6,000 penguin dives reveal how sea ice can make prey harder to reach

For nesting penguins in Antarctica, finding food is no longer just about how many fish or krill are in the ocean. It is also about how difficult those animals are to catch.Scientists who tracked more than 6,000 penguin dives beneath Antarctic sea ice found that prey can become much harder to reach even when their overall numbers have not fallen. Instead of eating their food until it nearly disappears, the repeated presence of hunting penguins causes krill and fish to change their behaviour, moving deeper into the water or spreading out to avoid the birds. This forces penguins to work much harder to find food.The study, published on July 15 in the Proceedings of the Royal Society B, changes how scientists understand predator-prey relationships in extreme environments.