California sea lions have managed to maintain — and, in the case of males, increase — their average body size as their population grows and competition for food becomes fiercer. This is in contrast to other marine mammals, whose average body size tends to decrease as their numbers increase. Researchers report that sexual selection was a strong driving force for males to grow bigger and to strengthen muscles in their neck and jaw that help them fight for mates. Both male and female sea lions evaded food shortages by diversifying their diets and, in some cases, foraging further from the shore.
Click here for original story, Male California sea lions are becoming bigger and better fighters as their population rebounds
Source: ScienceDaily