Polar bears are classified as marine mammals, but they’re also one of the largest terrestrial carnivores.
As adults, the bear species can weigh anywhere from a whopping 450 to 990 pounds depending on their sex. There have even been reports of bears weighing up to 1700 pounds.
Polar bears are some of the largest and heaviest bears in the world, much bigger than American black bears and smaller species like sun bears.
Statistics available on Polar bears seem to vary slightly the weight of the species as adults. For example, information about the species by the National Wildlife Federation (NWF) states male Polar bears can touch up to 1700 pounds as adults.
The Polar Bear Fact Sheet by World Wildlife Fund (WWF) states that adult male Polar bears can weigh between 770 to 1763 pounds.
And the largest polar bear ever weighted came to over 2000 points!
So, the species weight figures follow something like the following:
- Adult male Polar bears will usually weigh from 750 to 1720 pounds. Whereas female Polar bears, being much daintier, have a weight range of 330 to 650 pounds. That makes females almost half the weight of most male Polar bears.
- At birth, Polar bear cubs weigh a shocking 450 to 680 grams. At eight months of age, the cubs grow bigger on a diet of their mother’s milk and blubber and clock in at 90 10 100 pounds.
Why Do Polar Bears Weigh So Much?
Polar bears are heavy because they carry a lot of fat to stay warm. They usually have around 3.5 inches of fat around their bodies.
Animals adapt to their environment, from their physiology to behavior and diet, for one purpose – survival.
Polar bears are no different. They’re the largest carnivores on Earth because they have to be.
Unlike other members of the Ursidae, Polar bears have to survive the harsh Arctic landscape they inhabit.
The Arctic faces extreme temperatures, and that’s especially true during the winters. Winter temperatures in the Arctic are lower than anywhere else in the world. In fact, temperatures can hit as low as -76 F in some high areas of ice sheets.
Unlike humans, Polar bears can’t trek down to their local store for winterwear or rely on heaters to keep them warm. And, let’s not forget that Polar bears tend to hunt and feed well in the winters.
That means Polar bears have adapted over time to ensure they’re equipped to hunt and feed in winters (when the sea ice freezes over greatly). They’ve done so by growing larger than any other bear species on Earth because, this way, they have more room for fat.
The bodies of Polar bears are lined with a layer of fat that’s approximately 3.5 inches thick. The fat and two layers of fur keep them warm enough to hunt comfortably in temperatures that would kill lesser beings.
A Polar bear’s weight is also more than other bears’ also because their arms and legs are much larger and stronger than other species. This isn’t an unnecessary feature either. Instead, Polar bears need the strength of their legs to walk on ice and swim.
Their Weight Fluctuates
Polar bears don’t stay the same weight all their lives. Even as they feed during the winter, Polar bears can lose weight because their bodies utilize their fat layers for energy. The more cold they’re exposed to, the more fat they tend to lose.
A single Polar bear can weigh more than fifty percent more than its usual weight – after a productive hunting season. That’s because, more than anything, Polar bears need fat to survive. That’s also why the species prefers to eat fat-heavy marine animals like seals.
Fun fact: Polar bears don’t really have white fur. The hair of their coat is coarse and hollow, and it only appears white because their hair doesn’t absorb light – it reflects it by being transparent. Making it another gift of evolution – because it helps Polar bears blend in with their environment as they still hunt.
Even though all Polar bears appear pretty massive to human eyes, the largest Polar bear in recorded history clocked in at a staggering 2,209 pounds.
Unfortunately, the bear was shot and killed in Kotzebue Sound, Northwestern Alaska, in 1960.
The bear was displayed at the Seattle World Fair, where the mounted specimen stood more than eleven feet tall on two legs. There hasn’t been a Polar bear contender that’s come close to the 2000 pound mark since.
Polar bears are getting thinner as their food sources diminish due to climate change.
Just as climate change is wreaking havoc over human lives, Polar bears are one animal species that are the worst hit by the phenomenon.
Polar bears live, den, mate, give birth, hunt, and live out the majority of their lives on the Arctic sea ice. However, climate change has made it so that sea ice forms later and melts faster than it used to.
That means the species doesn’t have enough time to hunt and sustain themselves and work harder to survive. That’s one of the reasons why Polar bears are getting thinner and why their reproduction rates have also dropped.
Polar bears today are on average thinner than they were years ago. It might have to do with the fact that Polar bears live far away from most human civilizations – but their species is badly hit because of climate change and pollution. Still, these animals remain impressive and still qualify as the largest land carnivores. A Polar bear’s weight and size have a lot to do with where and how it lives. Their bodies are designed to thrive in freezing temperatures, and that’s why they need to carry so much fat on their bodies!
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