Blog #10: A Day with the Capuchins

Here at the field station, several teams of researchers busy themselves with their daily work, whatever their passion may be. Most keep to themselves as they come and go throughout the day. Some are here for only a short time. Others have sacrificed the comforts of modern-day living to stay here for a year or more in order to completely immerse themselves in their research.

One such team has been making our acquaintance over the last week or so, and I've found their work to be particularly fascinating. Their study pertains to the behavioral patterns of White-faced Capuchin Monkeys (Cebus capucinus), and requires that the team members rise before dawn each morning to follow the monkeys through the forest while documenting their every move.

Much of what interests me so much about ants is their social behaviors, so when Krisztina (one of the capuchin researchers) asked if I might want to join them for a day of observing the social behaviors of these monkeys in the field, I couldn't resist.

Krisztina asked me to meet her at just before 5 a.m., as it would take us about an hour to hike out to where the family of capuchins had settled the night before. Armed with plenty of water, walkie-talkies, and a device by which Krisztina would document each monkey’s every move, we set off to find them.

When we did, the group had recently awoken and were foraging for food (see Photo #1 below.) What I hadn't considered when agreeing to do this is that monkeys don’t follow any sort of trails. As obvious as this may seem, I don't think I’d mentally prepared myself for the amount of bushwhacking we’d be doing in the underbrush.

As the capuchins glided gracefully among the treetops (see Photo #2 below), we staggered up and over precipitous terrain and through thorny brambles and thickets. The pace at which we were moving was much faster than I ever imagined I could keep up with, but somehow I managed. I suddenly realized what great physical shape this team was in. It wasn't yet noon, and we must have already traversed over 10 miles.

As difficult as it was, however, I was having the time of my life. Krisztina explained to me that, because researchers had followed these monkeys daily since birth, our presence was as natural to them as anything else in the forest. This was apparent, as the group paid us no mind whatsoever. It was as if we were invisible to them. Our voices, our clambering around beneath them, drew no attention as they foraged for fruit and groomed each other (see Photo #3 below.) I was grateful when, during the hottest point of the afternoon, they decided to rest for a short time (see Photo #4 below.)

Capuchins make for valuable study subjects due to their high intelligence and familial social structure. Residing in such family-type units, capuchins are not territorial, but they can be aggressive toward members from other families. Each family usually consists of an alpha male and between one and three main females (see Photo #5 below.)

I was able to witness some of the hostility between alpha males when another family of capuchins interrupted the group’s afternoon rest. It appeared that the alpha male from this new family was interested in one of our family’s females. A raucous fight ensued, with loud screams between the females.

In fear, one of the females climbed down to the ground, as the others seemed to be settling the issue through loud screaming. This was my chance to get an up-close photo, and Photos #6 and #7 below show the anxiety on the female’s face as she watches the scene unfold. Once the alpha males had settled the issue, the passing family continued on their way, and the group that we were following went back to their normal routine of foraging and grooming.

The remainder of the day was much like the beginning and involved a large amount of hiking and bushwhacking (to see more of my monkey adventures, check out "Video Journal #8: More Cool Costa Rican Critters.") Twice while walking, I was brought suddenly to my knees by the sting of some sort of paper wasp (see Photo #8 below). It got me once in the shoulder/neck, and then in the knee. I'm not sure that I've ever felt anything quite like it.

It was an assault on my nervous system, and momentarily caused me to fall to the ground. It felt how I would imagine being shocked by a taser would feel. Once the initial shock wore off, a strange numbness crept in, along with swelling in my knee that turned various lumpy shades of purple and blue. While the ordeal was painful, I was admittedly fascinated to have been stung by something that gave me such a strange experience.

We returned back to the field station at around 5 p.m., 12 hours after leaving. Wild-eyed and exhausted, I recounted the day’s events to the rest of the team. If asked to do it again, I would in a heartbeat!

More soon,
Arista