Endangered Snakes Find A New Home At MacLeish

Picture a ten-foot by eight-foot hole, five feet deep, filled with rocks and logs in such a way that there are gaps between them. Three tunnels, made of clay roofing tiles, connect the hole's depths to the surrounding hillside. Flat rocks surrounding the hole warm in the winter sun.

Courtesy of Sarah Gygax ’28. Watercolor cross-section of the hibernaculum by Sarah Gygax ’28.

This likely does not sound like the best place for rest, unless you are an eastern ratsnake. 

Smith College students Alex Blaszczyk ’27 and Sarah Gygax ’28, along with Paul Wetzel, manager of MacLeish Field Station, built this structure, known as a hibernaculum, to provide a safe space for eastern ratsnakes to spend the winter at MacLeish. The hibernaculum was built in November of this past year as part of Smith's course IDP 218: Natural Resource Conservation and Restoration. 

As part of the course's final, students had to design a restoration home. Gygax joined forces with Blaszczyk to design a hibernaculum for the eastern ratsnake.

Eastern ratsnakes are native to the Eastern United States and are the longest snake species native to Massachusetts, with some exceeding 80 inches in length. They are characterized by their shiny black scales with traces of white skin and muscular bodies in adulthood. Eastern ratsnakes are non-venomous, and as their name suggests, very important in controlling rodent populations. 

“Eastern Rat Snake” by Animalia, available under CC BY-ND 3.0

MassWildlife’s Natural Heritage & Endangered Species Program classifies the eastern ratsnake as endangered in Massachusetts. Gygax highlighted habitat fragmentation, such as major roadways cutting through the landscape, as a large contributor to its endangered status. In addition to the danger of snakes being run over, smaller areas of habitat support fewer snakes because of limited food and resources. 

Eastern ratsnakes also face poaching. It is illegal to own or capture the eastern ratsnake in Massachusetts, but the large and docile snakes are sought-after pets. Because the eastern ratsnakes tend to return to the same hibernacula year after year, they are easily targeted by poachers.

Brumation is a similar state of dormancy as hibernation. Snakes enter a period of low activity during brumation, slowing their breathing and metabolic activity. Unlike hibernation, they are not in a period of deep sleep and can still move around, especially on particularly warm winter days. Without a place that won't freeze to spend the winter, snakes in colder climates would not survive. 

Wetzel notes that it’s not clear if there is a shortage of locations for the snakes to brumate at MacLeish, and it might take a couple of years before eastern ratsnakes utilize the hibernaculum. Other snakes may also use the hibernaculum. Snakes of many different species might brumate in the same spot. “I think of these snakes kind of intertwined,” Wetzel said with a laugh. “Joe, you’re on my tail!”

Whether or not the eastern ratsnake uses the hibernaculum, Wetzel views the project as a success. “You have to start thinking about what it's like to be the animal itself. [...] what was it going to need? How big should it be? How deep should it be, all that stuff. So that's a good exercise, just for thinking about conservation,” Wetzel said. 

Wetzel received funding for this project through the Mutual of Omaha Wild Kingdom and the National Wildlife Federation, which offers a grant for improving the habitat of threatened or endangered species on a college campus. Because MacLeish is considered part of Smith College’s campus, Wetzel was able to receive the funding.

Next year, the group hopes to add a camera trap facing the hibernaculum to capture the animals that might use it. 

Gygax highly recommends the Natural Resource Conservation and Restoration class. “Looking through the history of land use in the area, identifying problems, creating a plan–it was really, really fun to kind of bring that all together and get to [...] see it in action. And just to get to be a part of a really cool project to protect a really cool species was awesome,” Gygax said. 

By Maggie Sullivan and Lilly Butler