Thanks to Anbo, Murilo, Clay, and Ezra for their suggestions this week! Let's learn about some bears! Further reading: Snack attack: Bears munch on ants and help plants grow Extinct vegetarian cave bear diet mystery unravelled Ancient brown bear genomes sheds light on Ice Age losses and survival The sloth bear has shaggy ears and floppy lips [photo from this site]: An absolute unit of a Kodiak bear in captivity [photo by S. Taheri - zoo, own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1118252]: A polar bear: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re revisiting a popular topic, bears! We’ll talk about some bears we’ve never covered before, with suggestions from Anbo, Clay, Ezra, and Murilo. We’ll even discuss a small bear mystery which has mostly been solved by science. To start us off, Anbo wanted to learn about bears in general. We’ve had bear episodes before, but our last episode all about bears was way back in 2017, in episode 42. Some of our listeners weren’t even born back then, which makes me feel super old. Bears live throughout much of the world today, but they evolved in North America around 38 million years ago. These ancestral bears were small, about the size of a raccoon, but they were successful. They spread into Asia via the land bridge Beringia, where they were even more successful than in North America, so successful that by around 30 million years ago, descendants of those earliest bear ancestors migrated from Asia back into North America. But it wasn’t until the Pleistocene around 2 ½ million years ago that bears really came into their own. That’s because bears are megafauna, and megafauna evolved mainly as an adaptation to increasingly cold climates. As the ice ages advanced, a lot of animals grew larger so they could stay warm more easily. Predators also had to grow larger as their prey became larger, since if you want to hunt an animal the size of a bison or woolly rhinoceros, you’d better be pretty big and strong yourself. Bears mostly weren’t hunting animals that big, though. Modern studies suggest that overall, bears are omnivores, not fully carnivorous. Bears eat a lot of plant material even if you don’t count the panda, which isn’t very closely related to other bears. Even when a bear does eat other animals, they’re not usually very big ones. Let’s take Murilo’s suggestion as an example, the sloth bear. The sloth bear lives in India and is increasingly vulnerable due to habitat loss and poaching. It’s probably most closely related to the sun bear that we talked about in episode 234, which also lives in parts of South Asia. Both the sun bear and the sloth bear have long black hair and a white or yellowish V-shaped marking on the chest. The sloth bear’s hair is especially long on its neck and shoulders, like a mane, and its ears even have long hair. The sloth bear stands around 3 feet high at the shoulder at most, or 91 cm, and a big male can be over 6 feet tall, or almost 2 meters, when he stands on his hind legs. This isn’t gigantic for bears in general, but it’s not small either. Scientists think the V-shaped marking on its chest warns tigers to leave the sloth bear alone, and tigers mostly do. If tigers think twice about attacking an animal, you know that animal has to be pretty tough. The sloth bear has massive claws on big paws. The claws can measure 4 inches long, or 10 cm, although they’re not very sharp. The bear has an especially long muzzle but its teeth aren’t very large. Like most bears, it’s good at climbing trees and can run quite fast, and it swims well too. It even has webbed toes. With all this in mind, what do you think the sloth bear eats? I’ll give you some more hints. It has loose, kind of flappy lips, especially the lower lip. It doesn’t have any teeth in the front of its upper jaw. It mainly uses its huge claws to dig.
