The North American short-tailed shrew, genus Blarina, is the giant shrew of its family. There are three species of the short-tailed shrew: the northern Blarina brevicauda, the southern Blarina carolinensis, and Elliot’s Blarina hypophagia.
The genus Blarina is classified as “true shrews” from the family Soricidae, belonging to a larger mammal group known as Eulipotyphla.
Where Can You Find North American Short-tailed Shrews?
Short-tailed shrews can be found all over central and eastern North America. They make their homes in southern Saskatchewan to the Atlantic provinces of Canada and south to northern Arkansas and Georgia. They are found from southern to north-central Canada and from the northeastern United States to eastern Texas and Florida.
They are the most common shrews in the regions around the Great Lakes. They live in disturbed and undisturbed habitats, such as old fields, grasslands, fencerows, marshes, and deciduous and coniferous forests, and can also be found in household gardens. The habitats shrews prefer are moist and have leaf litter or are thick with plant cover.
Male shrews are more significant than females, particularly in the size of their heads compared to their bodies. They look robust and about the size of a meadow mouse. Their snouts are shorter and more substantial than those of other shrews. The tails are fast, they have small eyes, and their fur hides their ears.
How Does The North American Short-tailed Shrew Communicate?
Short-tailed shrews have poor vision and can only detect light and dark. They rely on sound reflections like ultrasounds to find their way about and get food. In this way, they can distinguish between objects found in their environment.
By sending out these ultrasounds, they listen for returning echoes. Their sense of touch is also very refined, and they get great help when looking for predators with their very sensitive whiskers. When communicating, they use many different sounds, among them twitters, chirps, and buzzes.
How Active Is The North American Short-tailed Shrew
They are incredibly active and known for consuming vast amounts of food. Their bodies require constant nutrition for them to survive. The shrew is one of the few venomous mammals. These shrews have thick, glossy dorsal fur. The fur can be black, brownish-black, or silvery gray. Their ventral hair is grayer and lighter. Their summer coats are golden and dark brown, and winter coats are thick and pale.
Short-tailed shrews tend to be active throughout the year and can be nocturnal. Their foraging begins after the sun has set but can also be active on cloudy days.
What Is The Habitat Of The North American Short-tailed Shrew
These shrews like to burrow underground through leaf litter or the interface at snow/ground. They can dig 2.5cm per minute in between taking periods of rest. They build their nests beneath logs or underground, lining them with leaves or the fur of a meadow vole. The nests are kept clean with deposit wastes left outside of them. Other parts of their burrow system are for storing food.
Shrews travel above ground, using runways they make through leaf litter and snow in the winter. They spend the rest of their time beneath the ground in burrows they excavate. They might also use tunnels once inhabited by voles or moles.
Their burrows can go down as deep as 50cm. The tunnels are flat on top and bottom. Shrews have powerful front feet that they can dig with, and they’ll kick out any loose soil with their muzzles or hind feet.
Inside these intricate tunnel systems, odorous secretions from their scent glands will mark territories. Their tunnel systems are very complex, and they know how to divide the environment well since they do not live together in groups.
Short-tailed shrews are solitary mammals that, when encountered by other members of their species, will show aggressive behavior. Because of their poor sense of smell and vision, they make up for this when foraging food by picking up reflected sound and their keen sense of touch.
They are carnivores, and their diets consist of insects, earthworms, snails, voles, and other shrews. They also include mice and salamanders in their diets. These shrews eat only a small portion of seeds and fungi.
How Does The North American Short-tailed Shrew Defend Itself?
These shrews are aggressive animals, and the short-tailed shrew will be ready to threaten all intruders. One of their best defense mechanisms is their ability to hide. They burrow into their underground tunnel systems so predators cannot find them.
They also have venom glands in their 32 very sharp teeth. The venom is not fatal to humans but can cause irritation and swelling. When it attacks prey, it kills with a bite or paralyzes it.
Short-tailed shrews also can release a musky and foul-smelling odor on their bellies and sides to keep predators from approaching. Weasels and foxes are often repelled by this odor and won’t attack the shrews.
If you want to know more about the venom of the shrew, I have written this article.
How Does The North American Short-tailed Shrew Mate?
There is not much known about the mating habits of short-tailed shrews. The mating season occurs from March through September, and most female shrews give birth in the early or late part of that period.
Male shrews use clicking sounds to attract females. They have two liters each season, with six to eight young shrews born. Shrewlets are the name for baby shrews and are suckled for 25 days.
The young, when born, are hairless and blind and weigh less than a gram. They become reproductively mature at 2 -3 months, and shrews born in the spring tend to mature more quickly. They will reproduce in the same year they were born.
What Are The Predators Too The North American Short-tailed Shrew?
In the areas where shrews make their homes, the predators they have to look out for include owls, snakes, raptors, canids, cats, skunks, raccoons, trout, and opossums.
The main threat that the short-tailed shrew faces are the destruction and degradation of their habitats due to urbanization and agriculture. They can suffer due to the loss of woody debris and soil dryness or when marshy areas are drained. Another threat they face is an increase in the feral cat population.
What Is The North American Short-tailed Shrews Role in the Ecosystem?
Short-tailed shrews are very abundant in the habitats where they make their homes. By eating vast quantities of invertebrates, they control the amount of the invertebrate population. However, they are also a prey species, with owls as their main enemies.
Shrews help humans by ridding regions of insect crop pests like the larch sawfly. They’ll also destroy mice and snails, keeping them from damaging crops.
Unfortunately, humans have to be careful not to be bitten by shrews. The venom from their glands can cause severe pain to a human, but this happens only when someone attempts to handle a shrew.
Want to know more about shrews? Find out here in 101 facts I have written about shrews.
Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.