Common Shrew

The common shrew's carnivorous and insectivorous diet consists of insects, slugs, spiders, worms, amphibians and small rodents. Shrews need to consume 200% to 300% of their body weight in food each day in order to survive; to achieve this they must eat every 2 to 3 hours, and they will starve if they go without food much longer than that. They do not hibernate because their bodies are too small to store sufficient fat reserves and they have a short fasting duration. Common shrews have evolved adaptations to survive through the winter. Their skulls shrink by nearly 20% and their brains get smaller by as much as 30%. Their other organs also lose mass and their spines get shorter. As a result, total body mass drops by about 18%. When spring returns, they grow until they reach roughly their original size. Scientists believe that low temperatures trigger their bodies to break down bones and tissues and absorb them. As temperatures start to rise with the onset of spring, their bodies start to rebuild the lost bones and tissues. This ability to shrink their bodies significantly reduces their food requirements and increases their chances of survival in the winter. …