Animals Who Totally Own Winter

With a lot of the US experiencing record cold, and all this talk of another “Polar Vortex,” I thought it would be fun to explore how certain animals deal with extreme cold. Nature has concocted some pretty awesome ways to thrive in cold weather, often involving stylish winter coats, cozy fat insulation, and other clever mechanisms to overcome extreme cold. Check out these animals who absolutely own winter.

Takins have some pretty cool adaptations that help them stay warm and dry during the bitter cold of winter in the rugged Himalayan Mountains. A thick, secondary coat is grown to keep out the chill, which they shed for the summer. Their nose also plays a role in keeping them warm. A takin’s large, moose-like snout has big sinus cavities to warm up the air inhaled before it gets to the lungs. Without this adaptation, takins would lose a large amount of body heat just by breathing.

Polar bears have an outer coat of long guard hairs that stick together when wet and protect a dense, thick undercoat of fur. On land, water rolls right off of the guard hairs. Even though polar bears look white, their hair is really made of clear, hollow tubes filled with air. Scarring or residue on the fur can cause the “white” fur to appear to human eyes as cream colored, yellow, or even pink in the Arctic light. Fat also plays a major role in a polar bear’s ability to survive cold. Fat acts as energy storage when food can’t be found and may provide the ability to generate heat to help insulate polar bears from the freezing air and cold water. This 2-4 inch think layer of fat may also help the bears float in water. Big is beautiful!

Native to the Arctic region of the Northern Hemisphere, the Arctic Fox has a dense, multi-layered coat that provides excellent insulation against the cold. It also has an impressive layer of fat that provides extra insulation, as well as a a specialized body shape that minimizes exposure to cold. This cleverly adapted canine also has fur on its feet to help it walk on snow and ice without issue.


Snow leopards move to different altitudes along with the summer and winter migrations of their prey animals, so their coats vary from fine in the summer to thick in the winter. Snow leopards have a relatively small head with a short, broad nose that has a large nasal cavity that passes cold air through and warms it. Their huge paws have fur on the bottom that protects and cushions their feet for walking, climbing, and jumping. The wide, furry paws also give the cat great traction on snow.


Reindeer originally inhabited the tundra and forests of Scandinavia and northern Russia and were then introduced into Iceland, Greenland, Alaska, and Canada. They are covered in hair from their nose to the bottom of their feet, and have two coat layers: an undercoat of fine, soft wool that stays right next to their skin, and a top layer of long, hollow guard hairs. The air trapped inside the guard hairs holds in body heat to keep the animal warm against wind and cold. The hollow hairs also help the reindeer float, allowing it to swim across a river, if needed.


Sea lions have a thick, slick, waterproof coat that allows them to glide through cold water with ease and comfort. Their flippers also serve to regulate the sea lion’s body temperature. When it’s cold, specially designed blood vessel in the thin-skinned flippers constrict to prevent heat loss, but when it’s hot, blood flow is increased to these surface areas to be cooled more quickly.

Sea Lion

Incredibly adaptable, wolves have inhabited, at one point, virtually all of North America, northern Europe, eastern Africa, and Asia. Employing a wide range of adaptations, wolves tolerate a massive range of temperatures, from -70 to 120 degrees Fahrenheit (-50 to 48.8 degrees Celsius). All of their senses are keen, and they can run, climb, lope, and swim incredibly well.


Lastly, here’s an animal that not only doesn’t wear a winter coat, but is a natural nudist. Yeah, naked mole-rats wouldn’t do so well in extreme cold. Be glad you’re not one of these guys this season. Happy winter everyone!

Matt Steele is the senior social media planner for San Diego Zoo Global. Read his previous post, 5 Turkey Myths Busted.





10 Festive Reindeer Facts

‘Tis the season to be jolly! What could be more merry than Santa’s sleigh? Well, without his dexterous reindeer, Old Saint Nick’s mode of transportation would not get very far. So today, we would like to share a few fun facts about this festive species.

Wild & Fun: 10 Festive Facts About Reindeer

1. Reindeer or caribou?
In Europe, they’re known as reindeer. In North America, the term reindeer is used for Eurasian populations, while the name caribou refers to wild populations found in the country. However, both reindeer and caribou are classified as the same genus and species, rangifer tarandus. So for the purpose of simplicity and sticking with the holiday theme, we’ll call them reindeer for the rest of this blog.

Wild & Fun: 10 Festive Facts About Reindeer

2. Males AND females grow antlers.
Male antlers may grow twice as long as their female counterparts; still, reindeer are the only deer species to practice gender equality when it comes to their most memorable characteristic. Males begin to grow antlers in February and females start in May. Both stop growing around the same time, but a male’s antlers typically drop off in November, while a female’s remain through winter until their calves are born in spring. If you’re following this logic, our good pal Rudolph the red-nosed reindeer was most likely a female, because she was rocking her antlers on Christmas Eve.

Wild & Fun: 10 Festive Facts About Reindeer

3. Hard antlers start out soft and fuzzy.
Since antlers fall off and grow back every year, a reindeer is said to be in “velvet” while the new pair of antlers grow. After the velvet dries up, the reindeer unveils its hard antler cores by rubbing its deciduous horns against a rock or tree. Ta-da!

Wild & Fun: 10 Festive Facts About Reindeer

4. Reindeer calves are quick learners.
Newborns are able to stand one hour after birth, and they can outrun humans when they reach one day old. Calves are also weaned from their mothers as early as one to six months of age.

Wild & Fun: 10 Festive Facts About Reindeer

5. They have hairy feet.
Reindeer are built for subzero temps, so they’re covered in hair from their nose to the bottom of their feet. The hair on their hooves provides an excellent grip when trekking over frozen landscapes. Thus, the hairy hooves of reindeer have adapted into snowshoes for these Arctic animals.

Wild & Fun: 10 Festive Facts About Reindeer

6. Reindeer hooves are anatomically noisy.
“Up On The Housetop” and other holiday jingles often imply that the “click, click, click” we hear upon Santa’s arrival is the result of his herd’s stampeding feet. In fact, many hoofed animals make loud noises when their feet meet hard surfaces, but not reindeer. The metallic sound of reindeer hooves is actually due to tendons slipping over their foot bones as they walk.

Wild & Fun: 10 Festive Facts About Reindeer

7. They love crowds…
… of other reindeer, of course. Since they are social animals, reindeer live in herds of 10 to several hundred. So Santa was somewhat limiting his holiday herd by having only nine reindeer. Imagine the horsepower his sleigh would have if his herd included 100 fancifully named members!

Wild & Fun: 10 Festive Facts About Reindeer

8. Reindeer are good swimmers.
Santa’s exclusive herd might be capable of flying, but the rest of the species is not. However, since reindeer migrate to follow their food supply and avoid harsh conditions, chances are they come into contact with water. Luckily, reindeer use their wide, two-toed hooves like paddles that push water and allow these mammals to swim from four to six miles per hour.

Wild & Fun: 10 Festive Facts About Reindeer

9. Their eyes change color in winter.
To adapt to the varying levels of light in their northern habitat, part of a reindeer’s eye changes color and increases their vision sensitivity. The layer of tissue behind the retina that reflects light (tapetum lucidum) turns blue during winter and allows reindeer to see slightly more of their surroundings, even if what they can see is not that sharp or in focus. This seasonal trade-off has its advantages, especially if it improves a reindeer’s ability to spot predators.

Wild & Fun: 10 Festive Facts About Reindeer

10. Like humans, reindeer “wear” layers.
A reindeer has two coat layers: the undercoat is made of soft, fine wool that grows next to the skin, and the top layer consists of long, hollow guard hairs. Similar to a hollow-fill winter jacket worn by humans, the stiff top layer insulates the animal and keeps it warm against the wind and cold. These hollow hairs also help reindeer float. In other words, reindeer have incredible fashion sense.

Do you have any reindeer facts to add to this list? Share your thoughts in the comments.


Jenn Beening is the social media specialist for San Diego Zoo Global. Read her previous post, What We’re Thankful For.


Ear Notches: Trash or Treasure?

Our newest reindeer calf’s DNA will soon be part of our Frozen Zoo.

We have over 8,500 individual animal cell lines represented in our Frozen Zoo®, a cell line collection started in 1975 by San Diego Zoo Institute for Conservation Research founder Kurt Benirschke and his laboratory technician, Arlene Kumamoto. They started establishing cell lines on what was an easy source of material at that time: ear notches. The San Diego Zoo Safari Park had just opened a few years earlier and was home to many hoofed animals (deer, gazelles, antelope, oryx). All of these animals were ear notched as a way to identify individuals out in the field (see post Picking One from the Herd). These small ear-notch pieces were put into vials with a transport media, instead of being disposed of, and taken back to our Genetics Laboratory.

A vial containing an ear notch sample in transport media.

We still receive many ear-notch samples each year on hoofed animals new to our collection. Once we have the samples at the laboratory, the ear notch is processed and set up. We log in all of the information on the animal—species, common name, identification number, and birth date—into the Frozen Zoo database. Then the sample is taken into our tissue culture laboratory and, while working in a biological safety cabinet, or “hood,” the sample is set up. To do this, we first clean up the ear notch by removing any hair or debris. Then we cut the sample into very small pieces, and the pieces are covered with an enzyme and put into an incubator for around four hours to digest.

An ear-notch sample is processed in our Genetics Lab.

Next, when the sample looks digested, it is put into a flask (a sterile tissue culture vessel), and a special media is added and then incubated. In the next 72 hours, we hope to see cells attached to the bottom of the flask. These cells will then start to divide and grow for about three to four weeks until we have enough cells to freeze and make this animal part of the Frozen Zoo’s cell line collection. At this point, we have this animal’s DNA saved as a living cell line. At any time we can thaw a vial of cells and put them back into the incubator, and they will start to grow and divide again.

Fibroblast cells from a Siberian reindeer.

Recently, we received an ear notch from our Siberian reindeer calf. We have his cells growing, and soon his DNA will be part of the Frozen Zoo. Even though I have seen the start of many cell lines, it still seems like magic when you see those first cells start to grow and divide. What species would you choose to add to the Frozen Zoo?

Suellen Charter is a research coordinator for the San Diego Zoo Institute for Conservation Research. Read her previous post, Counting Chromosomes.


Reindeer Boris Steps Out

Boris is growing before our eyes!

Boris, our young reindeer, mastered his base training and was ready to move on to a more advanced reindeer game (see Reindeer Boris: Basic Training).  Since he had done well so far, we decided it would be enriching and beneficial to introduce Boris to a halter so that he could walk with his keeper.

The first time Boris felt his halter slide over his long furry muzzle and up around his ears, he stood quietly for a few seconds, probably a little puzzled. Next, he tossed his head and rubbed his face on his keeper’s shirt, maybe trying to figure out what kind of large bug had landed on his muzzle and wrapped itself around his ears. Help! After a few  reassuring words, and a short, gentle introduction to this new creature called a “halter,” Boris began to relax and learn.

Boris takes Keeper Pamela for a walk.

Next, it was time to train Boris to walk calmly while on the lead. We were fortunate that Keeper Brad Wymer had some experience with training horses and was willing to help. He generously offered some pointers on halter training and tested them with Boris. After a few trial runs, Boris became calm and relaxed as he walked beside Brad and did very well with reindeer keepers Matt Price and Pamela Weber as well. Although his attention span was a little short, as long as we kept training sessions brief and positive, Boris responded well. Once again, he was proving himself to be a star pupil.

The reindeer is the only deer that can be domesticated and has been used by people in Lapland as long as 3,000 years ago. Even today, reindeer provide butter, meat, cheese, clothing, and transportation for the Lapp people. Its antlers and bones are used to make tools and utensils, and the tough sinews in its legs are used to make thread. Reindeer have been the economic basis of the Lapp culture for centuries. Because of their popularity, reindeer are raised in many areas of the world outside of their native Arctic.

Boris meets some San Diego Zoo guests. Click on all images to view in larger format.

Knowing that reindeer have been domesticated, we felt comfortable introducing Boris to a halter. That said, reindeer also deserve some healthy respect. Sharp antlers can be dangerous. Because of this, we understood that Boris’s time on a halter would be sweet but short lived. He has already grown into quite the handsome teenager, and will no doubt be an impressive adult.

Sigh….They grow so fast, don’t they? Did time speed up in December? The weeks have flown by, and the Christmas holiday season arrived quickly. It had become the season of holiday treats, Santa Claus, and, of course, reindeer. What a perfect opportunity to introduce our Zoo visitors to Boris! His first public debut was during a Sunrise Surprise Stroll.  Lucky visitors got a chance to meet our handsome young reindeer and hear his amazing story firsthand. Since then, Boris has been the star of several Strolls, and if you’re lucky you may see him practicing his stride on exhibit while his reindeer family looks on.

Raising Boris has been a team effort with great results. He has been a joy to raise and rewarding to work with. At just over three months of age, Boris was weaned on December 25, 2010. Christmas Day, of course! After all, he had work to do!

Kim Weibel is a senior keeper at the San Diego Zoo.


Reindeer Boris: Basic Training

Boris takes a bottle feeding from Lead Keeper Tammy Batson.

If you visit Wegeforth Bowl at the San Diego Zoo to see the animal show, you may be treated to watching a sea lion swim, a lynx pounce, or a serval cat leap. These amazing behaviors performed on cue are the result of the many hours of training put in by our dedicated animal behavior staff. Training is key to the success of our animal shows and presentations. Training is also instrumental in animal care and management. On a stroll through the Zoo, you might notice a keeper asking a lion to rub her side against a fence or asking an ape to present his hand or chest. Training is going on everywhere at the Zoo, with animals from great apes to meerkats. Not only can it make life on exhibit much easier for both the animal and its keeper, it is also enriching. Working with a baby animal allows us the unique opportunity to start training at an early and impressionable age. The behaviors young Boris, our newest reindeer, learns to display in his Zoo environment now will help us manage him as an adult reindeer. (See previous post, Boris Learns Reindeer Games.)

Training animals like Boris to become familiar with things like weighing platforms, crates, loading ramps, trainers, and hoof-trimming tools helps prepare them for routine care and management. To introduce Boris to some of these management practices, we began working on a few training basics. Foot and hoof care is occasionally necessary in adult hoofed animals. We wanted to teach Boris to be calm and quiet when having his feet handled, so we began by gently touching his legs and feet. When he was little, Boris made us laugh with his extreme reaction to any fly that might buzz around his legs. Poor Boris reacted to one single fly as if it were a swarm of 10,000, so we weren’t surprised when his first response to our touch was to stomp and snort, trying to escape our fingers. To him, our hands might as well have been a giant fly coming to get him. Aaack! Thankfully, with practice and gentle repetition, Boris learned to stand quietly and eventually even lifted his feet when his hooves were touched.

Another important part of animal care and health is monitoring body weight. To collect the reindeer’s weights, a large wooden platform was set up on top of a scale in the reindeer’s back area. When the adult reindeer walks onto the platform, the keeper can record each animal’s body weight without causing any stress to the animal. Boris had to learn to step up onto the weigh platform just like the adults. We encouraged him to step up onto the platform by using his bottle as the dangling carrot. On his first try, Boris stepped up onto the platform as if he’d done it a thousand times before. No problem for this little guy!

Some training days that were especially fun for Boris were also a comedic scene for us to witness. One day, when a trailer was available, we backed it up to the reindeer pens and opened the door so that Boris could walk in. He walked up and down the loading ramp and sniffed around exploring the big “new thing.” Boris showed no fear. He quickly made a game of the new thing and trotted up and down the ramp leading into the trailer as if he had claimed it as his new fort. He had conquered his first trailer session with ease.

Boris has proven to be a diligent and eager student. His training will be a continued and significant part of his life in our zoo. Although he still has much to learn, he has done very well with his sessions thus far, and we are very proud of him.

Kim Wiebel is a senior keeper at the San Diego Zoo.


Polar Bears: A New Look

Kalluk shakes off.

Why no Polar Cam? Have you looked recently? The Polar Cam has been replaced by a new HD camera system, and it looks so much better! And in keeping with our message of reducing our waste, the old camera will be reused in our Polar Bear Park (the new management yard behind the main polar bear exhibit)! We have been able to raise enough funds to add some cameras and the ability to pan-tilt-zoom! This will help us see where our bears are from inside the polar bear building and what antics our trio is up to. In addition—YES!—we will be installing an Internet hookup so that in the event Chinook has cubs, we will be able to show her den live on our Web site! With the installation of the cameras in the park, we will also be able to watch the bears in the pool. We are hoping to have all the work done by the beginning of July. We want to have lots of practice with it by the fall!

And for those of you wondering about weather conditions in San Diego, it would appear we are in for a “snow storm” on Saturday, June 5, in celebration of World Oceans Day! Luckily for beach goers, it will be an isolated storm directly in the Conrad Prebys Polar Bear Plunge. We are expecting the largest snowfall ever, and a few creative individuals will be building ice people; the bears will then get the choice of which is the best. So watch to see which one they knock over first! Note: Video of this fun activity is now posted!

Our arctic foxes Kaniq and Isiq have made themselves quite comfortable in their new digs (see New Neighbors for Polar Bears): every day we find a brand-new hole! It is so much fun to see them digging and rolling in the soil. They don’t seem to have much appreciation for landscape and have greatly enjoyed playing tug-of-war with the long grass and flowering plants in their area. Isiq also loves to race around with pieces of sod, tossing and jumping as though she is making a great lemming kill. When you visit, please take some time with these two. Morning is usually the best time.

The reindeer herd is now officially grown. Three yearling females have joined our other lady. Polar bear Kalluk is absolutely entranced by them. I’m not sure what he was trying to communicate when he brought his large beef femur bone over to show the reindeer at the fence line!

For those of you trying to tell the difference between Tatqiq and Chinook, it is quite easy these days: Chinook is oh so very pudgy! This is usually a time when she would be losing weight, and she is not. Not sure what this means, but she has not become her usual playful self after breeding season and instead seems to be a bit drifty and very mellow.

But if action is what you’re looking for, check out our brother-sister team! Kalluk and Tatqiq have rejoined to become quite the pair. As we get closer to summer, they are definitely swimming and playing together more, and Kalluk is back to his water-ball-dribbling and basketball-like antics!

With the fun days we have ahead, it’s difficult to hear of the latest report coming from the biologists in the Arctic. The ice has not been very good this year. The Western Hudson Bay area where I spend every fall reports the hardest news of all: it would appear that their population of polar bears is very close to the “tipping point.” This is a term used to define when a population decreases so greatly it has little chance of returning. It is estimated that a third of the Western Hudson population could be lost within a year’s time. The decline will be gradual until the threshold is passed, and then it will decline dramatically and very fast. In the 1980s, there were approximately 120 days during which the bears had a summer fast due to ice melt; this time it is increasing and it is estimated that when it reaches 180 days, 28 to 48 percent of the population will starve. This is very difficult to think about.

The disaster we watch every day in the Gulf is a good reminder that it is about our entire planet and how we use its resources. It is time to really act on common sense and what is good for our home by reducing our consumption and our waste. In the end, we are all impacted by it, whether it is happening off our coast, the equator, or at either pole.

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


Time for Reindeer to Shine

G’day everyone!

Now, most of our visitors to San Diego Zoo will be familiar with our polar bears. They are incredible, powerful, and very beautiful animals that are always popular with our guests. (Read blogs about the polar bear trio.) But what you may not have noticed is behind the polar bears, in the San Diego Zoo’s Polar Bear Plunge habitat, in a very cleverly designed exhibit that blends into the background are two Siberian reindeer.

For 11 months of the year, the reindeer are happy to keep a low profile and let the polar bears steal all the attention. But in December, the reindeer are the stars of the show! I haven’t seen any Christmas decorations, or TV specials where polar bears are helping Santa Claus deliver Christmas presents to the kids….

We have two female Siberian reindeer at San Diego Zoo; they have the affectionate names of “Ear-Notch 16” and “Ear-Notch 7” (Most hoofed animals at the Zoo have small notches in their ears to make identification easier.)

Reindeer are amazing animals. They are found throughout the world’s Arctic regions, including, yes, the North Pole. They are the only species of deer in which males AND females have antlers, and like other deer, these antlers are shed each year.

They are perfectly designed for living in freezing temperatures with thick coats, hooves that shrink and tighten depending on the conditions, and a nasal passage that heats the incoming air before it hits their lungs. Amazing!

Reindeer have been incredibly important to the indigenous people of the Arctic regions. They were one of the first animals to be domesticated, and while polar bears are terrorizing communities and reminding us all about global warming, reindeer are providing food, clothing, and transportation to people. And let’s not forget about gift delivery: very handy!

So next time you are at the Zoo admiring the polar bears, be patient, stick around, and have a look at our reindeer. And I’d be happy to hear anyone’s suggestions for some better names that EN-16 and EN-7, but sorry, there’s no way we are calling one Rudolph.

Merry Christmas!

Brent Clohesy is a keeper at the Melbourne Zoo in Australia doing a keeper exchange at the San Diego Zoo. Read his previous blog, An Aussie in San Diego.


An Aussie in San Diego

Brent with a lesser kudu

Brent with a lesser kudu

G’day! My name is Brent, and I am one of the Sumatran tiger keepers from the Melbourne Zoo in Australia. For the next three months I am lucky enough to be working at the San Diego Zoo, participating in a keeper exchange with a great guy named Adam. I’m working in the San Diego Zoo’s hoofed animals team, while he looks after our native animals at the Melbourne Zoo. It has been an outstanding experience so far! (Read Adam’s previous blog, Hopping along the Exchange.)

Now, most of the information I knew about America came from watching Jerry Springer on Australian TV, but so far I have not even seen ONE dwarf fighting with a large security guy. In fact, every single person I have met here at the San Diego Zoo and around San Diego have been absolutely fantastic. Californians seem like very relaxed and friendly people, just like back home in Australia. I think I might stick around and run for mayor.

One of the reasons I came to the San Diego Zoo was to learn more about ungulates (animals with hooves), and there is no better place in the world to do that than here at the San Diego Zoo and the San Diego Zoo’s Wild Animal Park. Being a tiger keeper, most of my hoofed animal knowledge revolved around how to prepare meat to feed to the tigers…but I needed more.

Adult dik dik

Adult dik dik

The animals that I get to care for are amazing. I’m learning about reindeer, Calamian deer, Sichuan takins, Japanese serow, Soemmering’s gazelles, red-flanked duikers, Cape blue duikers, hairy armadillos, lesser kudu, pronghorn, tufted deer, steenbok, and my favorite: the dik diks. They are amazing little African antelope weighing about six pounds (2.7 kilograms) and their name comes from the alarm call they make when they are startled. Visitors to the Zoo will be lucky enough to see our one-week old baby dik dik near the west end of the Skyfari aerial tram. He could be the cutest animal in history!

Speke's gazelle

Speke's gazelle

Another animal that I look after and I’m really enjoying learning about is the Speke’s gazelle. These guys are another African antelope weighing around 40 pounds (18 kilograms), and they are super quick. But their most unique feature is their nose: they have folds of skin over their nostrils that inflate when they get excited. If I am working in their enclosure and they think I’m getting a bit close, they will stamp their hoof on the ground and their nose inflates like a small tennis ball! Visitors to the Zoo can see the Speke’s gazelle in our large mixed species exhibit just before you get to the polar bears. And you shouldn’t have to wait too long to see a Speke’s gazelle inflate its nose sack, because these guys don’t mind fighting out of their weight division, and you could see them trying to intimidate much larger animals like lesser kudus, and gerenuks, all with the help of an inflatable nose!

So, I hope the great people of San Diego get a chance to come into the Zoo soon, and if you see an Australian going walkabout, then come and say G’day.

Brent Clohesy is a keeper at the Melbourne Zoo.