Question

Choose three examples that correctly predict the effect of a change on the ecosystem.

A.
A decrease in the desert tortoise population will cause a decrease in the rattlesnake population.

B.
A decrease in the rattlesnake population will cause an increase in the kangaroo rat population.

C.
An increase in the kangaroo rat population will cause an increase in the prickly pear cactus population.

D.
An increase in the red-tailed hawk population will cause an increase in the rattlesnake population.

E.
A decrease in the kangaroo rat population will cause a decrease in the coyote population.

F.
An increase in the desert cottontail population will cause a decrease in the yucca population.

Answer 1

B, E, and F.

- B: Rattlesnakes prey on kangaroo rats, so fewer rattlesnakes → less predation → kangaroo rat numbers rise.
- E: Coyotes eat kangaroo rats; a drop in kangaroo rats removes a food source → coyote numbers likely decline.
- F: Desert cottontails are herbivores that feed on plants (including yucca/other shrubs), so more cottontails → increased grazing → decreased yucca.