Download Unit 5: Keystone Species

Unit 5: Endangered and Keystone Species
KEYSTONE SPECIES
A keystone species is defined as one whose impact on its community or ecosystem is
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The term “keystone” was coined by ______________________________ and was based
on his studies of the rocky shore communities in California. When he removed a top
predator (_______________________________) from a section of the shore, aggressive
____________________________ multiplied, reducing the original 15 species
assemblage to 8. (Species assemblage included sea urchins, anemones, barnacles, sea
weeds, hermit crabs, etc.)
Effects of Keystone Species
1. ______________________________________________________________________
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2. ______________________________________________________________________
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3.______________________________________________________________________
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4. ______________________________________________________________________
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Examples of Keystone Species include:
1. Starfish (keep mussel populations in check)
2. Sea otter (keep sea urchin populations in check…sea urchins eat a lot of kelp)
3. Gopher Tortoise (as many as 362 other species use gopher tortoise burrows for
shelter. The burrow can be 40 feet long)
4. American Alligator ________________________________________________
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5. African Elephant __________________________________________________
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6. Salmon ___________________________________________________________
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7. Beaver ___________________________________________________________
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8. Prairie dog _______________________________________________________
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9. Horseshoe crab (Red Knots depend on their eggs)
SPECIALISTS
Specialists are ___________________________________________________________
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Examples:
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2.
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5.
6.
7.
Generalists are __________________________________________________________
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Examples:
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4.