New Plant Dietary Records for Two Sympatric Primate Species in Costa Rica

Abstract

Costa Rica hosts four primate species, including the frugivorous spider monkey Ateles geoffroyi and the omnivorous capuchin Cebus imitator. Although both species are relatively well studied, their diets continue to yield new records. Here we document two previously unreported food plants, a Ficus species consumed by A. geoffroyi and a euphorb eaten by C. imitator, observed during fieldwork in Northwestern Costa Rica. We conducted incidental wildlife observations while hiking the Las Pailas Trail in Rincón de la Vieja National Park, recording all visually or aurally detected vertebrates. For each primate sighting, we noted species, behavior, and foraging context. These records were obtained
during academic field visits aimed at documenting natural-history data across contrasting habitats, including dry forest, transitional forest, and geothermal areas. A female spider monkey was observed feeding intensively on Ficus popenoei, consuming at least 20 fruits from a heavily laden tree situated beside an active fumarole. Later, a troop of capuchins fed in a Hura crepitans tree, with one individual dropping a partially eaten fruit. These constitute novel dietary records for A. geoffroyi and C. imitator in Costa Rica. These observations expand the known diets of two Costa Rican primates and highlight their behavioral flexibility. Ateles geoffroyi exploited abundant figs of F. popenoei, a species not previously reported in its diet. Cebus imitator consumed H. crepitans, despite its mechanical and chemical defenses. Such records emphasize the value of natural-history observations for understanding primate ecology and informing conservation in changing landscapes.