Our researchers aren’t tweeting—but they’re listening in on the forests’ social channels.
A little over a year ago, 200 acres of trees snapped, uprooted, and fell to the forest floor, hundred-year-old giants bowing down to a tornado’s devastating 110 mph winds. Unlike a city, the forest isn’t putting things back to how it once was for the last 200 years. Instead flora waiting in the seed bank are taking advantage of the open sunlight. Fauna that live for forest clearings are flocking, fluttering, and scurrying to the new gaps. And we’re left wondering: How do these creatures know to return to a suitable habitat once it has reappeared? What signals do they hear and follow?
Mary Medlin, our resident avian research coordinator and master’s candidate at Auburn University, is not asking these questions philosophically but with an intention to find answers. This spring, with support from her academic advisor Dr. Kelsey McCune, Medlin is starting a years-long research project to understand how different species of eastern songbirds respond to their fellow birds’ calls to find new breeding sites. Her insights could help conservationists gain a new tool for attracting specific birds to newly restored habitats. But first, Medlin must play forest spy.
Medlin has spent the last couple months hunched over a table, eyes trained through a magnifying glass, assembling and soldering the delicate inner workings of playback recording devices (PRDs). These forest green toolkits have a speaker embedded on one side and a tiny microphone at the top. Medlin will hide the units in Paint Rock’s tornado-impacted sites, other logging sites with similar forest structures, and in adjacent undisturbed mature forests. The units have a timer set to start playing vocalizations of target species, to pause the playback, and to then start recording any responses.
Six bird species are of special interest: from the vulnerable cerulean warbler to ruffed grouse, Baltimore and orchard orioles, and blue-headed and yellow-throated vireos. Ceruleans have been in steep decline across their range due to a number of issues, namely the loss of mature forests with open understories and sweeping canopies. While ruffed grouse have relatively stable populations throughout their range, there haven’t been any confirmed breeding birds in Alabama in some time. Many would like to see them return.
“This vocal cue playback method can be incredibly useful for attracting species of conservation concern to areas that are being managed for their support, without having to wait for birds to find them all on their own—which can take many years or may never happen at all,” Medlin says. “The cerulean warbler and ruffed grouse are examples of such species in Alabama, and we are very excited to see if this technique will prove useful for them.” Furthermore, with the inclusion of other target species, the researchers may be able to determine how common the use of conspecific cues, the sounds, scents, and sights from the same species, appears across different passerine groups and guilds.
This first year, Medlin plans to develop a baseline of the target birds already present at the test sites. In the following years, she’ll start sending out calls and listening to hear what, and how many, birds respond. This is a social network we’re excited to tap into and report back on. Stay tuned for more “tweets” from Medlin’s work.