As the days inch closer to the holidays, we know your focus is all over the place—coordinating gatherings with friends and family, planning meals, and wrapping up any last-minute gift-giving efforts—so we’re keeping things simple this week by sharing a few of our favorite frozen friends living in the Arctic and Antarctic regions of our planet. Take a few minutes from your busy day to relax with some basic stats and lesser-known facts!
As of 2019, the polar bear population was 22,000–31,000, with their official status listed as vulnerable as of 2005. In fact, of the known populations of polar bears, four are in decline, and the global polar bear numbers are projected to decline by 30% by the year 2050, which is largely the result of the significant loss of sea ice in Northeast Canada and Northern Greenland.
Physically, polar bears are a formidable sight: At 6–9 feet in length and 300–700 pounds (females) and 800–1,300 pounds (males), polar bears are, on average, the largest members of the bear family. Even at this size, polar bears can run about as fast as the fastest human on earth at 40 kph, or 25 mph. And their bodies are built to protect them from the elements: Polar bears have three sets of eyelids, with the third serving as additional protection from the wind and cold. Also serving as protection are the four inches of fat underneath their skin, which is black (as is their tongue!), enabling them to absorb as much sunlight for warmth as possible.
One particularly special aspect of polar bears is their fur, which is the thickest of all bears and provides them with waterproofing, insulation, and protection. Despite appearing white in color, polar bears’ fur is actually transparent. So why do we see white fur? While human hair appears to be a specific color because of pigment that reflect specific wavelengths of light, the color of polar fur appears the way it does due to its structure. Each hair is hollow, allowing light to scatter inside into all colors. In this case, our eyes perceive white because the hair reflects back all of the visible wavelengths of light, rather than absorbing some of the wavelengths.
Unlike polar bears, arctic wolves fall within the category of “least concern” according to the World Wildlife Fund despite the decline in their traditional food supply of musk ox and Arctic hares. This is due in large part to their isolation. Populations of Arctic wolves are not threatened by hunting or habitat destruction like many of its southern relatives are.
Like the polar bear, the arctic wolf has a thick double coat that protects them from freezing in their extremely cold environment, and the inner layer of fur is waterproof. To communicate across their complex social hierarchy, Arctic wolves use scent marking, vocalization, and body language. Body language is used to convey the social rules of the pack. For instance, to communicate dominance, arctic wolves carry their tails high and stand tall. Less dominant wolves exhibit submissive behavior by holding their tails down and often lower their bodies while pawing at the higher-ranking wolves.
Arctic wolves are carnivorous hunters. Along with musk ox and Arctic hares, Arctic wolves’ diet includes the Arctic fox, caribou, lemming, and seals. Arctic wolves have strong jaws filled with 42 sharp teeth designed to tear flesh and crush bones, and they can consume more than 20 pounds of meat per meal. Despite these grisly facts, believe it or not, the Arctic wolf is the same species as your pet dog! Domestic dogs and Arctic wolves are both subspecies of gray wolf, Canis lupus.
Having more recently moved into the pop culture spotlight due to movies such as Elf and Ice Age, the narwhal is known as the “unicorn of the ocean” due to its distinctive horn, or tusk. At more than 80,000 in population, like the Arctic wolf, they are categorized as “least concern” in terms of their extinction risk.
The etymology behind the narwhal’s common name, while very interesting, is a bit gruesome, so if you’re feeling curious, check out the Norse history of “narwhal” here. The narwhal’s scientific name is Monodon monoceros. It is a member of the Monodontidae family, which is itself part of a larger group of animals known as the “toothed whales.” The only other species in the Monodontidae family is the closely related beluga whale.
Narwhals are, to be frank, massive. Adults can grow to be as long as 17 feet (6 m) and can weigh up to 4,200 pounds (1,900 kg).The huge spiral tusk of the Narwhal is an extended tooth that grows from a male narwhal’s upper jaw. The narwhal’s tusk can be as long as 10 feet (3 m) long! Tusks can be used for fighting and, recently, it was discovered that they also have a role in sensing the environment. In 2014, scientists from Harvard Medical School found that a narwhal's heart rate increases and decreases when the tusk is exposed to high or low salt concentrations in ocean water (Nweeia et al., 2014).
The last of our brief tour of cold-dwelling animals is the penguin. Of the animals discussed in this article, penguins are the only ones that live in the Southern Hemisphere. There are 18 species of penguins. Five of these live in Antarctica and another four live on sub-Antarctic islands.
Penguins are highly adapted for the marine environment. Although they are flightless, they are excellent swimmers and can dive to great depths (emperor penguins can dive to depths greater than 1,500 feet!). Their ability to swim is due, in part, to their bone structure. While most birds have hollow, air-filled bones to help them stay light for flight, penguins have solid bones instead. This helps them swim because solid bones reduce their buoyancy—the tendency to float. Additionally, their shape allows them to be extremely agile underwater. The feet and tail are like rudders, while the flippers act as propellers. They also have a waterproof plumage of short, overlapping feathers.
On land, penguins can use twice as much energy to walk compared to other animals of a similar size, so they occasionally make use of a movement often referred to as tobogganing to travel across the snow and ice during the right conditions. Tobogganing involves sliding across the ice on their bellies, using their flippers for guidance, and pushing forward with their feet.
Arctic Wolf. World Wildlife Fund. https://www.worldwildlife.org/species/arctic-wolf
Mangaly, J. (2019, Nov. 22). How do penguins move? Sciencing. https://sciencing.com/penguins-move-4567706.html
Narwhal. World Wildlife Fund. https://www.worldwildlife.org/species/narwhal
Nweeia, M. T., et al. (2014). Sensory ability in the narwhal tooth organ system. The Anatomical Record, 297(4), 599–790. https://doi.org/10.1002/ar.22886
Polar Bear. (2019). World Wildlife Fund. https://www.worldwildlife.org/species/polar-bear
