One good thing I can say about Capuchins is that they tend to be equal-opportunity bastards. That is, they don’t specifically target humans with their awful behavior. Rather, they are more than happy to terrorize, annoy, harass, rob, or poop on any kind of animal, as long as they aren’t a direct threat or potential food source. The shrieks, toothy threats, and falling branches that we endure as we follow them all day can also be directed at a number of other creatures, even other monkeys.
Guanacaste Dry Forest is also home to Black Mantled Howler Monkeys, and we regularly encounter them in the reserve. To us, they’re generally more of a distraction. Or a tease. I once spent several long minutes crashing through underbrush to stakeout a sleep tree where someone had seen monkeys the evening before. When I heard the first throaty beats, like an immense truck revving its engine, I knew that we’d been duped into tracking the wrong monkey and the morning was wasted.
But sometimes the two species encounter each other, and when they do, it rarely goes well for the howlers. See, as strict herbivores whose diet consists mostly of leaves, they tend to be sluggish and require a lot of sun-warmed siesta time to digest their food. They’re also heavier, and so they can’t climb on thinner branches or jump as far. This makes them easy prey for the Capuchins, when they get in their default mood of “let’s make life hell for everything around us.”
On an easy day, the worst the howlers have to endure is a few tail-pulls and dropped sticks. They react to this the way they react to most things: with nearly infra-sonic hoots and half-hearted attempts to move. But the other day the when the two troops overlapped in the same tree, the howlers had babies with them. That was when the Capuchins’ asshole dials went to 11.
Several adult capuchins lunged for the baby howlers, who were still riding on their mothers’ backs. Some were tiny–newborn, maybe. Had the capuchins grabbed them, they wouldn’t have stood a chance. As it happened, the females were trapped at the base of large branches. If they had attempted to climb, it would have exposed their babies to the little monkeys. They didn’t have the speed or claws to fight back.
In the end, one large male howler–who I can assume was the alpha–bullrushed the monkeys and sent the scattering, using nothing but his bulk as a weapon. It was the fastest I’ve ever seen a howler move, and sure enough, it worked. The capuchins fled, but stuck around long enough to bare their teeth some more from a safe distance.
What the capuchins were planning to do with the babies, I don’t know. Or, I probably do, but I’m not sure why. Would they have eaten them? While Capuchins commit infanticide all the times, there’s no record of cannibalism. But would it have counted with another monkey species? Did they view the howlers as a threat? Was this a demonstration of dominance among their own group? Were they just bored?
To the relief of myself and my new coworkers, no howler babies were killed that day. But we’re coming up on peak dry season now. Animal ranges shrink, and there is more competition around food and water sources. The forest dies back, and there is simply less to go around. Not everyone will survive. I’ve been warned to steel myself.