23 Facts About Polar Bears That May Surprise You

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23 Facts About Polar Bears That May Surprise You

Polar bears (Ursus maritimus) are fascinating creatures that few of us will have the opportunity to see in person. But, there’s a lot more to these Arctic-dwelling bears than first meets the eye.

In this article, we’ve pulled together some of the best facts about polar bears, with some that you might find quite surprising (check out number 12!)

1. There are fewer than 26,000 polar bears left

Polar bears live in the Arctic in the northernmost parts of the world. There are 19 subpopulations of polar bears that live across North America and Eurasia. The majority of them can be found in Canada, but they also live in Alaska, Greenland, Russia, and Norway.

It’s now estimated that there are fewer than 26,00 polar bears left in the wild1 (source: The Guardian), with some sub-populations experiencing steep declines such as those in western Hudson Bay where the number has dropped by 30% since 19872 (source: Polar Bears International).

Some scientists think that they may be extinct by 21003 (source: Nature Climate Change, P.K. Molnár, et al, Vol 10, 2020). Read fact number 22 to find out more about why the population is declining.


2. Polar bears are not white

Polar bears have two layers of fur; the shorter undercoat and longer guard hairs. An often overlooked fact is that these hairs are translucent, however, they reflect sunlight which makes polar bears look white4 (source: WWF).

If you look at polar bears under a grey sky they appear greyer and at sunset, they can seem redder.

Underneath their fur, they have black skin. This is an evolved trait since other bear species have pink fur, however, scientists are still unsure of the reason for this5 (source: Polar Bears: A Complete Guide to Their Biology and Behavior, A. E. Derocher, 2012).

Here’s a bonus polar bear fact: They can also appear green in captivity. This is because rough concrete pens can cause tiny holes in the guard hairs, then algae begin to grow due to the warmer climate.


3. They often share food with arctic foxes

Polar bears tend to eat animals with lots of fatty blubber which is why they prefer marine mammals. Generally, they do not eat arctic foxes and often (unwillingly) share food with them.

This is because the polar bear will usually leave the meaty part of a carcass behind. Arctic foxes will follow polar bears and scavenge on these remains.

Whilst polar bears do not normally eat arctic foxes when food is abundant, they must be cautious when food is scarce because the polar bear might get hungry and hunt it instead.


4. Only pregnant females hibernate

Polar bears do not hibernate like other species of bear, this is because they spend winter on the sea ice hunting seals and building up their fat reserves for summer which is spent on the mainland or small archipelagos in the arctic.

However, female polar bears do enter a hibernation-like state. They will enter the den around October with cubs being born around 60 days later, although they will remain in the den for a total of 7-8 months until the cubs can leave6 (source: Polar Bears, K. Allen, 2012).

During this time, they remain in a reduced metabolic state, they don’t eat, drink, urinate, or defecate to save energy.7 (source: Polar Bears: A Complete Guide to Their Biology and Behavior, A. E. Derocher, 2012)


5. The mother’s milk is like double cream

A polar bear’s diet of fatty blubber from seals and other marine mammals means that the mother’s milk is very high in fat, up to 48.8% according to the Guinness World Records. This is equivalent to feeding the cubs double cream as soon as they are born.


6. They are the only carnivorous bear

Although most bears are omnivores, polar bears are carnivorous as their primary diet is ringed and bearded seals.

However, polar bears are opportunistic hunters and will turn to many other food sources, especially during the summer when they cannot hunt seals.

This includes birds, terrestrial mammals, and even vegetation such as algae, and berries. For this reason, some experts call them hypercarnivores which is an animal that eats more than 70% meat.


7. Polar bears try to avoid human confrontation and attacks on humans are very rare

Despite the fact that they could easily hunt us if they wanted, polar bears do not eat humans and try to avoid confrontation, and can often be scared away by shouting or starting an engine8 (source: Polar Bears in Svalbard, Norweigan Polar Institute, 2005).

A review of attacks by polar bears on humans between 1870–2014 reported 73 attacks over the 44 year period across their entire range, including Canada, Greenland, Norway, Russia, and the United States.

During the 73 attacks, 20 people were killed which makes it very unlikely to be killed by a polar bear9 (source: Wildlife Society Bulletin, J. M. Wilder, Vol 41, Issue 3, 2017).


8. You can die from eating polar bear if it’s not prepared correctly

Although it is illegal for most people to hunt polar bears across the countries they can be found in, there are usually some exceptions for Indigenous populations who have relied on them as a source of food and income for many centuries.

You can eat polar bear meat, however, it comes with several risks. It must be well cooked to kill any Trichinella parasites. These cause Trichinosis which can result in mild symptoms such as nausea and vomiting, or in more severe cases it can cause death

Their liver is very dangerous because it is so high in vitamin A which can cause Hypervitaminosis A in humans. This is another deadly disease that can cause your hair to fall out and your skin to peel.

In the past, many explorers have died from eating raw polar bear meat, and there continue to be outbreaks today, although stringent testing has helped reduce the number10 (source: Veterinary Parasitology, L.N. Møller, et al, Vol 132, No. 1-2, 2005).


9. They are the largest bear species

One of the more well-known polar bear facts is that they are the largest bear species, but you might be astonished to hear just how big they are.

An adult male weighs between 350-680kg (775-1500lbs) and can be up to 3m (10 feet) in length. Females are smaller, weighing between 150-250kg (330-550lbs) and up to 2.4m (8 feet) from head to tail11 (source: The Polar Bear, A. Hemstock, 1999).

However, when they are first born, polar bear cubs can be as small as 30cm!


10. Debby, the oldest polar bear ever recorded, lived to be 41 years old.

In the wild, the maximum life expectancy of a polar bear is 30 years, although few make it to this age. Pup mortality is high and those who do make it to adulthood often don’t live to be older than 15 years12 (source: Survival and Reproductive Rates for Polar Bears at Svalbard, Ø. Wiig, 1998).

Common causes of death among polar bears in the wild are malnourishment, drowning, disease, and humans.

In captivity, polar bears that are treated well will live for much longer, with an average lifespan of 20.7 years for males and 24.2 years for females13 (source: Oregon Zoo).

The oldest polar bear on record was Debby who lived at a Canadian Zoo. She reached the age of 41 years old, more than double the life of most polar bears.


11. They are excellent swimmers

Since polar bears primarily prey on seals and whales, you won’t be surprised to learn that they are excellent swimmers.

They have large, slightly webbed paws which they use to swim and they can hold their breath well. The hairs on the outer layer of their fur are hollow which gives them additional buoyancy14 (source: Polar Bears, D.J. Tyler).

Polar bears must also swim for long distances when migrating from the melting sea ice to islands or the mainland. These long-distance swims are typically around 150km, although they have been recorded traveling up to 687km in a single swim that lasted 9 days in the water15 (source: Canadian Journal of Zoology, A.M. Pagano, et al., Vol 90, No. 5, 2012).


12. A female polar bear can give birth to cubs from different fathers at the same time

Polar bears are polygynous and will rarely mate with the same bear in different years.

Male polar bears are not paternal. After a week of mating, the male polar bear will only stay with the female for a few days before leaving.

The female may mate with another partner in the same breeding season, this can result in giving birth to offspring from different fathers at the same time16 (source: Canadian Journal of Zoology, E.Z.Fiskebeck, et al., Vol 87, No. 12, 2009).

See our full guide on how polar bears reproduce to learn more interesting facts.


13. They have built-in snow goggles

Whilst humans visiting the Arctic must wear special snow goggles to prevent snow blindness from the sun reflecting off the ice, polar bears have built-in membranes that filter out UV radiation that could cause eye damage17 (source: Guinness World Records).


14. Polar bears burn through 12,325 calories per day

Polar bears hunt marine mammals because they are high in fat which helps them remain in energetic balance.

A polar bear can burn through 12,325 calories per day so a solitary female must eat either one large adult seal, three small adult seals, or 19 newborn seal pups every 10-12 days just to maintain their body mass18 (source: Science, Pagano et al, Vol 359, 2018).


15. The tallest polar bear ever recorded stood at 3.4m (11’1”) tall

Stood on all fours, standing next to a polar bear is like being near a large pony. However, they can also stand on their hind legs to see and smell further or when they want to play.

According to Polar Bears International, on their hind legs, a polar bear is on average 3m (10’) tall.

The tallest polar bear ever recorded was at Kotzebue Sound, Alaska in 196019 (source: Guinness World Records). The bear stood 3.4m (11’1”) tall on its hind legs. It was shot and put on display outside Seattle World Fair two years later in 1962.


16. They have the most sensitive nose for a land mammal

Our next fact about polar bears relates to their excellent sense of smell.

Polar bears can smell prey up to 32km (20 miles) away20 (source: Polar Bears, S. Markle, 2004) or when they are hidden up to 1m below the surface of the snow.

According to the Guinness World Records, this means they have the most sensitive nose for a mammal that lives on land.


17. Polar bears can overheat

Polar bears are fast with a top speed of up to 40 km/h (25 mph)21 (source: Seaworld) which is even faster than Usain Bolt.

However, you’ll rarely see them sprinting at this speed because these huge creatures can quickly overheat. When this happens, they must dive into the cold arctic ocean to cool off.

You are more likely to see them wandering slowly across the ice at around 5.6 km/h (3.5 mph), with their side-to-side swing that helps them keep balanced on the ice.

This is why they tend to be lazy hunters, opting for a ‘sit and wait’ strategy near breathing holes and grabbing seals when they come to the surface.


18. Pup mortality is high

The first few years of a polar bear’s lifecycle are treacherous with high pup mortality rates with some studies suggesting that fewer than half of polar bear cubs making it past weaning22 (source: Ursus, Ø. Wiig, Vol 10, 1988).

Even at the subadult stage, they are not fully-fledged hunters and may struggle to compete with larger adults. In some cases, it has been known that male adults will hunt young cubs when food is scarce.

However, once they make it past the age of 4, things get better for the polar with a much improved 95% chance of surviving each year23 (source: Science Progress, Ø. Wiig, et al, Vol 21, No. 2, 2008).


19. They have many adaptations to prevent heat loss

Polar bears live in some of the most extreme climates on Earth, however, they are well adapted to survive this extreme cold.

Some of the adaptations of polar bears include:

  • Two layers of fur that provide insulation and camouflage by appearing white
  • The ability to quickly build up body fat for insulation and energy reserves
  • Large paws with a rough underside like giant snowshoes for walking on snow
  • Small tail and ears to reduce heat loss
  • Long but thin head and neck that helps them hunt seals through holes in the ice

20. Polar bears touch noses to share food

With a stomach that can hold 10-20% of its body weight, polar bears can eat a lot of food in one go and often up to 2kg (4.4 lbs) of fat across a single day24 (source: WWF).

However, larger marine mammals such as beluga whales can be as large as 1500KG so would be shared between a group of polar bears25 (source: Ecological Monographs, G. W. Thiemann, S. J. Iverson, and I. Sterling, Vol 78, Issue 4, 2008).

But they don’t just help themselves, when they want to share another bear’s food, they’ll slowly circle their way towards them and gently touch noses to ask if they can share26 (source: WWF).


21. They cannot climb trees

Bears evolved from the Miacidae, a small tree-climbing mammal that existed 62–34 million years ago, most species of bear have retained this ability. However, polar bears have evolved to life in the Arctic where there are no trees so they have lost this trait.

Although polar bears can’t climb trees, they do have a decent climbing ability. One was spotted ascending a ladder to reach a platform where seals were being stored for dog food27 (source: Polar Bears: A Complete Guide to Their Biology and Behavior, A. E. Derocher, 2012).


22. Contrary to popular belief, they do not scream while they poop

A popular internet myth suggests that polar bears scream while they poop. However, here at Polar Guidebook, we did some investigation work and found this to be a false claim.

We traced the original GIF back to a Reddit user in 2013 who also posted other polar bear jokes as well as memes of a cat eating ravioli from a fork and a sloth playing the banjo. We’re almost certain that these are fake too.


23. Melting sea ice poses a major threat

This final fact about polar bears is the most important so please pay attention.

Polar bears are facing serious threats from the changing climate.

They rely on the winter sea ice which they use when hunting seals, whales, and other marine mammals. They must build up their fatty reserves before heading to the mainland or islands for the summer where they will mostly live off these reserves, topping up with other terrestrial mammals and vegetation.

However, with the sea ice melting earlier each year, they are not having adequate time to build up the fatty reserves.

This also poses a threat to humans since malnourished polar bears are the most likely to attack humans at campsites and Inuit settlements28 (source: Wildlife Society Bulletin, J. M. Wilder, Vol 41, Issue 3, 2017).

Kieren

Kieren is the founder of Polar Guidebook. After visiting both of the polar regions and meeting the scientists and tour guides that work there, he developed a keen interest in the animals, climate, and geography of the Arctic and Antarctica.