Question

written - response question #2. scientists have been studying four populations in a swamp area. in this area, alligators eat gar (a type of large fish), and both gar and diving ducks eat crabs. the data showed that recently the alligator population has decreased. how could the decrease in the alligator population affect the other populations? be sure to explain whether the gar population, the diving duck population, and the crab population will change, and why.

Explanation:

Since alligators eat gar, with fewer alligators, the predation pressure on gar decreases, so gar population will likely increase. As gar and diving - ducks both eat crabs, an increase in gar population means more competition for crabs with diving - ducks. Also, with more gar, the demand for crabs will rise, which may lead to a decrease in the crab population. A decrease in crabs can then cause a decrease in the diving - duck population due to less food availability.

Answer:

The gar population will likely increase because there is less predation by alligators. The crab population may decrease due to increased predation by the growing gar population. The diving - duck population may decrease as there is more competition for crabs with gar and potentially less crab availability as a food source.