Question

The overall population of a species decreased. What could have occurred to make this happen?
The immigration rate increased, while the death rate decreased.
The birth rate decreased, while the death rate increased.
The carrying capacity increased, while the immigration increased.
The emigration increased, while the birth rate increased.

Answer 1

The birth rate decreased, while the death rate increased.

Reason: fewer births and more deaths both reduce net population growth. The other options either increase population (1 and 3) or are ambiguous because increased births could offset increased emigration (4).