Cows Will Help Conserve Bog Turtle in Delaware’s Brandywine Creek State Park
Bog turtle by Michelle Everson, USFWS.
Freshwater Marsh Nature Preserve in Delaware's Brandywine Creek State Park is protected from most forms of development by its location within a state park. However, invasive plants impact the wildlife there, including the federally threatened bog turtle (Clemmys muhlenbergii).The bog turtle is one of Delaware’s rarest vertebrates with only a few sites remaining in the state.
Invasive plants like reed canary grass, non-native sweet flag, mile-a-minute weed, Japanese stilt grass and purple loosestrife, crowd out, shade, and withhold nutrients from native plants and can also affect the water level in the marsh.
The U.S. Fish and Wildlife Service’s Chesapeake Bay Field Office and Delaware Bay Estuary Project Office, Delaware Natural Heritage and Endangered Species Program and the Delaware State Parks are working together to restore the marsh and a suite of native plants that support bog turtles and other wildlife.
Restoration of the marsh will occur using prescribed grazing with cows. Grazing is a beneficial tool to use in bog turtle wetlands to control vegetation. Grazing animals also create depressions throughout the wetland from their hooves. This helps maintain a mosaic of wet and dry areas that the turtles need for basking, feeding and refuge. It also precludes the need for chemical control of unwanted plants.
In October 2010, fencing was installed around approximately four acres of the site. This year, two cows will graze the wetland for 8 weeks in early spring to help control invasive plant growth. The grazing will be completed before bog turtle nesting occurs in early summer.