On July 14, 2016, FODM hosted 25 George Washington Middle School students participating in the Alexandria Public Schools’ summer STEM (science, technology, engineering and mathematics) program and two of their teachers. The students learned about the natural resources of Dyke Marsh and conducted some water testing using seine nets.
Two species of snake are often seen in Dyke Marsh in the summer.
On July 1, 2016, during a canoe trip in the southern part of Dyke Marsh, FODMers saw an encounter between a common water snake (Nerodia sipedon sipedon) and a catfish. Also called the northern water snake, it is probably the most abundant snake in Dyke Marsh.
These photos (by Ed Eder) indicate how the prey was snared in deeper water and dragged to the shore by a very determined snake.
During the May 20 and 21, 2016, national BioBlitz, FODMers, National Park Service (NPS) staff and friends identified 13 new spider species in the Dyke Marsh-Belle Haven Park area. Other records for Dyke Marsh: the first spring record for a Philadelphia vireo (Vireo philadelphicus); the second record for the hoary bat (Lasiurus cinereus); one new earthworm (Bimastos palustris), a native species; and two new terrestrial isopods (Porcellio laevis, Trichoniscus pusillus). At our “sister” park, Theodore Roosevelt Island, people found 17 new lichens.
Spring is breeding time in Dyke Marsh for many species of wildlife, including skinks. The American five-lined skink, (Plestiodon fasciatus), is one of the most commonly seen lizards in eastern North America and is frequently observed around logs along the Haul Road Trail (photo, skinks mating May 2016 by Ed Eder).
At the quarterly meeting of FODMers and friends on May 11, 2016, Alan Ford and Laura Beaty gave a presentation on the interrelationships of plants and animals and the important role of pollinators and leaf-eaters. Alan is president of the Potowmack Chapter of the Virginia Native Plant Society and Laura chairs the Propagation Committee.
Every spring, FODMers welcome the spring return of the ospreys (Pandion haliaetus) to Dyke Marsh and the Potomac River shoreline where these magnificent raptors build and refurbish their nests and raise their young. In recent years, there have been approximately 10 to 12 active osprey nests within FODM’s breeding bird survey tract, a three-mile area that extends from the Porto Vecchio condominiums near Hunting Creek to south of Morningside Lane.
Despite the rebound in the osprey population, threats still exist.
On the morning of April 29, 2016, 24 students and three teachers from Alexandria’s T.C. Williams High School’s International Academy visited Dyke Marsh to observe in action some of the lessons of their biology class and to try their hand at suppression of invasive plants.
Volunteers began lepidoptera and odonata surveys in Dyke Marsh on April 20, 2016, led by Jim Waggener. On the 20th, surveyors identified five butterfly species in a brief span. The peak time for surveys is May through September. This work helps identify and save critical habitat that preserves biodiversity in our region.
Under a steady drizzle, a steady stream of raptor fans attended the annual Raptor Rapture in Belle Haven Park on April 23, 2016, sponsored by FODM, the Raptor Conservancy of Virginia and the National Park Service.
Kent Knowles (pictured) and Gabby Hrycyshyn of the Conservancy brought an Eastern screech owl (gray morph), an American kestrel, peregrine falcon (photo), red-tailed hawk, barn owl and Harris’s hawk. These birds cannot live on their own in the wild.
As the weather warms, birds are busy breeding in the Dyke Marsh Wildlife Preserve. In April, FODMers observed red-bellied woodpeckers and northern flickers investigating potential nest cavities, despite facing stiff competition from European starlings. Observers have seen Carolina chickadees and fish crows carrying nesting material in the Belle Haven picnic area and along the Haul Road.
On April 16, 2016, 66 enthusiastic volunteers of all ages turned out on a beautiful spring day and collected trash along the Potomac River and Dyke Marsh shoreline. The group found plastic bottles, aluminum cans, fast food boxes and wrappers, plastic bags, pieces of Styrofoam, at least two tires and more – too much.
FODMers, guided by Dan Schwartz, soil scientist, Northern Virginia Soil and Water Conservation District, conducted biological water quality testing on two unnamed streams flowing into the western part of Dyke Marsh on April 2 and June 11, 2016.
The findings are disappointing, but not surprising. Most streams in Fairfax County are impaired.