Featured Creature: Smooth Greensnake

"Smooth Greensnake" by amdubois01 is licensed under CC BY-NC 2.0.

Which creature is nonvenomous, changes color throughout its lifetime, and is native to the Nearctic region? 

The Smooth Greensnake! (a.k.a. Grass Snake) 

“Smooth Greensnake” by amdubois01 is licensed under CC BY-NC 2.0.

During Memorial Day weekend several weeks ago, I went on a camping trip with my partner and two friends, Sophie and Griffin. Griffin has a special affinity for snakes, and so as we went on hikes through nearby trails and explored the campground, we also searched for snakes. (Excitingly, we sighted several throughout the weekend!) Over those several days, I also learned a lot from Griffin about various types of snakes and how to find them. I admired his enthusiasm and knowledge about snakes, because such a love for an often villainized creature is rare to find. 

One night, as we were sitting around the campfire, Griffin shared with us an especially cool species called the smooth greensnake. As he held up a picture of the snake on his illuminating iPhone, I immediately wrote down the species name so that I could write a Featured Creature about it as soon as I got home. So, without further ado, let’s explore the world of the smooth greensnake!

A gem of the snake world

The scientific name for the smooth greensnake is Opheodrys vernalis. “Opheodrys” is the name of the genus for the group of snakes called “greensnakes” and “vernalis” stems from the Latin word “vernus,” which means “of the spring.” 

As you can see from the picture above, the smooth greensnake is a striking creature. Measuring between 14-20 inches long, this thin snake has no markings, only a stunning emerald green color. The snake’s dorsal, or back, is typically a bright shade of green, and the underbelly is white or light yellow. The scales are very smooth, hence the species’ common name. Juveniles of the species sport a blue-gray or olive green color before growing into a stronger green color in adulthood. The shade of color in adulthood also differs slightly depending on the geographic location. For example, smooth greensnakes in Kansas have a bluer color than their olive-colored counterparts in Texas. Their coloration helps them camouflage into their surroundings!

After death, the smooth greensnake quickly turns blue or blue-gray again, like it was in adolescence. According to Maine.gov, this is because the green is created by a yellow pigment produced inside the snake’s scales. On the other hand, the blue color is a result of the scale shape. Together, the blue and yellow create the smooth greensnake’s distinctive tone.

Grassland Dweller

The smooth greensnake is native to the Nearctic region, which encompasses nearly all of North America. The largest concentration of smooth greensnakes is in New England, with other isolated and scattered populations found throughout the U.S., Canada, and some of Mexico. There are three subspecies: the eastern, western, and northern greensnake. No matter the geography, smooth greensnakes enjoy a specific habitat consisting of grassy areas such as meadows, mountain clearings, lawns, gardens, or grassy wetlands. If it has grass and a moist environment, chances are the smooth greensnake will love it! As a result, this species has been found in urban, suburban and rural areas. 

Smooth green snake at Cedar Creek Ecosystem Science Reserve, Minnesota” by Lorie Shaull is licensed under CC BY-SA 2.0.

Day to Day Life

The smooth greensnake has a solid phenological cycle (that is, a predictable pattern of behavior in time aligned with its ecosystem). When the New Year holiday comes around in January, the smooth greensnake can be found in a burrow underground with fellow snakes, where it has been since October and will stay until April. 

When the snakes emerge from hibernation in the spring, mating season begins to take place. The smooth greensnake usually mates throughout the spring and summer months. In late summer or early fall, smooth greensnake females lay their eggs under rocks or in the sand. Juveniles will typically hatch in clutches of 3 – 13 eggs by mid-fall. 

According to iNaturalist.org, “When it hunts, it turns its head from side to side, finding prey with its tongue and an organ on the roof of its mouth that interprets chemical signals. It has no ears, relying on vibrations to figure out its surroundings.” It can also swallow larger prey in their entirety. 

A Gentle Disposition

Not all snakes are aggressive, and the smooth greensnake is the perfect example of this. They are non-venomous and rarely attack humans. If you come across a smooth greensnake, it is very likely that they will try to escape quickly without causing harm. (However, it is important to always remember that any animal may become aggressive if they feel threatened.) 

The smooth greensnake likes to spend its days sunbathing on rocks or logs. It enjoys nice meals of insects, spiders, slugs throughout the day as well. Controlling insect populations is a huge ecosystem service that smooth greensnakes provide, in addition to serving as prey for animals like hawks, raccoons, foxes, and even larger snakes. Everyone has an important role to play in the food web!

Unfortunately, human alteration of the landscape, as well as the use of pesticides, has negatively affected the smooth greensnake population by eliminating its habitat. Luckily, states are beginning to recognize the declining numbers and important ecological role that the smooth greensnake has. It is currently a protected species of concern in Iowa, Missouri, Indiana, Michigan, North Carolina, Montana, Texas, Wyoming, Nebraska, and Colorado. 

What’s your favorite fact about the smooth greensnake? Would you like to receive more Featured Creatures about snake species in the future?

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