Question

As population density increases in harp seals (Phoca groenlandica), females

A) become sexually mature at a smaller body size.
B) refuse to mate with males.
C) begin reproduction at a later age.
D) often cannibalize their own offspring.

Answer 1

When population density increases in harp seals, females typically reach sexual maturity at a smaller body size. A decline in the seals' primary food source, likely due to factors like pollution or overfishing, would cause both the carrying capacity and population of seals to decrease.

Step-by-step explanation:

As population density increases in harp seals (Phoca groenlandica), females tend to become sexually mature at a smaller body size. In ecological terms, when resources such as food or space become scarce due to higher population densities, animals may exhibit changes in their life history strategies, such as alterations in size at sexual maturity. This is an adaptive response that allows the population to continue reproducing under more crowded conditions.

If the major food source of seals declines due to pollution or overfishing, likely outcomes include a decrease in the carrying capacity of seals, which is the maximum population size that the environment can sustain indefinitely given the food, habitat, water, and other necessities available in the environment. Consequently, the seal population would also likely decrease due to the decline in resources necessary for their survival and reproduction. This is reflected in Figure 19.6 that demonstrates real-world fluctuations of a seal population in response to environmental conditions.