All four of Costa Rica’s monkeys are found at our Piro Biological Station and Greg Gund Conservation Center in Osa: Central American Spider Monkey (Ateles geoffroyi), Mantled Howler (Alouatta palliata), White-faced Capuchin (Cebus capucinus), and Red-backed Squirrel Monkeys (Saimiri oerstedii oerstedii). Due to global loss of habitat, all of these species are considered threatened by IUCN.

Osa Conservation’s primate monitoring program focuses on the central american spider monkey as an indicator species for forest health. We collect data on the abundance of spider monkeys in rainforest plots and the important role these creatures play in the ecosystem. This information is helping us to understand the impacts and effectiveness of our forest conservation measures. Weekly surveys are carried out throughout primary and secondary forest to gather information about sighting frequency and troupe size.  A total of 970 surveys have been conducted to date with a total of nearly 600 sightings registered. Our surveys suggest that the number of spider monkeys found on our properties is comparable to that of nearby Corcovado National Park, indicating successful forest regeneration efforts.