If you are a regular visitor to the San Diego Zoo, you may have noticed that our sun bears have been off exhibit recently. Instead, there have been several people working on their exhibit because our nimble little female, Pagi, told us it needed some work. She has been exploring the nooks and crannies of the exhibit lately and has been seen several times moving vertically and horizontally across the walls, clinging by little toe holds.
Sun bears are well known to be highly arboreal. In the wild, adults have been spotted napping far above ground. They even make themselves something of a night nest to rest upon, a little like orangutans might do. We have seen Marcella drag burlap or paper sacks up onto a platform to cozy up with, her version of a nest; Palu has done this, too. Sun bears also climb to take advantage of fruits of giant, old-growth trees. Some of these can be tens of meters high, but sun bears take this in stride. They learn to climb at a very young age. At 20 weeks old, our cubs have been observed scaling the walls of their bedroom enclosures, grabbing onto crevices in the ceiling with their claws!
Sun bears aren’t the only bears with amazing climbing skills. In fact, they may be outdone by their cousins, the Andean (or spectacled) bears. Our collaborators at a field site in Peru have seen wild bears there scaling sheer cliffs, even when they have the choice to go around such an obstacle (see post The Bear Goes Over the Mountain). They have been seen leading their young cubs, barely out of the den, up and down such land features. These astounding feats of bear acrobatics are a testament to the great strength and agility these bears possess.
It’s an amazing sight to see: a bear climbing vertical, sometimes overhanging, surfaces. Pagi’s innate athleticism has encouraged us to go over the exhibit with a fine-toothed comb to ensure there are no toe holds that could get a curious little bear into trouble. Funny, her brother, Palu, seems in no risk for such antics; while playful, he is more comfortable sticking closer to his mother than Pagi. Nonetheless, efforts to trim the overhanging vegetation and more detailed exhibit modifications are underway.
Suzanne Hall is a senior research technician for the San Diego Zoo’s Institute for Conservation Research.