Transcript:

Program #5196

Science Diary: Monkeys Howler Crop Raiders

music; ambience howler monkeys

“You’re hearing a troupe of mantled howler monkeys. They are in a mango plantation, where they raid the crops and they enjoy mangos for about six weeks out of the year.”

Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside. Earthwatch scientist Tracy McKinney studies howler monkeys in the forests of Costa Rica.

[ambience: howlers]

They’re calling right now in response to another troupe of monkeys that are fairly nearby, and the reason howlers call most of the time is as a form of territorial defense. They have to minimize their energy expenditure, because they’re mostly leaf eaters. So they don’t want to waste time running around defending their territory. So they use vocalizations instead. And so these calls pretty much mean, These are our mangos. Stay out.’ The softer ooh-ooh-ooh’ sound that he’s making right now probably has as much to do with me and the tourists who just came by and the dog who’s hanging out here as with the monkeys. It’s more of a slight stress call.

[monkeys give a slight stress call]

“This is an excellent example of monkeys living in a human-altered environment. They’re living right in the middle of a mango plantation. These are not the types of trees monkeys would normally deal with in the wild. They’re all the same tree; there’s no real diversity here. But they’re making use of this for the few weeks of the year that mangos are in season. The monkeys are right here, and they forage as much as they can. So even though they’re mostly leaf eaters, howlers will take a lot of fruit, because it’s high in calories, high in sugar. It’s a good food for them if it’s available. And so they take advantage of it.”

This strategy has helped the howlers survive in spite of the deforestation of their natural habitat.

Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.