Current Nature: Exploring Nantucket's Snakes
As someone from Ireland, I have never seen a snake, whether or not that’s thanks to the legend of St. Patrick banishing snakes, you decide. When I arrived on Nantucket, I was fascinated to learn that it is actually home to six snake species! These are the eastern garter snake, ring-necked snake, eastern milk snake, northern water snake, eastern ribbon snake, and smooth green snake. The diversity was an interesting surprise.
Snakes often get a bad rap, but the more we learn about and understand them, the more we should appreciate and celebrate them. They are here for a reason! They are part of Nantucket’s ecosystem and play an important role in the food chain. If you noticed less mice around your property this winter, maybe thank a snake for that. If you still aren’t convinced, just remember, that none of the snakes on Nantucket are venomous, and are probably more scared of you than you are of them.
When we think of snakes, one of the first things that comes to mind is their forked tongue. Why do we see it so much? Is it a way of warding off predators? Not quite! Snakes have an excellent sense of smell, and actually use their tongue to smell their surroundings. They have a highly specialised organ called the Jacobson’s organ (or vomeronasal organ) which allows them to smell and taste the air! The snake flicks its forked tongue, collecting moisture-laden scent particles, then retracts it to dip the tips into the Jacobson organ's ducts. The forked feature allows them to sense from which direction a smell is coming.
Even on our small island, each species has its preferred habitat and range. Because of the unique habitats, lack of mammalian predators and species’ particular range within the island, some interesting characteristics have developed. From research done by the Nantucket Snake Consortium, comprising the Linda Loring Nature Foundation, Nantucket Conservation Foundation and Maria Mitchell Association, it was found that garter snakes (our most common species) on the western side of the island were significantly larger than those found on the eastern side. This could be due to diet availability, with less competition for resources (fewer milk snakes) on the western side.
Our garter snakes here also differ from those found on the mainland. A 2014 study conducted by Smyers et al. looked at color patterns of garter snakes compared to their mainland counterparts. They found that the island snakes’ color patterns differed greatly, with this possibly due to less mammalian predators on the island, and the vegetation found here. Nantucket garters are more checkered, while mainland snakes are more striped. The hypothesis is that our snakes have adapted to the unique vegetation on the island and the checkered pattern helps them camouflage better among the heathlands and shrubs of Nantucket.
Another interesting case is the smooth green snake. While it occupies a variety of habitats on the mainland, here, it can only be found on Coskata-Coatue. This snake has a wonderful green coloring, and as the name suggests, has smooth dorsal scales. It is quite docile and camouflages itself by bobbing its head in order to mimic vegetation blowing in the wind. It is thought to only inhabit Coskata-Coatue due to competition with the more aggressive milk snake.
This spring, snakes will emerge from brumation (a hibernation-like state for cold-blooded animals) to begin their active season of mating, searching for food and basking in the sun. Let’s be grateful that no staff-wielding figure came to Nantucket and banished them from our shores, allowing us to continue sharing the island with these fascinating creatures!
