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Chinook

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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.

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Science for Kids: Observing

Do you remember watching panda Su Lin when she was born in 2005?

We are coming up on bear pregnancy-watch season at the San Diego Zoo! Both our giant panda Bai Yun and polar bear Chinook have bred this year, and we are anxiously awaiting signs that they are pregnant. Our fingers are crossed, and all the tools we use to monitor their status are just about ready to go. Of course, we are all excited by the prospect of bear cubs in 2012, and I think it’s safe to say that we will all enjoy the opportunity we have to look into the bears’ dens and observe these ursid moms and their cubs.

An important aspect of our conservation research is the study of animal behavior, which tells us much about the biology of the animals we love and provides us with tools to assess how the animals are doing and what a “typical” animal should be doing during important phases of its life. The study of animal behavior can provide tremendous insights into a species’ biology and gives us tools we can use to help conserve them. While the behavioral data we collect fits into a scientifically devised systematic framework, there is much to be gained from simple observation as well.

I have tried to share the joy of observing animals with my kids in hopes that it will also provide a connection with science and what it means to be a scientist. Often, when we are out and about in our neighborhood or at the park near our home, we stop to watch what the various animals we see are doing. It is amazing how exciting and exotic a squirrel can seem if you really stop and take a few minutes to watch the way it interacts with its environment, the way it responds to your presence, and the various ways it vocalizes and flags its tail to send signals to other animals around it. One of our other favorite animal-watching activities is going on a “bug safari,” which simply entails going into our backyard and turning over a rock. This simple excursion provides a window into the fascinating world of potato bugs, ants, and worms. Very cool!

Panda Cam viewers watched Mei Sheng grow to roly-poly cuteness in the birthing den in 2003.

Another readily accessible way for most kids to experience being an animal behaviorist is to watch our own exotic bears through Panda Cam and Polar Cam. While giant panda and polar bear cubs are undeniably cute, they are also fascinating to watch, and the care and patience the mother bear shows while tending to her offspring is fascinating. After each of Bai Yun’s cubs, our scientific and animal care staff watches the activity in the den in great detail and with unflagging fascination. I love that this very same view into the den will be available to anyone who visits our website.

We are all counting the days to the (hoped for) panda and polar bear births. As part of that, we are making sure that all of our camera systems and microphones are ready in the dens so that we can continue our studies of maternal care behavior in bears. This time around, I hope some young scientists out there will study the bears along with us.

Megan Owen is a conservation program manager for the San Diego Zoo Institute for Conservation Research. Read her previous post, Children and Nature.

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Polar Bears: Breeding Season!

Kalluk and the rest of us eagerly await a polar bear cub or two!

We are all on pins and needles to see if the San Diego Zoo’s polar bears, Kalluk and Chinook, will breed this year. They have always been early birds by breeding in March and even as early as February! But normal breeding time for polar bears is April through May and sometimes as late as June, something we won’t even contemplate! From the looks of how flirtatious Chinook has been and how attentive Kalluk seems, our patience should be rewarded.

We are still participating in reproductive studies looking at hormones excreted in the bears’ urine and feces, but for the most part we still rely on behavior observations. One of the very interesting behaviors we see is with Chinook. Typically, a week before actual breeding and continuing right up to actual, we see her have seizure-like spasms followed by weakness in her back legs. The spasms last only seconds and the weakness only a few minutes. If you don’t know what these are, they can be very scary to see!

But there is no need to worry: Chinook is not alone with these. Most of the other breeding female polar bears show the same behavior. I have asked polar bear biologists who have spent many years observing bears in the Arctic and have sent them video of the process, and they are mystified as to its purpose. Perhaps it plays some role in preparing a female’s legs to hold the male during breeding, since males are usually twice the size, and she may bear his weight for long moments. In the last week we have seen Chinook have these spasms, and over the last few days they have increased both in frequency and intensity. This should be a sign that we are almost there!

We all know what follows: waiting to see if Chinook becomes pregnant and gives birth. I have been getting lots of experience working with polar bear cubs over the last few years since Kalluk and Tatqiq joined us as cubs in 2001. I have just returned from a second visit with Siku, the polar bear cub born at the Scandinavian Wildlife Park in Denmark. My first visit was to share what we learned in preparing our polar bear youngsters for life in San Diego. Siku still was not yet walking then and was not quite 13 weeks old. On my recent trip, Siku was now 21 weeks and was walking, running, swimming, and being overall an adorable monster!

Since Siku’s mom did not produce milk, the decision was made to hand raise him, which meant having close contact with him (not a problem when his fastest speed was a quick crawl!). He is now rambunctious and, as polar bears need to do, he is jumping, grabbing, and mouthing everything and everyone in sight. Mom polar bears are well equipped to handle this; human caregivers, not so much!

This trip was to help the team in Denmark move ahead with management that increases Siku’s independence and encourages his natural instincts as a polar bear. He did extremely well with every challenge of independence. You can imagine how difficult it is, though, for the team who has been caring for him all these months to see that maybe he didn’t need them as much anymore, or at least not in the same ways. I must say how proud I was to assure them and show them the close ties we have with our three polar bears and how much that strengthens when you’re not worried about when the next play jump comes from a now 60-pound and often wet white ball of teeth and claws! All meant in fun, but still dangerous for fragile humans!

Siku has lots of toys to encourage his natural learning behavior and is getting plenty of opportunities to learn with his training sessions. At 21 weeks, he has already learned several important behaviors from his keepers such as “sit,” “stand,” “down,” “shift,” “come,” and how to sit on a scale.

In choosing his name, thought was given to the chance to represent wild polar bears and the people who share the Arctic. Siku is from the Inuit language for sea ice. Siku will remind everyone that we are losing our arctic ice due to warming trends in our climate.  Science has proven this warming is caused by the increase of carbon emissions in our atmosphere. Siku and our three polar bears, Chinook, Kalluk, and Tatqiq, are ambassadors who remind all of us of their wild cousins and that we must make changes to help save their arctic home.

As you enjoy watching and hearing about these great ice bears, please keep in mind everything you can do to help. Then do it!

JoAnne Simerson is a senior keeper at the San Diego Zoo. Read her previous post, Polar Bears: Back to 3.

UPDATE: Two days after this was written, Kalluk and Chinook began breeding. November 2 is the first possible day of birth if Chinook is pregnant! The waiting begins. . .

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Polar Bears: Back to 3

Chinook enjoys some ice time in July.

Over the past week, Chinook has been more active and has been spending lots of time outside in our polar bear management yard instead of her bedrooms and den. On this past Sunday, we removed the den, and she seemed not to care. So this morning we reintroduced our fabulous threesome! After a brief greeting, all three settled on exhibit: Chinook in the mulch by the road, Kalluk on the point, and Tatqiq at the edge of the pool. All seem to be pleased with each other’s company. Chinook did go up to the doors after 30 minutes to see if we were around, but after sniffing and listening she went back out to her mulch bed.

The immediate future will be about continuing the ultrasound exams for a few weeks just to see any changes. Then as we approach the end of winter, we expect to see Kalluk’s behavior change, letting us know breeding season will be upon us shortly, and then. . .we all know the routine. So uncross you fingers and rest your hopes, at least until next fall!

JoAnne Simerson is a senior keeper at the San Diego Zoo. Read her previous post, Polar Bears: No Easy Answers.

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Polar Bears White and Brown

Chinook?

It has been a really busy beginning to 2011. Chinook let us know in December that cubs were not on the way (see post Polar Bears: What December Brings), and she was ready to join her buddies Kalluk and Tatqiq in life at Polar Bear Plunge. As keepers this is sometimes a worrisome time: not sure if the relationships from the past will still be there. Of course, after some initial greeting time, the famous three were up to their old antics. It is also the time of the year that the girls seem to be best friends, and Kalluk spends more time practicing his basketball skills!

Is that really you?

We used some of this time to do annual maintenance on the front pool: steam cleaning, replacement of lights, fresh mulch, etc. This meant that all three bears would be inside the bedrooms and yard—all together! With great affection, you must know that these three are beyond messy! Besides providing them with loads of boxes, burlap, and hay, they also felt it necessary to bring in fresh mulch from the yard into the bedrooms and the indoor pool—every day! Once back out to the main exhibit, Chinook definitely showed off that she truly is the queen of the mulch roll! Good thing Kalluk has a good sense of smell, as it appeared he was wondering where the brown bear came from!

Recently, Kalluk and Chinook have begun their great flirtation we see around breeding time. It seems a bit early this year, but they seem to be greatly enjoying each other’s company more than past years. Could this be a good sign? Tatqiq is now a bit of a loner and just stays away when the three are together. She has learned that this, too, will pass, and soon her silly, amorous buddies will be interested in playing again.

We are still collecting fecal samples from Chinook in hopes of being able to get a hormonal assay to determine pregnancy; we are now also collecting urine samples. Any information we can achieve will help us better understand polar bear reproduction.

We have also placed on the Wish List a request to give the polar bears snow. Take a look! If we reach our amount, we’ll be sure to give you notice to watch the fun on Polar Cam. Until then, keep doing your part to conserve and help the polar bears in the Arctic. Unfortunately, for all our cold weather down here it has been a very warm winter for our ice bears of the north!

JoAnne Simerson is a senior keeper at the San Diego Zoo.