POLAR BEARS: ROUGH, TOUGH, AND COOL
Dr. James J. S. Johnson
Let a man meet a bear robbed of her cubs, rather than a fool in his folly. (Proverbs 17:12)
What are Polar Bears like? Polar Bears (Ursus maritimus) are often called “white bears” because their fur looks like a slightly yellowish white. Designed for a polar lifestyle, a Polar Bear has small rounded ears, a muscular hump behind his or her neck, large claws on each of its large paws, and huge and powerful body. Its large furry feet are well-designed for walking on snow and ice. Its amazing fur is perfect for insulating the bear’s body from the super-cold temperatures (and freezing winds) of the polar North.
Are Polar Bears “marine mammals” or “land mammals”? Or should they be called “ice bears”? Polar bears routinely live on sea ice for months, and can swim (“dog paddle” style) for days – one did so for 9 days! Where do they live? The icy cold waters of the Arctic Ocean are the primary home range of the Polar Bear, especially in many ice floes that float about the saltwater, as well as the coastlands that touch those waters. They can smell seals a mile away or buried under 3 feet of snow. They have good ears and eyes. (Sometimes they stand, to see distant objects better.)
Although floating ice is their “principal place of business”, polar bears are at home hunting on land (and swimming in the ocean).
How are Polar Bears as different from other bears? Unlike the dish-faced profile of a Brown Bear (such as a “Grizzly”), the Polar Bear’s head shape is more straight-faced, like a Black Bear, yet is ears as smaller, so its overall head-muzzle shape is slightly more longish and cone-shaped than that of a Black Bear. Also, unlike the high shoulder hump of a Brown Bear (including that of a “Grizzly”), the rump of a Polar Bear, like that of a Black Bear, is the highest part of the bear’s body, when walking on all four paws (as opposed to when standing or walking on two feet, like a human – which all bears can do, but usually do not do). The diet of the Polar Bear is different, too, because it is meat almost all the time—though it can and will eat berries and other foods when convenient. Black Bears and Brown Bears are more omnivorous (eating a mix of animal flesh and plant food, such as berries, mushrooms, acorns, flowers, pine cones, and roots)—although they certainly enjoy fresh meat when it is available, especially fish (as Alaska’s Brown Bear population is famous for its “all-you-can-eat” fishing).
How are Polar Bears similar to other bears? Genetically speaking, all true bears are part of the same biogenetic family. This includes the Brown Bear, the Black Bear, and the Polar Bear – as well as the Sun Bear, Sloth Bear, Spectacled Bear (but does not include the so-called “Panda Bear”). One illustration of this hybridization was reported in National Geographic magazine, by John Roach:
Last week, DNA analysis confirmed that the bear’s father was a grizzly and his mother was a polar bear [Ursus maritimus]. … Fossil evidence of prehistoric polar bears is difficult to find, because polar bear ancestors lived in conditions that were poor for bone preservation, [David] Paetkau [of Wildlife Genetics Int’l] says. But the two species probably diverged ‘less than a million years ago’. By contrast, North American black bears [Ursus americanus] and grizzly bears [Ursus arctos] diverged about five million years ago, he says. … On the other hand, the warming Arctic environment is causing some animals to shift their range northward. It’s possible, Paetkau says, that grizzly bears and polar bears may have more offspring-producing encounters in the future.
Quoting John Roach, NATIONAL GEOGRAPHIC (May 16, 2006 issue). In other words, all true bears descend from a pair of bears that survived the global Flood aboard Noah’s Ark. Accordingly, they can interbreed, genetically, and sometime do – either in the wild, or in captivity, or both.
How do newborn Polar Bear babies survive the harsh sub-freezing temperatures of the polar North?
Dens offer pregnant [polar bear] females protection from the cold and predators while they give birth and rear their cubs. The temperature inside a [polar bear] den is often just below freezing [!] and fluctuates much less than outside temperature. The temperature inside a den can be 38°F (21°C) warmer than outside, and the warmth reduces energy use, which is important for small cubs and for females without access to food.
Quoting Andrew Derocher, Polar Bears: Complete Guide to their Biology and Behavior (Baltimore: Johns Hopkins University, 2012), p. 155, as quoted in James J. S. Johnson, “Why We Want to Go Home”, Acts & Facts, 44(4):20 (April AD2015), posted at www.icr.org/article/why-we-want-go-home .
Although baby polar bears are conceived during spring, the uterine implantation of bear embryos (like those of other bears, as well as mustelids and seals) is delayed until autumn (when mama bears enter their “maternity ward” dens), ensuring that the births, about 2 months later, occur in winter (i.e., during hibernation), so that the family’s den exodus is timed for spring (months later), when food availability is optimal, and when the infants are developed enough to travel to, and onto, sea ice. (See Andrew Derocher, Polar Bears, pages 172-173.)
Blue whales at birth are about 2% of their mother’s weight, humans about 6%, bats around 30%, and some rodents over 50%. Each polar bear cub is only 0.2% to 0.3% of its mother’s mass. Polar bear cubs at birth are extremely small relative to the size of their mother. A cub weighs about 1.5 pounds (0.7 kg) while its mother can easily top 440 to 660 pounds (200-300 kg).
Quoting Derocher, Polar Bears: Complete Guide to their Biology and Behavior, page 177.
In other words, Polar Bear babies are quite tiny compared to their mamas; in fact, amazingly (when you consider the growth they are designed for) they are even tiny compared to human babies! Compared to Polar Bear newborns, human newborns have birth weights that are about 5 times heavier!
Since polar bear cubs are born so small, after the protein-loaded antibody-rich colostrum, they need super-rich “get-fat-quick” milk to grow!
Polar bear milk … can be 46% fat. Fat content declines as cubs get older … as low as 5% just before the mother stops producing milk [~ 2.5 years after birth]. Protein content varies from 5% to 19%; sugars can constitute 6%. Minerals make up less than 2% of the milk, which has a variety of vitamins including A, B, D, and E.
Polar bear milk … is low in lactose (a sugar) but high in specialized sugars called oligosaccharides … [which] have an antibacterial role.
[Quoting Andrew Derocher, Polar Bears, p. 180.]
After being weaned from Mama’s milk, what is the favorite food of a Polar Bear? Seals! Especially Polar Bears are known for eating seals – especially Ringed Seals (Pusa hispida) and Bearded Seals (Erignathus barbatus). To do this they must learn to hunt, ranging the ice floes of the Arctic Ocean, and sometimes ranging on land, or swimming in the ocean. But, thanks to God’s caring bioengineering, Polar Bears are designed for trekking long distance on slippery ice—their feet (paws) are a perfect fit for their icy habitat.
Microscopic examination of polar bear feet reveals their ice-handling design features. It turned out that the pads of a polar bear’s foot are covered with small soft papillae [small bumps], which increase friction between the foot and the ice. There are also small depressions in the sole….
[Quoting Ian Stirling, Polar Bears (Ann Arbor, MI: University of Michigan Press, 1998), page 25, as quoted in Brian Thomas, “Beetles and Bears Inspire Technologies”, ICR News, posted 2-26-AD2016.]
Polar bears, eating blubber-loaded seals (as they try to store fat and protein for the coming winter), like to “pig out” – they can eat 20% of their body weight in one meal! (Calculate what 20% pf your body weight would be!) Males often weigh 700-1800 pounds; females ~ ½ that, at 350-1000 pounds!
Polar bears are happy to eat humans, too, if they can get at them! How emphatically, therefore, the Scriptures caution against meeting a “fool in his folly”:
Let a man meet a bear robbed of her cubs, rather than a fool in his folly. (Proverbs 17:12)
Does anyone eat Polar Bears? Actually, yes, though usually it is the Polar Bear that is the predator! When desperate enough, humans have been known to hunt and kill—and eat (!)—Polar Bears.
In one famous situation of shipwrecked sailors, in Svalbard (a small group of islands north of Russia), sailors ate ten of them!
In 1743 a Russian ship bound for Arctic walrus-hunting grounds was blown off course and trapped in ice off the coast of Svalbard … Four sailors [who faithfully prayed, as Russian Orthodox ‘Old Believers’, to God for His providential care] went shore with only two days’ supplies to look for an abandoned hut they knew about on the island.
[Quoting David Roberts, Four Against the Arctic: Shipwrecked for Six Years at the Top of the World (2003), intro.] The stranded Russians weathered a stormy night in the hut. When they returned, to where the ship had been, the ship and its icepack were both gone, apparently blown out to sea and destroyed by the storm. To survive there, for 6+ years, they made spears, bows and arrows, from driftwood, eventually killing 250 animals to eat, including 10 polar bears, some arctic foxes, and many caribou, plus scurvy grass. The one sailor who refused to eat scurvy grass died (you guessed it – he died of scurvy). The other 3 survived, thankfully, to be eventually rescued during AD1749, by another off-course Russian ship of “Old Believers”.
On the other side of the (polar North) world, Alaskan Eskimos have hunted Polar Bears, for many centuries, sometimes with success—even using bow and arrows!
Much more could (and should) be said—and appreciated—about that amazing ice-floe-trekking carnivore of the super-cold North, the Polar Bear. But for now, as you consider the meat-and-blubber-hungry habits of the ravenous Polar Bear, be thankful that God did not make you an Arctic Ocean-dwelling seal—who must surface through an “ice hole”, periodically, for air.) Because sometimes more than breathable air awaits a vulnerable seal, just above the surface! Yikes!
In other words, be glad that the Lord made you exactly whom you are (Psalm 102:18), with a life of blessings in the present (Acts 14:17), plus a wonderful future, so long as you believe in the Lord Jesus Christ (Luke 10:20)! ><> JJSJ
Dr. James J. S. Johnson’s background includes a love for animal ecology and the colder climates of the world. In addition to his (current) creation science education-focused work for ICR-SOBA, he has taught bioscience/ecology courses for Dallas Christian College and ACSI, written ecology-related curriculum for LeTourneau University, and served as lecturer aboard 9 international cruise ships, including 4 cruise ships visiting Alaska (Norwegian Wind, Norwegian Sky, Radiance of the Seas, Rhapsody of the Seas).