Competition and Niches
Organisms compete for limited resources.
About this topic
Competition happens when organisms need the same limited resources: food, water, light, space or mates. Intraspecific competition is within a species, and interspecific between species. An ecological niche is the role of a species: where it lives, what it eats and how it interacts with others.
The competitive exclusion principle states that two species cannot occupy exactly the same niche in the same place for long; one will outcompete the other. Species often avoid this by niche partitioning, using resources differently. Within a species, competition is usually fiercest because individuals need exactly the same things, which drives natural selection.
For example, different warblers in the same spruce tree feed in different zones, some at the top and some near the trunk. Red and grey squirrels in Britain competed for acorns, and the grey proved better at using them, so reds declined. Plants compete for light by growing tall, and desert plants compete for water with wide root systems.
Knowing niches helps conservation, since protecting a species means protecting the resources it needs. A common error is confusing habitat with niche: the habitat is the address, while the niche is the job. Competition is not always fighting; it is often just using up a shared resource.
Key ideas
- Intraspecific and interspecific
- Niche is a role
- Competitive exclusion
Quick check
Use cases: where Competition and Niches helps
- Homework: review the key idea behind Competition and Niches before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Competition and Niches without notes.
- Visual learning: play with the interactive lab to see how Competition and Niches changes when you adjust its inputs.
- Teaching a friend: explain Competition and Niches in your own words, then compare your version with the key ideas.
Biology underpins medicine, farming, conservation and biotechnology.
Frequently asked questions
What is Competition and Niches?
Organisms compete for limited resources.
What will I learn in Competition and Niches?
Intraspecific and interspecific. Niche is a role. Competitive exclusion.
Is Competition and Niches part of Biology?
Yes. It is one of 150 Biology topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Competition and Niches lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Competition and Niches?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.