Bald Eagle Common in 1700s and 1800s 1900s- decline in population Farmers Toxic chemical waste ...
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Transcript of Bald Eagle Common in 1700s and 1800s 1900s- decline in population Farmers Toxic chemical waste ...
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
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