Extinction and Extirpation

Transcription

1 Extinction and Extirpation

2 is the disappearance of every individual of a species from the entire planet. Extinction is a natural part of Earth s history. Most mass extinctions, like the one that killed off the dinosaurs, were likely caused by catastrophic events. These are events such as earthquakes or volcanic eruptions that cause sudden changes in the environment. Most extinctions are not mass extinctions. They take place over longer periods of time.

3 What caused the following extinctions:

4 is a local extinction, or the disappearance of a species from a particular area. EXAMPLE #1: The woodland caribou is currently at risk of being extirpated from the boreal forests of northern Alberta because of habitat degradation resulting from logging, forest fires, and increased interspecies competition. EXAMPLE #2 The swift fox was once common in Alberta, but by 1928 this species was completely extirpated from Canada. The Alberta Department of Environmental Protection, working with groups such as the World Wildlife Fund, is trying to reintroduce the fox to Alberta. To do this a major breeding program is under way.

5 are ones that are in immediate danger of extinction. are likely to become endangered if their current declines are not reversed.

6 Causes of Extinction/Extirpation Natural Causes Human Causes -catastrophic events - habitat destruction - volcanic eruptions - construction - floods - pollution - fires - introduction of non-native species - lack of food due to over population - overhunting - disease - organisms have specific adaptations for a few environment condition ex. pandas only eat bamboo - forests destroyed, died off/cut down

7 Assignment: Create 4 small powerpoints/notebooks. Detailing 4 different species of animal. 1 species should be extirpated 1 species should be extinct 1 species should be endangered 1 species should be threatened Your poster or powerpoint should include the following: 1. A picture of the animal 2. If its extinct/endangered/extirpated 3. The cause of the extinction, extirpation, or endangerment 4. Any other interesting facts you find 5. A source of where you got the information. See examples:

8 Extinction: Trilobite Trilobites were a crab like organism that lived on the bottom of the ocean. They became extinct about 250 million years ago at the end of the Permian. Became extinct due to natural causes The reason they are a mistake is a bit of mystery. It may be due to an increase in salinity in the oceans, a temperature change in the ocean, or they may have been outcompeted by modern arthropods. Source:

9 Extirpation The Grizzly Bear The grizzly bear is listed as extinct in Manitoba. This was due to over hunting and trapping during the fur trade era. It no longer lives in this area. Although there are reports that recently a number of bears have moved in the area and are now competing with polar bears. Became extirpated due to human causes Source:ttp://

10 Endangered Chinese Giant Salamander This is the largest amphibian in the world. It can get up to 5.5 feet in length. They are endangered because of pollution, habitat destruction, dams, and they are illegally hunted for meat, they are also captured illegally for pets. Endangered due to humans. Source: view=c&id=3&sp=413

11 Threatened Polar Bear Polar bears are listed as threatened due to a rise in global temperature. If the sea ice melts too early the bears main food source in the winter (seals) are uncatchable. This can also lead to drowning in the bears. Habitat loss is also a contributing factor. Threatened due to humans, and natural causes. Source: