Scientists report that some shrews change the size of their bodies seasonally to cope with winter cold. A Japanese study published in the *Proceedings of the Royal Society B: Biological Sciences* finds that, although earlier work shows winter shrinkage in shrews’ skulls and other tissues, the animals’ snouts follow the opposite pattern.
Researchers analyze long-clawed shrew skulls and describe a reversible “plasticity” in which skull size decreases during winter, then regrows in spring. In contrast, the snout elongates in winter and later shrinks again. The study examines how these different structures respond to seasonal conditions, building on previous observations tied to Dehnel’s phenomenon, in which body mass, skull size, brain mass, and some organs shrink in the cold months and regrow afterward.
The outlets agree on the core findings: winter brings reduced skull size but increased snout length in the same animals, followed by reversal in spring. The differing emphasis is that one outlet frames the results broadly as reversible size changes across anatomy, while the other highlights snout enlargement specifically as the notable winter adaptation.
