Save energy: Moles shrink their brains in winter

Created: 09/29/2022, 12:00 p.m

By: Anna Katharina Kusters

When it's too cold and there's not enough food, moles' brains shrink.

It never returns to its original size.

Researchers have uncovered the winter secret of the mole: As the team of scientists explains in the specialist journal "Royal Society Open Science", the European mole has a special ability to survive.

During the winter months, his brain shrinks to conserve energy.

Save energy: Moles shrink their brains in winter

In winter, the brain of the European mole shrinks.

(Iconic image) © Henry Ausloos/Imago

Moles are small energy bombs.

The tiny bodies burn the energy available to them in no time at all and the animal has to constantly provide supplies in the form of food.

In summer this is usually not a problem, then the European mole finds enough insects such as earthworms, snails or larvae.

In winter, however, these animals are in short supply and the mole gets into trouble.

Moles typically live to be five years old and don't hibernate, so they have a few winters ahead of them that, at best, will have to be survived.

In order not to starve to death, the mole's body can shift down a gear.

This means their body shrinks to use less energy.

This process is also known as the Dehnel phenomenon.

Researchers from the Max Planck Institute of Animal Behavior in Konstanz have now discovered that even the mole's brain loses size in winter.

Saving energy: It's not just a lack of feed that plays a role

However, according to the Max Planck Institute, insufficient food does not appear to be the sole reason for mole brain shrinkage.

The researchers compared the skull circumference of the European mole to that of the Iberian mole, which are closely related but live in different climate zones.

If the brain shrinkage was related only to a lack of food, the European mole's brain would have to shrink in winter when food is scarce due to cold, and the Iberian mole's brain would have to shrink in summer when it's hot and there is less food.

But that is not the case.

The brain of the Iberian mole keeps its size.

Red list: 10 animal species are threatened in Germany

View photo gallery

Save energy: brain stays smaller forever

Once the European mole's brain has shrunk, it will never regain its original size.

It grows back in spring when temperatures rise, but remains smaller than it was before.

So over the course of a mole's life, its brain gets smaller and smaller.