Download presentation
Presentation is loading. Please wait.
1
SPECIES AT-RISK Chapter 1.2 Chapter 1.3 http://www.youtube.com/watch?v=gEl6TXrkZnk
2
SPECIES AT RISK 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
3
Why are Species at Risk? 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 7. Competition 8. Increased use of pesticides and fertilizers 9. Natural environmental change / Mass Extinction
4
Classification system for At-Risk Species 1. EXTINCT – A species that is not found anywhere EXAMPLES: Blue Walleye (Type of Fish-1965 ) Passenger Pigeon ( 1914 )
5
Extinct Species Passenger Pigeon Blue Walleye
6
2. ENDANGERED 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 ) Gorillas Atlantic Salmon ( very shortly )
7
Endangered Species Beluga Whale
8
Endangered Species cont. Eastern Cougar Gorilla Atlantic Salmon
9
3. EXTIRPATED 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.)
10
Grizzly Bear
11
4. THREATENED 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.)
12
Threatened Peregrine FalconWood Bison
13
5. VULNERABLE or Special Concern 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
14
Vulnerable/Special Concern Grey Fox Blue Heron Atlantic CodWhite- Tailed Deer
15
Which at-risk category is the most devastating? Answer: Extinction
16
In the modern world, extinction rates of species on planet Earth are increasing at an alarming rate. Between 1600 – 1900 the estimate is that one species went extinct every four years. It is estimated 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 extinction is growing, at the rate of about 80 species per year.
17
Some species learn to adapt to major changes, others die. In either case, this has major effects on each ecosystem and food chain.
18
EFFECTS OF EXTINCTION 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.
19
EFFECTS OF EXTINCTION 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.
21
SEA OTTER EXAMPLE 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 caused a increase in Fish which balanced out the food chain and therefore the ecosystem.
22
PLEASE ANSWER QUESTION # 2 PAGE 15 OF TEXT
23
ANSWERS TO QUESTION #2 A) Threatened B) Endangered C) Extirpated
24
Endangered Species in Canada Booklet and Worksheet
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.