Watch this documentary by biologist Nick Baker on finding a wild three-toed pygmy sloth in the mangroves of Panama. Whilst two-toed and three-toed sloths are fairly abundant in the wild, pygmy sloths (about 40% the size of a normal three-toed sloth) are critically endangered. Only around 100 remain in the wild.
Skip to 39 minutes in for the finding of the pygmy sloth.