North American mammals face various threats to their environments and populations. Large predators like jaguars, gray wolves, and cougars faced historic declines due to hunting but some populations are now recovering through conservation efforts. However, they still face threats from habitat loss and human encroachment. Other species like bison, bighorn sheep, and sea lions experienced severe reductions from hunting and loss of habitat and food sources, but protected areas and laws have helped increase numbers for some. Conservation groups work to protect habitats and species while minimizing conflicts with human activities.
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North
American
Mammals
Physical Environment
By: Amy Leonard and Kevan Wright
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Climate
North America embraces every climatic zone, from tropical rain
forest and savanna on the lowlands of Central America to areas
of permanent ice cap in central Greenland.
Subarctic and tundra climates prevail in Northern Canada and
Northern Alaska
Desert and semiarid conditions are found in interior regions cut
off by high mountains from rain-bearing westerly winds
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Water
Many Lakes and Rivers
Great Lakes
Mississippi River
St. Johns River
Atlantic Ocean and Pacific Ocean border the continent
Swamps/Marshes/Everglades
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Jaguar
Endangered in Arizona,
California, Central and South
America, Louisiana, Mexico,
New Mexico, and Texas
Populations have declined
mainly due to hunting for its
beautiful coat in the 1960s and
1970s
Today, habitat loss is due
mainly to the clearing of forests
Some poaching still occurs
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Effect on other species
Jaguars becoming extinct is effecting other species because
they are an indicator species.
Jaguars need a lot of living space, and if an area of forest has
a healthy population of such animals, then we can be pretty
sure that the whole forest community is doing well.
If Jaguars become extinct, we will lose our indicator as to how
well a forest ecosystem is doing.
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What are we doing to help?
We are working to protect northern jaguars in the core of their
range through on-the-ground and through the establishing a
Northern Jaguar Reserve.
We are also building local support for conservation, minimizing
predator/livestock conflicts and implementing programs to
change the local community's perception of the jaguar from a
liability to an asset.
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American Bison
Endangered in Canada
Can weigh over 1950 lbs
Largest mammal in North
America
Population was over
160,000, but was reduced to
less than 250 by 1900 due to:
Hunting
Diseases
Populations have recovered
since the 1920s to a total
population of 9000 due to
conservation efforts by
Canadian conservationists
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Effect on Environment
Bison play a keystone role in grassland ecosystem health
Grazing by bison increases native plant and wildlife diversity
Nutrient cycling benefits plant growth and species distribution
Bison wallows create a unique habitat
Bison carcasses fertilize soil
The loss of Bison would eliminate all these advantages and
negatively effect the environment they were once a part of
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Gray Wolf
Found in Mexico and the U.S.
Largest of the canines
7000 to 9000 wolves in Alaska
More than 3500 in the lower 48 states
Once was over 2 million
Main threats:
Hunting and trapping because it was
thought of as a nuisance
Habitat loss due to human
encroachment into wolf territories
The gray wolf population was almost
completely wiped out, but the gray wolf is
now legally protected
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Gray Wolves Impact Elk
Wolves are altering the abundance, distribution, group sizes,
movements and vigilance of elk. There are some indications
that these interactions may be causing new growth in willows
as elk are kept on the move by wolves and don’t stay to browse
in any one area very long
Without wolves, elk would flourish in one particular area and
not be forced to migrate
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Yellowstone National Park
Reintroduce Grey Wolves
Yellowstone National Park and central Idaho reintroduced grey
wolves. “There will be no land use restrictions for wolves after
six packs are established. State and tribal wildlife agencies are
encouraged to lead wolf management outside national parks
and national wildlife refuges.”
This reintroduction resulted in wolf population recovery in and
around Yellowstone National Park and in central Idaho by 2002.
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Cougar
Also known as Puma or Mountain
Lion
Found in North, Central, and South
America
Over 20 subspecies
Can kill prey up to seven times their
body weight
Has made a dramatic recovery with
over 30,000 in the US alone
The main cause of decline is loss of
habitat
Only 30 to 50 Florida panthers remain
in the wild today
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Environmental Effects
Cougar Predation Key To Ecosystem HealthScienceDaily
(Oct. 24, 2006) — “The general disappearance of cougars
from a portion of Zion National Park in the past 70 years
has allowed deer populations to dramatically
increase, leading to severe ecological damage, loss of
cottonwood trees, eroding streambanks, and declining
biodiversity.”
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The Cougar Fund
“The Cougar Fund was founded to help ensure the
conservation and protection of cougars throughout their range
in the United States and the rest of the Western Hemisphere.
Scientific research has shown us that healthy cougar
populations help to conserve healthy landscapes and the
biodiversity that enrich and sustain human life...Conserving
healthy and well-connected cougar populations not only helps
us fulfill our moral obligation to protect nature but also yields
immeasurable benefits to humans.”
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Bighorn Sheep
Found in British Columbia,
Washington, Oregon, Idaho,
California, Nevada, Utah, and
North Dakota
There are an estimated 10,500
bighorn sheep left in the wild in
California
Primary threats:
unregulated or illegal hunting
predation by mountain lions
and coyotes
disease
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Mexican Brown Bear
Once found in Mexico and
southern United States
Said to be possibly extinct
The main cause of decline is a
dramatic reduction of habitat
due to human settlement
Hunted for sport and in some
areas are killed because they
are believed to be dangerous to
humans and a threat to
livestock
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Giant Kangaroo Rat
Found in California
1/20 species of kangaroo rats
Is only found in one area of less
than five square miles between
the Carrizo Plain and the city of
Taft, in west-central California
It is legally protected
Threatened by habitat loss to
agricultural development
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Mantled Howler Monkey
Endangered from Mexico to
South America
Threatened by habitat
destruction, rainforest
fragmentation and natural
disasters
It is legally protected, and about
1300 individuals can be found
in protected areas
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Steller Sea Lion
Endangered in
Alaska, California, Canada, North
Pacific Ocean, Oregon, and
Washington
Numbers have declined because
of :
Accidental capture in fishnets
Loss of food source to
fishermen, and hunting
Some are shot each year by
fishermen who consider them
competition or pests to the
fishing industry
This species is now legally
protected by the United
States, and intentional killing of
any Steller sea-lion is prohibited
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Interview with Donna Leonard
Click to hear interview