Wild Side : Three minutes at 50 stops make for a demanding day's count
Photo courtesy of U.S. Fish and Wildlife Service
For the last 12 years or so, a high point of my birding year has been covering a Breeding Bird Survey (BBS) route for the for the U.S. Geological Survey. The BBS, like the more familiar Christmas Bird Count, is a massive, continent-wide "citizen science" project: amateur observers pitch in to collect data that is reliable enough to support scientific analysis. Begun in 1966 as a response to concern over declining bird populations, the BBS now includes more than 4,500 survey routes in the U.S. and Canada.
As part of this enormous project, my Vineyard survey follows a carefully developed protocol for data collection. Like most observers, I try to minimize year-to-year variation in the data by running the route as close to the same date as possible. I shoot for the Sunday morning closest to June 10, using another day only if the weather forces me to.
I begin at the same predetermined time every year, 4:37 am. And each year I count birds from the same stops — 50 of them, roughly a half-mile apart, with a three-minute count period at each one.
The BBS relies heavily on an observer's ability to identify birds by song or call; probably 80 percent of the birds I record are heard and not seen. Of course, despite my care to standardize the process, my results still vary somewhat from year to year. But over time, and across the vast scope of the BBS as a whole, the project produces very solid statistics. It's the best tool we have for monitoring long-term trends in breeding bird populations.
This year, with a Sunday (chosen to minimize traffic noise) falling right on June 10 and a perfect weather forecast for birding, there was no doubt where I'd be at 4:37! And you'd really have be there to believe the racket at Lobsterville; while I tallied only eight species and 16 individual birds at my first stop, I surely missed birds that I couldn't distinguish in the din of birdsong.
And that's the pattern at each of the next several stops, as I head west along Lobsterville Road and turn right onto Lighthouse Road. Multiple towhees, catbirds, and common yellowthroats are in full song at each stop. I encounter nothing unusual or hard to identify, but extracting a good count of individuals out of the swirl of notes and calls takes all of my concentration. Three minutes by the watch; into the car to record data; key into the ignition, and on to the next stop.
Moving along Moshup Trail, I'm really hitting my stride. There are some disappointments: the willow flycatcher I usually get at my first Moshup stop is either not singing or perhaps not there this year.
But I'm feeling sharp. Songs seem to identify themselves in my mind; a quick glimpse through the binoculars reveals the identity of swallows overhead; I seem to develop an instant "mental map" of the birds I hear and see, with the two, or three, or six yellowthroats all clearly distinguished from each other and easy to count. The sun comes up. And best of all, I encounter no cars at all. It's just me and the birds.
Approaching State Road, the maritime scrub of Moshup Trail gives way to woodland, and the mix of birds changes noticeably: fewer yellowthroats, but redstarts and red-eyed vireos join the mix. A single car passes as I count from the broad apron that overlooks Quitsa Pond, and I tally my first starlings — both signs that I'm moving into civilization. Woodland birds continue to gain prominence: as I turn up the Menemsha Crossroad, I tally three woodpecker species at a single stop, plus the day's first eastern wood pewee. A northern parula warbler sings — always welcome since this species is listed as "Threatened" in Massachusetts.
Right onto North Road, vireos singing at every stop; the day's only wood thrush. I'm getting a little fatigued, losing track of what stop number I'm at or losing my concentration momentarily during a count. At Tea Lane, I rest a bit, stretch, and spend a few minutes birding just for fun to try to get myself back together. Two blue-winged warblers counter-singing, as I cross the line into West Tisbury! But cars are passing regularly now, each one representing ten seconds or so of "dead" time when I can't hear birds.
Back onto State Road: orioles and, of all things, the day's only indigo bunting at my stop in the driveway of the M.V. Savings Bank. As the hour gets later, birdsong is waning and traffic gets heavier. I turn right onto Old County Road and start getting scrub-oak birds like prairie warbler. I'm decidedly foggy now, tired and confused; bird songs I know I know suddenly stop registering. Did I already count that pine warbler?
Left onto the Edgartown-West Tisbury Road, and my survey winds down with four stops amid heavy traffic and a dull mix of birds. After four and a half hours, fifty stops, and perhaps 750 individual birds, I tally a chipping sparrow as my last bird of the day.
I'm beat. But I'm already wondering if my willow flycatcher will be back next year.