Sloths Like Chocolate

Go ahead—call sloths chocoholics. The slow-moving mammals have a penchant for cacao plantations, new research shows.

Jonathan Pauli and Zach Peery, wildlife ecologists at the University of Wisconsin-Madison, have been studying brown-throated three-toed and Hoffmann's two-toed (above) sloths at a Costa Rican cacao plantation. Rather than clear-cutting the land, the trees, whose seeds are used to make chocolate, grow in the shade beneath the rainforest canopy.

The pair has found that sloths are abundant on the cacao farm but not on neighboring lands where farmers grow bananas and pineapples or raise cattle and where there is far less shade. "The sloths don't use the areas where the monocultures of bananas and pineapple are," Pauli says. "It's just not suitable habitat for them."

The finding lends strong credence to their theory that well-managed shade-grown crops like cacao might be key for maintaining biodiversity in the tropics. Other research shows that shade-grown coffee, for instance, provides sanctuary for neotropical migratory birds such as golden-winged and Kentucky warblers.

The researchers hope to compare the cacao plantation sloths to those in larger, more intact rainforest habitat. They also want to understand whether the animals can disperse—there are many narrow stretches of rainforest along the country's rivers—thus allowing them to mix with other populations and avoid inbreeding.

Meanwhile, the scientists are studying these elusive mammals' behavior with the aid of radio collars and DNA samples. They've learned, for instance, that male territorial boundaries overlap and that the brown two-toed sloths are promiscuous. "They're rather cryptic animals," Pauli says. "They can be hard to detect."

What's easy to sniff out, however, is that the smell of conservation success for sloths has a chocolatey aroma.

This article originally ran in the November-December issue as, "Slow Food."