By Susan Milius
A tree-dwelling sloth’s climb down to ground level for its weekly bathroom break may not be pointless daintiness.
The trip is risky and (for a sloth) energetically expensive. Yet the effort could be the sloth’s contribution to a mutually beneficial, three-way partnership. The sloth’s trips seem to encourage moths that mate in the mammal’s fur and algae that thrive on moth detritus, suggests Jonathan Pauli of the University of Wisconsin-Madison.
The payoff for the sloth, after a Rube Goldberg-like string of actions by the other partners, could be rich blooms of nutritious algae to eat off its own fur, Pauli and his colleagues propose January 22 in the Proceedings of the Royal Society B.