A high point of the serious birder’s year, the Vineyard’s annual Christmas Bird Count (CBC) took place amid frigid conditions on Friday, Dec. 29. The count was the Vineyard’s 58th consecutive contribution to this multinational “citizen science” bird census.
In its 188th year overall, the CBC is coordinated by the National Audubon Society, and puts thousands of birders into the field each winter, counting as many birds as possible in fixed count areas. The vast data set that has resulted is a valuable resource for studying avian population trends and distribution.
Among nearly 600 similar counts, the 2017 Vineyard CBC tallied 120 species, and about 24,000 individual birds. Both figures are below average for the Vineyard, which a concentration of talent plus a marine-moderated climate usually place among the more productive counts in New England.
Temperatures ranging from 0° near sunrise to the mid-teens for a brief period in the afternoon challenged both birders and birds. While I generally follow the same route rather closely each year in my territory (West Chop, Vineyard Haven, and an adjacent sliver of Oak Bluffs), the cold inspired a few alterations as I sought out areas where I figured birds would be active, and tried to break my time away from my car’s heater into short periods.
Even our largest birds are fairly small animals. All birds, and tiny songbirds especially, struggle to maintain their body temperatures in frigid air, and there are two basic strategies by which they mitigate the risk of freezing.
Depending on the tendencies of their species and the resources available, individual birds try to balance minimizing their activity and exposure in order to conserve energy, and frantic foraging in order to take in more energy than they expend. Birds conserving energy are hard to detect; birds trying to take in calories concentrate in small, resource-rich areas. My strategy for the count was shaped by where and by what birds I anticipated would use each approach.
There was clearly, for example, little point in birding the mixed oak and huckleberry woodland that covers a good portion of my territory. This habitat offers bleak birding even in mild winter conditions, though I generally find enough woodpeckers, chickadees, and nuthatches to make checking a little of it worthwhile. This year, however, the oak woodlands were silent, not offering enough concentrations of food to entice birds into activity.
Instead of walking oak woodland, I spent extra time cruising for feeders and fruit-bearing shrubs in residential neighborhoods. These features represent welcome resources for a variety of birds, and this tactic paid off in gratifying numbers of robins, northern flickers, and cedar waxwings.
Similarly, I spent extra effort on the few freshwater wetlands — resource-rich areas for birds, which generally also offer thickets for shelter and concealment. For example, the shrub swamp in the kettle hole at Brightwood Park, Vineyard Haven, produced a winter wren along with a large mixed-species flock of songbirds, working the shrubs and lower tree canopy adjacent to the swamp. My territory’s limited agricultural fields also got special attention, since hedgerows and field edges combine food and shelter. A clay-colored sparrow, feeding with a group of song and white-throated sparrows along such a hedgerow, was among my best birds for the day.
The West Chop portion of my territory offers respectable sea-birding, and here again, the effects of the weather influenced my approach. The area around Vineyard Haven, on the lee side of the Chop, offered bearable if not exactly pleasant birding conditions. And the relatively sheltered conditions attracted good numbers of water birds. A flock of 480 greater scaup (“bluebills,” in duckhunter parlance) nestled right against the beach on the east side of Hines Point; a dispersed flock of ducks, including an immature male king eider, was spread out along the West Chop shoreline in outer Vineyard Haven Harbor.
But my usual stops on the Vineyard Sound shore were virtually unworkable. At the West Chop overlook, the beach at Wilfred’s Pond, and the parking lot at the Tashmoo opening, a robust west wind jiggled my spotting scope, drew tears from my eyes, and numbed my body. Spray and sea smoke reduced visibility. While those sites typically produce open-water birds like gannets, kittiwakes, and razorbills, on this count I found virtually nothing.
All in all, my nine cold hours in the field produced 56 species, eight or 10 fewer than I manage on typical CBCs, and 2,475 individual birds, also a low figure. I failed to find many expected species — eastern towhee, gray catbird, Cooper’s hawk, or swamp and field sparrows, for example. And many other species were detectable only in very low numbers (imagine a full day of birding on the Island that produces just one mourning dove!).
Still, a day of miserably cold birding is better than a pleasant day of most other things. The conditions challenged my ability to “think like a bird,” and the reticence of so many stressed birds demanded my most careful attention for faint call notes and hints of motion. And like most CBC participants, I take pleasure in knowing that my efforts are part of a larger bird study and conservation project. I’m hoping for more clement weather a year from now. But whatever the conditions are, I’ll be out there again, finding what I can.