Rail Callback Survey

On Wednesday, May 23^rd James Fischer and I did a Rail Callback Survey for the CT D.E.E.P. at seven locations in White Memorial. The Rallidae family consists of predominately small to medium-sized wetland birds that are often seen walking along muddy areas or shallow water. The expression “thin as a rail” comes from the rails’ body form, which is laterally compressed, allowing them to escape into dense grass or reeds making them extremely difficult to visually spot. Recent wetland habitat loss and degradation has resulted in population declines in many wetland dependent species. In order to protect these birds and their habitats, biologists need to know which wetlands are being used by the birds. The survey that we conducted was targeted towards nine species of wetland birds that can be found in Connecticut. The species include Black Rail, Least Bittern, Sora, Virginia Rail, King Rail, Clapper Rail, American Bittern, Common Moorhen, and Pied-billed Grebe. The survey must be performed either during sunrise or sunset, which are when the rails are most vocal. Due to a forecast of unfavorable weather in the afternoon it was decided that sunrise, 5:26 a.m. would be best to take the survey. We could not have asked for better rail surveying weather; calm wind, temperature in the 60s, and foggy. Prior to the survey we mapped out possible locations at White Memorial to conduct the callback. The callback is a pre-recorded tape, 12 minutes long of each of the previously listed species calling for 30 seconds, then 30 seconds of silence in-between calls. During the 30 second silences we tried to listen for any calls. Wetlands birds are typically secretive and difficult to study, and it has been discovered that the callback method provokes a vocal response from them if they are in close proximity.

Collecting data at the first Little Pond survey point.

Three survey points were conducted at different parts of the boardwalk surrounding Little Pond. One of the points gave us our first response of a Virginia Rail, which is a wheezy, and accelerating wep wep wep grunt. Two other points, at Mallard Marsh and Cranberry Pond also had a callback from Virginia Rails. An individual Sora was heard multiple times as well at Cranberry Pond. The Sora call sounded very close to us, but we were still unable to see it, emphasizing its stealth. Other locations that were not successful for rail callbacks were Miry Brook and the North Bay observation tower. There are many other marshy rail habitat locations on White Memorial’s property, so hopefully before the breeding season is over we can conduct surveys there to get the most accurate population abundance and location of these elusive birds.

Virginia Rail
Photo by Gerry Ellis
http://ridgefieldnwr.wordpress.com

Sora
Photo by Gerry Ellis
http://ridgefieldnwr.wordpress.com