The Eastern RatSnake: Vermont's Native Snake
What do ancient Egyptians, indigenous North Americans, and Christians around the world have in common? They all share stories and myths involving one of nature’s most valuable predators: the snake. These legless reptiles appear in culture and religion around the globe, fulfilling every role from shape-shifter and tempter to protector and giver of life. They may be viewed as a gateway to immortality, a healer of the land, and a protector of the earth.
At Southern Vermont Natural History Museum, we house a number of non-venomous snakes as education ambassadors, including one species native to Vermont, the Eastern Ratsnake (also known as the Black Rat Snake). Ember, our full grown Eastern Ratsnake, was an unwanted pet who was most likely bred in captivity for the pet trade, making her unsuitable for release into the wild.
The largest snake species in Vermont, these animals can reach 5 to 6 feet in length when full grown. The longest Eastern Ratsnake thus far recorded in the wild in Vermont measured 75 inches - just over 7 feet - from nose to tail! When full grown they display a thick, strong black body with a white and black checkerboard abdomen that fades to gray towards the tail.
Here in Vermont, the juveniles, which measure about 12 inches in length when they hatch, are grayish tan in color with dark blotches. They are sometimes mistaken for the Eastern Milk Snake, another native non-venomous snake. As the Eastern Ratsnake matures, their light grayish tan areas darken, obscuring the pattern of their youth. In the right light, this patterning may still be seen in fully grown snakes, and is often visible in their shed skins. Like all snakes, the Eastern Ratsnake sheds its skin an average of three of times a year. Shedding allows them to lose dead skin cells, parasites, and even some infections that they may have acquired.
When daytime temperatures consistently drop below 60 degrees, the Eastern Ratsnake makes its way to a hibernaculum, where they will spend the cooler seasons. Yet these animals do not truly hibernate - they brumate, a similar activity in which their metabolism drops very low, and they snooze away, emerging now and then on warm, sunny days for a quick drink or bite to eat.
As the days lengthen and the warmth returns to our region - usually between March and May - Ratsnakes will emerge from their winter dens. They will seek out mates between late May and mid-June. About five weeks after finding a mate the females will lay 12-20 eggs in a warm hollow under a log, or perhaps in an abandoned rodent burrow. Ten weeks later, the young will hatch from their eggs and begin to make their way in the world.
Ratsnakes and Their Prey
Independent from the time they hatch, the young snakes strike off on their own to find prey suitable for their body size, usually dining on tree frogs, lizards or young mice until they are big enough to tackle larger prey like full sized chipmunks. Using specialized scales on their abdomen they are even able to climb trees to raid the nests of songbirds. A constrictor, the Eastern Ratsnake will wrap coils around its prey and compress it tightly until its heart stops beating.
Although many of us were taught that the snake dislocates their jaw to swallow large prey, their mouths really are just much more flexible than our own, with looser ligaments and more joints in their jaw than mammals. This marvelous jaw with its specialized quadrate bones allows them to swallow prey that may even be larger than the width of their head. Since they are non-venomous snakes, they lack the frontal fangs of their venomous cousin the Timber Rattlesnake. Instead, they use rows of specialized backward facing teeth and their muscular bodies like a conveyor belt to pull and push their prey down into their stomach where strong digestive acids break down their meal.
They will not strike at something as large as a human unless provoked - we are clearly much too big to be dinner, and are really not worth their energy. Like any wild animal, a snake will bite if harassed, provoked or injured. Although the bite of a non-venomous snake is not usually any worse than a cat scratch, it’s important to give wildlife the space to be wild. The best defense against having a "bad day” with a snake? Let them go on about their business, and you go on about yours!
Not aggressive by nature, Eastern Ratsnakes will flatten their head, hiss, coil up and even vibrate their tail creating a rattle-like sound when they feel threatened. But their best defense may be a musk gland located at the base of their tail - the very pungent musk scent mimics the aroma of many poisons found in nature, discouraging a predator from continuing an attack.
Snakes use their tongues to “smell” the air around them in their search for prey or to warn them of the presence of danger. Their forked tongue flicks scents into the back of their mouth where a specialized organ called the Jacobson’s organ sits. Lots of animals have a version of this organ, including many mammals - if you have ever seen your pet house cat with their mouth open, huffing lightly to pull surrounding air across their tongue, you have seen the Jacobson’s (or vomeronasal) organ in action! Although we refer to this action as “smelling”, what really takes place is a complex chemical interaction between compounds in the air and specialized parts of the animal’s brain.
Venomous vs Poisonous
Eleven species of snakes inhabit Vermont, with only one classed as venomous - the Timber Rattlesnake. To help remember the difference between venomous and poisonous it helps to think of them in this way: if something is poisonous, it will hurt me if I eat or touch it - think poison ivy or mistletoe berries. But if something bites or stings me and hurts me (like a honey bee or a black widow spider) then it is venomous, not poisonous. Compared with their ancestors, these rare venomous rattlesnakes now inhabit a small fraction of their original habitat, and have suffered losses of up to 85% of their total peak population across the region.
Sadly, a similar fate has followed many other of our native snake species - and four Vermont snake species are considered Species of Greatest Conservation Need: the Eastern Ratsnake, Eastern Ribbonsnake, North American Racer, and Timber Rattlesnake. All snakes in the state of Vermont are considered important, and any sightings of any species should be reported to Vermont Fish and Wildlife. Location of the sighting, pictures from a safe six-foot distance if available, and the date and time of the sighting help researchers and wildlife managers keep track of these vitally important animals.
Removed from human interpretation, these reptiles are a necessary part of what keeps our ecosystem in balance. As rodent specialists, we need their presence to help control mouse and rat populations. And as a prey species, snakes provide valuable food sources for other animals, such as hawks and owls, foxes, and raccoons.
But the biggest threat to snakes in the wild is not other wildlife - it is us! Wild snake populations face severe challenges, including persecution and poaching for the black market by humans, habitat destruction caused by human expansion and climate change, and sickness in the form of the newly emerging Snake Fungal Disease. First noted in 2006 in a population of closely monitored Timber Rattlesnakes in southern New Hampshire, this rapidly spreading and often lethal infection has now been identified in many reptile species all across the eastern United States. It is believed that the loss of up to 85% of their population has so decreased their genetic diversity that reptiles can no longer fight off this disease as they once might have.
Stop by the museum (check website for opening hours) to get an up-close and personal look at our resident Eastern Ratsnake, Ember!