June 14, 2024

Flag - Moles like "Porsche Turbo Engines" - Wikipedia

Flag – Moles like “Porsche Turbo Engines” – Wikipedia

Konstanz (dpa) – According to a study, the brain of young European moles shrinks by a good tenth of their first winter.

As a result, it uses less energy, helping animals get through the season of nutrient poverty, researchers report in the “Royal Society Open Science” journal. In the summer, the skull and brain swell again, but not to the previous maximum size.

The decrease in the weight of the essential organs in the winter months when there is little food – sometimes by a fifth or more – is called the Dehniel phenomenon. The effect, named after the Polish zoologist August Dehnel, was first described in 1949 in the red-toothed shrew. Ermines and weasels are also able to do this.

cranial examination

Such species, weighing only 60-120 grams, European moles have a very high metabolism and are active all year round in cold climates. “Their little bodies are like turbocharged Porsche engines that use up their energy stores in a matter of hours,” explained co-author Dina Deichmann. According to the research team, insects cannot find enough food for this high rate during the cold winter months. To survive, they go into sleep mode – shrink.

Scientists led by Lucy Novakova of the Max Planck Institute for Animal Behavior in Constance measured the skulls of European and Iberian moles from the museum’s collections and compared their evolution over the course of the year. Closely related species live in different climatic zones.

The researchers found that not only the availability of food but also the winter climate played a role in altering the brain of the European mole. “If it was just about food, the European mole would have to shrivel in the winter when food is scarce, and the Iberian mole in the summer when extreme heat and drought make food scarce,” Deichmann explained. But: the skull of the Iberian mole does not change throughout the year.

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And there was another finding: the skulls and brains of European moles shrunk more in winter than they grew again in spring (an average of 11 versus 4 percent). This has already been observed in shrews, but they hardly live more than a year. In the case of moles, which can live up to five years or more, slower growth compared to shrinking means the animals are getting smaller every year. However, the researchers explained, the sample evaluated was too small to be able to assess this.

Moles are almost blind and rely on their senses of touch and smell to find food. They eat earthworms, caterpillars and snails, as well as small rodents and lizards. By digging underground passages, excess ground material is created, which pushes it to the surface of the earth – this is how hills are formed.

© dpa-infocom, dpa: 220925-99-887566 / 2