Sloths are slow-moving mammals inhabiting the rainforests of Central and South America. Their unhurried pace extends to every aspect of their lives, including their unique digestive processes. This deliberate lifestyle is an adaptation to their environment, influencing even their basic bodily functions.
The Peculiar Ritual of Sloth Defecation
Sloths engage in a peculiar ritual when they need to defecate. Unlike most arboreal animals that excrete from the trees, sloths descend to the forest floor for this purpose. This weekly or bi-weekly event is a significant undertaking, involving a slow climb down the tree trunk. Once on the ground, some sloths, particularly three-toed species, perform a “poo dance,” digging a small hole and then partially covering the waste.
The actual act of defecation is relatively quick, lasting only a few minutes. However, the entire process, including the descent and ascent, can take up to an hour or more. Sloths can expel a surprisingly large amount of waste during a single bowel movement, sometimes losing up to one-third of their body weight. This highlights the infrequent nature of their bathroom breaks.
Biological Reasons for the Duration
The extended duration between defecations in sloths is rooted in their unique biology and diet. Sloths primarily consume leaves, which are low in nutritional value and difficult for most animals to digest. To cope with this low-energy food source, sloths have an extremely slow metabolic rate, which is only about 40-45% of typical for their body weight. This slow metabolism means their digestive process is exceptionally sluggish.
It can take a sloth anywhere from 11 to 30 days, with an average of 16 days, to fully digest a single leaf. This is the slowest digestion rate recorded for any mammal. Their multi-chambered stomachs, similar to ruminants, contain specialized bacteria that ferment and break down the tough plant material, but this process requires considerable time and energy. Because their stomachs are constantly full, sloths cannot ingest much food daily, contributing to their low energy budget. Expelling waste is also an energy-intensive process for them, and their bodies prioritize conserving energy, leading to infrequent bowel movements.
The Dangerous Descent
Sloths typically descend from the canopy once a week to defecate, a behavior that carries significant risks. This journey to the ground makes them vulnerable to predators such as jaguars, ocelots, and harpy eagles. Over half of all sloth deaths are estimated to occur during these risky trips to the forest floor.
The descent and the act of defecation demand a considerable amount of energy from these already low-energy animals. Scientists estimate that each trip to the ground can cost a sloth approximately 8% of its daily energy needs. While the exact evolutionary reasons for this risky behavior are debated, theories include nutrient cycling, where the concentrated waste fertilizes the trees they inhabit, and communication with other sloths through scent marking at specific “latrine” sites. Another hypothesis suggests it supports a symbiotic relationship with sloth moths, which lay eggs in the feces.