Moths Are a Sloth’s Best Friend

Scientists propose that the three-toed sloth’s risky bathroom behavior is governed by mutualisms with moths and algae.

By | January 22, 2014

FLICKR, BILLTACULARThe three-toed sloth exhibits some pretty strange defecation behavior: once a week, the slow-moving mammals descend from the safety of their treetop perches to poop. But why these sloths would leave the comfort of the canopy and risk predation, among other things, has been somewhat of a mystery. Now, researchers at the University of Wisconsin-Madison propose that behavior helps to sustain an ecosystem within the animal’s fur that confers nutritional benefits. Their work was published today (January 22) in Proceedings of the Royal Society B.

The researchers found that three-toed sloths can harbor more phoretic moths than their two-toed counterparts because of greater concentrations of inorganic nitrogen and higher algal biomass in their fur. In turn, the researchers found that the moths increase algal growth, providing more sustenance for the algae-eating sloths. “By descending a tree to defecate, sloths transport moths to their oviposition sites in sloth dung, which facilitates moth colonization of sloth fur,” the authors wrote. “These linked mutualisms between moths, sloths, and algae appear to aid the sloth in overcoming a highly constrained lifestyle.”

But the University of São Paulo’s Adriano Chiarello, who was not involved in the work, is not entirely convinced that these mutualistic relationships are firm. Spending many hours observing these animals in the wild, “we never saw sloths behaving in a way that might suggest or indicate that they were somehow extracting algae or other nutrients from their fur,” Chiarello told National Georgraphic’s Not Exactly Rocket Science. However, he added: “Testing [this] hypothesis with sloths is not easy as they are difficult to capture and observe in their natural environment. . . . The authors are making their best with available data.”

Add a Comment

Avatar of: You



Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo

Popular Now

  1. Male Fish Borrows Egg to Clone Itself
  2. How to Tell a Person’s “Brain Age”
  3. Life Science Funding Cuts Leaked
    The Nutshell Life Science Funding Cuts Leaked

    According to a document posted online less than a day before the release of the official 2018 budget proposal, the National Institutes of Health could face even deeper cuts than previously suggested by the Trump administration.

  4. Cooking Up Cancer?
    Notebook Cooking Up Cancer?

    Overcooked potatoes and burnt toast contain acrylamide, a potential carcinogen that researchers have struggled to reliably link to human cancers.