Sloths' fur provides a feast for hungry birds

© Thomas Marent/Visuals Unlimited/Corbis

Sloths' fur provides a feast for hungry birds

While the three-toed sloth dines on leaves, other animals dine on the sloth. The sloth's fur is chock-full of moths (as well as other insects, algae, and fungi), which spend much of their lives on its back—using it like a matchmaking service to help them find mates, and laying their eggs in the sloth's poop, which nourishes their larvae. Now scientists report this month in Frontiers in Ecology and the Environment that hungry brown jays feast on this moving buffet of insects (as seen in this video). But is the brown jay friend or foe of the sloth? That depends on whether the tree-dwelling mammals benefit from their moth companions or merely tolerate them. Recent research suggests that sloths are gardeners, cultivating and eating the algae on their fur for the purpose of supplementing their diets. In that case, the moths are an essential player, as they act like fertilizer—when they die, the algae consume the nutrients in their remains. So sloths might be wise to bat away the moth-eating birds, if they can stand to lift a lethargic limb.