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Photo of JoAnne Simerson JoAnne Simerson
Polar Bear Picnic


At the San Diego Zoo's Polar Bear Plunge exhibit, animal behaviorist JoAnne Simerson treats polar bears to a varied "enrichment program" designed to keep them happy and healthy. Read JoAnne's answers to viewers' questions about the programs she creates for the bears and her work with other species at the zoo.



q Since polar bears usually live in northern areas, how do you keep them cool in California's climate?

A Polar bears, in the wild, develop a layer of fat which is over four inches deep. They get this fat from the seals they eat. The bears at the San Diego Zoo have never been through an arctic winter and have never developed the thick fat layer. Although we built their exhibit so that we can chill their pool down to 55 degrees, we have found that they don't like to go in unless it's at least 60 degrees.




q I am 13 and I want to work with wild animals and help to save these species when I grow up so I am starting a little research for myself on all the animals. I was wondering if you could tell me something you think is an interesting fact about the polar bears.

A Most people don't realize that polar bears don't always live on the ice and snow. In some areas the snow and ice melt in the summer. During this time, the polar bear eats fruits and vegetation, just like their cousins the brown and black bears.



q Will you ever return the polar bears to the wild?

A The two young females at the San Diego Zoo were rescued from a town dump in Manitoba, Canada. They were only about seven months old and without their mother. Wildlife officers did not think that the cubs would be able to defend themselves from other adult bears, and make it through the coming winter without their mother's help. The cubs were taken into a rehabilitation center where they quickly adjusted to being fed by people. Unfortunately, large carnivores that begin to associate people with food cannot be returned to the wild. Otherwise it's dangerous for both people and animals.



q Are all polar bears white?

A Actually there aren't any white polar bears. Polar bear fur is made of hollow hair shafts. The impression of "white" comes from the light reflected off of the clear hair. Polar bears can appear white, grey, blue and even a creamy yellow depending on the light reflected. The yellow color is seen in bears that have been eating a lot of seal fat. The oil builds up and causes the yellowing.



q How did you get interested in working with polar bears?

A I'm very lucky in my job here at the San Diego Zoo because I work with so many different species. Part of my job responsibilities beside animal enrichment is training animals for better health care. We've trained many of the animals to get on scales for weighing and to open their mouths for dental checks. I love working with our polar bears. The youngsters are especially fun and challenging, but our oldest bear "Bonnie" holds a special place in my heart.



q I just finished watching your video with Alan in my classroom. I loved it so much, it was very interesting. Are you starting any new enrichment programs for the polar bears? If so, what are they?

A Our enrichment program is ongoing not only with polar bears but all the animals at the Zoo. Novelty is the best enrichment. We use all kinds of scents from spices, lotions, perfumes and smells from other animals in the Zoo. We use toys such as large plastic balls and boxes, logs, branches, sod and kelp. And every few months we put snow into the exhibit.



q In the video you are shown adding things like palm leaves in the polar bear exhibit. You said that the bears liked the leaves, but do you think that it might be sending the wrong message to children? When you show the polar bears with the palm leaves, children might associate the palm leaves with the polar bears' natural environment. How many areas have both polar bears and palm leaves other than zoos?

A The most important aspect of enrichment is to give the bears something to increase mental and physical activity. Novelty is an important part of this process. We feel we are limited only by the imagination. Our exhibit area has graphics and photos of polar bears in the wild, and we spend a lot of time talking to our guests about the animals here. Everyone understands that palm fronds are not a natural element of an arctic habitat. It is interesting to hear some of the misconceptions people have about polar bears, however. A great many people ask if polar bears eat penguins in the wild. The answer is, of course, no, penguins and polar bears live at different ends of the world.



q Do the polar bears become friendly? How close can you get to them and can you pet them? Are you ever afraid of them?

A Polar bears are large carnivorous bears. Here at the San Diego Zoo we never forget that fact. Although the keepers develop very strong bonds with the polar bears, they do this through observation, not contact. It's important to remember that a wild animal is always a wild animal, not a pet.



q Are polar bears endangered?

A Polar bears are not endangered. But if you want to check on the status of any animal you can check the Web site of the I.U.C.N. (International Union of Conservation and Nature) at http://www.iucn.org



q What is a polar bears favorite food? Why do you feed polar bears fat-free dressing instead of regular dressing?

A Here at the San Diego Zoo we have a nutritionist who keeps an eye on the diets of our animals. It's important that the animals eat balanced diets, with all the nutrients that their species needs. The polar bears here, given the opportunity, would fill up on their favorite foods, foods with a high fat content such as fish. In the wild, the fat would be burned off by exposure to cold temperatures. In San Diego, polar bears don't need to eat so much fat, and it might even lead health problems. Anything outside of their regular diet, such as Caesar salad dressing, needs to be calorie free.



q How long is a polar bear's gestation period? Do polar bears hibernate in the wild? If so, do they continue in the zoo?

A A polar bear's gestation period varies from 195-265 days. This variation is due to delayed implantation, where the undeveloped embryo is held in a kind of suspended animation for a short time. This suspension is an adaptation insuring that the baby will be born at the most propitious time. In fact, most babies are born while their mothers are hibernating. Only pregnant polar bears hibernate for any length of time.




 

Scientific American Frontiers
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