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Sloths starve even with full bellies

They've got food in their stomach, but they're still starving. Here's the strange reason why

By Smartasaurus· 1 min read Wild

A three-toed sloth can have a belly completely full of fresh…

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The short version
  • They've got food in their stomach, but they're still starving. Here's the strange reason why
  • Because digestion is so energy-intensive, the sloth lives on a razor-thin metabolic budget.
  • In a strange twist of biology, the sloth’s fur grows in the opposite direction of most mammals—away from its extremities—to allow rainwater to run…

A three-toed sloth takes up to 30 days to digest a single leaf. Its stomach is a massive, four-chambered fermentation vat that makes up a third of its total body weight, filled with specialized bacteria that slowly grind down tough cellulose.

This process is so sluggish that if a sloth gets too cold, the bacteria in its gut stop working entirely. The sloth can have a belly full of leaves and still starve to death because it can no longer extract nutrients from the food sitting inside it. It effectively freezes its own fuel line.

Because digestion is so energy-intensive, the sloth lives on a razor-thin metabolic budget. It only leaves the safety of the canopy once a week to use the bathroom. This trip is the most dangerous moment of its life, as it loses up to one-third of its body weight in a single sitting on the forest floor.

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What secrets hide past a black hole's edge
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