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DECREASING POPULATIONS. When a population decreases significantly, the species can become extinct, endangered or threatened. Extinctions. 99.9% of all species that ever lived on Earth are now extinct.
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DECREASING POPULATIONS When a population decreases significantly, the species can become extinct, endangered or threatened.
Extinctions • 99.9% of all species that ever lived on Earth are now extinct. • Extinction appears to be a natural cycle and part of our changing Earth, but the cause of early extinctions are a cause for concern.
Mass Extinction • Dinosaurs were believed to be extinct due to a meteorite crashing into Earth. • Are humans causing the next mass extinction- the sixth in the history of life on Earth?
Extinct Species • An extinct species is one that has died out and left no living relatives. • Species become extinct due to due to climate change, disease, destruction of habitat, natural disasters and development into a new species.
Dodo Bird • The dodo bird was found on the Island of Mauritius in 1505. • The last dodo bird was killed in 1681.
Quaggas • Quaggas were hunted to the brink of extinction in the mid 1900s. • The last Quagga died in the Amsterdam zoo in 1883.
Mastodons • Mastodons roamed the Earth 15 million years ago. • They became extinct about 16,000 years ago.
Endangered Species • Endangered species are species that numbers are so small, they are in danger of becoming extinct.
The Miami Blue Butterfly • The Miami butterfly lives mainly in Florida • Their numbers are believed to be only around 50 to 60 adults.
Gray wolf of Yellowstone • The gray wolf numbers are declining rapidly. • They are being killed by farmers and hunters.
Leatherback Turtles • Leatherback turtles weigh 1,000 pounds and have roamed the oceans for hundreds of years. • It is now on the endangered list.
Threatened Species • Threatened Species are species that are vulnerable to become endangered in the future.
Polar Bears • Polar Bears are threatened due to global warming and the changing of their habitat.
Orca Whales • Orca whales are residents of the Pacific Northwest. • Due to population decline, many realize they are a species threatened to become extinct.
Marine Turtles • Although marine turtles have been around for millions of years, they are now threatened. • Reasons for their decline are poachers and predators pillaging their nests as well as habitat degradation by human impact.