Warm as a snake's belly on a sun-baked trail

Warm as a snake's belly on a sun-baked trail
John C. Lorson

Stretched flat and taking its good, old time, this harmless and docile eastern milk snake is using the warmth of the sun’s rays stored in the thick asphalt of the bicycle trail to raise its own body temperature in anticipation of a cool autumn night. An ectotherm, the snake depends on its surroundings to modulate its own body temperature.


Our grandson was at our place last weekend, and when he’s in town, the rest of the world takes a pause while “Gee-gee” and “Papa” do backflips all day to keep the 18-month-old entertained.

When his parents finally packed him up midway through Sunday afternoon to head for home, I waved them out of the driveway, took 10 steps toward the house and laid down in the glow of a sunbeam on the concrete patio. Within seconds I drifted away right there on the warm slab. Two hours later I woke up with ants in my hair, but the deathlike slumber that had come before was pure, sweet therapy. There’s nothing like a warm spot on a cool sunny day to recharge the batteries.

Imagine now that your own body temperature corresponded to whatever the climate and conditions had to offer on any given day. A warm, sunny afternoon would be a delight with all your biological systems running optimally. A cold, gray October morning, however, would leave you every bit as cold and gray as everything around you. Such is the life of an ectotherm. They run at the temperature of their surroundings.

Amphibians (frogs, toads, salamanders), reptiles (lizards, snakes, turtles) fishes and the entire spectrum of invertebrates (insects, earthworms, snails) are all ectotherms and are therefore at the mercy of the seasons here in the American Midwest.

A common misconception of ectotherms is they are utterly defenseless against the fickle thermal whims of Mother Nature. This is only true in a very general sense, as one trait most individual animals possess is the ability to move in the direction of comfort or advantage. Small movements can sometimes yield big results. For instance, if a painted turtle is uncomfortable in the chilly waters of the springtime marsh, it can climb onto a sun-soaked log, and in minutes that very act can work to raise the beast’s body temperature by 10 or 20 degrees with its own metabolism and mobility rising right along with it.

Autumn is a good time of year to keep in mind the desire of our cold-blooded friends to find warmth in the strangest of places. That snake you find curled up next to the foundation of your house is likely just working on keeping itself from going full chill in the cool overnight hours. Similarly, a snake stretched across the trail or roadway late on a crisp October afternoon is simply soaking up the noonday’s sun baked in the black asphalt. Give them a moment to clear the way, and everyone can get on with their own thing.

I’ve seen some very “snakey” days in the past couple of weeks as the overnight temperatures dumped from a bright daytime high of 80 F down to the clear and silent mark somewhere in the mid-40s. Weather like that brings snakes to the trail like cats to an open tuna can. One particular beauty I came across recently was a fully 3-foot-long eastern milk snake.

A beautiful mix of color and pattern, the tan, brown and black reptile was mistakenly named when its tendency to show up in dairy barns was misconstrued. The snake wasn’t seeking milk but rather the ever-present concentration of mice and rats to be found anywhere livestock feed is stored or consumed. The dairyman that kills a milk snake does himself a great disservice as the species is a top-notch mouser, killing by silent stalk and constriction, and is typically more than happy to simply move along when approached by humans or other such potential ill-doers.

The snake I encountered was stretched straight across the trail with its checker-board belly flattened out on the tarmac, soaking up as much stored sunshine as it could. It posed for a brief photo shoot before winding its way off the trail and under a fallen tree for the night.

There’s no shame in taking a moment to recharge your batteries. Whether a snake on a trail or a grandpa on a patio, a warm spot on a cool day is balm for the soul.

Remember, if you have comments on this column or questions about the natural world, write The Rail Trail Naturalist, P.O. Box 170, Fredericksburg, OH 44627, or email jlorson@alonovus.com. You also can follow along on Instagram @railtrailnaturalist.

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