Polar Bear Summer
Posted at 8:21 am July 7, 2009 by JoAnne Simerson
Chinook enjoys a lettuce snack.
The fat layer provides great insulation against the Arctic winds. A polar bear must have a minimum of 4 inches (10 centimeters) of fat to survive the cold. It also provides buoyancy if the bear needs to swim. The layer of fat also provides energy storage when a meal is not around. This energy storage is especially critical for pregnant females that can go without eating for as long as eight months in some areas of the polar bear’s range. The wild diet of the polar bear is 90 to 95 percent fat to provide the fat layer.
In San Diego, Chinook, Kalluk, and Tatqiq have a diet that is only 5 to 10 percent fat. This gives them the right amount nutritionally for our climate but doesn’t give them the amount of fat to build a fat layer for warmth! But yes, they think they should get more. And that is where all the carrots come in to play. We give them as many carrots as they want all day, every day. They really do like them! The bears are never hungry since any time they want a snack they eat their carrots. And although no real study has been done on the ability of polar bears to absorb calories from carrots, from years of picking up the (ahem) piles after digestion, it would appear they go right through!
Another benefit of carrots: the crunching keeps their teeth beautifully clean. Zoo guests are always surprised to see all the carrots, thinking polar bears are carnivores. They ARE the most carnivorous of all the bear species, but in the wild they do eat kelp, grasses, leaves, and berries if they can find them. However, the nutrition they receive from any vegetation is not enough to live on for this specialized bear.
And you are now all asking, But what if Chinook is pregnant? Doesn’t she need more of a fat layer? YES. We have already begun to raise her weight up in the event she dens up and has cubs. She is currently almost 15 percent above her normal weight, and the plan is to continue to allow her to gradually gain weight. Remember: a newborn polar bear is only 1½ to 2 pounds (0.6 to 0.9 kilograms). We don’t want her to put on too much weight either, as she needs to remain comfortable in the den and not feel too warm. Hint: When looking at “who’s who” on Polar Cam, Chinook is the roundest!
There is another way our polar bears stay cool in the summer and even year round in San Diego: our 130,000-gallon (494,000-liter) pool is chilled. We typically keep it between 55 and 60 degrees Fahrenheit (13 and 15 degrees Celsius). We can chill it more, but our San Diego bears won’t go in then. Remember: They don’t have that extra insulation! You can expect to see them swimming more often in the summer and playing as well.
JoAnne Simerson is a senior keeper at the San Diego Zoo.
P.S. Still no word on Chinook. We are moving ahead as though she is pregnant, but we won’t know for sure until we see cubs sometime this fall.
You can follow any responses to this entry through the RSS 2.0 feed. Scroll to the end to leave a comment. Pinging is not allowed.
July 7th, 2009 at 8:38 am
Would the group stay together if cubs are born or will Chinook raise them alone??
July 7th, 2009 at 9:57 am
Thanks for the informational update, JoAnne. If anyone wonders what animal curators do in their spare time, just read their posts. Not only do they plan menus, keep snacks handy, and monitor water temps, they also get to pick up bear droppings! And you thought they had a glamorous life with the polar bears. Well, I know that the love between the humans and bears is strong enough, that you don’t mind picking up the poop, as we all do for our own beloved pets. And I am so happy that you all are there to take care of these wonderful giants.
July 7th, 2009 at 10:18 am
Thanks JoAnne for a most informative message. I love learning about these marvelous animals from these blogs. My friends and family want to know how I know so much about zoo animals and where I learned it. The answer is obvious to regular SDZ blog readers. It is great information, easy to understand, and helps to solidify my desire to help all animals sharing our planet to survive in their native and captive habitats.
Many thanks to all at SDZ for making this possible, especially in bad worldwide recession.
I went Walmart last night and noticed the huge wide aisles and very little merchandise. The worldwide economy is hitting everyone hard, I’ve been unemployed since 12-31-08, and I hope that it doesn NOT impact the care the animals in captive environments receive. Food gets super expensive when oil prices go up, so it makes it that much harder to maintain the high quality diet animals such as Chinook need for their health and that of their potential young.
July 7th, 2009 at 10:30 am
interesting and informative post JoAnne. I always wondered why so many carrots! lettuce too I see! now that I think of it, it only stands to reason why their fat consumption would be cut down. see, that’s why we need you experts to figure all these things out. they are certainly not underweight or under nourished by any means!! very healthy looking bears I must say! hopefully cubs in the fall!
July 7th, 2009 at 10:58 am
Chinook would raise the cubs alone as father polar bears play no part in cub raising. A more likely social situation would probably be Tatqiq, Chinook and the cubs once the cubs were about a year or so old
July 7th, 2009 at 11:01 am
Jo-Anne, this is probably a silly question but here goes: if we humans eat too much Vitamin A, for example by eating loads and loads of carrots, we can turn orange. I’m assuming that, as the bears definitely are not orange that they don’t eat enough of them? And could they if they ate too many?
The piccy of Chinook is gorgeous.
July 7th, 2009 at 11:11 am
Thanks so much for the update!
July 7th, 2009 at 11:28 am
Thanks for the most interesting update, JoAnne. I’ve always been a big Panda fan and now I include the beautiful Polars on my list of favorites. They are so much fun to watch, playing and interacting with each other. Seeing them playing with a ball and jumping in and out of the plunge is such a joy, they are like kids in a pool. It is obvious how much caring you bring to the job each day, not to mention all the hard work. But the end result must be worth it to you, seeing happy and healthy bears for all the world to get to know and appreciate. Thanks JoAnne and all the keepers for all you do.
July 7th, 2009 at 11:12 pm
Such a cute picture!
July 8th, 2009 at 1:42 am
Ow, I didn’t know they love carrots that much. I suppose they don’t see carrots in the Arctic. Susan (#6), I’m curious about the same thing. Will they turned to orange if they eat too much carrots? That will be weird (yet CUTE!) to see three oranges polar bears. But guess there’s one thing we can be sure, eh? That their eyes are good, considering the daily intake of vitamin A … is it true, JoAnne?
I can’t wait to see Chinook with her cub(s). And of course I can’t wait to see panda cub(s), too!
Go Chinook! Go Bai Yun!
July 8th, 2009 at 6:54 am
Oh how I have missed blogs on our Polar bears. Thanx for the update Joanne. I was going through Polar Bear update withdrawls ! =) Thank You !!
July 8th, 2009 at 7:36 am
The knowledge we have about polar bear digestion would indicate that they receive little if any nutrient or caloric value from vegetation so it would follow that we won’t see our bears turning orange no matter how many carrots they eat.
July 8th, 2009 at 9:57 am
Aahh… poor Chinook — sounds like she lost her girlish figure — and just in time for bathing suit season — bummer. Oh well — hopefully it will pay off with little cubbies!!
July 8th, 2009 at 10:14 am
Remember, bears have bear sensibilities. For lady polar bears, I believe it’s stylish to be chubby during swimsuit season.
July 8th, 2009 at 10:49 am
Thanks JoAnne. I should have worked that out from your post really, shouldn’t I!!!
I have heard that the latest polar bear swimsuit fashion is a frilly skirt, preferably in purple.
July 8th, 2009 at 11:41 am
Hmmm… wish that were the case in San Diego!!
July 8th, 2009 at 11:47 am
Chinook is so photogenic! She even smiles while eating lettuce!! She should have her own calendar. Oops! We can’t slight the others, so make it the 3 Bears calendar.
July 8th, 2009 at 1:11 pm
Well rounded, healthy, and maybe even voluptuous! Let’s use those positive words and keep thinking positive thoughts for polar bear cub(s)!!!
July 8th, 2009 at 2:12 pm
I LOVE the picture of Chinook with her lettuce salad. I can just picture her saying did you get my best side. We want to be sure we capture my best eating for two or three.
July 8th, 2009 at 3:20 pm
Glad to see the purple ball is still a bear favorite. I can just barely see someone in the shady part of the plunge near the rock table have a great, splashy time playing with it. Better stock up on those!
July 9th, 2009 at 5:44 am
About bear shapeliness: there is a cute story out on the internet, that starts “In this life I’m a woman. In my next life, I’d like to come back as a bear”. It then talks about the 6 months of sleeping, birthing cubs the size of walnuts, and concludes “If you’re a bear, your mate EXPECTS you to wake up growling. He EXPECTS that you will have hairy legs and excess body fat. Yup, gonna be a bear!”
A skinny polar bear would be a sad sight indeed.
July 9th, 2009 at 11:59 am
Got my fingers crossed for you, Chinook. I think you would make a GREAT Momma bear!!
And you are indeed very photogenic. I think all the bears are!
July 9th, 2009 at 12:03 pm
Hmmm… maybe I AM a polar bear!! LOL
July 9th, 2009 at 2:45 pm
Hi! Well, I was going to ask about Chinook and her possible pregnancy, but that got answered in this latest article! Thanks for the update, Keepers! I also enjoyed reading the article about the bears’ diet, food, and snacks. Those 3 bears are pampered to say the least! I’m glad that you all are going ahead with the den preps. I’m praying that Chinook IS pregnant, and we’ll be seeing one or two cubs this fall! Being positive!! I’ve seen all 3 bears in the pool on the cam off and on, too! They are fun to watch in that pool! On the other side of the bear story, just got my email newsletter from Pandas International today. They have the first of the Baby Updates, and the mother pandas that were the first ones to give birth were Hua Mei and Gong Zhu! Both moms just had one cub each. Who would’ve thunk that Hua Mei, our former SDZ resident, would be the first mother panda to have her baby this year?? Hua Mei and Gong Zhu’s babies were born just 20 minutes apart with Hua Mei having her baby first, which gave the panda staff at Bifengxia a very busy few days watching these 2 mommas 24/7! Great start to the panda birthing season this year! We’re all waiting for more baby news from China! And, we are waiting on Bai Yun to have a baby panda, too! Keep your fingers crossed for Bai and Chinook!
Well, gonna go for now. Will check back in later on for more updates about Chinook!
Chari Mercier
St. Pete, FL
July 9th, 2009 at 6:41 pm
Wonderful article, JoAnne! I love hearing about the Polar Bear diet, both in the wild and at the SDZ. I knew they loved their carrots and lettuce, but was not aware that they ate kelp, berries, etc. in the wild. It is lovely to hear that you are “rounding out” Chinook, just in case, and helping her prepare for the very best situation. You must all be on pins and needles for fall! The photo of her is beautiful and cute! I also never even thought of how the carrots would also help clean their teeth. Do they eat/get other things to help keep their teeth clean and healthy? Chew on bones, floss with lettuce?
JoAnne responds: Yes. They also get large beef femur bones two times a week.
July 10th, 2009 at 8:21 pm
I just caught someone moving the camera and checking up on things. Are my eyes playing tricks or was one of the bedroom doors open and the bear sleeping out by the water and refusing to come in? lol
July 11th, 2009 at 11:38 am
Question for the Keepers: Which bear is it that stands beside the rock table and throws the ball against the rock wall and grabs it as it bounces back? Looks for all the world like a teenager throwing a basketball against the garage door!!! The bear seems to be having grand fun!!!
P.S. The photo of Chinook enjoying the lettuce treat is precious!!
JoAnne responds: The “basketbear” player is Kalluk. He has done that from the time he was little. One time he threw his toy in the bedroom and it stuck on the door ledge. He was too small to reach it. He looked around and then pushed one of the big ice block toys over, climbed up, grabbed his toy off the ledge and then threw it in another direction. Smart bear!
July 12th, 2009 at 10:37 am
What a stunningly beautiful bear on the cam. I rushed for my camera, found it was out of batteries and did the quickest battery change you’ve ever seen!!
Is it Chinook? Looks a little grubby round the edges so I’m assuming it is. To whoever was operating the cam, thank you, thank you.
Keepers respond: It was most likely Chinook.
July 12th, 2009 at 11:05 am
There is a beautiful closeup, right now, of one of the bears just getting ready to take a nap. Lots of rubbing of the back, the face, the feet! It took a while to get all comfy, but comfy they are, and in the shade (who is this, please?) and so gorgeous! What big feet they have! Five toes on both front and back paws? I am also curious if they ever “cuddle” with their bedding or toys when they sleep? My cats always did. They loved having one toy that they would sleep on, rub their face against, hold in their paws (either front or back), snuggle to their chest or be just within reach, but always in sight! I am sure they considered it a hunting catch of sorts, but it was interesting to see how attached they became to “stuff”! I guess we all have our security blankets!
Keepers respond: It was probably Chinook. And yes, the bears do cuddle with favorite items. Kalluk in particular enjoys making a pillow out of burlap bags.
July 12th, 2009 at 11:37 am
There are three bears? I only see two. However, I remember visiting the zoo during the late 70’s & 80’s. The polar bears just paced back & forth out of anxiety. Now they are in bear heaven. These are very blessed bears. They are really having a great time. They sure do love their pool. They are in such a better state than they were years past. Congratulations on a very successful transition.
July 12th, 2009 at 1:30 pm
Another wonderful sighting! A bear (Tatqiq??) is in the water playing with a bright pink floaty tube shaped toy, diving on it, sinking it, watching it pop up, tossing it hard against the stones and glass walls, watching it bounce back to her, tossing it up out of the water, and waiting for it to roll back down into the water, biting it, licking it, swimming with it, rubbing their face with it. This is one very happy bear!
Keepers respond: That was Kalluk. He loves those floaty tubes!
July 13th, 2009 at 10:17 am
I am enjoying reading the comments on this blog so much! Who knew that Kalluk behaves like such a teenage boy by throwing ball against the wall and bouncing back and forth? I have always known that these polar bears are very intelligent creatures, but have scientists done any research in this area? (This comes merely out of my personal curiosity.) It seems that many have survived due to some intelligent adaptations of their behaviors in the wild. However, given the state of these bears, my guess is there are probably more research done on preserving the species than on studies of their intelligence.
Polar bear researcher Megan Owen responds: Anyone who has worked with or studied polar bears knows that they are very intelligent animals. Our work on the hearing sensitivity of the bears did not explore this question, but the success of the study depended on their intelligence! And they were able to accomplish what we asked of them with ease. (Read Megan’s post, http://www.sandiegozoo.org/wordpress/default/can-you-hear-me-now/).
You are right in that, with the current conservation crisis polar bears face, research efforts if focused on those questions will aid in their conservation. Polar bear scientists agree that 99.9% of research efforts and resources should be focused on conservation.
July 13th, 2009 at 1:23 pm
1 to 1:15 p.m. P. T.: I have been watching ’someone’, I’m guessing Chinook, repeatedly diving, diving, diving under the forward ledge of the beach and close to the log. Whoever it is totally wore me out. It looked as if she was diving for something that she was bringing up to the top, then eating? No close up, so I couldn’t tell. I was also watching Kalluk the other day tossing around his plastic tube in the water. He tossed it so far it landed on the beach, then didn’t roll back to him. He watched it for a few seconds, then found something else to amuse himself with.
Moderator’s note: Our keepers tell us it was Chinook with a bone.
July 13th, 2009 at 3:43 pm
Thank you, Keepers! It was wonderful fun watching Kalluk with the floaty tubes! And a beautiful display of his agility and strength throwing and smacking it around the plunge! He seems to get a kick out of trying to sink it and watching it pop back up to the surface!
Dianne #33, I saw that part, too. It was sad to see it not roll all the way back into the water, but he seemed to be tiring out, too. He had quite a workout, didn’t he? So, that was Chinook with a bone! I was wondering what she was up to!
It amazes me as to how mentally involved they get with their playtime. It is all very important looking, like one cannot leave the water until one gets a certain thing done, be it smacking around a floaty tube or giving your bone a good soaking!
July 13th, 2009 at 6:16 pm
Debi in MA #34: I know. You can almost see the wheels turning in their heads. Then I get so wrapped up in what they are doing, it wears me out too. Like watching a football game. I am exhausted when the game is over. At Memphis Zoo, their plunge is canal-like. One of the bears swims continuously, back and forth, like an endless journey. After 5 or 10 minutes, I feel exhausted, almost water-logged. I mean, I really do have a life, folks; but I just get so immersed with watching the polar bears and panda bears. It’s very tiring! ; D Have a great evening, everyone.
August 19th, 2009 at 2:34 pm
Thank you for the cute, cute picture of Chinook! Saw on the cam yesterday two bears having a delightful play wrestle game in the pool.