Habitat use by Weddell seals and emperor penguins foraging in the Ross Sea, Antarctica

The only apex predators that live year-round at high latitudes of the Ross Sea are the Weddell seal and emperor penguin. The seasonal distribution, fo raging depths, and diet of these two species appear to overlap. What makes it possible for emperor penguins and Weddell seals to co-exist at high lati tude throughout the winter when other marine tetrapods apparently cannot? B oth species have similar adaptations for exploitation of the deep-water hab itat, forage on the same species, and routinely make long and deep dives. Y et, despite these similarities, there is probably little trophic overlap be tween the adults of both species due to geographical and seasonal differenc es in habitat use. For example, during the winter months while female emper or penguins are ranging widely in the pack ice, adult seals are foraging an d fattening for the upcoming summer fast, literally beneath the feet of the male penguins. However, there is more extensive overlap between juvenile s eals and adult penguins, and shifts in prey abundance and/or distribution w ould likely affect these two groups similarly. In contrast, juvenile pengui ns appear to avoid inter- and intra-specific competition by leaving the Ros s Sea once they molt.