Penguins are noisy, as any visitor to an aquarium knows. Penguins may be noisy in others ways too, according to a new study published in Nature Communications. Scientists have long used Adélie penguin populations to monitor the health of the Southern Ocean and to understand how major factors such as fishing and climate change impact the oceans and the animals that rely on them. Now an extensive analysis of all known data on Adélie penguin populations over the last 35 years has found that only a small fraction of year-to-year changes in Adélie penguin populations can be attributed to measureable factors such as changes in sea ice.