Generalist and Specialist Species
Introduced| English |
|---|
| generalist/ˈdʒenərəlɪst/ |
| specialist/ˈspeʃəlɪst/ |
| niche/niːʃ/ |
Jack of all trades, or master of one
- A raccoon eats almost anything and lives almost anywhere.
- A panda eats almost only bamboo.
- These two ways of life are called generalist and specialist.
- Which strategy a species uses shapes how it copes with change.
A species' niche
- A niche 生态位 is a species' role — what it eats, where it lives, and the conditions it needs.
- A wide niche means many foods and habitats.
- A narrow niche means only a few, very specific ones.
- The width of the niche sorts species into two types.
A species' niche is…
A niche is a species' role — what it eats, where it lives, and the conditions it needs.
Generalists: wide niche
- A generalist 广适性 uses a wide range of resources.
- It can eat many foods and live in many places.
- Raccoons, rats, and humans are all generalists.
- This flexibility lets them thrive in changing conditions.
A generalist species…
A generalist has a wide niche — it can eat many foods and live in many places.
A species with a narrow niche, using very few resources, is a ____.
A specialist uses a narrow set of resources — like a panda that eats almost only bamboo.
Specialists: narrow niche
- A specialist 特化 uses a narrow range of resources.
- A panda eats almost only bamboo; a koala eats only eucalyptus.
- In a stable habitat, specialists can be very successful.
- But if their one resource disappears, they are in serious trouble.
Generalist or specialist?
Sort each species by whether it uses a wide range of resources (generalist) or a narrow one (specialist).
Generalists usually cope better with environmental change than specialists.
With flexible needs, generalists adapt to change; specialists can lose their one resource.
Select all true statements about generalists and specialists.
Specialists are more at risk from change, not less. The other three are correct.
Specialists are more vulnerable to change, not less. A generalist that eats many things simply switches food when one runs out. A specialist tied to a single resource has nowhere to turn — which is why so many endangered species are specialists.
Why pandas are endangered:
- Pandas are extreme specialists: bamboo makes up almost their entire diet.
- When bamboo forests are cleared, the pandas have nothing else to eat.
- A generalist could switch foods, but the panda's narrow niche leaves it with no options — putting it at high risk.
A species' niche is its role and the range of resources it uses. A generalist has a wide niche (many foods and habitats) and copes well with change; a specialist has a narrow niche (few resources) and thrives in stable habitats but is far more vulnerable when its resource disappears.