the base of the tree; 2) cover feces and avoid predation; 3) chemical communication between individuals; 4) pick up trace nutrients in their claws, that are then ingested; and 5) favor a mutualistic relationship with populations of fur moths. More recently, a new hypothesis has emerged, which presents evidence against the previous ones and proposes that all current sloths are descendants from species that defecated on the ground, and there simply has not been enough selective pressure to abandon this behavior, since cases of predation during defecation are actually very rare. In addition to the algae in their fur, brown-throated sloths also live commensally with a species of moth, Cryptoses choloepi, which lives in their fur, and lays its eggs in the dung. Jaguars and harpy eagles are among the few natural predators of the brown-throated sloth. The yellow-headed caracara has been observed to forage for small invertebrates in the fur of the sloths, apparently without the sloth being disturbed by the attention. The female of the species is known to emit a loud, shrill scream during the mating season to attract males. Its cry sounds like "ay ay", much like that of a woman screaming. The male can be identified by a black stripe surrounded by orange fur on its back between the shoulders. Reproduction Brown-throated sloths have a polygynous mating system. Studies of the brown-throated sloth indicate that mating is most common between January and March in at least the northern parts of its range, but this may vary elsewhere. Gestation lasts at least seven months, and the single young is born fully furred and clawed. Young sloths cling to the mother's underside for five months or more, even though they are fully weaned after just four to five weeks. The mammary glands of the females do not store significant quantities of milk as most other mammals do, since the infant sloth remains attached to the nipple at all times, and consumes the milk as soon as it is generated. The young begin to take solid food as early as four days after birth, initially licking particles of food from their mother's mouths. This process apparently allows them to quickly identify edible leaves, and young sloths typically have the same preferences for leaf types as their mothers. In the wild, the lifespan of adult brown-throated three-toed sloths is typically between 30 and 40 years. Taxonomy The brown-throated sloth