Howler Monkey Reintroduction

More than 20 years ago, when I began running the Pacuare River, and organizing trips of two or more days, camping at solitary spots in the rainforest, I was always intrigued by the fact that I never encountered monkeys on the river’s left bank, which is oddly enough the side with more primary tropical forest. For years, I’ve wondered about the reason for this unusual lack of primates. I’ve heard all kinds of explanations, but the most probable one is that they were victims of hunting. This is a theory, which like the others, has not been reliably corroborated.

Now, independent of why there aren’t any monkeys in those marvelous and impressive tropical forests, I’ve always had the desire to do something about it. For many years, I’ve been asking around and investigating the possibility of reintroducing monkeys in the area. After asking lots of questions, I got in touch with a group of scientists at the University of Costa Rica, lead by Gustavo Gutierrés Espeleta Ph.D. and Ronald Sánchez M.S., who together with a group of biologists and students managed to make this project a reality.

They located an area near the Pacuare, approximately one hour away by 4x4 vehicle, where agricultural expansion has destroyed practically all of the natural forest that was home to primates. The selected area has cattle ranches and palm plantations with small, if not tiny patches of trees and bushes where a troop of howler monkeys had taken refuge. There was no other place from them, and no corridor that the monkeys could use to move to a forested area, just an insignificant patch of trees.

The capture was impeccably executed and the team managed to catch the entire troop in record time, sedating them one by one, weighing each individual, taking blood samples, and other doing tests that could aid the scientific study of these monkeys. They were the placed the animals in sacks and tool them in a 4x4 to the Pacuare Lodge, which is the base for reintroducing and monitoring the howler monkeys. The howler monkeys were immediately released and the biologists began to log their subsequent activity, their movements through the forest, their process of adaptation, the signs and sounds with which the demonstrated their acceptance of the area, the trees the feed on, etc. etc.

The study showed that after two weeks in the Pacuare Lodge’s reserve, the monkey’s adaptation process was developing excellently. In fact, a female that arrived pregnant gave birth during the second week there, and all the signs since then have been positive and encouraging.

This project, which is sponsored by the Pacuare Lodge in cooperation with the University of Costa Rica, signifies an important step for us in our commitment to the environment and sustainability. We are extremely pleased to have made this small contribution to the important goal of rescuing and reintroducing howler monkeys to the Pacuare area, which is of incalculable value. To be able to watch those monkeys in their new home, with its abundant tree species and natural conditions, after witnessing their dramatic situation before, when their survival was extremely precarious, is a gift from God.