Roles in Ecosystems

1. Roles in Ecosystems

2. Habitat • A habitat is the place an organism lives.

3. Ecological Niche • The ecological niche is an organism’s “job” in an ecosystem. • It includes: • its place in the food web • where it lives • the time of day it is active

4. Ecological Niche • Each organism in an ecosystem usually has a different niche. • This helps to reduce the amount of competition for habitat and resources (like food, water, etc.).

5. Do they have the same niche?

6. Do they have the same niche? • Red-tailed hawk • - eats mice • - hunts in fields • - hunts during the day

7. Do they have the same niche? • 2) Eastern screech owl • - eats mice • - hunts in forests • - hunts at night

8. Native vs. Introduced Species • A native species is a species (type of living thing) that has lived in an ecosystem for a long time. • An introduced species is a species that is new to an ecosystem. • Introduced species can arrive naturally (animals move, seeds carried by wind) or by humans.

9. Impact of Introduced Species • Introduced species usually cause problems in an ecosystem. • They compete for a niche with the native species.

10. Example - Starling • Sixty European starlings were released in North America in honour of Shakespeare. • There are now 200 million of them!

11. Example – Cane Toad • Cane toads were introduced into Australia to control insects.

12. Example – Cane Toad • They did not really help with the insects. • Now they are causing a lot of problems. • They are poisonous, so anything that eats them dies. • They are HUGE – and will eat anything they can swallow including many native species.

13. Example – Rabbits • Rabbits were brought to Australia by people. People brought rabbits to Australia.

14. Example – Rabbits • When the rabbits multiplied, they tried many ways to stop them: - fences - viruses - fleas • Nothing has worked!

15. Vocabulary Make sure you know these words! • Habitat • Ecological niche • Competition • Native species • Introduced species