Science investigates earwax: whales stressed during the war

Whales had a lot of stress during the Second World War.

The researchers studied earwax of fin whales, humpbacks and blue whales. Such plugs are in natural history museums around the world. In that earwax you can find out what hormones the animals have produced in their lives and what kind of pollution they are exposed to. The oldest prop is from 1870, the most recent from 2016.