Surveying White Memorial's Bat Population

 

 This summer, White Memorial adds its efforts to an ongoing survey of Connecticut's bat species. Begun in 2010 by the Department of Energy and Environmental Protection, the survey uses sound recordings to monitor bat activity. Starting a half-hour after sunset and continuing until late at night, White Memorial's research technicians drive a 24-mile route through the woods roads of the property, using a truck-mounted microphone to record high-pitched sounds. The microphone is sensitive to sounds well above the range of human hearing, and records the calls of bats as they seek out insects for food, along with any high-pitched background noise from nearby telephone wires, insects, and radio transmissions. We'll pass these recordings on to the DEEP, where computer analysis will distinguish the bat calls from surrounding noise and identify the bats by species based on their unique sound patterns. We'll likely find evidence of big brown bats (Eptesicus fuscus), little brown bats (Myotis lucifugus), and northern long-eared bats (Myotis septentrionalis), all known to inhabit White Memorial's property.


     Relying on acoustic recordings of bats allows us to form a much more detailed picture of bat populations, distributions, and activity than do older methods such as counting bats caught in mist nets. Furthermore, as white nose syndrome continues to decimate bat populations in the eastern United States, bat monitoring has become increasingly important. The white nose fungus (Pseudogymnoascus destructans) has been present in Connecticut since the winter of 2007-2008, when it was found among hibernating bats in northern Litchfield county. Bats affected by the fungus exhaust their fat reserves and die during their winter hibernation. Monitoring efforts at White Memorial and in towns around Connecticut will help measure surviving bat populations, determine which species are affected and not affected, and provide long-term data against which management efforts can be judged.

Elusive Marsh Bird Callback Survey

Summer intern Molly Mullen paddles up the Bantam River at dawn

White Memorial Conservation Center is conducting a callback survey for elusive marsh birds as part of a nation-wide project coordinated by USGS and the US Fish and Wildlife Service.   We are looking for black, sora, Virginia, clapper and king rails, as well as the American and least bitterns and the pied billed grebe.  The survey has two routes, one walking and driving to different points, and one taking a canoe down the Bantam River.  For each survey, several points along the routes are selected, and at those points we play recordings of different marsh bird calls, separated by periods of silence.  The survey must begin at first light, half an hour before dawn.  This time of year, males are setting up territory and defending it against rivals.  By playing a call, we’re announcing ourselves and possibly challenging the boundaries of established birds.

            Hopefully, they will rise to the challenge and call back.  Odds are that several of the species on the CD would not even be present at a freshwater marsh so far inland, but even the rails we can expect to find here, like the Virginia rail or the sora rail, are difficult to find.  We may not ever actually see them, and even hearing them is unusual.  They’re cryptically colored in earth tones, not very big, and extremely shy.  It’s hard to tell whether or not a species is in trouble if you never see them.  Recent data shows a decline in populations of many marsh birds, making it all the more important to keep an eye on their populations.  These birds can act as indicators; we learn about how the marsh is functioning as habitat based on what birds are choosing to use it.  So far, we have detected Virginia rails at two locations, and a sora rail at one.