Smooth Greensnakes and Their Fight for Survival



After half an hour of turning stones on a sweltering September morning, beads of sweat rolling down our brows, we decided to switch tactics. Walking alongside a path, we gently moved our feet in a sweeping motion through the vegetation, watching closely for the movement of small animals. It didn’t take long for me to catch my first glimpse of a snake I hadn’t laid eyes on in years. The vibrant green tail was unmistakable as it vanished into the grass. Smooth Greensnakes are easy to lose track of, so I was quick to call my two companions to the scene for help. The more eyes on the ground, the better our odds of catching the snake. Moments later, Rosy had it in-hand, and not 10 seconds after that, she had another. Encountering a Smooth Greensnake is always a treat, but to find two in quick succession is no easy feat. 

Smooth Greensnake posting on the edge of a walking path. Photo by Kiley Briggs

At home in moist grassy fields, meadows, and near the edges of wetlands, the Smooth Greensnake blends in perfectly with its surroundings. Greensnakes even bob their head back and forth as they move, mimicking the motion of a blade of grass fluttering in the wind. This gives them stealth, helping them evade both predators and herpetologists alike. Their camouflage also helps them sneak up on and capture small insects, which make up the bulk of their diet. Their insectivorous nature, however, may play a part in why I don’t see this species very often. 

Smooth Greensnakes blend in very well amongst grass and other vegetation, allowing them to evade predators and sneak up on the small insects that make up the bulk of their diet. Photo by Nick Arms

Anecdotally, I’ve heard from many people in my parent’s generation that they used to see Greensnakes quite often, but rarely, if ever see them today. Data, although limited, backs up such claims. The Smooth Greensnake, it would seem, is in decline, and there are several reasons at play. 

Grassy beaver meadows are great places for Smooth Greensnakes to live. Photo by Kiley Briggs

Wildlife that depend on insects for food face an uphill battle across the entire planet. Insect populations worldwide have dropped drastically in recent decades. Ask anybody who drove a car prior to the mid-2000s and they’ll tell you that the amount of insect splatter they need to clean off their windshield today is nothing compared to how it used to be (and not just because cars are more aerodynamic). This trend even has a name: the “Windshield Phenomenon”. Pesticide use, invasive plants and parasites, meadows being converted to single-species crops, and a multitude of other factors all contribute. As insect populations collapse, so too can the numbers of insect eaters. For example, the numbers of insect-eating birds, such as Nighthawks and Whip-poor-wills, have dropped sharply along with the abundance of their prey. Likewise, it stands to reason that the Smooth Greensnake is also impacted by insect declines.

Farm fields and gardens are also places where Smooth Greensnakes can be found, although insecticides and mowing do pose threats to the species on many farms. Photo by Kiley Briggs

The Smooth Greensnake is also up against habitat loss. As farm fields turn into housing developments and shopping centers, there aren’t as many places for greensnakes to live. Modern agricultural practices also increase the risk of snakes being killed by mowing equipment. Invasive vegetation, such as phragmites (a towering grass also called ‘giant reed’) can overrun native plants along the edges of wetlands, crowding out the snakes. Even reforestation, which is generally considered a very good thing for wildlife, can push greensnakes out of their habitat when abandoned farm fields return to a more natural state. 

The joy on Rosy's face after finding two Smooth Greensnakes seconds apart mirrors my own feelings as well. We were very excited to see this remarkable species. Photo by Kiley Briggs

However, it’s not all bad news.  If you’re lucky enough to live in an area with Smooth Greensnakes, there are steps you might be able to take to help them thrive. Creating pollinator gardens to boost native insect diversity around your home can make a significant difference for all sorts of wildlife. Once the insects are happy, the greensnakes may follow suit. And no, it doesn’t mean you’ll need to deal with more mosquitos or that your home will be crawling with bugs. Although it can be a lot of work, replacing portions of grass lawns with native wildflowers also really helps. Mowing grass less often or at a greater height reduces the chances of the snakes being killed. And, if you manage a larger field and only mow it to stop trees and shrubs from establishing, mowing late in the fall after the snakes move underground for the winter will keep them safe (late October in New England). While these actions alone may not save the species, they can make a meaningful impact on Smooth Greensnakes in your neighborhood. Many other wildlife species will benefit as well.

Despite concerns that the habitat or Smooth Greensnake population may have changed since my last visit to the site over 10 years ago, it was comforting to know that the habitat and greensnakes on-site were about the same as I remembered. Photo by Kiley Briggs

When we made plans to visit the reservoir to search for greensnakes, I wasn’t sure what to expect. I know the spot very well, having grown up nearby. It was the first place I ever saw a Smooth Greensnake, and it is the only place I have ever been able to find them reliably. I hadn’t been back in over 10 years, however, and with the species in decline, I prepared myself for the possibility that the snakes might be gone, or too scarce to find. I would have been happy to find just one Smooth Greensnake that day, but to our delight, we found four. Knowing the Smooth Greensnake is still doing ok at this very special site was quite heartening. To say that it made my week would be an understatement.