Penguin diet changed when humans arrived

Around 200 years ago, a group of Antarctic penguins switched from eating mostly big fish to a diet of tiny crustaceans. And new research suggests humans might have forced the change.

Associate Professor Steven Emslie from the University of North Carolina Wilmington and Professor William Patterson from the University of Saskatchewan publish their findings today in the Proceedings of the National Academy of Sciences.

The researchers analysed more than 220 fossilised penguin eggshells from 100 to 38,000 years old.

They collected the shells from abandoned Adélie penguin colony sites from three major regions in Antarctica: the Ross Sea, East Antarctica and the Antarctic Peninsula.

After crushing bits of the shells with a mortar and pestle, the scientists measured the ratio of carbon and nitrogen stable isotopes to determine past and present penguin diets.

Read full article