Tundra
What is the tundra biome?
The tundra biome
Tundra is the coldest of all the biomes. Tundra comes
from the Finnish word tunturi, meaning treeless plain.
It is noted for its frost-molded landscapes, extremely
low temperatures, little precipitation, poor nutrients,
and short growing seasons. Dead organic material
functions as a nutrient pool. The two major nutrients
are nitrogen and phosphorus. Nitrogen is created by
biological fixation, and phosphorus is created by
precipitation.
Tundra along the Colville River, Alaska.
Characteristics of tundra include:
1. Extremely cold climate
2. Low biotic diversity
3. Simple vegetation structure
4. Limitation of drainage
5. Short season of growth and reproduction
6. Energy and nutrients in the form of dead organic material
7. Large population oscillations
Source: http://www.ucmp.berkeley.edu/exhibits/biomes/tundra.php
Source: http://www.ucmp.berkeley.edu/exhibits/biomes/tundra.php
Grizzly Bear
Click on this link for the World Book grizzly bear entry plus audio files
and a short vidéo :
http://www.worldbookonline.com/student/article?id=ar237060&st=gri
zzly+bear
Grizzly Bear
A subspecies of the larger coastal brown bear, the grizzly bear gets its name from the grayish, or grizzled, tips of its
fur.
Photograph by John Eastcott and Yva Momatiuk
Map
Grizzly Bear Range
Fast Facts
Type:
Mammal
Diet:
Omnivore
Average life span in the wild:
25 years
Size:
5 to 8 ft (1.5 to 2.5 m)
Weight:
800 lbs (363 kg)
Protection status:
Threatened
Size relative to a 6-ft (2-m) man:
The grizzly bear is a North American subspecies of the brown bear.
These awe-inspiring giants tend to be solitary animals—with the exception of females and their
cubs—but at times they do congregate. Dramatic gatherings of grizzly bears can be seen at
prime Alaskan fishing spots when the salmon run upstream for summer spawning. In this
season, dozens of bears may gather to feast on the fish, craving fats that will sustain them
through the long winter ahead.
Brown bears dig dens for winter hibernation, often holing up in a suitable-looking hillside.
Females give birth during this winter rest and their offspring are often twins.
Grizzly bears are powerful, top-of-the-food-chain predators, yet much of their diet consists of
nuts, berries, fruit, leaves, and roots. Bears also eat other animals, from rodents to moose.
Grizzlies are typically brown, though their fur can appear to be white-tipped, or grizzled, lending
them their traditional name.
Despite their impressive size, grizzlies are quite fast and have been clocked at 30 miles (48
kilometers) an hour. They can be dangerous to humans, particularly if surprised or if humans
come between a mother and her cubs.
Grizzlies once lived in much of western North America and even roamed the Great Plains.
European settlement gradually eliminated the bears from much of this range, and today only
about 1,000 grizzlies remain in the continental U.S., where they are protected by law. Many
grizzlies still roam the wilds of Canada and Alaska, where hunters pursue them as big game
trophies.
Source: http://animals.nationalgeographic.com/animals/mammals/grizzly-bear/#
Click this link to see a short video of a grizzly bear teaching her cubs to
catch salmon – begins with a short ad:
http://video.nationalgeographic.com/video/animals/mammalsanimals/bears-and-pandas/bear_grizzly_teachingcubs/
Grizzly Bears Moving Into Canada's Polar Bear Capital
After rebounding from years of intense hunting, male grizzly bears are exploring new Canadian
territories, a new study says (file photo).
Photograph by Norbert Rosing, National Geographic Stock
Anne Casselman
for National Geographic News
Published February 26, 2010
There may now be two kings of the Canadian tundra—grizzly bears sightings are on the rise in
the polar bear capital of the world, a new study says.
The preliminary report notes an increase in grizzly bear sightings in Wapusk National Park, just
south of Churchill, Manitoba.
Nine grizzlies have been seen in the park between 1996 and 2009 in an area where grizzly
sightings have never been confirmed before, researchers say. Four of the large bears were
spotted in the summer of 2009.
It's unclear whether a viable population of grizzlies has established in the park, as males are
known to disperse great distances from their home territories in northern Canada.
Experts also aren't sure what's causing the influx of bears, but it's more likely due to reduced
hunting pressure than global warming.
"There's been a real upswing in numbers," said study leader Robert Rockwell, a population
ecologist at the City University of New York.
"We wanted to make the point that this is a new top-end carnivore on the scene."
Grizzly vs. Polar Bear
But speculation about grizzly-polar bear conflicts may be moot, since few polar bears will likely
inhabit the northeastern corner of Manitoba—where the grizzlies were seen—by the end of the
century. That's because the polar bears will follow Arctic sea ice as it retreats farther north.
"It's unlikely that we will still have polar bears in Wapusk National Park by the end of the
century, given the current patterns of sea ice loss in Hudson Bay," said Andrew Derocher, a
polar bear biologist at the University of Alberta in Edmonton, Canada.
A recently published model shows sea ice retreating from the area by the year 2050, which will
lead to a decline in polar bears, he added.
Even if a grizzly does encounter a polar bear, there likely wouldn't be an major tussle, said study
leader Rockwell, whose research appeared in the February 2010 issue of the Canadian Field
Naturalist. The journal publishes scientific papers by amateur and professional naturalists and
field biologists.
"What top-end carnivores do is ... pretty much stay away from each other, like schoolyard
bullies," he said.
There could be a scenario in which polar bear females clash with grizzly males as the females
emerge from hibernation.
But in the Beaufort Sea, where University of Alberta's Derocher conducts his fieldwork, the two
species den in overlapping areas with no fuss: The grizzly bear males come out of dens about a
month after female polar bears have left.
"Grolar Bear?"
And what of the prospect of grizzlies and polar bears begetting that epic beast, the "pizzly" or
"grolar bear?"
To date, scientists know of only one hybridization event in the wild between the two bear
species. In 2006 a hunter shot a grizzly-polar bear hybrid in Canada's Northwest Territories.
The possibility of the two species meeting each other "is going to be rare event, and I don't
think it's going to be a really big deal," study leader Rockwell said.
However, the arrival of the grizzly may impact the park's ecosystem in other ways. For instance,
Rockwell predicts the grizzlies could give polar bears an extra meal or two.
That's because a grizzly would rather abandon its kill than get in a skirmish with its much larger
cousin, which can be attracted to the scent of the freshly killed prey. And grizzlies often take
down caribou, prey that polar bears aren't fast enough to catch.
Whatever the outcome, Rockwell is curious to see what happens: "It's a neat living laboratory."
Source: http://news.nationalgeographic.com/news/2010/02/100226-grizzly-bears-polar-bears-hybrid-canada/
Click this link to see a short video on how to survive a grizzly bear attack
– begins with a brief ad:
http://video.nationalgeographic.com/video/adventure/survivalguide/survival-guide-bear-attack/
Source: http://www.hcn.org/issues/43.19/the-forgotten-north-cascades-grizzly-bear/u.s.-grizzly-recovery-areas
Grizzly Bear Photographed in North Cascades
A grizzly bear has been photographed in the North Cascades National Park for the first time in
more than four decades, confirming estimates of a small population of “ursus horribilis” in
mountains of northern Washington.
“It’s a relief after years of waiting: God, I thought they were like vampires, and that you couldn’t
get them on camera,” said Mitch Friedman of Conservation Northwest, which has championed
grizzly and wolf recovery in the “American Alps.”
Grizzlies once ranged through the Cascades of the Northwest and Sierra Nevada mountains of
California: A grizzly decorates California’s state flag, although the bears have been extinct in the
Golden Bear State for nearly 90 years.
The only healthy populations of grizzlies remaining in the “lower 48″ are in Montana’s Glacier
National Park and nearby wilderness areas, and in the Greater Yellowstone Ecosystem in
Wyoming.
The North Cascades grizzly was sighted and photographed last October. It took the
photographer half a year to contact the National Park Service with the news.
The last confirmed grizzly sighting was in the 1960′s when a bear was shot by hunters in the
remote valley of Fisher Creek south of Diablo Lake. In 1968, the valley became part of the newly
created North Cascades National Park.
The U.S. Fish and Wildlife Service has estimated a population of as many as 10 grizzlies in the
North Cascades. A few bears are also believed to reside in the Salmo-Priest Wilderness Area, in
the southern Selkirk Mountains where the borders of Washington, Idaho and British Columbia
come together.
Grizzlies were sighted in the 1950′s near the east end of the North Cascades in what is now the
Pasayten Wilderness Area. A veteran outdoorsman named Bill Louden — namesake of a small
lake in the Pasayten — memorably rode over a ride to discover a grizzly lumbering up the other
side. Luckily, the wind was blowing toward Lowden.
The exact location of the latest sighting is not being disclosed. People have shot animals in a
newly reestablished wolf pack in upper reaches of the Methow Valley near the east boundary of
the North Cascades National Park.
By Joe Sebille
Source: http://blog.seattlepi.com/seattlepolitics/2011/07/01/grizzly-photographed-in-north-cascades/
Source: http://timpanogos.wordpress.com/2009/08/24/poachers-kill-massive-grizzly-in-montana/
Source: http://www.cartoonstock.com/directory/g/grizzly_bear.asp