NPS Photo
Aerial view of Dyke Marsh
Animals of the Marsh
Dyke Marsh provides habitat which supports a diverse array of animals. Beavers and muskrat live and play in the marsh. At dusk, little brown bats and red fox begin their nightly forays. Other mammal species observed in the marsh include: cottontail rabbit, gray squirrel, shrews and field mice.
Several species of reptiles and amphibians also inhabit Dyke Marsh. Bullfrogs and leopard frogs are on the lookout for northern water snakes and snapping turtles. During the summer months, painted turtles may be seen on logs absorbing the sun's warmth and a box turtle might be seen roaming the floodplain in search of food.
"O-KA-LEEEE!"
Perhaps the most common sound heard in Dyke Marsh is the trill of the red-winged blackbird. Commonly associated with wetlands, red-winged blackbirds nest among the cattails and feed on insects and seeds.
Nearly 300 species of birds have been observed in Dyke Marsh Wildlife Preserve. As a result, Dyke Marsh Wildlife Preserve is one of the premier birdwatching spots in the Metropolitan Washington D.C. Area.
Plants, Plants, and More Plants
To date, more than 360 species of plants have been recorded in Dyke Marsh. The dominant species of the marsh itself is the narrow-leafed cattail, which typically develops its characteristic flower spike by June. Other species associated with the tidal marsh include: arrowhead (a.k.a. duck potato), a plant whose starchy tubers are favored by waterfowl; arrow arum, a distinctive plant with large triangular leaf blades; pickerelweed; sweetflag; spatter-pond lily; and northern wild rice, the grains of which are enjoyed by red-winged blackbirds, waterfowl, and people.
The Human Factor
Today, Dyke Marsh is much different than just 50 years ago. Originally, it is believe that the marsh once consisted of 650 acres. Dredging done during the 1950s and 60s led to the current size and configuration of the marsh. Dredging along the outer fringes of the southern part of the marsh resulted in the removal of approximately one-third of the emergent marsh, which was replaced with deep water that reaches 30 feet (9 m) below mean tide level. Even today, visitors can see the impacts of dredging, including shoreline erosion, trash from dredging operations, and deep holes in the marsh which are most visible at low tide.
Exotic or non-native plants are another result of human impacts at Dyke Marsh Wildlife Preserve. Exotic species are very opportunistic, growing in disturbed areas and often out-competing beneficial native species.
Several exotic vines smothering portions of the floodplain forest, including porcelain-berry, Japanese honeysuckle, and Asiatic bittersweet. The marsh is not immune to exotics either. Yellow iris and the common reed are present and efforts are being made to prevent the introduction of purple loosestrife.
