Spotted Turtle, Clemmys guttata. Photo: Danielle O’Dell

Spotted turtles are a relatively uncommon species of freshwater turtle in Massachusetts but Nantucket has fairly sizable and robust populations. Still, they are seldom seen, certainly not as frequently as their cousins, the other resident shelled reptilians, snapping and painted turtles. Spotted turtles are secretive and very picky about the kinds of habitat they prefer. Where snapping and painted turtles will inhabit just about any body of water they can find, often in large numbers, spotted turtles are very specific about the types of wetlands they will call home. You’re very unlikely to find spotted turtles in a deep, open body of water. They prefer mucky-bottomed bogs and dense, shrubby wetlands – the more grape vines and spiny greenbriar tangles, the better! Marshes with cattail towering over your head are good too. Dark pools in red maples swamps with lots of thick sphagnum moss and forests of impenetrable highbush blueberry and winterberry holly are also favorites. In short, places that are impossible for humans to move through are prime territory for spotted turtles.

Spotted Turtle habitat at Windswept Bog. Photo: Danielle O’Dell

We love these kinds of places and have spent many a field season learning about the way spotted turtles use habitat, especially at Squam Farm, Medouie Creek, and Sanford Farm/Ram Pasture. For the last two field seasons, we’ve been focusing our energy on studying the population of spotted turtles at the Windswept Bogs. Since retiring the Windswept Cranberry Bogs from farming in 2018, the Nantucket Conservation Foundation’s Science and Stewardship Department has been exploring the potential for a wetland restoration project on this property. The partners that we are working with and the process involved in beginning this exploration is described in detail in one of our blog posts from earlier this year – you can read up on that here.

Part of envisioning a restoration concept for the future is knowing what you have at a site to begin with. With that in mind, we have been searching high and low for spotted turtles within the old cranberry bogs as well as in the wetlands surrounding the property to get a handle on the population size and demographics before we implement any change. We have also been placing radio transmitters on the shells of spotted turtles at Windswept so that we can follow their movements throughout the year. All of this information will allow us to make informed decisions on wetland restoration so that we can improve habitat for spotted turtles in the area.

It is important for us to learn where they are all year, but especially critical to get an idea of what wetlands they inhabit in the winter when they are hibernating (or bromating as herpetologists refer to turtle hibernation). If we do move forward with wetland restoration, most of the physical work would be conducted in the winter at a time when spotted turtles are essentially dormant and would be unable to respond to any disturbance.

While our sample size is still small, we have found most of our turtles use the ditches in the cranberry bogs in the spring and early summer, but with the warmer, drier weather in the late summer, they tend to move out of the bogs and in to the surrounding wetlands where they remain through the winter. This is encouraging preliminary news as we want to avoid disturbing our turtles in any restoration work that we may do!

Spotted turtles hibernate in wetlands similar to where they spend the rest of their year – we have most often found them hibernating underneath the roots balls and hummocks of sphagnum moss, winterberry holly, highbush blueberry and swamp red maples. They often hibernate either singly or in groups with other spotted turtles and occasionally painted and snapping turtles as well.

Danielle shows Windswept visitors a spotted turtle hatchling. Photo: Neil Foley

Whenever we describe the life cycle of a turtle, especially when speaking to children, we are always asked where turtles go in the winter, and upon learning that they spend the winter under water, they ask “How do they breathe?” This is my favorite question because I love seeing the expressions when I tell them “They breathe through their bums”!

How does THAT work?!

Turtles are ectotherms – meaning that they cannot regulate their own body temperature. Therefore, their body temperature generally matches that of the outside environment. Spotted turtles remain submerged 1-2 feet below the surface of the water. As winter approaches and water temperatures fall, a turtle’s body temperature will drop as well. While a turtle’s metabolism slows down dramatically, winter for a turtle in the north is long and they do still need some oxygen to survive. They continue to uptake oxygen through areas of the body where blood vessels are very close to the surface of the skin. The best spot on a turtle where the skin is loaded with surface blood vessels is actually the skin surrounding the cloaca, the posterior opening to the digestive, reproductive and urinary tracts. Excretion of solid and liquid waste as well and turtle sex all occur in the same place! Of course, acquiring oxygen through the skin surrounding the cloaca is not actually the same as breathing by mouth, but it is respiration in the fact that the uptake of oxygen and the diffusion of carbon dioxide occurs, but it occurs at the surface of the skin. Long story short and simply put, turtles breathe through bums in order to get through the winter 🙂

So, there you go, now you know. You can spice up your Holiday Zoom parties with facts on turtle bum breathing. Happy Holidays!

The Nantucket Conservation Foundation is a private, non-profit land trust that depends on contributions from our members and community to support our science projects, conservation property acquisitions and land management efforts. If you are not already a member, please join us now!