Eating or living on another species isn't competition
- The idea
- Predict
- See it
- Why
- Check
The idea
“When one organism hurts or depends on another, the two are competing.”
A hawk grabbing a mouse looks like a contest, so calling it competition feels natural. In ecology, competition means two organisms after the same scarce thing.
The short version
The mistake: When one organism hurts or depends on another, the two are competing.
What's actually true: Competition is when organisms use the same limited resource, so each one's use leaves less for the other.
- Competition means two organisms use the same resource and there isn't enough for both. Food, water, light and space can all be that resource.
- When one organism eats another, it's predation, or herbivory if the food is a plant. The one being eaten is the resource.
- Symbiosis is two species living closely together. Mutualism helps both. Parasitism helps one and harms the other. Commensalism helps one and leaves the other unaffected.
On the exam: Find the limited resource both organisms use. If one is the other's food or host, it isn't competition.