Question

Use the following information to answer the next two questions. The southern elephant seal is extremely polygynous, with large, dominant males ("beachmasters") defending harems on swaths of beach. Pregnant females come to these beaches to give birth and mate with the beachmaster before returning to sea. While virtually all females who come ashore mate with the dominant male, females that are not pregnant often avoid the stress of the harem and remain at sea. These females choose to mate with smaller, subordinate males. Q4.15. When would a male be expected to improve his fitness by attempting to mate at sea rather than establishing a harem? A large, competitively dominant male will do better mating at sea when small males are relatively abundant. A large, competitively dominant male will do better mating at sea when suitable beaches are more common than are large, dominant males. A small male will do better mating at sea when suitable beaches are rare and successfully defended by large males. A small male will do better mating at sea when suitable beaches are more common than are large, dominant males. Submit Q4.16. Under what conditions would a female be expected to improve her fitness by mating with a small male at sea rather than with a large male defending a harem on shore? She would do better mating with a small male at sea: If a male seal's size and dominance is an honest signal of the expected survival of his offspring. If her offspring's survival is improved more by her continuing to feed at sea than by the superior genes of the beachmaster. If large, dominant males improve her survival by offering protection from the harassment of rival males. If the larger size of the dominant males is due to sexual selection. Submit

Answer 1

4.15

Option 3 - A small male will do better mating at sea when suitable beaches are rare and successfully defended by large males

When beaches with dominant males are rare it would be better for mating with small males and at the sea for the improvement of male fitness.

4.16

Option 2 - If her offspring’s survival is improved more by her continuing to feed at sea than by the superior genes of the beachmaster

If the feed is available more at sea than shore it would be easier for growing of offspring and survival rate. If these sourses are good at sea and survival rate is as good as that of mating at beach with dominant males, the females avoid the stress of reaching shore for mating and giving birth.