ANIMALS AT RISK Going, Going, Gone

Species At Risk When a species population is below a certain level is is considered to be at risk.  Ex. Harlequin duck had about in the 1940’s. Now it has about In Canada about 250 plant and animal species are at risk See Table 1: Pg. 14

Extinct: Not Found ANYWHERE in the world. Blue Walleye Passenger Pigeon

Endangered: Close to Extinction/Not existing Eastern Cougar Beluga Whale

Extirpated: No longer exists in one part of Canada but exists in others Sage Grouse ch?v=m0M8pZnNlnI ch?v=m0M8pZnNlnI Grizzly Bear

Threatened: Likely to become endangered if certain factors are not reversed Wood Bison Peregrine Falcon

Vulnerable: At risk, or has low numbers Grey Fox Atlantic Cod

Extinction The extinction rate is soaring. In the 21 st century it is predicted that one species will become extinct every 30 minutes

What Are the Main Causes and Effects of Extinction? Causes:  Loss of habitat  Pollution of air and water  Natural environmental change  Poor reproductive success  Climate change  Competition with other organisms  Hunting by humans Effects:  Loss of biodiversity  Food chain collapses.  Entire Ecosystems suffer

What Causes Extinction? 1. Natural Environmental Change  Ex: Ice Age (245 million yrs ago)  80% of all species died.  Large Asteroid hit the Yucatan Peninsula (65 million yrs ago)  When the dinosaurs became extinct  Crater was 9.6 km deep, 300km wide  Earth quakes and volcanic eruptions  Dust blocked the sun

What Causes Extinction? 2. Pollution of Air and Water

What Causes Extinction? 2. Pollution of Air and Water Pollution of the air by burning of fossil fuels such as coal, oil and gas by vehicles and industry can produce acid rain. Acid rain falls in lakes and ponds increasing the acidic levels. Also, run off of fertilizers, pesticides and industrial waste into lakes and ponds can lead to extinction of aquatic dwelling organisms

What Causes Extinction? 3. Climate Changes

What Causes Extinction? 3. Climate Changes Human activities that are causing a change in climate have also been linked to the disappearance of organisms. There is evidence of a global warming trend. One hypothesis links increasing global temperatures with the increased use of fossil fuels by automobiles. Climate changes can cause important changes in local ecosystems. For example, if the climate becomes drier, frogs will suffer. No frog can stay in the sun too long or completely separate itself from fresh water.

What Causes Extinction? 4. Habitat Loss

What Causes Extinction? 4. Habitat Loss Logging, oil exploration, expansion of agriculture, road construction and expanding cities are destroying habitats. Frog species are exceptionally vulnerable to such expansion of human territory.

Poor reproductive success

Competition for food Competition for Food

Effects of Extinction The “Domino Effect” where the extinction of one species can cause the collapse of an entire food chain. This will reduce the biodiversity, or variety of different species in an ecosystem

Effects of Extinction For example, over hunting of sea otters along the west coast of North America removed the main predator of the sea urchin and the number of sea urchins increased. Sea urchins eat kelp and as the number of sea urchins grew, the amount of kelp declined and so did the fish that relied on the kelp for food and habitat. Reintroducing the otter resulted in the fish numbers increasing

Environment Canada: Species at Risk fm?stype=species&lng=e&index=1&cosid=&common =&scientific=&population=&taxid=0&locid=7&desid =0&schid=0&desid2=0& fm?stype=species&lng=e&index=1&cosid=&common =&scientific=&population=&taxid=0&locid=7&desid =0&schid=0&desid2=0&