Polar Bears

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Order: Carnivora
Family: Ursidae
Genus: Ursus
Life Span: 10 - 30 years
Population: 21,000 - 30,000
Species Status: Threatened

Fun Factoid

Did you know? The largest Polar Bear ever recorded was over 2000 lbs and stood 12 ft tall!

Welcome to the world of Polar Bears (Ursus maritimus)! Of the eight species of bear in the world, Polar Bears are the only ones specially adapted to thrive on the frigid sea ice and continuous cold of the Arctic circle. Polar bears are closest related to their cousins, the Brown Bears, who sometimes share the same habitat, however, Polar Bears spend most of their time on the sea ice, where Brown Bears spend their time on land. Polar Bears are the largest of any of the bear species, but also the largest of any land-dwelling carnivore! Polar bears can range in weight anywhere from 500 – 1500 lbs and the largest can stand about 10 ft tall on their hind legs!

Geography

Fun Factoid

Polar Bears have transparent fur that is so bright white because it reflects the light of the sun and snow!

Polar Bears are only found in the polar regions at the very North point of the Earth called the Arctic. This is different than the Antarctic regions at the South point of the Earth. Much of the Polar Bears’ habitat includes the polar regions of Norway, Canada, Greenland, Russia, and Alaska. Polar Bears rely on the abundant sea ice that is found in the area and use it to hunt, rest, raise their young, and more. Polar Bears spend almost all of their lives on the sea ice, except for certain times of the year when the ice shrinks due to warm weather. This is now happening for longer periods of time, forcing Polar Bears to spend up to 2 months on land in some places. Polar Bears are expertly adapted to life on the sea ice, and without it, they can struggle.

What are Polar Bears?

Polar Bears are 1 of only of 8 bear species spread throughout the world today who are all in the taxonomic Family Ursidae, also known as “true bears”. The other 7 bear species include the American Black Bear, Andean Bear, Sloth Bear, Brown Bear, Asiatic Black Bear, Panda Bear, and the Sun Bear. Polar Bears are most closely related to the Brown Bear. It is believed that these bears shared a common ancestor about 15,000 years ago, before the last Ice Age, when Polar Bears began to adapt for life on the sea ice. Today these adaptations include their large size, transparent hollow fur, two layers of fur insulation, black skin, a thick layer of body fat, large feet for walking on snow, exclusively carnivorous diet, small ears and more. They are so well adapted to the cold, that they struggle more with overheating than they do with freezing and they become overheated in temperatures warmer than 50 degrees f. Polar Bears are also excellent swimmers and can swim up to 6 miles per hour with their large, flat paws. They are excellent hunters with a great sense of smell, and due to their life on the sea ice, they do not eat vegetation. This is another adaptation for their life in a place where there are not many plants growing throughout the years.

Fun Factoid

Did you know? Polar Bears and Brown Bears are so closely related that they are able to breed and have cubs. However, they cannot stay long in each other’s habitat and almost never breed.

Behavior

Polar Bears, like Brown Bears, spend a lot of time alone unless it is breeding season. They tend to sleep, den, and hunt solitarily, however, this does not mean they are aggressive towards each other. Young Polar Bears, often siblings, will spend time together and even play together. Another cold climate adaptation is that unlike their Brown Bear cousins, Polar Bears do not hibernate or den. Because they live in extreme cold year-round and their food sources are almost always active, they do not need to den like some other bears who rely more on vegetation. Instead, only pregnant Polar Bears den so their cubs can be warm and safe when they are born. Polar Bears are also shy and tend to avoid human interaction as much as possible, although, they are curious and love to explore. They are very intelligent and are quick to learn and adapt to their surroundings, especially when hunting.

Fun Factoid

Did you know? Adult Polar Bears can make friends with other Polar Bears and they will sometimes spend long periods of time together eating, sleeping, and playing!

Diet

Fun Factoid

Did you know? Polar bears are able to use their strong arms and swimming skills to jump on to and catch some of their larger aquatic prey.

Polar Bears eat almost exclusively meat, making them true carnivores. This is due to the fact that no vegetation grows out on the sea ice, where Polar Bears spend almost all their time. Occasionally they may eat some kind of vegetation like kelp when they spend time on land, however, it is not important in their diet. Polar Bears are Apex predators, and have no natural predators, except for humans. Seals make up the largest portion of Polar Bears’ diets, since they are high in fat, which is important for the Polar Bears to keep their thick layer of blubber. They will also eat other prey as well, like water birds, reindeer, fish, and sometimes even larger animals like walruses, narwhals, and beluga whales. Because a lot of their prey are aquatic, Polar Bears are masters of patiently waiting. They frequently wait to strike at holes in the ice that seals create to breather when ice becomes thick.

Reproduction

Although Polar bears only live between 10 – 30, most male bears are not ready to mate until around 8 – 10 years old. Female bears are ready between the ages of 5 – 6 years. The Polar Bear breeding season begins in January and ends in June. Female and male Polar Bears will spend about a week together, and then part ways. Although a female bear may be pregnant, just like other bear species, she experiences something called delayed implantation. This means that the fertilized eggs will hold off on developing until the fall, and only if her body has enough fat and nutrients stored to grow healthy cubs. Once fall arrives, pregnant bears will begin to den for the winter. Polar Bears usually have litters of 1 to 2 cubs born between November and January who weigh about 1 lb each and are born blind and deaf. By two months old, cubs will have teeth and are able to begin walking. Around March and April, the cubs will weigh around 20 to 30 lbs and leave their dens with their mothers to begin learning how to survive. Polar Bear mothers are very protective and attentive, and teach their cubs everything they need to know to survive. By the age of 2, Polar Bear cubs will leave on their own.

Fun Factoid

It is most common for Polar Bears to give birth to twins, but very rarely they can have three cubs in one liter!

Threats

Although Polar Bears have no natural predators, they face many threats. The biggest threat is climate change, which is rapidly changing their Arctic habitat. Polar Bears rely on sea ice to live. They use it to travel, build their dens, hunt, raise their cubs, and much more. With how much the planet in warming in the Arctic, sea ice is becoming less stable and lessening in many places where Polar Bear habitat is. This causes many issues, including that the Polar Bears are losing much of their historic habitat and giving them less places to be. This forces them into smaller areas and onto the mainland where they can come into contact with more people. Polar Bears also use sea ice to hunt, and without reliable sea ice, Polar Bears are not able to hunt their main food sources, which can cause them to starve, or even go into human settlements and eat trash. Polar Bears overheat very easily in temperatures above 50 degrees f, and due to the warming climate in the Arctic, they are struggling to stay cool. They are now beginning to face threats from oil and gas companies, who are pushing further into the Arctic to mine for natural resources. This can put the whole Arctic at risk of oil spills, and terrible pollution.

Population

At the moment, Polar Bears are only labelled as Threatened as an Endangered Species, however, they face many threats that could cause their population to drop significantly in the next few decades. Throughout Polar Bear habitat, there are a few different population groups of Polar Bears which are spread out across the Arctic region. Of those populations, most are stable, while a few are steadily decreasing. Some Polar Bear populations have even been steadily increasing, thanks to strict conservation efforts and rules on hunting Polar Bears.

How to Help

Even though Polar Bears live all the way in the Arctic, there are ways you can help! The threats Polar Bears face are caused by our changing climate, which is affected by things like greenhouse gases, pollution, and other factors.
Things that can help reduce the extremes of climate change include…
Using less electricity! At the moment, electricity can be powered by things that release a lot of emissions and pollution into the atmosphere. By shutting off lights when you don’t need them, unplugging small appliances when not in use, and using energy efficient light bulbs and power strips, you can help Polar Bears!
Avoid using your car when possible! For some people this may be impossible, but if you can, try walking or riding your bike to school and work! If your commute isn’t walkable or bike-able, try using public transportation like subways and buses. When people use public transportation, it reduces the number of vehicles releasing harmful emissions into the atmosphere.
Spread the word about Polar Bears! The more people who know about Polar Bears plight, the more people there will be who can begin making more mindful choices and thinking about the environment. Polar Bear prosperity is tied directly to our changing climate, the more you do to help reduce climate change, the more you can help save the Polar Bears.

Fun Factoid

Did you know? Polar Bears can smell their prey over a half a mile away!