Saturday, October 10, the San Diego Zoo is holding the 4th annual Walk on the Wild Side presented by USA Fed Credit Union event. This year the funds raised will go toward our work with our conservation partner Polar Bears International. Thank you to all the teams that have signed up to walk and to everyone who has pledged a donation! Chinook, Kalluk, and Tatqiq wish your feet well.
This is a great opportunity to talk about polar bear feet. First and foremost: they are large! Some males’ feet can grow to 12 inches (30 centimeters) wide. The front feet are round and the back feet are elongated. They have five toes on each foot, and each toe has a cleat-shaped, non-retractable claw. The bottoms of their feet have fur growing around each pad. This fur grows very long as the bear ages. I have seen some bears in the wild with fabulous furry slippers from the long fur that surrounds each foot. The pads of a polar bear foot have many tiny soft bumps called papillae. These help to create friction when walking on the ice so as to decrease slipping.
One of the only places on a polar bear’s body that it loses body heat is the feet. A polar bear’s body temperature is 98.6 degrees Fahrenheit (37 degrees Celsuis). Polar bears walk across flat ice, and the heat from their paws causes the ice to melt ever so slightly. If the snow is blowing, you can see where the snow then refreezes to the paw print. This makes for beautiful photos of polar bear prints across the flat ice.
What do polar bear prints tell you about the bear? The size can tell how large the bear is, potentially the age, and if you’re seeing a mother and cub. Cubs often walk in their mother’s prints, mimicking everything she does to learn about their world. Following polar bear prints can also tell you if a bear was walking or running. If a polar bear is walking at a normal pace, the back foot is placed where the front foot had been. If a polar bear picks up its pace, the hind foot is placed further away from the front foot, and all four prints can then be seen. The prints of a walking polar bear appear only as two feet. This is one of the reasons so many native stories talk about polar bears as being human and walking upright.
Polar bear feet also hold a key to polar bear communication (see post, Polar Bears: Is it the Perfume?). The foot of the polar bear has apocrine glands just as our skin does. The scent coming from these glands may give important information for safety, identification, or timing of breeding between bears. You can imagine the critical aspect of this if the scent path of polar bears disappears with the ice. We know our Kalluk is always enthralled by the scent of Chinook’s foot path around breeding season. This is often the first behavioral clue we see that things are changing. He presses his nose against her print, spreads his nostrils, and slurps and inhales all at the same time. If he is inside, the sound travels throughout the building, putting human’s noisy soup-slurping to shame!
As you walk around town, keep in mind the furry feet of our polar bear friends. Continue doing all you can to conserve. Walk a little more to reduce your footprint. And thank you for supporting our efforts to learn more about polar bears and save their habitat. See you Saturday!
JoAnne Simerson is a senior keeper at the San Diego Zoo. Read her previous post, Polar Bear Happenings.
Note: To participate in the Walk on the Wild Side, sponsor a participant, or make a donation, click here…
Watch the Zoo’s polar bears daily on Polar Cam.