Woodland Jumping Mouse – LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED

For many species of terrestrial vertebrates living in the lower Susquehanna valley, it’s time to take refuge in a safe place below ground to enter a winter-long slumber. The numerous frosty nights of the past two weeks have expedited the stragglers’ efforts to find a suitable place to pass our coldest months.

Wood Turtles — Aside from the Eastern Box Turtle (Terrapene carolina carolina), the Wood Turtle (Glyptemys insculpta) is our most terrestrial species of testudine, however it is seldom found far from wet bottomlands. Last week, we found this pair preparing to burrow into alluvial soils along the edge of a floodplain wetland where they will spend the winter. In recent years, Wood Turtle numbers have plummeted due to habitat fragmentation and loss, and due to collecting by short-sighted petkeepers and profiteers.

A sluggish Wood Turtle catching a few last rays of sunshine before digging in for the winter. If you encounter these or any turtles now or at any time of year, it’s important that they not be disturbed. Look and leave them be.

And now, just in time for Halloween, a look at some hibernating species that some of our more squeamish readers consider to be “scary”.

In the mountainous forests of the Ridge and Valley Province, there lives a seldom seen little mouse which, unlike the more familiar species found in the fields, farms, and homes of our valleys and Piedmont, spends almost half the year in true hibernation.

The Woodland Jumping Mouse (Napaeozapus insignis) is a nocturnal species of rodent found primarily on rocky forest slopes, particularly those with growths of Eastern White Pine and Eastern Hemlock. Unlike the similar White-footed Mouse, a species that sometimes enters homes in the fall and remains active year-round, the Woodland Jumping Mouse builds a small subterranean nest among rocks and boulders where it will enter a long winter slumber, often not emerging until the milder days of April. During the long hibernation, these mice sometimes fatally diminish the energy stored in their body fat; up to 75% may perish before spring arrives (Merritt, 1987).

In spring and fall, Eastern (Black) Ratsnakes are frequently seen basking in the sun as they absorb heat and get their metabolism going. During the hottest days of summer, when ambient air temperature is sufficient for their needs, they become nocturnal, hunting mice and other creatures that are also active at night. During October, they make their way back to a winter den where they will remain until March or April.

Eastern Ratsnake — A last-minute Eastern (Black) Ratsnake makes a slow late-October trek across a mountain road toward a winter den on the south slope of the ridge.

That’s right, all three of these snakes are known to cohabitate, not just during hibernation, but at other times of the year as well. And you thought they were mean and nasty to anything and everything in their path, didn’t you?

Here in the northeastern United States, fear of indigenous wild snakes is a totally irrational anxiety. It’s a figment of our indoctrination. Their wicked reputation is almost exclusively the result of a never-ending stream of demonizing propaganda from the pulpit, press, parents, panicked, and picture shows. All they want from you and I is to be left alone. Want something to really be afraid of this Halloween? Try domestic dogs. That’s right—the “friendly” pooch. In the United States, they’ll land hundreds of people in the emergency room today. Don’t like that one. How ’bout cars and trucks. They’ll kill and maim people all day long. And don’t forget about sugar. Yes friends, that sweet treat is pure poison that kills all day long. Happy Halloween!

SOURCES

Merritt, Joseph F. 1987. Guide to the Mammals of Pennsylvania. University of Pittsburgh Press. Pittsburgh, PA. pp.230-233.

Shaffer, Larry L. 1991. Pennsylvania Amphibians and Reptiles. Pennsylvania Fish Commission. Harrisburg, PA.

Category: Woodland Jumping Mouse

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