August Dehnel

August Dehnel (1903–1962) was a Polish zoologist. He is credited with discovering that the braincase of shrews shrinks significantly over the winter and expands again in the spring. This fact, which he published in 1949, has come to be known as the Dehnel phenomenon. It affects not only the brain, but also other major organs such as the liver and kidneys. This factor explains why such small animals can survive harsh winters with associated reduction in food availability. The phenomenon may be responsible for the preservation of certain rare populations such as the Suisun Shrew.