The Mystery of Vermont’s Box Turtles

Views:

636 views

Throughout much of the United States, Box Turtles are the turtle people are most familiar with. As a completely terrestrial species that can live in and around residential developments, people have a chance to see them throughout the entire warm season, not just in the spring when aquatic turtles venture onto land to lay eggs, and people often find them right in their own backyards. That is not the case in much of Northern New England, especially high elevation and boreal regions of Northern Vermont, New Hampshire, and Maine where harsh winters would make it difficult for populations to thrive. In Vermont, for example, although Box Turtles occasionally turn up in unusual places, it was long thought that those turtles were released pets and not part of a breeding population. Box Turtles are incredibly common in the pet trade and, even though they are not legal to keep as pets in Vermont, most people don’t know that and some bring their turtles in from other states. Because they can live over a century and some folk who buy one lose interest after only a year or so, these turtles are sometimes released into the wild (unlawfully). So, when a Box Turtle turns up in an urban Vermont  park or in a very cold part of the state a week after college freshmen vacate the dorms, it’s not hard to guess where that turtle might have come from. Recently, however, it has become clear that the Box Turtles turning up in at least one part of Vermont are most likely native wild animals, and part of a breeding population – the released pet theory simply isn’t holding up anymore.

Adult Eastern Box Turtle with typical coloration. Photo by Chris Slesar

Eastern Box Turtles, the species native throughout most of the Eastern United States, get about five inches long, have highly domed/rounded shells, and can completely close their shells using hinges on their plastron (the bottom part of their shell) to protect their head and legs. Their pattern is highly variable, but both their skin and shell are usually dark brown or yellow with bright yellow spots or stripes. Sometimes they are almost entirely yellow, or mostly black, and can have brilliant red coloration as well. In the northeast, the species most easily mistaken for a Box Turtle is the Wood Turtle, which has a black head, an orange neck and legs, and a highly textured shell that is typically brown with some yellow spots or striations. Wood Turtles also get considerably larger, topping off around nine inches in length, and they cannot close their shell at all (some people call them ‘red-legged Box Turtles).

The plastron of Box Turtles have two visible hinges that allow the shell to fully close. Photo by Chris Slesar.

Over the years, observations of Box Turtles sent into the Vermont Reptile and Amphibian Atlas began to reveal a pattern that became difficult to ignore. From the 1990s through mid-2000s, the small number of Box Turtle records were scattered randomly throughout the state, and a single record separated from the next closest observation by a distance of 40 or so miles really doesn’t mean much when the species is so common in captivity (despite the illegality of keeping them in VT), and those records can easily be explained by unlawful releases. More recently, however, a very consistent trend has developed. In the Southern Connecticut River Valley, (pretty much the entire eastern half of Windham County), almost every town has at least one Box Turtle record, and there have been more recent reports a little farther north. Some of these records are old, but they keep coming in, about one every year or so. A bunch of towns in one area with released pet records might make sense in a more urban part of the state, but the Southern Connecticut River Valley? It is very difficult to explain those turtles as all being released pets. And the area makes a lot of sense – Box Turtles are native in the Connecticut River Valley of Massachusetts only a little farther south. Another cluster of records from north/central VT is somewhat more curious, but again, it is getting harder to explain those records as all being of former pets.

The distribution of Box Turtle records in Vermont. Map produced by The Orianne Society for the Vermont Reptile and Amphibian Atlas. Visit VTHerpAtlas.org to learn more.

So, what’s going on down there? Have Box Turtles expanded their range into Vermont? That is HIGHLY unlikely. Eastern Box Turtles are in decline almost everywhere they are known to occur, including in Massachusetts where they are listed as a species of Special Concern, and the species is endangered in New Hampshire. Much more likely, is that Box Turtles have always occurred in the Southern Connecticut River Valley of Vermont, but in such incredibly low numbers that the odds of someone finding and also reporting the sighting was just very small until the past few years now that pretty much everybody has a camera and the internet in their pocket. This happened in New Hampshire as well, and it wasn’t that long ago that biologists in New Hampshire verified that Box Turtles in at least on part of the state are actually native, not just released pets.

This Eastern Box Turtle, now in the care of The Orianne Society, was brought to us by a local game warden after the people who kept it as a pet learned they are unlawful to possess in Vermont and contacted the state to find out what to do with it. Because these turtles cannot be released to the wild, they are typically rehomed to organizations permitted to keep native wildlife for educational use.

The key to truly figuring out if these turtles are native and part of a breeding population will be finding one or more, collecting a genetic sample to compare against nearby native populations, and following a few of these turtles by attaching radio transmitters to their shell so we can learn about their habits and home ranges. While that may sound relatively simple, there is one major problem with that plan, which is that to-date, nobody has ever found a Box Turtle in Vermont on purpose, and every record that comes in has been days, weeks, or even years after the sighting. While we have a couple very promising leads where multiple Box Turtles have been found within a relatively small area, searches of that habitat have thus far been fruitless. 

A more brilliantly-colored Eastern Box Turtle. Photo by Erin Talmadge.

So please, if you are in Vermont and see a Box Turtle at any point in time, let us know. Sightings from many years ago are very useful and will help us find good places to survey, but if you found this post because you are in Vermont and found a Box Turtle right before turning to google to learn more, please take a photo and email me immediately! Your observation might very well be the key to unlocking the mystery behind Vermont’s Box Turtles.  And, if you have a pet Box Turtle and now know that it is not legal to keep here, please do not release it to the wild as may spread exotic diseases to native turtles and would not survive long if released in the wrong environment. Instead, I encourage you to contact Vermont Fish and Wildlife to find out how to get your turtle into an educational facility permitted to keep the species or.