Nature At Risk: North American Least Shrews In Monroe County

By Carol Hillestad for the Brodhead Watershed Association

We humans love to be awed by size. The blue whale, for instance. It’s the largest animal that ever lived on the planet. Its heart — just its heart! — weighs more than half a ton.

At the other end of the scale, consider the North American least shrew. At birth, they weigh basically nothing — about as much as one pea. Full-grown, an adult is about three inches long and still weighs less than a nickel.

But these little guys are bundles of energy. Their hearts beat faster than a hummingbird’s, up to 1,300 times a minute. 

They eat their own weight in insects every day. They have to capture food every 15 to 30 minutes around the clock, so they sleep just a few minutes at a time. 

If you had their metabolism, you’d have to eat 195 pounds of food a day.

With an appetite like that, least shrews (Cryptotis parvus) are good at keeping caterpillars, beetles, centipedes, slugs and sow bugs in check — a good thing in any garden. 

In commercial agriculture, they are important economically, destroying insects and slugs that harm crops. Beekeepers are not fond of least shrews, however, since they can take up residence in a hive and eat all the larvae. 

In their turn, least shrews are part of the food chain for larger predators like owls and hawks, though mammals shun them for their musky smell.

You may never have seen a least shrew. They were once common in our area, though, back when the Poconos had been clear cut in the 1800s and through the 1960s, until the woods grew back. 

Least shrews prefer grassy, shrubby, overgrown fields, and so today are rarely seen here. 

Though local isolated groups of least shrews may exist, only three populations have been confirmed in York and Adams counties since 1990, when they were classified as endangered and protected in Pennsylvania.

Then again, you’ve probably never seen a blue whale, either. But isn’t it grand to know our world is still big enough to contain creatures as wondrous as these?

Click Here to learn more about the Least Shrew.

For more information on programs, initiatives and other upcoming events, visit the Brodhead Watershed Association website or Follow them on Facebook.  Click Here to sign up for regular updates from the Association.  Click Here to become a member.

Related Article:

-- Protecting Clean Water Together: Talking Dirt And Downpours In Monroe County - By Carol Hillestad for the Brodhead Watershed Association  [PaEN]

[Posted: August 29, 2023]  PA Environment Digest