This blog post is an initial look into polar bears. This particular post isn't looking into their threats; it's researching them as a species and their physical and biological traits. I wanted to further my knowledge on them, and so I spent some time looking into facts and figures, discovering a huge amount of things that I didn't know before.
Polar bears are the largest land carnivore in the world, and can be as tall as 12 feet when standing on their hind legs. They are also extremely heavy, with males weighing around 700kg and females weighing around 300kg. Despite being heavy, polar bears are still extremely agile, and can reach speeds of up to 25mph.
Polar bears also have an amazing sense of smell. They have around 2000 scent receptors, which is five times more than humans. This means that they're able to smell prey on the ice from up to 20 miles away, and smell prey under the ice up to half a mile away. The reason why they've adapted to have such a strong sense of smell is becasue of their environment. Due to the snow and ice, their ability to visually spot prey is limited, and so they rely heavily on smell when hunting.
Their strong sense of smell doesn't just allow them to smell things far away, but it's also allows them to easily distinguish between different types of smells. This means that they can tell the difference in smells between different species of prey, and target which prey is going to be most nutritious and fulfilling for them.
So, what is their prey? Around 90% of a polar bear's diet is made up of ringed and bearded seals. This is because they're full of fat, which gives the bear a huge amount of energy compared to other prey in the same environment. However, polar bears are an apex predator, which means they're at the top of the food chain in the Arctic. Because of this, they will eat anything below them on that food chain, including fish and walruses.
When they hunt, they stalk their prey. They will smell the prey from a long distance away, approach quietly and wait for the right moment to attack. They will then use their immense speed and strength to make a quick dash at their prey. Polar bears almost always hunt for their prey on the ice. Even when attempting to catch fish, they'll look for them in pools within the ice, or shallow areas of water off the edge of the ice. Therefore, with a lack of ice, they become unable to hunt for their food, or even get far enough out to sea to reach it.
Polar bears appear white, but their fur is in fact transparent. The fur appears white because the transparent fur reflects light, which allows them to easily camouflage within their environment. So, why don't they just have white fur instead? Well, the environment in which they live isn't always completely white. It can be different shades of white, grey and blue depending on the time of day, weather and location. Therefore, if their fur was white, they wouldn't be able to adapt to the different shades. However, with transparent fur, they can more easily adapt to the environment that they're in.
The physical structure of their hair is interesting, too. The hair on a polar bear is made up of two layers; an inner layer and an outer layer. The inner layer (undercoat) is made up of hollow tubes which trap air close to the bear's skin, keeping it warm in Arctic temperatures. The outer layer (guard layer) is made up of longer, coarser hairs. These hairs act like prisms and reflect the light, making the bear appear white (as previously mentioned).
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