Northern Short-tailed Shrew
Description & Range:
Short-tailed shrews aren’t much to look at. They have beady eyes, pointed noses and a dark grayish body with a stumpy tail. They are the largest shrews in North America, clocking in at a whopping 4.3 to 5.5 inches in length. These tiny
critters require respect, though, as they are the only venomous mammals in the
United States! The saliva of these little beasts packs a potent punch to its
prey in the form of a neurotoxin. Short-tailed shrews can be deadly to animals
as large as frogs and small rodents, but they are not dangerous to humans or
domestic animals. Short-tailed shrews still can deliver a sharp bite if handled,
Short-tailed shrews can be found throughout Maryland as well as much of the
eastern United States and southern Canada.
The short-tailed shrew is one of the most common mammals in the eastern United
States and can be found in forests, fields and backyards.
Short-tailed shrews have a set of 32 teeth adapted for chewing on plants,
invertebrates and other small mammals. Their favorite foods are grubs.
Short-tailed shrews have a voracious appetite and tend to eat up to 3 times
their body weight in food everyday. In the fall and winter, short-tailed shrews
tend to hoard food, and one study found that they cache (store) as much as 87%
of their food.
Short-tailed shrews mate from March through September. After mating, gestation
takes 21-22 days until a litter of 4-7 young are born. The young spend about 25
days in the nest before they are weaned. Short-tailed shrews can later become
sexually mature at 2-3 months of age. Interestingly enough, shrews born earlier
in the mating season mature faster than those born later. Shrews can have up to
3 litters of young per year.
During mating, male shrews will make clicking sounds to court females. Shrews
also make ultrasonic noises, similar to bats, but instead of using echolocation
to find food, they use it to explore their surroundings.
Short-tailed shrews spend much of their time underground or burrowing under leaf litter. Aside from mating, most short-tailed shrews have a solitary lifestyle
and are often very territorial.
During the winter, short-tailed shrews tend to eat 40% more food in order to
maintain their body temperature. Like newborns and hibernating mammals,
short-tailed shrews also possess brown adipose (fat) tissue that also aids the
shrew in maintaining body heat during the cold winter months.