Although commonly known for their famous appearance in the movie “The Killer Shrews,” short-tailed and long-tailed shrews are not dangerous… to humans. With their thirty-two razor-sharp teeth and venomous neurotoxin, hunting insects, earthworms and even small mammals is possible. However, because of their extremely fast metabolic rate (their highest recorded heartbeat is 1200 beats  per minute), they constantly have to hunt and do not hibernate during the winter. Normally, shrews eat almost half of their body weight in order to maintain themselves. This is especially difficult when raising young.

The mating season for shrews is generally from March to September. This can be determined by the different scents and high-pitched squeaks and twitters that are used to communicate with each other. There is a 50/50 chance that mating will occur; if the female is not ready, the pair will ultimately fight. If mating does occur, the gestation period tends to be around twenty-four days, which results in three to eight offspring. These offspring will then live a long life of two to three years if not hunted by predators. 

This information is based on the average shrew’s life, but each individual species of shrew generally follows this information with small adjustments. The main difference between the shrew groups is their naming. For example, in the Carleton Arboretum, two of the shrew species present are the short-tailed and the long-tailed shrew. In general, these two species of shrew are identical. However, the short-tailed shrew has a tail length of 1 to 1.5 inches, while the long-tailed shrew has a tail length of 2.2 to 2.5 inches. Determining the difference between these two lengths is next to impossible unless you have a ruler and a stationary shrew. 

In the Carleton Arboretum, shrews can be found in moist areas where the dirt is easily moved. Due to their small size, shrews rely on other organisms in the Arb for access to underground burrows. Their tail helps them maintain their balance while they traverse through mossy rocks and other bumpy surfaces (more information regarding any species of shrew can be found on https://www.dnr.state.mn.us/). 

• Jose Ortega 25’