1. New Species Introductions

2. Ecological Niche Ecological niche
No two species have the same niche. This reduces competition.

3. Owl vs. Hawk
Both the owl and the hawk live in the forest and feed on the same organisms (mice, moles, rabbits, etc).

4. The owl and hawk do not compete because they have different ecological niches.

5. New Species Introductions
When a new species enters an ecosystem, it causes a disturbance.
Why?

6. Exotic Species exotic species – native species –
also called invasive or alien species
native species –

7. Causes of New Species Introductions
Natural Introductions
Human Introductions

8. Consequences
Sometimes exotic species grow so much in number.

9. African Bees
Brazil, 1957
honey producers introduced wild African bees, which are more aggressive than native species
thought they would produce more honey

10. African Bees did produce more honey, but… wiped out native species
led to an overall decline in honey production
“killer bees” swarm and attack animals (also humans)
no natural predators, so numbers increased a lot
1986, spread to Mexico; 1990 to Texas, and continue to move north

11. Cane Toad
Introduced to Australia in 1935 as a way to control the cane beetle (a pest)
cane beetles ate sugar cane crops in Australia
cane toad was used in the Caribbean and Hawaii to destroy beetle…the government wanted to try them in Australia

12. Cane Toad had no impact on beetle population
bred like flies (can lay eggs per spawning)
develop faster than native frog species so outcompete for food
no natural predators (poisonous) – whatever eats it dies
eats everything (insects, mice, dog food, native frogs)