Private Landowners Lend a Hand to Threatened Bog Turtle
One-year-old bog turtle. Photo by Julie Slacum, USFWS
The bog turtle (Clemmys muhlenbergii) is one of North America's smallest turtles with a light brown to ebony carapace (covering shell) between 2.9 – 4.4 inches in length. A bright orange, yellow or red blotch on the side of the head and neck distinguishes the bog turtle from other small turtles. The plastron (underside of the shell) is yellow with black patches.
The northern population of the bog turtle extends from western Massachusetts to northern Maryland and Delaware. Though the geographic distribution of the bog turtle is fairly extensive, they are limited to a specific and rare type of wetland.
Saturated, spring fed wetlands such as bogs, fens, wet meadows, sedge marshes and pastures with thick mucky organic soils provide the habitat these turtles require for feeding, breeding and hibernation. These wetlands are dominated by low grasses and sedges with a mix of shrub species.
The bog turtle was listed as threatened under the Endangered Species Act in 1997 due to excessive collection for the pet trade and loss of the unique wetlands on which the turtles depend. The collection of bog turtles has diminished since its listing, but loss of these rare wetlands still occurs. Development, shifts in land use, woody plant succession and encroachment of invasive plants all contribute to loss of bog turtle habitat.
It’s been hypothesized that, prior to settlement by Europeans, bog turtle wetlands were grazed by large herbivores such as bison, helping to maintain the open canopy and pockets of muddy substrate.
Bog turtle burrowing in, well, a bog. Photo by Scott Smith, MD DNR.
Over the last century, the abundance of bog turtles in pastured wetlands indicates that grazing has been instrumental in maintaining the openness of wetlands needed for habitat. In the absence of grazing, bog turtle wetlands have been overgrown with woody shrubs and small trees and dense thickets of exotic invasive plants like multiflora rose (Rosa multiflora).
Restoration of these overgrown wetlands typically requires removal of vegetation using physical, mechanical and chemical treatment. Some bog turtle wetlands have been over grazed so restoration work includes stream fencing, pasture management and creating other water resources for livestock.
More than 97% of bog turtle wetlands occur on private lands, so recovery of this species depends heavily on private landowners. Since 1997, various habitat restoration techniques have been completed at 17 wetlands on private lands in Maryland totaling more than 150 acres.
Through the Coastal Program and Endangered Species Program, the Chesapeake Bay Field Office is working with private landowners and other partners to protect and restore bog turtles and the wetlands they need. Current activities include:
Adult bog turtle. Photo my Michelle Everson.
Installing fences on six acres at two sites in Maryland and on one three acre site in Delaware to protect these sites from overgrazing.
Controlling hardwood vegetation from encroaching into 13 acres of bog turtle wetlands at three Maryland sites.
Working with a Maryland landowner and the Natural Resource Conservation Service to protect 30 acres of bog turtle habitat through the Wetland Restoration Program. The protected site includes 3 acres of emergent wetland, 12 acres of forested wetland and 15 acres of forested upland buffer.
Prioritizing 65 bog turtle sites in Maryland for future restoration efforts based on population size, reproductive activity, and connectivity to each other bog turtle sites.
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