New Species Introductions

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

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

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

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

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

Causes of New Species Introductions Natural Introductions Human Introductions

Consequences Sometimes exotic species grow so much in number.

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

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

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

Cane Toad had no impact on beetle population bred like flies (can lay 33 000 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)