping, and increase the breaking distance needed to decelerate the body upon impact. Additional relationships between body size, substrate preference, and positional behavior in callitrichines are discussed.