HOURS OF OPERATION
Thursday, 10:00 a.m. to 5:00 p.m.
Friday, 10:00 a.m. to 5:00 p.m.
Saturday, 10:00 a.m. to 5:00 p.m.
Sunday, 12:00 noon to 5:00 p.m.
Eastern box turtles (Terrapene carolina carolina) were once a frequent and beloved sight in Maryland's woods. In recent years, however, their populations have started to diminish, resulting in far fewer encounters. The primary causes for their decline are urbanization, building roads, and collection as pets. Much of the turtles' habitat has been cut down to build housing communities, towns, stores, etc. Also, roads cut through what remains of their woods results in many turtles getting hit as they attempt to cross. Further, many turtles are taken out of their natural habitat by people who simply believe they will make good pets. To help save the remaining populations, many organizations are conducting extensive studies on them.
Radio telemetry is the primary method used to study the turtle population at the Anita C. Leight Estuary Center. Small radio transmitters are attached to the turtles' carapaces (the top portion of the shell). Each transmitter has a different frequency that can be picked up by a receiver. Researchers and volunteers follow the receiver's 'beeps' to the turtle. Once a turtle is found, its GPS position as well as data about the habitat, the weather, and the turtle's behavior are recorded. The GPS data is then used to map out the turtle's home range. This is important because it tells us how much space they need and what habitat they prefer. During 2011, 10 different turtles will be tracked using this method, and a total of 15 turtles have been tracked in past years.
In addition to tracking certain turtles, we monitor the population using a notch code system. Currently, 116 turtles have been found and notched. Many of these have been recaptured at least once. Whenever a turtle is found, the age, sex, size, weight, GPS location, and anything unusual is recorded. This allows us to map the population as well as determine its health, size, age, sex ratio, etc.
Thread surveys are another useful tool for studying box turtles. Duct tape is used to attach spools of dental floss (thread) to the turtles' carapaces. The thread then unwinds as the turtle walks, creating a trail of exactly where the turtle traveled. If the turtle gets stuck, or reaches the end of its spool, the duct tape will pull off allowing the turtle to keep going. Thread surveys give us a very precise picture of where the turtles moved, and we can use that information to determine their plant preferences, movement ratios, microhabitat needs, etc.
During 2009, thread surveys were used to determine box turtlesâ€™ plant preferences within our park. To conduct this part of the study, a large grid was set up in part of the forest. This grid consisted of 219 plots, each of which was nine square meters (3m x 3m). After establishing the grid, the percent cover of all the major shrub species in each plot was recorded (percent cover is simply an estimate of the amount of a certain plant species in a given area). Finally, whenever a thread survey was conducted in the grid, the plots that the turtle passed through were recorded. This data was then used to see if there was a correlation between shrub species and turtle movement. It was determined that the box turtles in our park generally prefer to move in areas with dense ground cover rather than areas with only a few plants on the ground. The data also indicates that box turtles may have an aversion to mountain laurel, and a specific preference for trumpet creeper, false nettle, and multiflora rose. This research was published in Herpetology Notes and the full article can be accessed here for free.
There are several simple ways that you can help the remaining box turtle populations. First, if you see a turtle crossing the road, stop and help it across. Take it to the side it was heading towards and let it go several feet from the road. Many turtles die trying to cross roads, so stopping and moving them across is a big help. Second, please do not relocate turtles. Many people are compelled to remove turtles from an area that they think is "unsafe" and move them to a "safer" location, such as a nature center. While this may sound like a good idea, it actually creates several problems. First, when relocated, box turtles will often try to return to the location they were taken from. This frequently forces the turtle to cross roads, often resulting in them getting hit. Also, relocating turtles can spread diseases from one population to another. So, if you find a turtle, just leave it where it is, even if you think it would be better off somewhere else. Finally, please do not take box turtles home as pets. They may seem like excellent pets, but they need to be left in the wild. If you take a turtle out of the wild, then it is no longer there to play its role in the environment and to breed with other turtles to sustain the population. So while it may live a long life in your cage, you have eliminated the animal from the population. Also, proper care for turtles is not common knowledge. Many pet turtles become sick or do not do well in captivity. The best thing you can do for a turtle is to leave it right where you found it.
You can read Donald McKnight's article on the turtle's movements following last year's hurricane which came out this summer in the Herpetological Review.