1. Competition in Communities
Section 17.2
Competition in Communities

2. Competition When 2 species use the same resource = competition
Examples: food, nesting sites, water, light, soil minerals
The resources an organism needs are its niche

3. Niches
Fundamental niche – all the resources in the ecosystem that the animal could use
All of this niche can’t be used because of competition with other species
Realized niche – the resources that the animal actually uses

4. How animals deal with competition
Competitive exclusion – 2 species can’t use the same resource at the same time
One animal ‘wins’ and the other animal ‘loses’
Usually not a fight to the death
One animal just moves to a different location

5. How animals deal with competition…
Resource partitioning – a way to reduce competition
When 2 animals are trying to use the same limited resource, they may divide it between themselves
Example: hawks hunt during the day and owls at night

6. Predation and competition
Predators keep the prey population under control
Without this control the competition for resources can increase
More competition can cause less biodiversity as weaker species are eliminated