By Bill Williams
Thirty-six bird surveys of the Conservation Park of Virginia in Charles City County were conducted from April 2010 through March 2012. The primary purpose of these surveys was to determine the status and habitat use distribution of the Park’s Northern Bobwhite population. The survey protocol was designed to sample as much of the potentially suitable Northern Bobwhite habitat as possible during the time allotted. Each survey lasted 4.5 hours commencing approximately one hour before sunrise.
Observations began predawn at the Park’s skeet/trap shooting range. The remainder of the survey was accomplished by walking the unpaved perimeter road past the rifle/pistol range, through the loblolly pine stand towards the power line right of way, then across the railroad tracks following the road along the secondary growth to the Chickahominy River, ending at the shallow pond at marker 18. The return trip retraced the dirt road across the railroad tracks, through the power line right of way then up the road adjacent to the skeet/trap shooting range to the main entry road. As weather and seasonal conditions allowed side forays were taken through the fallow fields and/or cultivated areas below the power line across the railroad tracks. A running tally of all bird species detected by sight and/or sound was maintained throughout every survey.
There were 53 Northern Bobwhite detections during 22 (61%) of the 36 survey visits. Thirty-nine (74%) of the 53 detections were from and/or adjacent to the fallow field in front of the shooting stations (see map). Fifty-one (96%) of these detections were of Northern Bobwhite that were heard, either in full song or from covey calls. Northern Bobwhite were only seen during 3 visits, one of which was a single bird heard first, then flushed. The maximum number of Northern Bobwhite encountered was 11on 15 March 2011. A covey was initially heard then purposely flushed in order to determine the number of individuals present.
A total of 140 bird species was recorded during this 24-month project. All avian related data were posted to the Cornell Laboratory of Ornithology’s eBird website, an on-line international citizen-science database. Among the most noteworthy observations were a Pied-billed Grebe with downy young, Anhinga on two occasions, a Barn Owl, and nesting Cedar Waxwings. The Park’s wooded swamplands support wintering Rusty Blackbirds, a species critically threatened by habitat loss across its range. Chuck-will’s-widows and Eastern Whip-poor-will’s are present on Park property throughout the spring and summer. Both species almost certainly breed there. American Woodcock display over the fallow fields from late fall through spring, a strong indication this game-bird species probably nests in the Park.
Anecdotal data were kept on all other fauna incidentally encountered during the surveys. Those fauna included 11 mammal species, 9 reptiles species (4 turtles, 3 snakes, 2 lizards), 8 amphibian species (all frogs), 23 butterfly species, and 13 dragonfly species.
Three significant habitat alterations took place during the project’s 24 months. The first, clearing for the installation of parallel electrical transmission lines through the middle of the Park property, was in progress when the project was initiated in April 2010. The removal of trees and associated understory through that right of way effectively doubled potentially suitable vegetative conditions for Northern Bobwhite in some areas.
A controlled burn of the fallow field below the skeet range was conducted on 14 March 2011. The detection evidence cited above suggests that burn sustained, and/or enhanced, habitat preferred by Northern Bobwhite.
The third alteration occurred with the passage of Hurricane/Tropical Storm Irene 27-28 August 2011. That event toppled numerous trees throughout the area, but did not change or produce any habitats that would favor or inhibit Northern Bobwhite.
The Conservation Park of Virginia encompasses a broad spectrum of naturally occurring and purposefully manipulated habitats that support a rich diversity of wildlife. Most importantly, the Park’s habitat management strategies seem to be contributing to a sustainable Northern Bobwhite population.
It was noted that Wood Duck nest boxes had been placed in the Chickahominy River drainage. Habitats suitable for the installation of nest boxes for American Kestrel, Eastern Bluebird and Prothonotary Warbler exist within the Park.