Shrews Grow Bigger Snouts in Winter

Shrews are small animals. In winter, they grow bigger snouts. This helps them deal with cold air. Researchers studied shrews from Japan. They found that shrews shrink their skulls but grow their snouts. This is called the reverse Dehnel's phenomenon.

Researchers have discovered that long-clawed shrews adapt to winter by growing larger snouts. This adaptation helps them cope with cold air. While their skulls shrink in size during winter, their snouts become longer and wider. This phenomenon is known as the reverse Dehnel's phenomenon, and it was documented in a study of shrew skulls collected in Japan over several decades.

A recent study has revealed that long-clawed shrews exhibit a unique adaptation to winter conditions by increasing the size of their snouts, a phenomenon termed the reverse Dehnel's phenomenon. While previous research has shown that certain small mammals, like the common shrew, shrink their body mass and skull size during winter, the long-clawed shrew demonstrates an opposite trend for its snout. Researchers analyzed 136 skulls collected in Japan, noting that while the brain case height decreased by 12% in winter specimens, the snout's height and width increased by 7% and 6%, respectively. This adaptation may help the shrews cope with the cold air they encounter during the winter months.