4. Polar bears habitual range
Five nations have polar bear populations: the
United States
(Alaska), Canada, Russia, Greenland, and
5. Basic facts
sea bear, started to evolve about five million years
ago from brown bear ancestors
weigh
length
fur
skin
295 - 490 kg
2.5 – 3 metres
thick-10cm fat layer
yellowish or white
black to absorb heat
6. Communication
Polar bears use a combination of body
languageand vocalizations to communicate.
Head wagging from side to side often occurs
when polar bears want to play. Adult bears
initiate play—which is actually ritualized fighting
or mock battling—by standing on their hind
legs, chin lowered to their chests, and front
paws hanging by their sides
7. Nose-to-nose greetings are the way a
bear asks another bear for something, such
as food. The guest bear will approach
slowly, circle around a carcass, and then
meekly touch the other bear's nose. Bears
who use proper manners are often allowed
to share a kill.
Attacking polar bears charge forward with
heads down and ears laid back.
8. Chuffing sounds are a response to stress, often
heard when a mother bear is worried for her
cubs' safety. Mother bears scold cubs with
a low growl or soft cuff. When a male
approaches a female with cubs, she rushes
toward him with her head lowered.
Hissing and snorting and a lowered head all
signify aggression.
Loud roars or growls communicate anger.
Deep growls are warnings, perhaps in defense
of a food source.
9. FUR
Polar bears look whitest when they are
clean and in sunlight, especially just after
the molt period, which usually begins in
spring and is complete by late summer.
Before molting, oils from the seals they eat
can make them look yellow
Molt period – línání,pelíchání
10. CUBS
Usually 2 (1 or triplets)
stays with mother for 3 months
weigh 0.5-1kg
hairless ,blind,deaf
Usually 2 (1 or triplets)
stays with mother for 3
months
weigh 0.5-1kg
hairless ,blind,deaf
11. CUBS
For at least 20 months, cubs drink their
mother's milk and depend on her for survival.
Her success at hunting is critical for her own
needs and for teaching cubs to find food for
themselves.
In the Low Arctic weaning occurs as cubs
approach their second birthday. Cubs in the
High Arctic generally receive an additional year
of care.
13. GLOBAL WARMING
• Floods. Droughts. Heat waves. Monster
tornadoes
Floods. Droughts(sucho). Heat
waves(vlny veder). Monster
tornadoes. Climate change is
not just about polar bears, the
iconic symbol of a melting(tající)
Arctic
14. How are polar bears affected by
global warming?
Polar bears have evolved for a life on the sea
ice, which they rely on(spoléhají se na) for
reaching their seal prey(kořist). But the arctic
sea ice is rapidly diminishing(mizí) due to(díky)
a warming Earth.
reduced access(omezenýpřístup) to food
drop in(pokles) body condition
lower cub survival rates(míra přežití)
increase in drowning(utopení)
increase in cannibalism
15. The problem of global warming
Because the temperature on Earth is constantly
increasing, the sea ice is melting. The polar ice-
cap gets further from the land. It´s more difficult for
bears to get their food, especially for mothers to
that go to the land to give birth to their babies.
They will need to swim back to the ice cap to hunt
for their food. But it´s a very long distance.
Sometimes it can be more than one hundred
kilometres. Every year. Many bears die from
starvation. They can die by drowning, too.
16. Polar bears - Patient seal hunters
Polar bears need the ice to hunt their
favourite meal – seals. Seals swim in the
sea and they go to the edges of ice- caps.
That´s where the bears catch them. But
how?
A bear uses its excellent sense of smell to
find holes in the ice that seals use for
breathing. Then, it waits patiently to catch
the seal. It can také several days but the fat
from one seal is enough for one week.
17. Polar bears in captivity
History of polar bears in captivity. The earliest
known captive polar bear was housed by Ptolemy
II, king of ancient Egypt (285-246 B.C.), in his
private zoo in Alexandria. Romans probably also
kept polar bears.
In 57 A.D., Calpurnius wrote of bears pitted
against seals in a flooded amphitheater.
Harold the Fair-haired of Norway received a
mother and cubs in 880 A.D. from a hunter and
rewarded the man with a ship filled with wood.
18. Polar bears in captivity
Early maps led to sources of polar bears and
white falcons. Viking hunters killed mother
bears and caught her cubs by attracting them
to her pelt.
Early rulers in
Denmark, England, Germany, and Damascus
kept captive polar bears.
In 1874, America's first zoo opened in
Philadelphia. Its bear pits were its most popular
attraction.
19. HUNTING
Today, legal hunting continues on a
limited, regulated basis for native peoples.
Norway is the only polar bear nation that protects
polar bears from all forms of hunting. Three of the
other four nations permit native hunts—a
traditionally important cultural activity and source
of income. Canada is the only nation that allows
sport or trophy hunting by non-natives and non-
citizens.
20. Walking
Walking. Polar bears walk at
about five to six kilometers
per hour. Females with small
cubs slow their speed to two
and a half to four kilometers
per hour.
Polar bears are well known
for their slow, plodding gait.
21. Running
Running. Polar bears can run as fast as 40
kilometers per hour—but only for short
distances. Younger, leaner bears are the
best runners. They can cover two kilometers
without stopping. Older, larger bears quickly
overheat.
22. Polar bears - sleeping
Sleeping. Most polar bears sleep for seven to eight hours
at a stretch and they take naps, too. In that way, they're
a lot like people.
On the ice in spring and summer, polar bears tend to
sleep more during the day than at night, probably
because seals are more active at night.
But day and nighthold little meaning in the Arctic where
there are 24 hours of daylight in summer and 24 hours of
darkness in winter.
Polar bears nap just about anywhere and any time, and
especially after feeding on a seal. Napping helps bears
conserve energy. A polar bear's entire existence centers
on hunting and conserving energy.
23. Maternity
Polar bears sleep right through blizzards in day beds
dug in the lee of a ridge. The snow piles up on top of
them and provides an insulating blanket. Sometimes
they stay curled up under the snow for several days
until the storm passes.
In summer, polar bears curl up on the tundra or on an
ice patch, sometimes using a block of ice or an
outstretched paw as a pillow. Landlocked bears
dig sleeping pits in the sand or in gravel ridges along
the shoreline.
Pregnant females dig maternity dens in snow banks in
fall and give birth to cubs in early winter. Until March or
April when they emerge from the den, mother and
cubs spend their time sleeping.
