FORAGING BEHAVIOR OF A TAMARIN GROUP (SAGUINUS-FUSCICOLLIS WEDDELLI) AND INTERACTIONS WITH MARMOSETS (CALLITHRIX-EMILIAE)

We present data on aspects of the behavioral ecology of a free-ranging group of Saguinus fuscicollis weddelli at a site in Brazilian Amazoni a where a second callitrichid, Callithrix emiliae, is syntopic. Diet, activity patterns, and ranging behavior are broadly similar to those o f S. fuscicollis from sites in Bolivia, Brazil, and Peru, though signi ficant seasonal changes include an extreme and atypical form of rangin g behavior in which they foraged in central-place fashion around a sou rce of exudate-Parkia pendula. S. f. weddelli was active at relatively low levels in the forest both in absolute terms and relative to C. em iliae, which appears to be an important factor in their niche partitio ning. Association between the two species appeared to be less systemat ic overall than those observed between S. fuscicollis and congeners at other sites, though this may be partly a result of observation condit ions. During the period of central-place foraging, the two species exh ibited a high degree of association. Other characteristics of the beha vior of S. f. weddelli at the study site include the frequent use of t ree holes as sleeping sites.