Snow buntings

Snow buntings are a rare treat on the Vineyard in the winter. They are easy to spot, with a prominent patch of white wing and outer tail feathers. —Ken Magnuson

Some winters back, I was out birding Lobsterville with the late Vern Laux and a couple of beginning birders. When we found a flock of snow buntings scuttling across the barren beach, one of the beginners asked, “What do they eat?”

“Sand,” replied Vern, in a perfect deadpan.

Of course he was joking. While snow buntings, like other birds, may ingest grit accidentally, or on purpose to aid the digestion of seeds, birds cannot live by sand alone. But given the habits of this elegant songbird — its association with winter, the high arctic, and austere, open environments — one could suppose that Vern’s answer was serious.

On the Vineyard, these birds are an uncommon and irregular wintertime specialty, turning up for at least part of most winters, but coming and going on no predictable schedule. While Island records span the period from early October to mid-April, a average arrival date is probably around the middle of November. The species will be here, intermittently and often in fair-size flocks, through the colder months until, as is the case with many other wintering species, they abruptly disappear.

When they’re around, snow buntings are invariably found on open land: Beaches, plowed fields, sometimes pastures or fields if the grass is short. Over the past few years, flocks have turned up with some regularity along the Beach Road between Oak Bluffs and Edgartown. And a dirt parking area near the end of Herring Creek Road (the “Right Fork” out to Katama), just north of the Herring Creek, seems to hold some mysterious attraction for these birds.

While they may not be feeding on sand, their actual food — largely grass seeds — is so tiny that it’s hard for a human to imagine how these birds subsist in cold weather. (They are reported able to flourish in temperatures down to -30° Fahrenheit, and to survive even deeper cold.) On their breeding grounds, they take whatever insects are available, and even at our latitude, insects surely figure in their diet if the weather is warm enough.

How they avoid starvation is a good question. Sharp eyes are clearly part of the answer, along with wasting very little time: snow buntings feed almost constantly, and are active from first light until darkness. While they pick most of their food off the ground, they reach up or even hop into the air to take seeds from a standing stalk. Standard life histories of this bird report that they sometimes perch in trees; while I’ve seen the odd snow bunting perch on a wire fence, I can’t recall seeing one roost any higher off the ground than that.

If their hardiness here is impressive, their habits in the rest of the year are awe-inspiring. After a winter of irregular wanderings, the population drifts north on a variable schedule, apparently determined by the weather. While there are a few breeding outposts at temperate latitudes — Cape Breton, mountaintops and northern islands in Scotland — the core breeding range of this species, which occurs around the Northern Hemisphere, is the high Arctic. They nest as far north as there is land, cramming their entire breeding cycle into the few months of very long days of an Arctic summer.

Even on their breeding grounds, snow buntings are said to prefer areas with little vegetation: beaches, hilltops, and outcrops, in preference to grassy tundra. Prudently, given the high latitude at which they nest, snow buntings typically build their nests in sheltered spots: crevices among rocks, under clumps of moss, or even, reportedly, inside the odd musk ox skull!

Distinctive pale birds with prominent white wing patches and white outer tail feathers, snow buntings are not hard to spot if they’re around. They molt into fresh feathers in late summer, while still on their breeding grounds. But over time, the brownish feather edges of this fresh plumage wear off, eventually revealing the striking black-and-white pattern of their breeding plumage.

Single birds are sometimes encountered, but the classic sighting involves a flock of dozens or, sometimes, hundreds. Constantly alert for predators such as falcons, snow buntings take flight at the least sign of danger. Even when not alarmed, a flock often moves briskly across the ground in a distinctive rolling pattern.

Experienced birders never assume that a flock of snow buntings consists only of snow buntings. Other open-country songbirds may be mixed in, so it’s worth checking carefully for pipits, horned larks, or, especially, Lapland longspurs, which are rare on the Vineyard and may turn up with snow buntings more often than on their own.

Snow bunting call notes are also distinctive, though often hard to hear, given the preference of these birds for windswept areas. They give a very musical “Teu!” note, as well as a sort of “prrrt” call that sounds to me like the teeth on a comb being plucked.

I wish I could steer you toward a spot where you could count on seeing snow buntings. But their erratic habits make this impossible. Still, if you spend enough wintertime on beaches and near open fields, your odds are good for encountering these rugged little travelers.