Question

A population of foxes inhabits a small forest. The size of the population is currently below the forest's carrying capacity for the foxes. Which factor could cause an increase in the population's growth rate?

A.
A lack of mating opportunities increases the population's level of emigration.
B.
An increase in food availability increases the birth rate in the population.
C.
The population's level of immigration falls below its level of emigration.
D.
The population's birth rate falls below its death rate after a predator is introduced.

Answer 1

B. An increase in food availability increases the birth rate in the population.

Step-by-step explanation:

We will use process of elimination:

A - this answer is wrong because as the foxes encounter a lack of mating opportunities and increasingly emigrate out of the fox population in the small forest, the population of foxes gets smaller, not larger.

B - more food for the foxes means that the foxes have more energy to devote to reproduction. This answer is correct because an increase in birth rate will cause an increase in the growth rate of a population, all other things being equal.

C - if more foxes are leaving the small forest than entering the small forest, the population of foxes will naturally decline. Definitely not an increase in the growth rate of a population.

D - again, if more foxes are dying than being born, the population of foxes in the forest will decrease. This option is incorrect.