counting the bellwether birds
Many have been inspired by the Bobolink’s melodic call. Describing the grassland bird, Thoreau wrote, “This flashing, tinkling meteor bursts through the expectant meadow air, leaving a train of tinkling notes behind.” Natural Lands volunteer and retired music professor Jim McVoy expressed his appreciation for those “tinkling notes” as few of us can: he composed a solo piano piece called “Songflight” that premiered at a recital at West Chester University in 2008.
Jim knows the Bobolink well. Since 2003, he has spent many hours sitting cross-legged in the grassy meadows at our Stroud Preserve peering through his binoculars to observe Bobolinks and Eastern Meadowlarks. Each year from April to early July he visits several preselected sites, initially to count nests (which both species prefer to make in tall, dense grasses) and then later in the season to assess fledglings. Over the years, we have used Jim’s research results to direct our mowing and grazing practices and to reconfigure land cover to help minimize threats to Bobolink and Meadowlark nests.
“When I was originally asked about the project, it was to be a one-time count and population assessment. I felt that, to gather any statistically useful information, I should monitor several sites over the entire nesting season and preferably for several successive years. I made more work for myself, but my records have demonstrated that the Bobolink nesting fields should be mowed at least a few weeks later than past practices to give the fledglings time to develop their independence. If my time in the field has accomplished even that little bit, it has been worth every minute.”
According to the Pennsylvania Game Commission, the state has lost 1.1 million acres of farmland in the past 40 years. Since that time, major declines have occurred in almost all groups of grassland-associated wildlife. According to the North American Breeding Bird Survey, the Bobolink and Eastern Meadowlark, along with several other species, have declined by 80 percent or more in the last four decades.
Birds, like frogs, are an environmental bellwether. Scientists have long used changes in bird populations, behavior, and reproductive ability to examine the effects of habitat fragmentation and invasive species, monitor water quality, and identify environmental pollutants. Because of their rapid metabolism and wide geographical range, they reflect changes in the environment quickly and warn us when things are out of balance. The documented observations of volunteer birders like Jim McVoy provide valuable data about bird populations over a broad geographical range.
Photo: Frank Miles
Besides the grassland bird study, Jim also has been compiling a list of all Stroud Preserve bird species and their relative seasonal abundance. (His observations and diligent data collection were instrumental in the “Important Bird Area” designation our Stroud Preserve received from the Audubon Society.) Jim’s goal is to create a checklist that would be available to all preserve visitors. So far, he has collected data on over 148 species!
Ultimately, it is Jim’s love of the birds—and, by extension, their grass-land habitat—that drives his volunteer efforts on their behalf. “Every spring the Bobolinks’ arrival at Stroud is a moment of wonder for me. I know that some of these birds were here the previous summer and have flown to their South American wintering grounds and back. The thrill of witnessing their return after crossing two continents is one I want to be able to share with my grandchildren. I’m just doing what I can to help ensure their survival so I can do just that.