Protected Species in Pennsylvania: The Bog Turtle

The Bog turtle (Glyptemys muhlenbergii) is a rather small species of turtle, only measuring about 3-4 inches long, and is easily identifiable yellow-orange spots on each side of its head. Otherwise, the turtle's appearance is very similar to any other turtle you might find in swampy/bog-like areas. The species exists in two distinct populations. The northern population ranges from New York and Western Massachusetts down to Maryland. The southern section ranges from the Appalachian Mountains from Virginia to Georgia and tends to stay at lower elevations. Currently, only the northern species is protected, but to avoid confusion and to avoid any loopholes, both populations are protected.

Federal Protection of the Bog Turtle

The Bog turtle was listed under Endangered Species Act as "threatened" in 1997. The Endangered Species Act is a policy passed by congress in the early 1970s with the sole purpose of protecting species whose populations were in danger of becoming extinct in the future. Species listed as endangered means that the species is expected to go extinct in the near future. The threatened label means that unless changes are made, the species will very likely become endangered in the foreseeable future. There are two federal agencies that enforce this act, U.S. Fish and Wildlife Service and the National Oceanic and Atmospheric Administration. State agencies, such as the Pennsylvania Fish and Boat Commission and Department of Natural Resources and Conservation, are also responsible for ensuring federally listed species are protected within Pennsylvania.

Why Were They Listed?

The biggest threat to the Bog Turtle is the extensive shift in habitat conditions for the turtle. Bog turtles prefer spring-fed boglands called fens. Fens have a moderate level of water flows and saturated soil. The water in fens is also more basic and alkaline. In contrast, what is more typically known a bog is more acidic with slower water flows.

Basking in sunlight is important for these turtles as they are cold-blooded and use the sun to regulate their body temperature. The encroachment of tall-growing woody invasive plants crowd out native sedges, grasses, forbs, and sphagnum mosses which the Bog turtles prefer. The tall plants also prevent the turtles from getting adequate sunlight for proper basking. This in turn can hindering the turtle's growth and success in reproduction. While overgrazing by cattle has been found to lead to wetland degradation, research has found moderate levels of grazing can benefit the Bog turtle by keeping down woody invasive plants around fens.

Another major threat is habitat loss and fragmentation due to roadways and residential and commercial development. The roadways harm the turtle by breaking up their habitat making it difficult to move up and downstream. Turtles can also be crushed by vehicles as they cross roadways to get to nesting micro-habitats. Impervious surfaces associated with increased development also impacts water flows and water levels in adjacent bogs. Pollutants within the watershed are also a problem. Fertilizer runoff can lead to uncontrolled algae blooms leading to low oxygen levels in the water. Herbicides and road salts in the water can also lead to chemical changes in pH, which Bog turtles are very sensitive towards.

The illegal removal of turtles for the pet industry is another important threat to the Bog turtle. Due to their diminutive size and ease of capture the Bog turtle has been a desirable species on the illegal wildlife trade for many years. Enforcement of federal regulations protecting the turtle has been difficult since many turtles are collected in remote areas and traded online and out of sight.

Who is Helping Protect the Bog Turtle?

Since its listing, the US Fish and Wildlife Service has created a recovery plan to address the problems facing the Bog turtle. The goal is to protect both the populations and the habitat required by the Bog turtle so that it can eventually be removed from the threatened species list. To do this, the northern population has been divided into 5 different recovery units based on habitat distinctiveness, biogeographical and ecological affinities, and the intensity and severity of the threats to the species. Then they establish how many viable populations would need to be protected in each recovery unit to meet the long-term goal of delisting. Also supporting Bog turtle recovery is the Nature Conservancy. The Conservancy assists private landowners who want to remove individual trees near important wetland habitats and establish cattle grazing areas to help keep down tree encroachment. The Conservancy also does extensive fieldwork using radio telemetry to monitor turtle behaviors and population success.

Why Should We Care?

There are several important reasons why we should help protect Bog turtles. The turtle has biological and cultural significance as one of the smallest turtles in the United States. The Bog turtle also serves as a litmus test for the health of fens along the east coast, which are also important habitat for a wide range of other important plant and animal species.

How Can you Help?

If you have the pleasure of encountering one of these little guys, the first thing you should do is leave it alone and just observe from a distance. You can also contact the U.S. Fish and Wildlife Service or a state agency and let them know that you found a Bog Turtle and where is it located. They will likely go out to see whether there is a new population and set up monitoring protocols. You can also tell friends and family about the importance of being careful when selecting turtles for pets. Since it is so small and has such striking colors, it is at great risk of being snatched up and sold on the black-market pet trade. You can also report any observations of the Bog turtle being traded or kept as a pet.

 For more information, check out these links:

• PA Fish and Boat Commission. Bog Turtles Species Action Plan 
• U.S. Fish and Wildlife Service. Bog turtle
• National Fish and Wildlife Foundation. Bog turtle    

Student Authors

This article was written in collaboration with undergraduate students as part of a class assignment at Penn State.

References

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Jason Tesauro, and David Ehrenfeld. "The Effects of Livestock Grazing on the Bog Turtle [Glyptemys (= Clemmys) Muhlenbergii]." Herpetologica, vol. 63, no. 3, 2007, pp. 293–300. JSTOR. Accessed 24 Mar. 2021.

Knoerr, M. D., Graeter, G. J., & Barrett, K. (2021). Hatch Success and Recruitment Patterns of the Bog Turtle. The Journal of Wildlife Management, 85(2), 293-302.

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PGC-PFBC (Pennsylvania Game Commission and Pennsylvania Fish and Boat Commission). 2015. Pennsylvania Wildlife Action Plan, 2015-2025. C. Haffner and D. Day, editors. Pennsylvania Game Commission and Pennsylvania Fish & Boat Commission, Harrisburg, Pennsylvania.

Sirois, Angela Marie, et al. "Effects of Habitat Alterations on Bog Turtles (Glyptetnys Tnuhlenbergii): A Comparison of Two Populations." Journal of Herpetology, vol. 48, no. 4, 2014, pp. 455–460. JSTOR. Accessed 24 Mar. 2021.

"Threats to Fens." Native Plants and Ecosystem Services, Michigan State University.

US Fish and Wildlife Service. (2001). Bog Turtle (Clemmys muhlenbergii), Northern Population Recovery Plan. Bog Turtle (Clemmys muhlenbergii), Northern Population Recovery Plan