Nature Notes

Who’s afraid of snakes these days? Many people, it seems. The snakes in our area are harmless (unless you’re an earthworm, frog, mouse, or other small creature), yet some people still feel an urge to “kill it!” There’s no need for that. Not only are our local snakes harmless, but like so many other wild animals, they prefer to avoid people. A snake that you spot is likely to be moving away from you, or staying put and minding its own business.

Snakes seem less scary when you know something about them and how they behave. In Westborough and nearby towns, people are most likely to encounter a common garter snake (Thamnophis sirtalis) or a northern water snake (Nerodia sipedon). These snakes are around from March to October, but hibernate in the winter.

You might find a garter snake in your garden or along a trail through woods or fields. Adults are usually 1-1/2 to 3 feet long, with three long, yellow stripes on a dark background. Earthworms, toads, frogs, insects, and mice are their main food.

You might see a northern water snake in a wet area – a pond, stream, wetland, or even a culvert – either on land or in water. Adults are typically 2 to 3-1/2 feet long and several inches around. They’re generally dark-looking – gray, brown, or black – with a light underside. They’re usually patterned with bands that are wider than the spaces between them. The pattern can be difficult to see, but less difficult if the snake is in water. They swim well and typically eat fish and frogs.

We hear that snakes are “cold-blooded,” which simply means that they don’t generate body heat to keep themselves at a certain body temperature the way we humans, other mammals, and birds do. Instead, snakes rely on behavior to warm up or cool off. (We too behave in ways that warm or cool us, but that’s not the main way for “warm-blooded” creatures to regulate body temperature.) You might see a snake basking in the sun to warm up (like butterflies and turtles do), perhaps on warm rocks. Sometimes snakes gather together in a warm place. You might spot water snakes doing this on shore on a cool day. It’s nothing to fear. When it’s hot out, snakes seek cool, shady places, perhaps under a rock or in a hole in the ground.

Snakes are predators, but when it comes to hunting, our local snakes are not interested in us. They might be attracted by mice, slugs, and various insects that frequent human surroundings. They hunt by scent and by sight. Have you seen a snake, perhaps a small garter snake, flicking its forked tongue in and out? This might look scary, but the snake is just using its sense of smell. Again, nothing to fear. It’s sampling the air with its tongue, then touching its tongue to the roof of its mouth to deliver the sample to a specialized scent organ there. The slightly different scent information from the two forks of its tongue helps the snake to locate what it smells, much as differing information from our two ears helps us to locate the direction of a sound.

Snakes are also prey, especially for birds. Just as robins capture and swallow worms, larger birds – hawks, owls, herons, wild turkeys, crows – catch and eat snakes. By staying hidden and camouflaged by their patterning, snakes avoid becoming bird food. Other animals, including raccoons, foxes, opossums, skunks, snapping turtles, large fish, other snakes, bullfrogs, dogs, and cats, also take snakes. If captured, most snakes, including our local snakes, defend themselves by thrashing and releasing foul-smelling liquid from their back end onto their captor (much as toads do). They may also try to bite.

When it comes to reproduction, garter snakes and water snakes mate in the spring soon after coming out of hibernation. If you spot a garter snake sliding across a trail with a couple of smaller ones in seeming pursuit, you may be witnessing males following a female. Nothing for us to fear.

Garter snakes and water snakes give birth to live young in late summer. Garter snakes typically bear 12-40 young (5-8 inches long), water snakes 20-40 young (6-12 inches long). The young are on their own right away, although they may follow their mother’s scent trail. They risk becoming bird food for blue jays, crows, or robins.

There are fun facts to know about our snakes. They can climb shrubs and trees. Snakes have only one lung in their slim bodies. They’re not slimy. Some snakes, such garter snakes, have smooth scales. Others, such as water snakes, have rough scales known as keeled scales. Snakes’ eyes are protected by a clear scale, and snakes don’t blink. Our local snakes have only tiny teeth (no fangs!) which they use to grip prey as they swallow it whole.

What about other snakes? Massachusetts has 14 native species of snakes. Of these, the only two venomous snakes (not found around here) are the timber rattlesnake (Crotalus horridus) and the copperhead (Agkistrodon contortrix). These two are exceedingly rare and listed in Massachusetts as “endangered,” making it Illegal to harass, kill, collect or possess them.

This season, consider yourself lucky if you see a garter snake, water snake, or other harmless snake. There’s nothing to fear, but respect the snake. As with other wild animals, don’t try to corner it, touch it, or pick it up. These actions would be threatening to the snake (how would you feel and react if a stranger tried to corner, touch, or grab you?) Leave it in peace. To identify a snake, check the UMass guide, Snakes of Massachusetts (http://www.masnakes.org/guide.html).