Roles in Ecosystems Image from

Habitat A habitat is the place an organism lives.

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

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.).

Do they have the same niche?

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

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

Biodiversity Biodiversity is the variety of life in a particular ecosystem; also known as biological diversity Since organisms within an ecosystem have different niches, it allows for greater diversity

Native vs. Introduced Species A native species is a species 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.

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

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

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

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.

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

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

Make sure you know these words! Vocabulary Make sure you know these words! Habitat Ecological niche Competition Native species Introduced species Image from www.nrc.gov/.../basic-ref/students/waste.html