Ice
provides no habitat for plants or found animals,
even polar bear are likely only to hunt where
they can find prey- and they are difficult and
dangerous to hunt. Seabirds, fish and seals,
where there is water, are the potential foods.
Foxes-the arctic fox turns white in winter-
sometimes follows polar bears on to sea ice
to scavenge their kills. Northern wildlife is
migratory and availability depends on season
Tundra and forest. Animals in the arctic have
adapted to handle cold winters and to breed
and raise young quickly in the very short and
cool summers.
The
Arctic Fox
The Arctic fox has unique adaptations which
enables it to survive in the arctic environment.
Arctic foxes live in dens where ther pups are
born also.The dens excavated by the adults in
sandy, well-drained soils of low mounds and
river cutbanks and extend from 6 to 12 feet
underground. The Mating season is in early March
and early April. On average seven pups are born
in a litter each newborn arctic fox pups have
a short velvety dark brown fur which changes
as it matures. Both parents aid in bringing
food to the den and in rearing the pups. Pups
emerge from the den at about 3 weeks old and
begin to hunt and range away from the den at
about 3 months.
Fully
grown arctic foxes weigh from 6 to 10 pounds
and approxiamtely 43 inches (109 cm) in length
including the tail. Their short legs and body,
short ears, and dense winter fur give them a
stocky appearance. Arctic foxes molt twice each
year. The white foxes begin to shed their long
winter fur in early April. By late June the
face, legs, and upper parts of the body are
covered with short, brown summer fur. The fur
of the lower sides and abdomen is yellowish-white.
The change to winter pelage occurs in September
and October. By November the luxurious white
winter coat is complete. Foxes of the blue phase
remain dark or charcoal colored year round but
become somewhat lighter in winter.
Food
Source
Arctic
foxes feed primarily on small mammals, including
lemmings and tundra voles during the summer.
If their dens are near near rocky cliffs along
the seacoast they may feed on nesting seabirds
such as auklets, puffins, and murres. Arctic
foxes are omnivorous. They sometimes eat berries,
eggs, and scavenged remains of other animals.
During
winter many foxes venture out onto the sea ice
to eat the remains of seals killed by polar
bears and as a result they may move long distances
over sea ice.They are also hunted by humans
for their pelts their demand has diminished
in recent years, however in coastal Native villages
trading of the pelts is still common.
Caribou
Caribou
are large, wild, elk-like animals which can
be found above the tree-line in arctic North
America and Greenland. Because they can live
on lichens in the winter they are very well
adapted for the harsh arctic tundra where they
migrate great distances each year. Caribou cows
and bulls both grow distinctive antlers and
bull antlers can reach 4 feet in width! A Caribou
calf can run within 90 minutes of its birth.
It must do this to keep up with the migrating
herds.
The
caribou has unique hairs which trap air providing
them with excellent insulation. These hairs
also help keep them buoyant in the water. They
are very strong swimmers and can move across
wide rushing rivers and even the frozen ice
of the Arctic Ocean!
Both
sexes has antlers which are fully developed
in the autumn. The male, locally known as "sarv"
shed theirs in December/January. The females,
locally knowns as "vaja" remain the
antlers during the winter and shed thiers in
the spring around May. The antlers of the female
are smaller than the males. The calf keep its
antlers for the first winter.
Muskox
Muskox
are large animals that look a lot like bison,
but have wool like sheep. Their long brown wool
hangs almost to their feet. Most of the arctic
tundra was host to the musk ox long ago. Neolithic
hunters hunted them almost to extinction. Today
they can be found in northern Canada roaming
wild, and on farms in Unalakleet, Alaska where
they are raised for wool.
Muskox
roam wild in herds of 10-20 individuals. When
they are threatened by a wolf their main predator
(other than man) they will form a circle around
their young to protect them. Muskox have been
known to scoop up wolves with their horns, hurl
them into the air and then stomp them under
hoof. Although this may seem violent, muskox
are mainly peaceful animals who eat only plants.
Their name comes from the musky smell of their
urine which is especially strong in mating season.
Muskox usually bear one calf every two years.
Beluga
Whale
Beluga
or "white whales" are not born white.
They are grey at birth and get lighter and lighter
until at about age six they are completely white.
Belugas are one of the three whales that spend
all their lives in arctic waters. The other
two are the bowhead and the narwhal. Beluga
are special among all whales because they can
turn their heads. Maybe this is so that they
can communicate with each other better! Beluga
are very social and make a wide variety of sounds.
A group of beluga can be loud! They have been
nick-named "sea canaries." Beluga
use sound to help them find their prey. They
send out a sound which bounces off things in
the water and allows them to hear how far away
something is. This is called "echolocation."
Beluga will work together using this and other
techniques to herd fish into shallow water.
It has also been reported by native people that
beluga whales help each other give birth! They
use many subtle forms of communication including
a wide variety of facial expressions. Unlike
some other whales, beluga have good vision.What
they don't have is a dorsal fin, earning them
the name "delphinapterus" or dolphin-without-a-wing.
Polar
Bears
Polar
bears are the largest land carnivore.The largest
polar bear ever recorded was a male weighing
1,002 kg (2,209 lb.) and measuring 3.7 m (12
ft.) long. Polar bears live year round near
arctic waters hunting seal and other animals,
rarely coming on land except on islands and
rocky points. In winter they hunt along the
Arctic shelfs looking for tasty seals, fish,
and even humans!
Physical
Adaptations
Fur
| The coat can vary from pure white to creamy
yellow to light brown depending upon season
and angle of light. Their white coats provide
camouflage in the ice and snow which make them
almost invisible as they stalk their prey. he
hind limbs are longer than the forelimbs. Polar
bears are completely furred except for the nose
and footpads, which are black.
Its
dense, woolly, coat is about 2.5 to 5 cm (1.2
in.) thick and acts as an insulating layer.
Polar bear fur is oily and water repellent.
Polar bears are strong swimmers and can stay
submerged for two minutes at a time. Their fur
is made of hollow hairs which trap air and help
to insulate them in the frigid waters. The hairs
don't mat or stick when wet, allowing the polar
bears to easily shake free of water and any
ice that may form after swimming. Ice forms
when the wet fur is exposed to air temperatures
at or below freezing. The hairs of the fur reflect
light, giving a polar bear its white coloration.
Polar bears completely shed and replace their
fur annually, in May or June. Although their
coat is white apolar bear's skin is black.
Paws
and Feet
This makes the large, muscular hind end stand
higher than the shoulders. The large paws of
a polar bear act like snowshoes, spreading out
the bear's weight as it moves over ice.Its nonretractable
claws are used for grasping prey and for traction
when running or climbing on ice.
In
winter, when they are far from land they search
for breathing holes made by seals. When the
seal comes up for air, the polar bear will kill
it and flip it out of the water with a single
blow of its great clawed paw. The sole of a
polar bear's foot has thick, black pads covered
with small, soft papillae (dermal bumps). The
papillae create friction between the foot and
ice to prevent slippage. Long hairs growing
between pads and toes also help prevent slippage.
Teeth
Polar bears have 42 teeth, which they use for
catching food and for aggressive behavior. Their
incisors are used to shear off pieces of blubber
and flesh and thier canine teeth grasp prey
and tear tough hides. Polar bears often swallow
most food in large chunks rather than chewing.
In
November polar bears retire to dens dug out
of the snow or permafrost. The females remain
until the spring when they emerge with one or
two cubs who stay with them for the next year
and a half. The males spend a shorter time in
the dens and may be seen out and about at any
time of the year.
Swimming
Strength.
Polar bears are strong swimmers; they swim across
bays or wide leads without hesitation. They
can swim for several hours at a time over long
distances. They've been seen swimming continuously
for 100 km and can obtain a maximum swimming
speed of 10 kph.
A polar bear's front paws propel them through
the water dog-paddle style. The hind feet and
legs are held flat and are used as rudders.
A thick layer of blubber (fat), up to 11 cm
(4.3 in.) thick, keeps the polar bear warm while
swimming in cold water.
Diving.
Polar
bears make shallow dives when stalking prey,
navigating ice floes, or searching for kelp.
Polar bears usually swim under water at depths
of only about 3 to 4.5 m (9.8-14.8 ft.). They
can remain submerged for as long as two minutes.
No one knows how deep a polar bear can dive.
One researcher estimates that polar bears dive
no deeper than 6 m (20 ft.).
Regulation
of Body Temperature
Body
temperature, which is normally 37C, is maintained
through a thick layer of fur, a tough hide,
and an insulating layer of blubber. This excellent
insulation keeps a polar bear warm even when
air temperatures drop as low as -37C
Diet
and Eating Habits.
Polar bears feed mainly on ringed seals and
bearded seals. Depending upon their location,
they also eat harp and hooded seals and scavenge
on carcasses of beluga whales, walruses, narwhals,
and bowhead whales. On occasion, polar bears
kill young walruses and beluga whales. A polar
bear's stomach can hold an estimated 15% to
20% of its body weight. Polar bears need an
average of 2 kg (4.4 lb.) of fat per day to
survive. A ringed seal weighing 55 kg (121lb)
could provide up to eight days of energy for
a polar bear.
Hunting
Usually stalks on land. The polar bear remains
motionless beside a breathing hole or lead edge
waiting for a seal to surface. When a seal surfaces,
the polar bear bites onto the head or upper
body, then flips the entire seal onto the ice.Sometimes
they still hunting which usually takes less
than one hour, but polar bears will wait much
longer. Stalking is a hunting method used in
summer when seals haul out on sea ice. Once
spotted, the seal is slowly and steadily stalked
by the polar bear. At 15 to 30 m (49.98 ft.)
away, the polar bear suddenly charges the seal.
With its claws or teeth, the polar bear grabs
the seal before the seal can leave the ice.
The aquatic stalk is a method also used in summer
when seals haul out on sea ice. The polar bear
swims toward a hauled-out seal. Once the polar
bear reaches the ice edge, the bear quickly
emerges from the water and grabs the seal with
its claws or teeth.
Stalking
ringed seals at their birth lairs is a hunting
method polar bears use in spring, when ringed
seals give birth to their pups. Ringed seal
birth lairs are caves built under snow drifts
next to a hole in the ice. The snow drifts are
on stable sea ice attached to land. Once a polar
bear identifies a birth lair, it slowly and
quietly positions itself next to the lair. If
a polar bear smells or hears a seal in the lair,
it slowly raises up on its hind legs and crashes
down with its front paws to break through the
lair roof. To break the roof's hard surface,
several tries are sometimes needed, which may
allow the seal to escape into the water. This
method is most commonly used by polar bear females
with cubs under one year old.
Once
a seal is captured, a polar bear bites it several
times on the head and neck before dragging it
several meters from the water to feed. The skin
and fat are eaten first, followed by the meat.
Polar bears often stop to wash during feeding,
using water nearby or rubbing in the snow. Polar
bears don't always eat the entire kill. Carcass
remains are scavenged by other bears, arctic
foxes, and gulls.
Life
Span Causes of Death.
Polar
bears can live 20 to 30 years, but only a small
proportion of polar bears live past 15 to 18
years.
The
oldest known polar bear in the Arctic lived
32 years. The oldest known polar bear in a zoological
park lived 41 years. Males occasionally kill
other males competing for mates. Males periodically
kill females protecting cubs. Cubs less than
one year old sometimes are prey to adult male
polar bears and other carnivores, such as wolves.
As
prey
Polar
bears have been hunted for thousands of years.
Evidence of human polar bear hunts have been
found in 2,500- to 3,000-year-old ruins. Arctic
peoples have traditionally hunted polar bears
for food, clothing, bedding, and religious purposes.
Commercial hunting of polar bears for hides
began as early as the 1500s and flourished by
the 1700s. Kills increased substantially in
the 1950s and 1960s when hunters began using
snowmobiles, boats, and airplanes to hunt polar
bears.This led to an international agreement
in 1973 banning the use of aircraft or large
motorized boats for polar bear hunts. Hunting
is the greatest single cause of polar bear mortality.
Today, polar bears are hunted by native Arctic
populations primarily for food, clothing, handicrafts,
and sale of skins. Polar bears are also killed
in defense of people or property.
Sea
Otters
Sea Otters are playful animals that spend almost
all their time in the sea. They eat, sleep,
and even have their babies in the water. In
the daytime sea otters float on their backs
eating Abalone, their favorite food. To open
the Abalone shell they place a small rock on
their chest and smash the shell against it.
Sea otters are one of the few mammals, beside
humans, that use tools. They will use strands
of kelp to tie themselves into the kelp beds
for a secure night's sleep. They love to frolic
with other otters and seals. Unlike seals and
walrus, sea otters have no blubber to keep them
warm in the cold arctic waters. Air trapped
in their fur keeps them warm and bouyant. Oil
spills can damage this fine fur and cause the
otter to get very cold and die. That is why
volunteers cleaned the sea otters so carefully
after the oil spills in Alaska.
Sea
otters also faced great dangers from hunters
who wanted their valuable coats. They were hunted
so heavily in the 18-19th Centuries that they
had to be placed on the U.S. government endangered
species list. Now the populations have come
back to a large extent, but conservationists
would like to continue to protect them. Fishermen
would like them off the endangered species list
in order to protect the abalone harvest.
Siwimming
& Diving
Seals swim in Arctic waters eating fish like
arctic cod as well as crustaceans and mollusks.
Their rear flippers are turned backward. This
improves their swimming, but makes it difficult
to move around on land because their toes point
backwards. Try walking around with your toes
pointing backwards! Instead they prefer sliding
around on the ice.
One
species, the ringed seal, spends most of its
time beneath the ice. It digs up through the
ice with its strong claws to open breathing
holes and must keep pushing it nose through
the ice to keep the holes from icing over. This
is easier than making new holes, but if they
aren't careful a polar bear will see their hole
and catch them.
Seals
are great divers and can stay under water for
long periods of time without returning to the
surface for a breath. Mature seals mate in the
spring. Calves are born in the spring of the
following year, and stay with their mothers
for a few weeks until they are able to catch
prey for themselves. Besides, their soft baby
fur is not warm enough to be alone, and they
must wait until their white fur has changed
to a darker thicker pelt better suited for arctic
waters.
Seals
were over hunted by humans for many years, but
now many seal species are protected and can
only be caught by native people in the Arctic.
Seals
swim in Arctic waters eating fish like arctic
cod as well as crustaceans and mollusks. Their
rear flippers are turned backward. This improves
their swimming, but makes it difficult to move
around on land because their toes point backwards.
Try walking around with your toes pointing backwards!
Instead they prefer sliding around on the ice.
One
species, the ringed seal, spends most of its
time beneath the ice. It digs up through the
ice with its strong claws to open breathing
holes and must keep pushing it nose through
the ice to keep the holes from icing over. This
is easier than making new holes, but if they
aren't careful a polar bear will see their hole
and catch them.
Seals
are great divers and can stay under water for
long periods of time without returning to the
surface for a breath. Mature seals mate in the
spring. Calves are born in the spring of the
following year, and stay with their mothers
for a few weeks until they are able to catch
prey for themselves. Besides, their soft baby
fur is not warm enough to be alone, and they
must wait until their white fur has changed
to a darker thicker pelt better suited for arctic
waters.
Seals
were over hunted by humans for many years, but
now many seal species are protected and can
only be caught by native people in the Arctic.
Walrus
Everyone
knows what a walrus looks like! Its long ivory
tusks are used for many things, including protection
from attack by polar bears, killer whales and
local hunters in kayaks.
Walrus
are very slow on land because they are so big
and clumsy, but in the water they are very fast
and strong. They can dive down 300 feet to retrieve
their favorite food, clams, from the sea bottom.
A walrus can eat 4,000 clams in one feeding!
Air
sacs in the walrus' neck allow it to sleep with
its head held up in the water. Nursing females
use this standing position as they nurse. The
pups, born approximately every two years, nurse
upside down.
Walrus
will dive into the water at the faintest scent
of a human. Walrus numbers were very reduced
by commercial hunters until 1972 when the Marine
Mammal Act started protecting them. Now only
native people in the Arctic may hunt them and
the populations have grown in size. Native peoples
in the Arctic hunt the walrus for food and put
every part of its body to good use. They use
the tusks for the delicate art of carving called
"scrimshaw."
Orcas/
Killer Whales
When
they dive, killer whales usually go to depths
of about 30.5 to 61 m (100 - 200 ft.). Killer
whales generally do not dive deep, although
the deepest dive known under experimental conditions
was 274.3 m (900 ft.).
When
diving, killer whales may surface about every
four to five minutes. At the surface they generally
take two to five breaths at five to ten second
intervals before another dive. They make approximately
three to five short dives, each lasting 10 to
35 seconds. These are followed by longer dives
lasting about one to four minutes. Dives up
to 10 minutes and longer have been seen, with
the longest dive observed in the ocean lasting
12 minutes. Under experimental conditions, killer
whales have made dives lasting as long as 15
minutes.
These adaptations enable a killer whale to conserve
oxygen while under water. Killer whales, like
other marine mammals, have a slower heart rate
while diving. A killer whale's heart rate can
slow from 60 beats to 30 beats per minute while
diving.
Reindeer
Reindeer
are slightly smaller and were domesticated in
northern Eurasia about 2000 years ago. Today,
they are herded by many Arctic peoples in Europe
and Asia including the Sami in Scandinavia and
the Nenets, Chukchi and others in Russia. These
peoples depend on the reindeer for almost everything
in their economy including food, clothing and
shelter. Some Nenets even keep reindeer for
pets! Reindeer were introduced into Alaska and
Canada last century, but most attempts failed.
Native peoples in these countries still prefer
to hunt caribou rather than herd reindeer. |