1. Ecosystem Threats II Ecosystems Unit, May 23 rd 2007

2. **Major (man-made) Threats to our Ecosystems: 1. Habitat Loss 2. Chemical Pollution 3. Introduced Species 4. Acid Rain 5. Climate Change

3. 3. Introduced Species Humans have both intentionally and unintentionally brought new plants and animals to new habitats. unintentionally Usually the new species has no natural predators or diseases to limit their populations in this new habitat so their population numbers increase rapidly!

4. Examples of Introduced Species 1. Starlings from Eurasia to North America 2. Rabbits from England to Australia 3. Purple Loosestrife from Europe to North America 4. Cane Toads from South America to Australia

5. STARLINGS In 1890 100 starlings were introduced to Central Park, New York Today there are over 200 million starlings! Starlings take over the nesting habitats of our native birds. Their large flocks also cause lots of waste, noise and eat farmer’s grain.

6. Rabbits to Australia In 1859, 24 rabbits were brought from England to Australia for sport hunting. Australia had no natural predators that ate rabbits. Despite lots of shooting, by 1950 there were 600 million rabbits! Rabbits have caused the extinction of many native plants and animals in Australia.

7. Invasive Rabbits in Australia Video Clip

8. PURPLE LOOSESTRIFE In early 1800s Purple loosestrife was accidentally brought to North America from Europe. Seeds of the plants were in the sand that was put in the ballast of ships sailing from Europe. This plant had no natural predators in North America. Each plant could produce 3 million seeds/yr!

9. Purple Loosestrife taking over a wetland

10. Leaf Eating Beetles

11. Effects of Beetles on Purple Loosestrife in a wetland in Ontario Video of Water Hyacinth

12. Cane Toads http://www3.nationalgeographic.com/a nimals/video/toad_cane.html http://www3.nationalgeographic.com/a nimals/video/toad_cane.html

13. Solutions… Never release unwanted pets into the wild! If possible, eliminate the new species from the introduced habitat.eliminate Control the population of invasive species to prevent further damage.