Species Spotlight: Eastern Musk Turtle

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Eastern Musk Turtles go by a few different names, but they all mean the same thing. Some folk call them stinkpots, and among academic circles their scientific name, Sternotherus odoratus, is just as common. The clear sense you should be getting from all three of these names is that musk turtles are pretty smelly, but since most people never have the opportunity to sniff one, their malodorous qualities shouldn’t detract at all from the fact that they are interesting little turtles.

Small compared to most other species, Musk Turtle shell length tops off around 5 inches.

I first encountered an Eastern Musk Turtle around 11 or 12 years of age when, sadly, a dead one had washed up on the shore of Lapham Bay only a hundred or so yards from my house. The turtle appeared to have been killed with buckshot, and it was not the first turtle I had observed down there that had met an untimely death at the hands of humans. It was, however, the first dead turtle I did not immediately know the identity of. In this case, the discovery turned out to be fairly important, as the species had not yet been documented in the area, and with an assist from my mother, we delivered the carcass to Jim Andrews of the Vermont Reptile and Amphibian Atlas so the shell could be cleaned up and used for educational programs. After the shell was prepared, we learned the turtle had been shot on more than one occasion, and out of the 5 holes in the shell, roughly half had bone that had grown around the wound, indicating that before the fatal shot in the late 1990s, it had survived and recovered from a similar injury, possibly from decades prior as the species can live at least 50 years.

An Eastern Musk Turtle that appears to survived at least one encounter with a shotgun.

At that point in time, not a lot was known about the distribution of Musk Turtles in Vermont, largely due to the fact that they are very secretive animals. Unlike Painted Turtles, they don’t typically sun themselves out in the open on rocks and logs. While other turtles often swim at the surface of the water, Musk Turtles are much more likely to simply walk along the leaf litter and debris at the bottom, further decreasing their likelihood of being noticed. Whereas both Painted and Snapping Turtles can travel considerable distances to lay eggs in the spring, crossing roads and ending up in lawns and gardens in the process, Musk Turtles lay their eggs mere yards from the shoreline and then go straight back to the water. And while this is not the case in other states where they inhabit a variety of backwater and marshland habitats, here in Vermont, Musk Turtles have a very limited range, occurring only in the shallow bays of Lake Champlain and a handful of inland lakes and ponds, but only in Western Rutland County for reasons yet unknown.

On the rare occasions Eastern Musk Turtles are observed backing, they are sometimes seen using less than obvious structures on which to sun themselves, such as this completely shaded beam under a dock.

Drably-patterned, Musk Turtles are usually gray in color (sometimes with pinkish skin) with a dark shell and light lines running along the face and through the eyes. They also have fleshy barbels on their chins and throats, which in the northeast is unique only to Musk Turtles and closely-related Mud Turtles. Topping off around 5-inches in length, their shells are highly domed and elongate, almost pill-shaped, and their plastron (bottom of the shell) is quite small compared to other species. The plastron also is somewhat flexible and has one hinge, allowing it to bend. Owing to the small size of the plastron, though, Musk Turtles cannot close their shell up like a Box Turtle. A small, flexible plastron, however, gives the turtle’s legs a greater range of motion which may improve their ability to walk at the bottom of the water or allow them to better climb up onto the logs and the limbs of partially submerged trees on the rare occasions that they do bask. Indeed, you’ll read about people having Musk Turtles fall from trees into boats, though I have never personally observed one more than 5 inches above the surface of the water.

Common through much of of the eastern United States, the Eastern Musk Turtle is at risk in some locations, especially along the northern edge of its range.

Musk Turtles lay no more than 9 eggs a year, but their eggs have a somewhat hard calcified shell, which is very different from the leathery eggs almost every other species of turtle lay. Hatching in the late summer, young Musk Turtles are largely carnivorous, eating invertebrates, small fish, and scavenging any submerged carrion they can find. Adults have a more variable diet and also consume a fair amount of vegetation. As with most other turtles, just about every predator out there will happily eat their eggs and hatchlings, but adult turtles are protected from many predators by their shells. Some predators, such as mink and otter, however, are adept at preying upon even full-grown Musk Turtles, and the foul smell the turtles produce from glands in their skin may be a trick they employ to deter such animals.

Due to the secretive nature of Eastern Musk Turtles, catch-and-release trapping (permit required) is one of the most reliable ways to document the species in the northeast. Note: the above trap contains only Painted Turtles.

Overall, Eastern Musk Turtles are common throughout most of their range, which encompasses the majority of the eastern United States. Here in Vermont we just happen to be on the absolute northeastern edge of the species’ range, which is why they are not found in most of the state, but within their limited local range the species isn’t too hard to find if you know how to look. Despite that, any population of a species at the edge of the their range is at high risk of decline, and even localized extinction, in response to new stressors on the environment. In Vermont, for example, we have most likely lost two edge herp species over the past decade (Boreal Chorus Frog and Fowler’s Toad), and others are teetering on the edge of extirpation (North American Racer, to name one)

Ubiquitous in many places in the eastern US, Musk Turtles and their relatives aren’t species many people are aware of, but the more we understand about the diversity of species we share the landscape with, the greater appreciation we will all have of the need to conserve these incredibly complex systems, which is why I felt it worthwhile to feature the Eastern Musk Turtle as this month’s #FacesOfTheForest species spotlight.