Because they spend most of their lives on the sea
ice of the Arctic Ocean depending on the ocean for their food and
habitat, polar bears are the only bear species to be considered marine
mammals.
2. A polar bear skin is actually black
Beneath all that thick fur, polar bears have jet
black skin. The polar bear’s fur is also translucent, and only appears
white because it reflects visible light.
3. They can swim constantly for days at a time
As well as reaching speeds of up to 6mph in the
water, polar bears can swim for long distances and steadily for many
hours to get from one piece of ice to another. Their large paws are
specially adapted for swimming, which they’ll use to paddle through the
water while holding their hind legs flat like a rudder.
4. Less than 2% of polar bear hunts are successful
Although about half of a polar bear’s life is spent
hunting for food, their hunts are rarely successful. A polar bear’s
main prey consists of ringed seals and bearded seals, which they hunt in
a variety of ways. Either by breaking into pupping dens, waiting at
breathing holes or at the water’s edge, or stalking seals that have
hauled out to rest on the ice. Besides catching seals, polar bears will
also scavenge carcasses or settle for small mammals, birds, eggs and
vegetation.
5. Scientists can extract polar bear DNA from just their footprints
An innovative new technique developed by WWF and
DNA specialist firm SPYGEN allows scientists to isolate DNA from a polar
bear’s footprint in the snow. Two tiny scoops of snow from a polar bear
track revealed not just the DNA of the polar bear that made it, but
even from a seal it had recently eaten.
6. They face more threats than climate change
While climate change remains the greatest threat to
the polar bear’s survival, that is not all that the predator is up
against. The oil and gas industry is turning its eyes to the arctic, and
with it comes the potential risks of habitat destruction from oil
exploration work. Contact with oil spills can reduce the insulating
effect of a bear’s fur requiring them to use more energy to get warm,
and can poison them if ingested. Polar bears can also be exposed to
toxic chemicals such as pesticides through their prey, which can affect a
bear's biological functioning and ability to reproduce.
Melting sea ice from climate change has increased human-polar bear
conflicts when hungry polar bears go searching for food in the summer.
Fortunately, people are learning to adapt to the polar bear's presence
and take preventative measures to reduce the risk of conflict. Learn
more about the threats to polar bears and how we are working to solve them.
7. Grizzly-polar bear hybrids exist
As recently as 2006 genetic testing confirmed the
existence of polar bear-grizzly bear hybrids, also known as ‘grolar
bear’ or ‘pizzly bear’. The hybrid bear physically resembles an
intermediate between the two species, but as wild hybrids are usually
birthed from polar bear mothers they are raised and behave like polar
bears. The ability for polar bears and grizzly bears to interbreed is
unsurprising when you consider that polar bears evolved from brown bears
as recently as 150,000 years ago!
8. There are as many as 19 subpopulations of polar bear
The total population of approximately 26,000 wild
polar bears are divided into 19 units or subpopulations. Of these just 1
subpopulation is increasing, 5 are stable and 4 are in decline. The
remaining 9 have not been assessed as they are data deficient – we
simply don’t have enough information about them to know how they’re
doing.
9. Male polar bears can weigh as much as 10 men
Male polar bears can weigh up to 800kg, and are
twice the size of females. Polar bears can also grow up to 3 metres
long, making them the largest bear species and the largest land
carnivore in the world.
10. They can smell their prey up to a kilometer away
Polar bears have a very strong sense of smell,
which they use to find seal breathing holes in the ice. Once it has
found the hole, the bear will wait patiently until the seal comes up for
air to attack. They can even detect a seal in the water beneath a metre
of compacted snow.
WWF's work
WWF is working with researchers to track polar bears in the Arctic to
understand the impact that climate change and other threats are
having on them as well as helping to monitor their health.
We’re also advocating for governments to recognise and mitigate the effects of a changing Arctic on these bears.
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