Warming Antarctic risks diet of Emperor Penguins

The most beautiful birds in Antartic, Emperor Penguins eat a variety of fish but diminishing sea ice in the warming Antarctic means less fish to eat.

The tallest and heaviest of all living penguin species, Emperor Penguin, have a varied menu that changes with the season.

Researchers at the Woods Hole Oceanographic Institution (WHOI) have developed a way to help determine the foraging success of Emperor penguins.

Off all the penguin species, Emperor penguins tend to be the biggest eaters. And for good reason: they make exceptionally long treks on sea ice to reach their foraging grounds and feed their large chicks when they return. But as sea ice diminishes, so does the microscopic plankton living underneath, which serves as the primary food source for fish that penguins eat.

Sea ice also provides an important resting platform for the penguins in between foraging dives, so melting can make foraging that much harder.

"Global warming may be cutting in on food availability for Emperor penguins," said Dan Zitterbart, co-author of the study.

"And if their diets change significantly, it could have implications on the health and longevity of these animals -- which are already expected to be highly threatened or close to extinct by the end of this century. With this new approach, we now have a logistically viable way to determine the foraging success of these animals by taking images of their behaviour once they return back to the colony from their foraging trips," he added.

According to a previous WHOI study, the species is critically endangered, the global population will have declined by 20 percent and some colonies might reduce by as much as 70 percent of the current number of breeding pairs of Emperor penguins if heat-trapping gas emissions continue to rise and Antarctic sea ice continues to retreat.

The study concluded that it is important to know which colonies are going to be the first most affected by climate change, so if it appears that a certain colony will remain strong over the next century, conservation measures like marine protected areas can be established to better protect them.

The findings were published in the Journal of Applied Physics.