The Sloth – A Weird and Wonderful Animal

SlothThe sloth is the only animal I know of that was named after one of the seven deadly sins.

The Sloth is slow. He hangs upside down on tree branches. He has so much algae growing on his fur that he looks green. His claws are so long and curved that walking on the ground is almost impossible. Friends who visited Costa Rica told me that a sloth makes a very good pet (they certainly can’t run away from you like a cat or husky will). But in much of the early literature on the sloth, they were held in remarkable contempt. ‘Cause they’re slow.

You don’t usually think of a scientist making moral judgements about the behavior of animals, but here’s what the great French naturalist Georges Buffon said about sloths in his eighteenth-century book Histoire naturelle:

“… we must speak more of wretchedness than laziness–more of default, deprivation, and defect in their constitution: no incisor or canine teeth, small and covered eyes, a thick and heavy jaw, flattened hair that looks like dried grass…legs too short, badly turned, and badly terminated….Slowness, stupidity, neglect of its own body, and even habitual sadness, result from this bizarre and neglected conformation…These sloths are the lowest term of existence in the order of animals with flesh and blood; one more defect would have made their existence impossible.”

Gee, you’d think Mr. Buffon didn’t like sloths very much, wouldn’t you?

Here are some interesting facts about sloths –

Their body temperature is much lower than most mammals, varying between 82 and 90 degrees.

  • They have lots of teeth, but they are related to anteaters, who have no teeth at all.
  • They sleep about 18 hours a day (upside down), and spend almost all of their lives hanging in trees, where their slowness and greeness makes them very difficult to see.
  • They come down from their trees once every 8 days or so, to deficate and urinate (everything about a sloth is slow).
  • While almost all mammals on earth have seven neck vertebrae, (even giraffes), the two toed sloth has six, and the three toed sloth has nine. Because of the extra vertebrae, the three toed sloth can turn it’s head around farther than any other mammal.

The best place to learn about sloths is at your local zoo, where you’ll find these slow-moving (but maybe not really “lazy”) creatures hanging upside down in the nocturnal house.

I got most of my information from a chapter in the book Leonardo’s Mountain of Clams and the Diet of Worms, by Stephen Jay Gould, who has written some of my favorite books on the subject of animals, paleontology and evolution. He passed away this year, and he will be sorely missed.

Be sure to check out this site about the Giant Ground Sloth, an extinct species from southern California and Mexico, that weighed a ton and had armor plating on it’s shoulders.