ENDANGERED SPECIES

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Transcript ENDANGERED SPECIES

SPECIES AT-RISK
Chapter 1.2
Chapter 1.3
What’s Out There?
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"Scientists were startled in 1980 by the
discovery of a tremendous diversity of
insects in tropical forests. In one study of just
19 trees in Panama, 80% of the 1,200 beetle
species discovered were previously unknown
to science... Surprisingly, scientists have a
better understanding of how many stars
there are in the galaxy than how many
species there are on Earth."
SPECIES AT RISK
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Species whose populations decline below a
certain level are considered to be at risk.
In Canada, there are 585 species in various
degrees of risk as of April 2009, according to
COSEWIC (Committee of the Status of
Endangered Wildlife in Canada).
Summary table of Wildlife species assessed by COSEWIC
http://www.cosewic.gc.ca/eng/sct0/index_e.cfm#sar
Why are Species at Risk?
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The reasons for an ecosystem decline, are the same
reasons why certain species are put at risk.
1. Loss of habitat
2. Pollution
3. Diseases
4. Climate change / global warming
5. Accidental introduction of new species
6. Over harvesting certain species(hunting)
7. Competition
8. Increased use of pesticides and fertilizers
9. Natural environmental change / Mass Extinction
Classification system for At-Risk
Species
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1. EXTINCT – A species that is not found
anywhere
EXAMPLES:
Blue Walleye (Type of Fish-1965 )
Passenger Pigeon ( 1914 ) link
Extinct Species
Passenger Pigeon
Blue Walleye
2. ENDANGERED
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A species that is close to extinction in all
parts of Canada or in a significantly large
location.
EXAMPLES:
Eastern Cougar ( very rare sightings)
Beluga Whale ( St. Lawrence River )
Tigers (Not in Canada – link)
Atlantic Salmon ( very shortly )
Endangered Species
Beluga Whale
Endangered Species cont.
Eastern Cougar
Gorilla
Atlantic Salmon
3. EXTIRPATED
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Any species that no longer exists in one part
of Canada, but can be found in others
EXAMPLES:
Grizzly Bear (no longer in Man. and Sask.
but found in Alberta and BC)
Grizzly Bear
4. THREATENED
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Any species that is likely to become
endangered if factors that make it vulnerable
are not reversed.
EXAMPLES:
Wood Bison (small number)
Anatum Peregrine Falcon (captive breeding
is helping to restore population)
Threatened
Peregrine Falcon
Wood Bison
5. VULNERABLE or Special Concern
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Any species that is at risk because of low or
declining numbers at the fringe of its range or
in some restricted area.
EXAMPLES:
Grey Fox
Atlantic Cod
Blue Heron
White tail Deer
Vulnerable/Special Concern
Grey Fox
Atlantic Cod
Blue Heron
WhiteTailed
Deer
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Which at-risk category is the most devastating?
Answer:
Extinction
The rapid loss of species we are seeing today is estimated by
experts to be between 1,000 and 10,000 times higher than the
natural extinction rate.
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These experts calculate that between 0.01 and 0.1% of all
species will become extinct each year.
If the low estimate of the number of species out there is true
- i.e. that there are around 2 million different species on our
planet - then that means between 200 and 2,000 extinctions
occur every year.
But if the upper estimate of species numbers is true - that
there are 100 million different species co-existing with us on
our planet - then between 10,000 and 100,000 species are
becoming extinct each year.
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In the modern world, extinction rates of species on
planet Earth are increasing at an alarming rate.
Between the years1600 and1900 the estimate is that
one species went extinct every four years.
It was projected that we lose one species every 30
minutes, that is about 17,500 per year… Gone
forever!
Species extinction rates are increasing dramatically
as the human population grows.
Species at risk of extinction is growing, at the rate of
about 80 species per year.
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Some species learn to adapt to major
changes in their ecosystems, others die.
In either case, this has major effects on each
ecosystem and food chain.
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Biological diversity is the resource upon
which families, communities, nations and
future generations depend. It is the link
between all organisms on earth, binding
each into an interdependent ecosystem, in
which all species have their role. It is the
web of life.
EFFECTS OF EXTINCTION
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The number and variety of species in an
ecosystem is described as the biological
diversity or BIODIVERSITY of the
ecosystem.
The reduction in biodiversity caused by the
extinction of a single species can cause a
“domino effect” with many negative effects.
When the threatened species acts as a
predator, it keeps the population of its prey in
check.
EFFECTS OF EXTINCTION
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When it acts as prey, it provides an important
food source.
So, An increase in Biodiversity = Healthy
ecosystem.
A decrease in Biodiversity = greater chance
of Ecosystem Collapse.
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SEA OTTER EXAMPLE
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Decrease in the Sea Otter (predator)
Means an increase in Sea Urchins
Means a decrease in Kelp (form of seaweed)
Means a decrease in Fish (relies on seaweed
for habitat and food)
By protecting the Sea Otters it caused an
increase in fish which balanced out the food
chain and therefore the ecosystem.
PLEASE ANSWER QUESTION # 2
PAGE 15 OF TEXT
ANSWERS TO QUESTION #2
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A) Threatened
B) Endangered
C) Extirpated
Endangered Species in Canada
Booklet and Worksheet