This was a fun collaboration with lots of
students in my lab and funded by NSF. Open access HERE: www.journals.uchicago.edu/doi/epdf/10....

We also showed that this is a general phenomenon in Sorex shrews. Based on just the climate at our North Carolina site, we were able to predict the magnitude of shrinkage that we observed in the field.

Here is a cool image of the braincase shrinkage between Spring and subsequent Winter💀

Winter decreases in body mass, braincase height, and femur length were 13%, 11.5%, and 8.7%. Each rebounds the following spring in second-year individuals.

But, the phenomenon has been studied only sporadically in North American shrews. So, we studied the masked shrew (Sorex cinereus) in the Southern Appalachian Mountains of North Carolina for two years. This species weighs 2-5 grams and is active all winter.

Called “Dehnel’s Phenomenon”, this was first observed by the naturalist August Dehnel in 1949.

en.wikipedia.org/wiki/August_...

Mammals make it through the tough times in different ways. Some hibernate, some use torpor (short bouts of inactivity), and some even migrate to new areas. Red-toothed shrews do something totally different – they shrink their bodies to reduce total energy demand.🤔