News Animals

Shrews’ noses grow in winter as their brains shrink

The pint-sized Pinocchios may get an olfactory boost or shield their brain from cold air

A taiga shrew (Sorex isodon) is shown on lush green grass

Long-clawed shrews (a close relative of Sorex isodon, shown) go through some curious wintertime changes to their skull. Their snout expands while their braincase shrinks.

Sergey_Cher/iNaturalist (CC BY-NC 4.0)

By Jake Buehler

This nose grows. During harsh Japanese winters, long-clawed shrews’ snouts temporarily expand.

The seasonal swelling is the opposite of the previously known winter pattern in shrews, in which the brain and surrounding cranium shrink.