On a recent trip to Costa Rica my friends and I had an unexpected encounter with a Hoffmann’s two-toed sloth that challenged my perception of a sloth as being a clumsy, slow animal.
We were at Tirimbina Biological Station, on the Caribbean slopes of the Continental Divide. Tirimbina is well known for its suspension bridges, on of which is the country’s longest and possibly doggiest, stretching for 262 meters above Sarapiqui River. The second bridge stretches through the canopy of primary forest 35 meters above ground.
One morning after a rainy night we were standing on the Canopy bridge watching the small stream meandering through the jungle floor below, hoping to spot a thirsty mammal coming in for a drink. We were so intent on looking away from the bridge that I got a fright when out of the corner on my eye I saw a large shape approaching us along the top support cable of the bridge. When I turned around I could barely believe my eyes. A female sloth with a young clinging to her belly was steadily making her way across in broad day light. She was already no more than 3 meters away from us. Since she looked a bit miserable, wet from the night’s rain, we decided that she was eager to get to the top of the canopy to find a sunny spot to dry out. And she was making impressive progress. Nowhere near as slowly as I would imagine a sloth to move, she was weaving her way around the vertical cables of the bridge. She seemed incredibly agile.
All but ignoring us she passed right above our heads heading for the opposite end of the bridge. Once she got level with the trees growing next to the bridge she started looking for a way to climb onto the trees, but there were only thin and wobbly lianas within her reach. We were certain she would realize the futility of her attempts and find a better spot to cross over. There was no way such an ungainly animal would make such a delicate crossing.
But she proved us wrong. Without much hesitation she grabbed the closest liana, lifted herself up and with just a couple of movements she maneuvered herself onto the tree. I was absolutely and totally impressed.
Once she made it onto the firm branches of the trees, she let her young go for a little wander – must’ve needed a rest after such an epic adventure.