Big Sky Blog

A Montana Fish, Wildlife & Parks crew prospecting for small mammals made a landmark discovery earlier this month, documenting an animal previously unknown in Montana.

The big short-tailed shrew, a voracious insect-eating predator that could easily fit in a shirt pocket, was discovered on a federal waterfowl production area northeast of Plentywood, about 90 miles farther south and 60 miles farther west than its previous known range in North Dakota. The discovery makes the big short-tailed shrew the 109^th mammal documented in Montana, and the eleventh shrew species in the state.

Shrews are among the most prodigious predators in the world. They eat primarily insects, mostly spiders, caterpillars and earthworms, but will feed on small vertebrates as well. The big short-tailed shrew is the only poisonous mammal in North America. It injects a debilitating poison through grooves in its teeth.

“Shrews are amazing animals,” says FWP native species biologist Ryan Rauscher, whose crew discovered the big short-tailed shrew. “They have an incredibly fast metabolism which requires them to eat one to two times their own body weight every day. Their average life span seldom exceeds a year and a half.”