Seed predation by monkeys and macaws in eastern Venezuela: Preliminary findings

Abstract

Feeding data collected concurrently on bearded sakis (Chiropotes satanas) and red and green macaws (Ara chloroptera) on a large island in Guri, Venezuela provides preliminary evidence that these two seed predators have similar diets. Individuals of both species were equally capable of opening very hard, protected fruits. Of the seven fruit species used by macaws during the study period, four species were also ingested by sakis at the same stage of ripeness, two species were ingested at different stages of ripeness (macaws earlier than sakis), and one species was never observed to have been eaten by sakis. The second finding, that macaws ingest young seeds of the Anacardiaceae and Burseraceae families and the bearded sakis ingest only the ripe mesocarp of these species suggests that the most distinguishable difference in their diets might be a tolerance of toxins by the macaws that act as feeding deterrents for the monkeys. Although we did not document the location of local clay licks in eastern Venezuela, the use of clay licks by macaws in Peru (Munn, 1992) suggests that this activity (that is not practiced by the sakis) may be helpful in detoxifying or ameliorating the effects of ingesting chemically protected fruit.