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Polar Bears

78

Spring Cleaning for Polar Bears

Tatqiq really enjoyed her snow day last year!

Tatqiq really enjoyed her snow day last year!

The San Diego Zoo’s polar bears will be off exhibit through today while we spruce up their exhibit a bit. Our goal is to provide a dynamic environment for the bears. It is quite the undertaking to move around all of those giant root balls and logs in the exhibit, as well as bring in new ones.

We brought in a crane to lift a 5,000-pound root ball from the elephant yard and place it in the polar exhibit. We hope to be able to do this at least two to three times a year to change up the exhibit for our bears. A wild polar bear’s environment is constantly changing due to the movement of the sea ice, and we feel it is important for our bears as well. We want them to have an exhibit and a home that isn’t always the same every time they leave the bedrooms. At this time you will also see a completely empty exhibit pool. All 150,000 gallons were drained so that we could go in to steam clean and pressure wash the entire surface of the pool. This is something we do once or twice a year.

In addition to moving around existing exhibit features and bringing in new ones, we will also be completely changing their exhibit on Saturday, May 17, by bringing in 18 tons of ice that will be run through a chipper to create snow for our bears. They will have a blast sliding down the hills, tunneling through the snow, and searching for things that we have buried. Generally the snow lasts for four to six days, but with the warm weather we are currently experiencing in San Diego, it could be gone in a day or two.

We hope you will be able to join us on Saturday, May 17, either in person or on Polar Cam so that you can witness all the fun before the snow is gone.

The Polar Bear Team

4

Climate Change: Polar bears, Sea Ice, and Beyond

Kalluk enjoys last year's snow day at the San Diego Zoo.

Kalluk enjoys last year’s snow day at the San Diego Zoo.

Climate change is back in the news and, unfortunately, the news has not been good. A number of recent reports indicate that carbon dioxide in our atmosphere has reached unprecedented levels. At over 400 parts per million, we have reached a number that would have seemed unimaginable just decades ago. But while the scale of this problem is immense, the real power for changing the current trend is within each of us. The choices we make—what we buy, how we spend our time—can lead to dramatic differences in our carbon footprint. It is possible to reverse the current trend if we all commit to changing our daily habits.

There is a vast array of information now available that outlines the many-faceted ways that the changing climate will impact people and ecosystems all over the world. From extreme weather to climate warming, the reach of climate change is broad. And the reason our climate is changing is known: human activities have driven the release of unprecedented levels of carbon dioxide into the Earth’s atmosphere. Carbon dioxide (CO2) is a greenhouse gas that effectively blankets the Earth, increasing the amount of heat that stays in our atmosphere. And while we typically associate carbon dioxide emissions with the burning of fossil fuels, such as gas and coal, there are other sources as well that are not as well known. One of the largest contributors to atmospheric carbon is deforestation. Each year, the burning and clearing of tropical forests contributes over 2 billion tons of carbon pollution to the atmosphere.

At the San Diego Zoo, our mission is to connect people to wildlife because that connection can be a powerful force for conservation. I can speak from personal experience as to the power of that connection. Destined for medical school, my career path shifted dramatically because of a chance connection with wildlife. For me, that connection started with the polar bear, a species whose plight has provided some of the defining images associated with climate change, a species whose future we hold in our hands.

As a graduate student, my first field season was spent working out of a remote field camp on the western Hudson Bay, about 15 miles east of Churchill, Manitoba (a.k.a. the Polar Bear Capital of the World). This area, so nicknamed because of the large number of polar bears that congregate there in the fall, was also home to an incredible array of wildlife, including Arctic nesting birds, large herds of caribou, and beluga whales. While polar bears are most numerous and visible during the fall, the bears actually start coming ashore during the summer as the ice on the Bay begins to melt out, and the bears are forced ashore to begin a long fast.

Our field research was primarily done on foot, with miles and miles of walking over the course of the long Arctic summer days, and the possibility of bumping into a polar bear meant that safety measures were taken seriously and practiced regularly. The most basic and important safety measure we had while walking in the field was to scan the horizon with binoculars every few minute, in hopes of spotting any polar bears in the vicinity while they were still a good distance away. On the day I saw my first bear, it was relatively early in the season for polar bears, but the ice had begun to break up on the Bay, a harbinger of polar bears to come. Scan after scan, I saw nothing and continued with my work. And then suddenly, I looked up, and saw a young male bear easily without binoculars, less than 50 feet away. How long had he been following me? Luckily, I was able to make my way safely back to camp. And while it was truly scary to see a bear so close, it was also an event that left an enormous impression on me. It initiated my love of the species and cemented my passion for conserving wildlife and wild places.

Around that same time (the mid-1990s), biologists studying polar bears in the Canadian Arctic documented changes that were occurring within that population of polar bears. These scientists found that reductions in reproductive parameters were correlated with the warming air temperatures that had been documented between 1950 and 1990 and, most importantly, with an increasingly long period where the Hudson Bay was ice free. Because polar bears are completely dependent upon the sea ice for their survival, the directional trend toward less and less ice was of great concern. Twenty years later, I am happy to say that the polar bear is one of the species that I get to study, but saddened to say that the Earth’s CO2 emissions have continued to increase and that the impacts of climate change on polar bears have intensified. No other species better illustrates the impact of climate change on wildlife. Like a real-life version of the game “Break the Ice,” the polar bear’s habitat is disappearing, the ice literally melting at their feet. Their fate is in our hands.

Chinook and Kalluk have been breeding for the past couple of weeks, and we are hopeful, as in years past, that this breeding season will result in the birth of a polar cub in the fall. We will monitor Chinook closely for behavioral and physiological signs of pregnancy and learn as much as we can about the reproductive biology of these amazing animals. Keepers, researchers, and visitors alike have an amazing opportunity to observe our bears in the water and on land at the San Diego Zoo, and in so doing, learn about climate change and the impact that this human-driven change is having on wild polar bears and the Arctic sea ice environment. Polar bears exemplify the role of “conservation ambassadors,” and it is hard to deny the impressive nature of their strength, intelligence, and adaptations to life on the frozen Arctic Ocean.

Climate change may sound like old news to some. Images of polar bears stranded on ice floes were once a common sight in the popular press, but like most news stories, many people have moved on. Unfortunately, climate change has not gone away, and the negative impacts of sea-ice losses on polar bears continue to eke away at their once-pristine Arctic home. I am hopeful that the reemergence of climate change into the news cycle will invigorate people’s interest in doing their part to reverse the trends in CO2 emissions. I am hopeful also that we all seek those connections to nature and wildlife that are so important for engaging us in conservation issues. We can all make a difference.

For those who love our polar bears, and for those who are interested in learning more about how climate change is impacting the species’ Arctic sea ice habitat, I recommend visiting the National Snow and Ice Data Center (NSIDC) website. This page provides daily updates on sea ice conditions in the polar regions, as well as year by year interactive graphics of the dynamic changes in sea ice extent.

Megan Owen is an associate director with the San Diego Zoo Institute for Conservation Research. Read her previous post, Our Panda Conservation Program.

14

Tatqiq: Odd Bear Out

Tatqiq is sure to enjoy Snow Day on Saturday, May 17, 2014!

Tatqiq is sure to enjoy Snow Day on Saturday, May 17, 2014!

Breeding season for polar bears is typically January through June. For Kalluk and Chinook in particular, it can happen anytime in that window. This year, the breeding window began on April 23, 2014, and usually lasts anywhere from 4 to 14 days. In 2013, it occurred in January and only lasted four days. This year, we are seven days into the process and breeding is still happening. However, the frequency has diminished quite a bit from the first few days.

Science still knows very little about polar bear reproduction. What we do know is that polar bears are both induced “ovulators” and delayed “implanters.”

Induced ovulation means that the females don’t have a normal estrus cycle like many mammals do. Male bears follow around females for days or weeks at a time, “wining and dining” them until they are receptive to breeding. Once ovulation is induced, then breeding will commence.

Delayed implantation is tricky because it makes gestation periods and birth dates difficult to predict. Unlike most mammals, after polar bears successfully copulate, they are not immediately pregnant. The fertilized egg remains in a suspended state until conditions are right, at which point the egg implants in the uterus and gestation can begin.

Until late May/early June, Tatqiq is, unfortunately, the odd bear out. Chinook’s hormones are raging, and she is less tolerant of Tatqiq during this time period. Kalluk generally does a good job of breaking up squabbles and moving his sister to a safer spot away from Chinook. If you have been watching the Polar Cam in recent weeks, you have probably noticed Tatqiq seeking refuge in the back corner near the waterfall. This is her safety zone and the spot where she feels she can best defend herself. It is our job as keepers to recognize these changes in behavior and adapt our management strategy. Because of the increased tension between the two females, you will usually only see Kalluk and Chinook on exhibit after 12:30 p.m. When the keepers pull the bears off exhibit for their final meal of the day, we give Tatqiq the polar bear penthouse where she has her own private pool, grass, trees, and air-conditioned bedrooms.

Once breeding season is over, you will again see Kalluk and Tatqiq playing together and there will be less aggression between the two females. Be sure to watch the action daily on Polar Cam!

The Polar Bear Team

34

Spring in Air for Polar Bears

Kalluk digs a pile of snow.

Kalluk digs a pile of snow.

For those of us who live in San Diego, it nearly always feels like spring. (Sorry to those who are experiencing the polar vortex that hit a majority of the country recently!) Despite our consistent temperatures in San Diego, our polar bears follow seasonal changes similar to their wild counterparts in the Arctic.

We recently completed denning season, which normally occurs in the fall months (see Is Chinook Pregnant?). Now we are expecting to start a new cycle: breeding season! Those of you watching our Polar Cam may have noticed three bears on exhibit again. Chinook was reintroduced to Kalluk and Tatqiq after her months of requested seclusion. Chinook was showing some interesting behaviors associated with den making, but we eventually determined that she would not have cubs this time around.

The reintroduction went smoothly, and all the bears acted calmly. At first, Kalluk followed Chinook very closely while she walked around the exhibit. Then they both jumped into the pool for over an hour of play. Eventually, Kalluk was able to separate himself from Chinook, and all the bears rested in their favorite spots in Polar Bear Plunge.

Kalluk has been showing signs that he is getting ready for breeding season, such as an increased interest in sniffing Chinook’s footsteps and urine. However, Chinook is mainly acting coy and disinterested in Kalluk other than play (which certainly could be interpreted as slightly flirtatious behavior). Stay tuned as the saga continues…

Polar Bear Team

43

Is Chinook Pregnant?

Chinook, left, and Kalluk frolicked in the snow a few months ago.

Chinook, left, and Kalluk frolicked in the snow a few months ago.

Around this time of year for the past few years, the number one question we are asked by those familiar with our polar bears is “Is Chinook pregnant?” We nearly always answer with “We sure hope so, but….” Some of you may wonder why we are so elusive with our answer year after year. There are a number of reasons, none of them clandestine. Mainly, the polar bear community is still searching for all the answers. Things are complex in the polar bear world!

Did you know that polar bears have a wide range for gestation, spanning from 164 to 294 days in the wild (195 to 265 days in managed care)? If we determined possible birth on this information alone, this year Chinook could have given birth from July through September, based on when she bred with our male, Kalluk. However, we are aware of research that has studied historic data of births of wild bears and with other observations in the wild. It is hypothesized that date of breeding may not solely determine date of possible birth. Instead, it is a little more complicated than counting days from breeding time. Births generally occur between November and December, with the occasional birth outside those months even when breeding occurs in January, for example (when Kalluk and Chinook bred). Lastly, female polar bears have both induced ovulation and delayed implantation, which makes determining timing and the triggers involved difficult.

We are trying! Through research, we are continuing to learn more and more. Every other day, we collect urine samples from Chinook and fecal samples three times per week, all for hormone analysis. With Chinook’s full cooperation, we perform ultrasound exams weekly once her den is in place. (The den was set up this year at the end of September.) Through research and collaboration, we hope to gain new insights into the complexities of polar bear reproduction and give you more definitive answers in the future to the question, “Is Chinook pregnant?”

The Polar Bear Team, San Diego  Zoo

Watch the bears daily on Polar Cam.

142

Polar Bears: Hormones

Kalluk enjoyed snow day earlier this month.

Kalluk enjoyed snow day earlier this month.

Many Polar Cam viewers have expressed concern about our male polar bear, Kalluk, and his repetitive or restless behaviors. It is hard to see him so driven by his hormones at breeding time if you don’t see his full day. He does eat and rest, but not for the long periods of time as he does when his hormones are not driving him. He is not suffering but just supremely distracted!

The reason we suspect his focus is at the one end of the exhibit is due to the stimulation he may receive there. There is certainly more visual activity with buses and guests stopping to look at him, and the breeze comes right through there, carrying great scent stimuli. Research has shown that there are chemical similarities between many industrial aromas and reproductive hormones. It may well be that Kalluk is constantly testing the breeze in case there is a receptive female polar bear about to come join him. No one really knows how far a polar bear can smell, but no one doubts that their sense of smell is more than anything we could compare.

We know from past testing of his testosterone levels that Kalluk experiences exceptionally high levels for a male polar bear. A recent study indicates that male polar bears’ highest testosterone levels occur from the age of 12 to 18. Kalluk just turned 12, so we may have a tough time for the next few years. We did witness one day of breeding last month on the day after Chinook rejoined Kalluk and Tatqiq; she had been by herself on a pregnancy watch for a few weeks. Their reunion seemed to be more about the excitement of getting together again instead of actual estrus. We fully expect to see another breeding period that lasts anywhere from a few days to a few weeks.

Once Chinook’s hormones indicate that she is ready for breeding, and her behavior indicates she is ready, Kalluk’s attention will turn to only her. Then, as the breeding season wanes, we will get our fun-loving boy back. Polar bear breeding season can last from January to June! Until then, we have increased the amount of fat in his diet, increasing the calories he has to use. We strategically give him enrichment, especially scents, and strategically make beds for him that are in his interest zone.

Rest assured that we are monitoring him closely and responding to whatever he shows might alleviate some of his frustration. Keep watching Chinook as well; she also gives indicators, although much more subtle, of her breeding season!

JoAnne Simerson is a senior keeper at the San Diego Zoo. Read her previous post, Polar Bears: Exam for Tatqiq.

100

Polar Bears: Well, Chinook?

Is she or isn’t she?

*Is she or isn’t she? We still don’t know for sure. Here’s what we do know: Chinook’s fecal hormone profile as of mid-November indicated that pregnancy was still a possibility but birth most likely would be no sooner than January. We have been doing weekly ultrasound exams since October, and the images neither confirm nor deny pregnancy. Polar bears are delayed implanters, so we don’t usually see the uterus unless there is something happening. As of the ultrasound exam this week, our veterinarians are still able to see her uterus. With both these indicators, we are definitely not throwing in the towel.

Chinook’s behavior, though, is picking up. She is playing every day on exhibit and in her back pool. Chinook is also soliciting lots of play time with her keepers. She does, however, go to sleep in her massive bed by noon, again both good and not-so-good signs for pregnancy. The good part: whatever the outcome, our girl is having a very comfortable time keeping us all on pins and needles!

*UPDATE: Chinook has very effectively communicated as of January 1, 2013 that she is NOT pregnant and please very much would like to go play with Tatqiq and that very handsome Kalluk. Today’s ultrasound session also convinced us that we are no longer on pins and needles. So tomorrow all three will be re-united. So uncross those fingers and toes and let them rest until next year!

JoAnne Simerson is a senior keeper at the San Diego Zoo. Read her previous post, Polar Bears: A Wild Study.

56

Polar Bears: A Wild Study

A polar bear mother with her yearling cubs strolls in the wilds of Manitoba, Canada.

It’s hard for me to believe that this year is my 12th in Churchill, in Manitoba, Canada, for polar bear season. Because of the unique water currents, geography, and ice formation, polar bears pass through this northern town every year on their way to hunting ringed seals after a few months of fasting when Hudson Bay is ice-free. The majority of time, visitors spend the days observing polar bears in the Churchill Wildlife Management Area beginning 15.5 miles (25 kilometers) from town. But today we are moving out to Wapusk National Park and Cape Churchill, another 15.5 miles away. Tundra Buggy Adventures is granted permits exclusively by Parks Canada to travel into this remote tundra habitat.

This travel requires hitching up all the Tundra Buggy lodge trailers to individual buggies and hauling them through tidal flats, snow drifts, and around large boulders. It’s a slow process, but along the way great views of the tundra and polar bear habitat can be seen. We are now just two hours into the drive and have already seen a fabulous gyrfalcon, fox prints, and polar bears: several subadult bears, one particularly large male, and a mom with two yearling cubs. I was extremely happy to see yearling cubs, as over the past three years I had not seen any older cubs, just cubs of the year, aka COY. Not seeing older cubs was unusual and perhaps indicates that cubs are not surviving past their first year.

Tundra buggies make their way to Wapusk National Park.

This year we are also seeing the ice forming a bit earlier than it has in the last few years. We have seen many bears already head out to begin hunting. Over the past decade, this would be a normal occurrence, but in the last few years the ice has not been formed enough for bears to get out and hunt for the winter until December. It is also good news, since most of the polar bears in Hudson Bay lost their hunting ice in July. Scientists studying this population estimate that the ice is disappearing a full three weeks earlier than normal for this region. The aerial survey from last year to evaluate the population of the Western Hudson Bay resulted in an estimated 1,000 polar bears, consistent with surveys from a few years ago. Unfortunately, average litter sizes were the lowest recorded, and yearlings and COY were proportionately fewer. This is possibly due to not only the earlier ice loss but also the later ice formation giving females less time to hunt and to provide for offspring.

Our destination tonight will be Cape Churchill, which has a great history of polar bear observation for both scientist and bear enthusiast. Typically this is where the biggest males stay, biding their time sparring while waiting for the ice. This area, too, is where, once the males have moved on, moms with cubs make their last walk to the coast and out to the ice. The opportunities to study polar bears and their behavior are hard to match anywhere else in the world.

We should reach the Cape in another eight hours. It will have been a very long day of travel. The reward will be tomorrow when we wake up in perhaps one of the most inspiring lands of ice and bears. I think how unbelievably blessed I have been for 12 seasons to be able to be a part of this. I can’t bear to think that this may all be disappearing quickly. The colleagues I travel with inspire me with knowledge that we can make a difference, the guests sharing this adventure inspire me with knowing there are some really great folks who are willing to make changes in their lives now to save this area by lowering their greenhouse gas emissions, and most importantly, I am inspired by the incredible polar bears that survive and thrive in this ice world.

I am so happy to see a mom and her two yearling cubs. It is their future that we hold in our hands, as well as the future of our own children, so that they, too, may be blessed to witness this amazing animal in this inspiring world of ice.

JoAnne Simerson is a senior keeper at the San Diego Zoo. Read her previous post, Polar Bears: Quiet Season.

120

Polar Bears and Climate Change

This is not a test!

Each day, the first thing I do when I sit down at my computer is to check with the National Snow and Ice Data Center (NSIDC) for the latest information on sea ice conditions and sea ice extent in the Arctic. At the beginning of August, it looked like the changes in sea ice extent over the summer were on pace to approach, or maybe even equal, the historic 2007 low. However, over the last couple of weeks, it has become clear that we were on a pace to overtake the 2007 record low and set a new minimum record for sea ice extent.

Several days ago, I checked the latest data; not only had we surpassed the 2007 low, we did it several weeks ahead of when the sea ice is typically at its lowest. This means we still have a few more weeks of sea ice melt to go, and the ultimate sea ice nadir for 2012 has not yet been reached. It is not hard to connect the dots and see that this is bad news for polar bears. However, what may not be obvious to most people is that this is bad news for wildlife all over the world and bad news for us.

Polar bears and the Arctic sea ice have long been noted as a “canary in a coal mine”; the changes in the Arctic environment provide a warning—a clear, loud, and un-ignorable warning—of how dramatically climate warming is changing our planet. We have to reduce our carbon footprint, and we have to do it NOW!

Even in light of this grim news, there are still signs that we are beginning to turn things around. Recent surveys have shown that an increasing majority of Americans understand that climate change is real and that the warming trends that have been documented over the past several decades are the result of human greenhouse gas emissions. The results of these surveys also suggest that most people understand that climate change will have catastrophic impacts on polar bears and other Arctic wildlife. For many of us, making the connection between our own everyday actions and the persistence of polar bears in the wild is enough to get us to make energy efficient choices.

However, we must also understand that, while the impacts of climate change are most vividly obvious in the remote Arctic, they are also impacting other habitats all over the world, including our own backyards, and that the resulting changes to our Earth will have far-reaching consequences for people everywhere. We have to do more. We have to move from “understanding” the impacts of climate change to “taking action” to reduce our carbon footprint.

Each and every one of us has the power to change our habitats in order to reduce our own personal greenhouse gas emissions. Future generations, and future generations of polar bears, are counting on you to reduce your carbon footprint.

Megan Owen is a conservation program manager for the San Diego Zoo Institute for Conservation Research. Read her previous post, Panda Cub: 704 Grams.

Calculate your own carbon footprint and get suggestions and easy household tips that help you reduce your carbon footprint (and energy bill), or visit Polar Bears International.

40

Polar Bears: Keeping Cool

Tatqiq knows how to stay cool!

The summer of 2012 will go down in history as one of the hottest on record. This brings lots of questions as to how polar bears at the San Diego Zoo can live in even the milder heat here. The first answer: our 130,000-gallon (490,000 liters) pool is chilled to under 55 degrees Fahrenheit (12 degrees Celsius). The shallow area allows the bears to lie down and even sleep if they choose. The mid-range allows for great soaking opportunities, and the 12-foot (3.6 meters) deep end allows for complete submersion and swimming. On most summer days, the breeze through the exhibit comes right off of San Diego Bay, so it is a cooling sea breeze. Throughout the exhibit there are numerous shaded areas with various bedding materials for the bears to sleep on. There is also a portable air conditioner we can direct up by the back area where they especially like to sleep. Inside the bedroom area, we also have air conditioning to take the heat out if absolutely necessary.

The real reason we can keep our polar bears comfortable, even on the hottest days, is by limiting the amount of fat they have on their body. For polar bears to survive the cold of the Arctic, they must build up at least 4.5 inches (11 centimeters) of fat over their body. They do this by eating seal blubber. A polar bear’s diet is 90 to 95 percent fat in the wild. They are so specialized for eating fat that they metabolize close to 90 percent of what they eat into body fat.

Here in San Diego, our nutrition staff has developed a diet that is 5- to 10-percent fat, so our polar bears get what they need for good health but not for bulking up for a cold winter. All of our bears would weigh much more than they do now if they had those fat layers. Kalluk, who is now over 1,100 pounds (500 kilograms), would probably be closer to 1,600 pounds (725 kilograms)! When polar bears put fat on, it goes first on their belly to protect their core. Do you know that the body temperature of a polar bear is the same as ours? 98.6 degrees Fahrenheit (37 degrees Celsius)! The fat then layers over their bum and spreads out over their body.

Here’s one way to tell our three apart: When you look at them in profile, Kalluk and Tatqiq have a rounding of their bellies, but from the top of the hip to the tail it’s flat. Since we keep a bit more weight on Chinook (just in case she might be pregnant), her belly is nice and round, and her bum matches! And let’s not forget the CARROTS! Polar bears get little to no nutrition or calorie from vegetation. Our three can eat as much as they like and not put on a pound. Currently, they get 100 pounds (45 kilograms) a day between them that gets chewed, swallowed, slightly steamed in their bellies, and then eliminated. As keepers, we call that job security!

One problem with warm weather we seem to be challenged with this summer is the algae growth. Our water quality team constantly monitors the pool’s water for safety and cleanliness, but algae is airborne until it finds moisture. With the warm temperatures and direct sun, we’re experiencing quite a bloom. We add rock salt to help, but, unfortunately, some of it has imbedded into Tatqiq and Kalluk’s hollow hair shafts. It sneaks in through the small breaks in the shaft formed by grooming. This won’t harm them in any way, but it’s pretty embarrassing to have polar bears with a greenish hue! Our polar bears were once famous for being green when they lived in the smaller grotto exhibit decades ago. Since moving to this exhibit in 1996, we’ve not had any “greening,” until this year. So in the next few days we’ll be hosting “spa days” for a purpose—mineral salt-water soaks for all! Chinook and Tatqiq have always been pros at the soak; Kalluk will be challenging, since he thinks it’s only about dive bombing his sister and then slurping the saltwater off his giant paws. He’s got 13 inches (33 centimeters) on each foot to slurp from!

Summer brings great fun but also great danger with the dry heat. It is sad to hear of fires burning across our nation, so many losing their homes. It’s heartbreaking to lose so much; thank goodness for insurance. In the past few decades, polar bears have lost their ice homes in an area the size of Texas and Alaska combined. We now see forest fires burning in the Canadian tundra, the place with one of the highest densities of polar bear denning, the place where our beloved Chinook was born. What insurance do they have? They have us. We must be the guardians of our planet. We must continue to reduce our greenhouse gas emissions, especially when it seems there is no hope. We still know it can be done. We must be the insurance to protect and insure that our children and grandchildren will still have the opportunity see the magnificent polar bear roaming our planet.

JoAnne Simerson is a senior keeper at the San Diego Zoo. Read her previous post, Polar Bears: Breeding Season.

Watch the polar bears daily on Polar Cam.