Did you know that despite their differences in appearance, polar bears are actually closely related to brown bears? Genetic studies have shown that evolution-wise, the two species split around 600,000 years ago (Hailer et al., 2012). However, polar bears obviously live in much more extreme climates and must have adapted to do so. In this section, we'll cover some of the known adaptations that polar bears developed to survive their harsh environment.
- Fur Color
Not only does their fur provide camouflage amongst the bear's snowy background, but its ability to scatter light also helps absorb and retain solar radiation heat.
On a sunny day, incident light will enter a hair and scatter, partly passing through to neighboring hair. That light, along with incident light from the Sun itself, will enter the nearby hairs and scatter, repeating the pattern until the energy is dissipated or absorbed by the bear's skin (Khattab and Tributsch, 2016). Additionally and through similar mechanisms, it helps retain the bear's own body heat which is typically lost to the much colder environment.
- Paws and Claws
The paws of polar bears also help when it comes to swimming. Seeing as they live mainly on ice and in water, it's reasonable to assume these animals do a lot of swimming. Polar bear paws can measure up to almost 12 inches, and their large size help the forepaws act as paddles. The hind paws, which are elongated, serve as rudders and assist with steering as the bear is swimming (Polar Bears International).
- Body Features
The ears and tails of polar bears are particularly short, and therefore serve as a perfect example of this idea! Since they live in extremely cold environments, conservation of body heat is important whenever possible. Not having large or long ears reduces the amount of energy required to maintain sufficient blood flow and body heat to these extremities (Bedolfe, 2012).
- Diet