Just what has set the boffins talking this year?
Over their long lives, whales accumulate earwax plugs that can get as long as ten inches in large species.
The plugs show bands that correspond with their age – every year, they have heavy feeding times and migration times that change the color of the wax.
In a report published in the journal Nature Communications in November, researchers described how they studied the chemical make-up of the bands and discovered that the whales produced significantly more of the stress hormone cortisol during years when the most whales were being hunted (the early 20th century and the 1960s), as well as during World War II, when whaling was low but submarines, battleships, and depth charges were common.
Cortisol levels have been steadily rising in recent decades too, despite the fact that whaling has been uncommon since the 1970s hunting moratoriums were put in place.
Warming sea temperatures appear to be creating stress for the marine mammals, scientists told the Atlantic.
Feeling stressed? Don’t go digging in your ears – here’s 17 steps you can take to lower your blood pressure.