Written by R. Ellis
It isn’t often that New World monkeys depart from the safety of the towering trees they call home. In fact, when studying Neotropical primates, researchers spend most of their day looking up 20-30 meters into the canopy, watching the animals go about their lives in the skies. Some monkeys, like spiders and howlers, will come down to eat the mineral rich clay of salt licks, but it is very uncommon to see a woolly come down deliberately (falling out of the tree on accident, on the other hand, is a different story). Accordingly, it’s always exciting to see any arboreal monkey plant its toes into the terrestrial environment, but on this day, it was an extraordinary and exhilarating experience.
Kelley (the other assistant) and I were with Group C, one of my favorite groups, and had followed the monkeys as far as we could into a flooded region. Most had crossed over, and we were only left with Cora, an adult female, her juvenile male offspring, Colugo, and the collared adult male of Group C, Clash. There were about forty-five minutes left of the day, and the three of them weren’t up to much, half-heartedly foraging and chirping every once in a while. We were sitting down, when there was a slight movement in the canopy, nothing attention grabbing. Suddenly, we heard screaming and saw Colugo bolting out from above us across the canopy, moving through the branches as if his life depended on it. Right on his heels was Clash, vocalizing right back at him. And right behind him was Cora, trying to keep up with her panicked son, who was clambering awkwardly between the trees, nearly falling out once. Then, to our surprise, he actually did fall out after missing a jump between trees, about 20 meters from us. There was a liana tangle obstructing our view and we couldn’t see what happened to him so Kelley ran forward to investigate. I turned around to see how Clash reacted and was confronted by him jumping out of the tree less than 10 feet from where I was standing, seemingly in a trajectory toward me. My immediate thought was, “Is he rabid?” and I turned to escape him. However, he paid me no attention (a true sign of complete habituation if he felt comfortable enough to just jump out of the tree right next to me), and made a beeline to where Colugo had fallen. Kelley saw him chase Colugo across the forest floor for several seconds, eventually jumping back up into a tree, where he became cool as a cucumber, relaxing as if nothing had happened. Whatever reason he had for chasing Colugo to such a degree and then losing interest so quickly will always perplex me.
Meanwhile, we had no idea what happened to poor little Colugo, and neither did Cora. He kept running on the ground after Clash ended his pursuit, and Kelley wasn’t able to see where he went through the vegetation. Cora was chirping desperately and pathetically to no avail. We could see her moving her head, searching both the forest floor and the canopy for Colugo. She eventually gave up the search and settled down for bed, still chirping softly. Occasionally Clash would respond to her chirps, oblivious to the fact that he was the reason for their existence. As darkness approached, we reluctantly ended our follow. We were scheduled to wake up with them up in the morning, and to our surprise, they had already moved to where the rest of the group was. When we finally met up with them, we were relieved to see that Colugo was safe and back with his mom, happy as can be. But perhaps that unbridled happiness had to do with Clash being exiled to the periphery of the group the entire day…