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Canada’s Endangered Species. Bald Eagle. Common in 1700s and 1800s 1900s- decline in population Farmers Toxic chemical waste Health of top-level carnivores indicates whether toxins are entering an ecosystem. COSEWIC. Committee On the Status of Endangered Wildlife In Canada
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Bald Eagle • Common in 1700s and 1800s • 1900s- decline in population • Farmers • Toxic chemical waste • Health of top-level carnivores indicates whether toxins are entering an ecosystem
COSEWIC • Committee On the Status of Endangered Wildlife In Canada • Assesses and designates which wild species are in danger of disappearing • http://canadianbiodiversity.mcgill.ca/english/species/endangered/extinct.htm
Classifying Species at Risk • Extinct • Extirpated • Endangered • Threatened • Special Concern
Extinct • Species that is no longer found anywhere • Example: Great Auk • QC, NB, NS, NL • Over-hunting • Extinct since 1844
Extirpated • Species that no longer exists in one area but can be found in others (Locally extinct) • Example: Grizzly Bear • No longer found in the Canadian prairies • Hunting and habitat destruction
Endangered • Species that is close to extinction in a significantly large location • Example: Beluga Whale • Arctic and Atlantic Ocean • Over-hunting • Habitat Degradation
Threatened • Any species that is likely to become endangered if things are not reversed • Example: Killer Whale • Pacific Ocean • Decrease in prey (salmon) • Physical and Accoustical Disturbances • Oil spills and contaminants
Special Concern • Species that are particularly sensitive to human activities or natural events and could become endangered or threatened • Example: Polar Bear • YT, NT, NU, MB, ON, QC, NL, Arctic Ocean • Overharvest • Climate Change
SARA • Species at Risk Act • Established in 2003 • Purpose is to protect wildlife species at risk in Canada. • Government must legally protect species designated by COSEWIC.
Extinction in Modern World • Extinction rates are increasing • Causes????? • Mostly human activities • Mass extinction occurred before humans • Caused by major catastrophes • Example: Yucatan Peninsula- Asteroid
Effects of Extinction • Biodiversity- number of species in an ecosystem • “Domino Effect”- Removal of one part can cause the collapse of the entire food chain. • Example: over-hunting of sea otters • Sea urchin population increased • led to destruction of kelp beds
What is our role?Restoring the Balance Once an ecosystem is damaged, should it be fixed? • Example: Petitcodiac River • Example: Wolves of Yellowstone National Park • Example: Peregrine Falcons in NB