On the back end of 2014, volunteers with an initiative called eMammal did some research in Fairfax County. eMammal is a collaboration among citizen scientists, researchers at the Smithsonian Institution, and North Carolina State University.
Volunteers, with permission and in coordination with the Fairfax County Park Authority, set up camera traps in parks and at other Fairfax County natural areas to learn more about the numbers and distribution of wildlife mammals in urban areas throughout the Washington, D.C./ Northern Virginia / West Virginia / Maryland region. Motion and heat sensors triggered the cameras, and volunteers monitored the equipment and the results. It was a bit like throwing dice. You know a number is going to come up, but you don’t really know what you’re going to get.
The Smithsonian Institution is storing the camera trap photos as digital museum “specimens” that will be curated as a publicly accessible Smithsonian collection. The repository also will be accessible to other institutions to store, search, and analyze their own camera trap data.
The survey results do indicate the relative abundance of animals in an area, but the initiative is not an accurate way to determine the density of an animal population, i.e., how many of a certain species live in a given area.
Following is some of the 2014-2015 data that appears in eMammal’s report on the project.
Here is the list of sites that hosted eMammal camera traps, with the number of days a camera was in the field between July and November of 2014 in parentheses. Some sites had more than one camera trap:
Little Difficult Run Stream Valley (27), Holmes Run Stream Valley (22), McLean Hamlet (24), Lake Mercer (21), Marie Butler Leven Preserve (21), Willow Pond (3), Accotink Stream Valley (22), Lake Accotink (21, 23), Pimmit Run Stream Valley (22), Twin Lakes Golf Course (23), Bush Hill Park (25), Ellanor C. Lawrence Park (22, 24), Patriot Park (22), Cub Run Stream Valley (21, 26, 22), Lake Fairfax (23, 23), Franconia Park (72), Mark Twain Park (28), Dogue Creek (29), Groveton Heights (29), Manchester Lakes (29), Huntley Meadows (22, 21, 23), Springfield Forest (21), Fitzhugh Park (29), Wakefield Park (29), Lee High Park (22), Poplar Ford Park (22), Rocky Run (22), and Fred Crabtree Park (24).
eMammal cameras captured:
- 83 photos of the camera trap volunteers
- One blue jay – at Lake Accotink
- 16 coyotes – nine of those at Franconia Park on five different days. Coyotes were also photographed at Mark Twain, Lake Accotink, Patriot Park, Holmes Run SV, and Little Difficult Run SV among other parks
- 9 domestic cats, with Franconia Park and Groveton Heights leading the way
- 165 domestic dogs
- 17 Eastern cottontails, with Groveton Heights producing the largest number of them
- 2 Eastern fox squirrels at Bush Hill Park and Groveton Heights (these would be unusual here)
- 809 Eastern gray squirrels
- 1 Northern flying squirrel at Dogue Creek
- 1 gray fox at Ellanor C. Lawrence. Most of our locals are red foxes.
- 237 red foxes
- 672 humans
- 182 Northern raccoon, and again Groveton Heights led the way
- 1 striped skunk at Cub Run Stream Valley
- 1 unknown owl at Dogue Creek along with other birds, canines, foxes, and unidentifiable squirrels
- 1 bicycle at Lake Accotink
- 16 Virginia Opossum, most at Fitzhugh Park and Lake Accotink
- 1 wild turkey at Huntley Meadows
- 1,365 white-tailed deer