Why do sloths poop on the ground?

Abstract

The bizarre ground-based defecation behavior of two- and three-toed sloths remains one of the most paradoxical and humorous mysteries in canopy biology. Both two-toed (Choloepus sp.) and three-toed (Bradypus sp.) sloths defecate and urinate only once every 4–8 days in the wild. Although all other arboreal mammals release their excrement from the forest canopy, all sloths climb down from the treetops and relieve themselves on the forest floor. In the canopy, sloths have few predators, but on the ground, sloths expose themselves to great variety of predators. There must be some defining reason behind this high-risk behavior.