Any day of the week, you will find visitors to the San Diego Zoo at Polar Bear Plunge watching every move Kalluk, Chinook, or Tatqiq make. Sometimes it may be something as simple as a yawn, stretch, or roll during an afternoon nap. But other times, visitors are rapt with attention while watching our bears wrestle with each other underwater, play with any number of enrichment items, or making eye contact and interacting through the glass with them. There is just something about polar bears that captures the imagination and attention of people of all ages.

In recent years, this fascination with polar bears has taken on a new dimension as the public has become aware of the possible fate of polar bears if global climate change continues to warm the Arctic and melt the sea ice. Can you imagine an Arctic without polar bears? I can’t! Researchers and animal care staff here at the San Diego Zoo, in collaboration with Polar Bears International, are doing everything we can to help polar bears survive in the wild through conservation-based scientific research and education.

Conservation Status of Polar Bears: How are they doing and what are the threats to their continued survival?

In the 1950s and 1960s, polar bears were reduced to as few as 5,000 individuals worldwide due to overhunting. The current total number of polar bears is estimated to be about 22,000 bears, divided amongst 19 subpopulations. The worldwide population has remained stable at this level for many years now, thanks to intensive management of hunting quotas. The rebound in the polar bear population numbers is a great reminder that humans can make a positive difference. Unfortunately, in recent years scientists are starting to see declines in population numbers in several subpopulations. These declines are undoubtedly the result of the loss of sea ice resulting from global climate change.

Through science-based management of hunting, and the fact that the Arctic has long been inhospitable to large-scale human development, polar bears are the only species of bear that still inhabits the entirety of its historic range. But that range, the Arctic sea ice, is disappearing at an alarming rate. If global climate warming continues at its current pace, the Arctic summer sea ice (that is, the ice that should be in the Arctic year-round) could be gone within 50 years. This stark statement is actually a relatively moderate prediction put forth by the ACIA (Arctic Climate Impact Assessment) working group, and is based on an average of predictions from various, reputable, climactic models. This prediction, along with others, prompted the Center for Biological Diversity to file a petition to the U.S. Fish and Wildlife Service in January of 2007 to list the polar bear as threatened under the Endangered Species Act (1972). The decision as to whether or not the polar bear should be “listed” under the ESA is imminent, and most polar bear biologists agree that “all, or a significant proportion of the total population [of polar bears] will become endangered in the foreseeable future” if no action is taken.

What does this mean for polar bears? Action needs to be taken to slow down, and ultimately reverse, the melting of the Arctic sea ice because polar bears (and many other animals) depend on this sea ice to survive. They feed on it, they find each other and breed on it, and many females’ den and give birth to cubs on it. Although polar bears are adept swimmers and are classified as marine mammals under the Marine Mammal Protection Act (1973), they are not adapted to a fully aquatic existence in the way that seals and whales are. The marine environment in which they thrive is that frozen platform of ocean that gives them an ideal perch from which to hunt seals. The fat from these seals provides polar bears with all the calories they need to survive in the Arctic cold. In fact, polar bears typically only eat the fat from the seals, leaving the remaining carcass for Arctic foxes and other scavengers. Polar bears, like all bears, will feed opportunistically on other food items. But the nutrition gained from these other sources simply does not provide the energy that a polar bear requires to survive.

Zoo Based Research: Filling in the details

Although exhibiting happy and healthy animals is a major focus of our work here at the San Diego Zoo, another of our goals is to study the animals in our charge in a scientific and systematic way. By making this a priority, we are contributing to the body of knowledge on polar bears and other animals that allows for good management in the wild. Polar bears can be difficult to study in the wild. Their harsh Arctic habitat and vastly roaming, solitary lifestyle makes the study of certain aspects of their biology virtually impossible. An example of this would be how their sensory systems are tailored to the environment in which they live, and how sensitive are these senses to human disturbance. At the San Diego Zoo, scientists are leading research that will help clarify how polar bears perceive the world around them. Some of our projects:

Polar Bear Hearing Sensitivity: Wildlife managers are concerned about the noise emitted from human industrial activities (such as petroleum exploration and extraction). But how sensitive are polar bears to noise? Researchers from our Zoo, in collaboration with Hubbs-SeaWorld Research Institute, and animal care staff from both institutions, are completing research that will tell us a lot about how sensitive polar bear hearing is (see blog: Can You Hear Me Now?).

Scent Communication: As warming in the Arctic and the level of fragmentation of the polar bears’ sea ice habitat increases, how will this impact their ability to find each other over hundreds of miles during the breeding season? For that matter, how do they find each other over hundreds of miles? Again, researchers from the San Diego Zoo, with support from Polar Bears International, and participation from zoos around the country, are embarking on research that will give us insight into how important olfactory (aka scent) communication is to polar bears when they need to find each other over great distances (see blog: Is It the Perfume?).

Zoo Experience: A first-hand education in the beauty and inherent value of polar bears

San Diego is an enormously popular tourist destination, and one of the star attractions for any visitor is a trip to the San Diego Zoo or Wild Animal Park. For those of us who work here at the Zoo, we see this as a golden opportunity to not only introduce people to the beauty and wonder of polar bears and other exotic animals, but to let people know what these animals need to survive and thrive in the wild. Photographs and words can bring people closer to wildlife and enhance one’s appreciation for animals, but there is nothing like a polar bear swimming gracefully in the water a few feet away to convince people that they are majestic creatures truly deserving of our stewardship and protection. Couple this experience with some basic information regarding what polar bears need to survive in the wild, and how an average person can make a difference, and you have a life changing conservation experience.

Conservation in Action: What can you do to help the polar bear?

You’ve probably heard it before: Reduce, Re-Use, Recycle! These three words can guide each and every one of us to a lifestyle that will help the environment, reduce greenhouse gases, and help slow-down, and ultimately reverse, global climate change. Every year the average American produces about 7 tons of CO2 (the primary greenhouse gas responsible for global temperature change). Simple actions, such as driving less and in fuel-efficient vehicles, can greatly reduce this number. The take-home message is that we can all make a difference: By changing the way we live in our homes, we can help polar bears survive in their home. To learn more about what you can do to cut down on your CO2 emissions, join Polar Bears International’s “Project Polar Bear.” This innovative program is a great way for young people to make a big difference and help reduce atmospheric levels of CO2.

Megan Owen is a conservation program specialist in the San Diego Zoo’s Applied Animal Ecology Division.

View the Zoo’s polar bears daily on Polar Cam…
Listen to an iZoofari Chat about polar bears with Megan…

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