Polyspecific Associations of Callimico Goeldii, Saguinus Labiatus, and Saguinus Fuscicollis in Acre, Brazil

441 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003.This study examines the behavioral ecology and polyspecific associations of three New World callitrichids, Callimico goeldii (Goeldi's monkey, callimico) Saguinus labiatus (red-chested tamarin) and Saguinus fuscicollis (saddle-backed tamarin). These closely-related primates form polyspecific associations (PSAs), in which all three species feed, forage, travel, and rest together. Like monospecific groups, associations presumably function to reduce predation risk or improve foraging efficiency. Behavioral and ecological data were collected on the study species over a total of 15 months at the Fazenda Experimental Catuaba, an 820 ha rainforest site in Acre, Brazil. All three species were in association 67% of observation time, and PSAs occurred during all activities. Associations were less common during the dry season correlating with a change in each species' diet, presumably as a response to lower fruit availability. During the wet season, the diets of all three species were composed of fruit and animal prey (primarily invertebrates), while during the dry season C. goeldii fed extensively on fungus and plant exudates, and both species of Saguinus fed on more exudates and nectar. There were low levels of agonistic interactions among species, suggesting that the PSAs do not impose heavy costs due to direct contest competition. Based on species' foraging methods and habitat use, scramble competition for plant resources is likely more prevalent. Reduced association in the dry season may relate to limiting possible association costs, as may result from scramble and exploitation competition, or opportunity costs resulting from maintaining PSAs. All three species of the main study group shared an identical range of 48 ha, 23% of which overlapped the ranges of neighboring mixed groups, and overall each species used different habitat types in proportion to their estimated availability. There was no strong evidence that the associations benefitted any of the study species in terms of better defense or access to resources, although it is possible that they may be able to monitor depletion of certain plant resources while associated. The ubiquity of the associations and behavioral responses to predators suggests the associations may serve an antipredation function.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD