What are the causes of animal extinction
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Transcript of What are the causes of animal extinction
What are the causesof animal extinction?
Risa Oba
Out Line
Introduction Deforestation Water pollution Alien species Conclusion Discussion
Introduction
5~15 million species 50,000 vertebrate
fish ,birds ,mammals etc. 50,000 species vanish a year
=more than 100 species a day
Introduction
Main causes of animal extinction
Deforest-
ation
Water pollutio
n
Alien animal
s
Deforestation
1 ½ acres lost every 1 sec
Deforestation
shortage of food→destroying ecosystem
plant insect birds mammals
Deforestation
Shortage of habitate.g. Java tiger (died out in 1972)
Water Pollution
Littering• Killing 100,000 animals & a million sea
birdsevery year!
Water Pollution
Oil Spill Ship accident, war etc. Exxon Valdez oil spill (1989)
kill 2,800 sea otters & 250,000 seabirds
Water Pollution
Polluted agricultural water 46.7% fish killing e.g. Iowa states
5.7 million fish dead
Water Pollution
Alien Species
Alien species: come from foreign country To kill harmful animals Accidentally
Caused hundred of extinction Mongoose in Hawaii Brown tree snake in Guam Mallard duck in Hawaii
Alien Species
Mongoose Puerto Rico->Hawaii To kill rats & snakes 12 reptiles & amphibian
-> extinction
Alien Species
Brown tree snake ? -> Guam Accidentally More than 10 birds
-> extinction
Alien Species
Mallard duck ? -> Hawaii To hunt Crossing with native ducks
Lose antibodyBecome sterile
※sterile: not able to produce babies.
Conclusion
1. Deforestation Destroying ecosystem & habitat
2. Water pollution Littering, oil spill & polluted water
3. Alien species Competition, predation & crossing
Conclusion
Endangered species23% mammals (1,130)
12% birds (1,194)
Discussion
What should we do to stop the animal extinction?
Thank you for listening!