Comparisons of feeding behavior in captive squirrel and titi monkeys (Saimiri sciureus and Callicebus moloch).

Abstract

This research investigated feeding behavior in captive squirrel monkeys (Saimiri sciureus) and titi monkeys (Callicebus moloch). In view of behavioral differences seen in natural environments, one might expect that feeding and foraging patterns draw upon different behavioral tendencies in the two species. Some of these tendencies were identified in this research. In the home cage, in the presence of abundant food, squirrel monkeys were rapid, wasteful, and relatively asocial feeders. Titis in the same setting were slower, more selective, thorough, and socially involved feeders. Passive sharing of food between titi pair-mates was common. When competition was increased by presenting a single food item, titis continued to rely on positive social interactions to obtain food; squirrel monkeys still relied mainly on asocial stratagems to obtain food. The species' food preferences in paired-comparison tests were quite similar, although their patterns of obtaining and consuming the foods were not. Squirrel monkeys took food more quickly but consumed less than titis. When the same foods were presented repetitively, squirrel monkeys remained more wasteful consumers and were satiated more quickly than titis, even with highly preferred foods. These differences are discussed in terms of their probable contributions to each species' modal foraging patterns in natural environments. The findings are placed in the framework of an adaptive profile for each species, based on data accumulated in a series of studies conducted over the last decade.