Subnivean Life: A World Beneath the Snow

                                 Definition of “subnivean”:                                 the zone in or underneath the snowpack. 

Entrance hole in the snow.
Entrance hole in the snow. Photo by Patty Wakefield, OPRHP.

During the winter months when the temperatures fall into the single digits or below zero, and snow covers the landscape, survival in such harsh conditions is often challenging. Have you ever thought about the small mammals that reside in the fields along some of our country roads? One of those critters is the meadow vole (Microtus pennsylvanicus); which means small ears of Pennsylvania. The meadow vole is an integral part of the food chain for many prey species such as the red-tailed hawk (Buteo jamaicensis) and the red fox (Vulpes vulpes).

Meadow vole Photo courtesy of www.fcps.edu.
Meadow vole Photo courtesy of http://www.fcps.edu.

How do they survive? Meadow voles form runways or paths in dense grass in fields and/or wooded areas in the spring and summer months. You can see evidence of these tunnels by entrance holes.

Grass entrance
Entrance holes. Photo courtesy of http://www.pbase.com.

 

Grass Tunnels
Tunnels. Photo courtesy of http://www.pennlive.com.

These runways allow the meadow voles to forage, reproduce and survive while protecting them from predation. Meadow voles also dig shallow burrows where nests are constructed. During the winter months, the tunnels are under the snow.

Tunnels1

 

The snow actually works as an insulator to help protect them from the cold.

Tunnels2
Evidence of snow tunnels (2 images). Photos by Patty Wakefield, OPRHP.

Meadow voles often eat the green basal (bottom) parts of grass, berries and the cambium (under bark) of small saplings and bushes.

Tree damage
Sapling chewed by voles. Photo courtesy of http://www.tlehcs.com.
Cute voles eating
Voles eating berries. Photo courtesy of http://www.mnginteractive.com.

 

Next time you take a walk in a State Park see if you can find traces of these remarkable little winter warriors. The beauty and wonders of nature is all around us. We need just take the time to observe and see what we can see.

Post by Patty Wakefield.

 

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s