Sometimes the most fleeting glimpse of a bird is enough to hint at a rarity. Something about the shape, the color, the flight, the location, the behavior. Seasoned birders know what is expected and what is not, so they react very quickly to the possibility of an unusual species. Last fall I was walking the south side of Black Point Pond in Chilmark with two birding chums, when a dark brown shape the size of a large owl skimmed over the dune grass to the ocean side, out of sight and maybe lost to us. I said to the wind, “I bet that was a whimbrel!” I hustled to the top of the dunes to scan both ways along the beach. No large birds in sight. We moved east along the pond edge, enjoying great close-up looks at semi-palmated and white-rumped sandpipers. Then we rounded a sandy point to enter another crescent of shoreline, and there, dead center on the beach, was a gorgeous whimbrel, a curlew of regal stature and plaintive cries. This shorebird, among the thousands of its kind making their way south to distant landfalls, had somehow graced the Vineyard with its presence.
Across the United States and Canada, birders may tally about sixty species of shorebirds. On the Vineyard, a very good year might produce more than thirty of these. Like their human counterparts, there are the tourists passing through, the ones that are seasonal residents, and those that remain throughout the winter. The seasonal residents include six species that nest on the Vineyard. Three are common here and easy to find: the American oystercatcher, the willet, and the recently notorious (and endangered) piping plover. The three others – the killdeer, the spotted sandpiper, and the American woodcock – are not as plentiful here, nor easy to find.
The shorebirds moving through the Vineyard in the spring are in a hurry to get north and do not linger. By Memorial Day, black-bellied plovers and the rarer golden plover have migrated through; dunlins and sanderlings, some of which may have wintered here or nearby, have headed out; the wintering purple sandpipers are long gone; very small groups of red knots touch down briefly; and a few yellowlegs, ruddy turnstones, and even a pectoral sandpiper may show up, but will not stay. The only ones that stay here intend to raise a family.
During June and the first half of July, there is a dearth of transient birds on the beaches – just the locals are here. After about three to four weeks of brooding, babies generally emerge in June and it’s another three to four weeks before the young can fly. As mid-summer advances, southbound birds fresh from the Arctic start arriving – short-billed dowitchers, semi-palmated plovers, black-bellied plovers, least sandpipers, and others. We are used to thinking of birds migrating south as an annual phenomenon that occurs in the fall, but many shorebirds begin their passage south by late July or early August. They are likely adult birds that have left their self-sufficient young to fend for themselves during the long days of the short Arctic summer. The youngsters will quickly grow new body and flight feathers, then wing southward guided by instinct alone. The migratory arrivals here, including those within the same species, may be spread over a wide time span.
The shorebirds that come here to nest have no interest in flying any further north. They have evolved to prefer the habitat and foods they find right here, and in contrast to the long-distance migrants, they tend to be much more engaged with the upbringing of their broods. Because of the more temperate climate on-Island, they can arrive relatively early and depart relatively late in the season and thus spend time teaching their offspring how to manage. They also have to deal with a more daunting concentration of predators and other environmental dangers, from great black-backed gulls and night herons to skunks and Jeeps.
The pattern of shorebird migratory routes north and south across the U.S. and Canada is apt to be asymmetrical. It varies with the species. Many shorebirds migrate north through the middle of the continent, while some fly up along the coastlines. A typical series of stopovers for southward flights from the Arctic tundra could include the Hudson and James bays, and the Bay of Fundy off New Brunswick, all in Canada, then South Beach and the Monomoy Islands off the elbow of Cape Cod. After that, they may make their way via Nantucket, the Vineyard, and on down to Cape May, New Jersey, or the Carolinas’ Outer Banks. But depending on the species, the weather conditions, and the intended destination, they could just as likely set out over the open ocean from Newfoundland, Nova Scotia, or New Brunswick on incredibly arduous and dangerous non-stop journeys to destinations in South America, with landfalls in Surinam, Venezuela, or the north coast of Brazil. It’s hard to fathom, but some shorebirds routinely fly more than two thousand miles without food or rest. If they stop flying before they reach land, they die. It’s that fundamental.
Researchers studying the migrations of shorebirds from the Arctic to Patagonia and back to the Arctic recaptured a bird in 2000 that had been first trapped and banded in 1987. They knew they held in their hands a red knot that was at least thirteen years old; its body was less than ten inches long, and its wingspan about twenty. The migration flights of one of these birds add up to about 9,300 miles, each way, each year. That captive bird in 2000 had flown in its lifetime as many miles as it takes to fly to the moon.
Shorebirds are a taxonomic group that includes species of diverse structure (size, shape, leg and bill length) that are connected by behavior (wading, eating invertebrates, and producing precocial young that hatch with near-immediate self-sufficiency) and habitat (tidal zones, marshes, and open tundra). Red knots fall toward the middle of the size spectrum for shorebirds, about midway between the smallest sandpipers, referred to collectively as peeps, at one end, and avocets, curlews, oystercatchers, and godwits at the other.
In September of 2007, satellite tags attached by researchers to bar-tailed godwits summering in Alaska showed that these large shorebirds accomplish the longest known non-stop flight of any bird when they cover more than 7,100 miles over open Pacific waters to get to New Zealand for the austral summer. It took the record-setting bird nine days, flying at up to two-and-a-half miles high and an average speed of just under thirty-five miles per hour. Amazing!
What the southbound migrants are doing on our beaches is fueling up for these long flights, sometimes even doubling their weight with fat reserves at this food-rich foraging stop. If the food resources were not here, the birds would pass us by. While we do not get the volume of birds found at some other staging sites, such as Hudson Bay or the Bay of Fundy, we do have the same variety of species that gather elsewhere. We are located at the edge of a funnel for migrating shorebirds winging south.
The Vineyard’s dunes and sandy expanses of barrier beach are essential to certain species for nesting, foraging, and resting. (As a general rule, shorebirds tend to rest during a high tide and forage when more beach is exposed.) However, the miles of shoreline around the perimeter of Martha’s Vineyard are not the only places attracting shorebirds. Tidal bays, estuaries, and marshes flooded by seawater are probably the most important habitats for providing food. The great ponds strung along the southern side of the outwash plain, especially when open to the Atlantic, are very attractive to shorebirds that will feed on the abundance of life within and washing over tidal mud flats.
For anyone moving through shorebird habitat, remember that human-related disturbance can amount to habitat loss, so please tread lightly near feeding or resting shorebirds. For example, don’t allow your adorable young canine to rouse a flock of sleeping birds.
August is really good for shorebird watching on the Vineyard. The locals are fledged, and many of the long-distance migrants are here beefing up for strenuous journeys ahead. By fortuitous coincidence, Labor Day weekend has peak potential for vagrant birds showing up on the Cape and Islands. Unusual species, generally single birds, tend to arrive around this time in their post-breeding dispersal. They are often juveniles that have wandered off track during their inaugural migration trek. Storms and strong winds from the east or south are also factors that will ground shorebirds on the Vineyard until conditions improve for moving on.
That whimbrel we saw at Black Point was led there by eons of collective experience, influenced by the shifting forces of pressure systems, temperature gradients, precipitation, and the length of daylight. Often it is only a single of this species that one encounters, a sentinel on the beach, a golden-brown, exquisitely tailored traveler, assessing its next move. Then from overhead, a whimbrel call – a set of even liquid whistles – says this bird is not alone after all, and it lofts to join the others of its kind.
Six shorebirds that nest on the Vineyard
American oystercatcher
The most distinctive shorebird around, resident or transient, is the American oystercatcher (Haematopus palliatus). Its prominent orange-red bill, striking white-over-black coloring on the wings and tail, and its insistent whistling calls are anything but subtle. With boisterous courtship and territorial displays, breeding pairs vie for nest sites from Dogfish Bar in Aquinnah to the outer reaches of Cape Pogue. Instead of melding into the barrier-beach background, oystercatchers actually stand out at quite a long distance both visually and audibly. Presumably their vigilant and staunch defense of their young against predator threats is key to their fledging successes, as they aggressively brandish a long chisel-like bill that routinely conquers bivalves (which, as we know, is very much an acquired and respected skill among those other bivalve predators – the ones that boast arms, opposable thumbs, and clam knives).
Vineyard Birds II (Vineyard Stories, 2007) cites 1969 as the first breeding year recorded for American oystercatchers in the state of Massachusetts. Those first nests were discovered at Cape Pogue and at Wasque on Chappaquiddick. Since then the northern-range expansion of the oystercatcher up the East Coast has been extensive and they are now a widespread and expected colonizer of the Vineyard’s beaches. By their unique looks and hysterical antics, they have become iconic here. If you are fortunate to encounter these birds up close – they can be very friendly if you are digging for clams as the birds look for leftovers – or by optical means, note the stout, pale pink legs that often carry a plastic identifying band; and look at their red-rimmed yellow eyes, unlike any other bird’s.
Willet
If you approach a tidal marsh and soon hear a lot of complaining from a light brown, crow-sized bird with long legs, that’s likely a willet (Tringa semipalmata). They have very little tolerance for intruders into their nesting territory. They see you coming, make a big loud fuss, and persist until you are well gone. This aggressive defense of territory must work, because the willet never flags in its dedication to making the interloper regret the choice to pass through. If you do not get the message, willets will fly right at you at eye level, flaring at the last moment or winging right over your head. It’s really not a game to them, and they let you know it. They are best viewed from a distance or when they no longer have young at risk.
Willets are marsh specialists during the nesting season (the youngster pictured above is almost as large as its parents, but it still looks like a teenager). Sengekontacket, Eel Pond, and Katama Bay are likely locations for them. When the young can fly, willet families are apt to venture farther afield, and it is not unusual to see them foraging along the ocean shore.
It is curious from an evolutionary point of view that both the oystercatcher and the willet have a similarly striped wing pattern that boldly flashes black and white, while the body feathering of a willet is cryptically patterned in gray and brown, and that of the oystercatcher is eye-catching in bright white and blue-black.
Piping plover
The “piping” in the name refers to the plaintive whistle of the adult birds. Piping plovers (Charadrius melodus) are colored like light sand and prefer the upper beach much of the time, at least for raising young. In size, plumage pattern, and behavior, they are very similar to semi-palmated plovers, which do not nest here but are common in transit. Itinerant semi-palmateds are brown-backed to match the darker mud flats where they forage. If you find both species resting together at the beach, the dark ones are apt to be standing next to something dark, like seaweed on the wrack line, and the light ones will be on the light-colored sand.
The federal Endangered Species Act gave protection to the piping plover, designating it as “threatened” back in 1986. We are lucky to have a number of pairs tolerant enough of all the traffic at our beaches to attempt nesting every year, though the attempts are often not successful – even with the protections (fenced exclosures and roped-off areas) from human, pet, and vehicular interference during the nesting season. People usually do not willfully destroy the nests; they just don’t see the eggs or young and tread on or drive over them. The habit of plover young to crouch down unmoving when under threat and to seek refuge within depressions in the sand, like tire tracks, is counter-productive in this respect. A dedicated team of predators is also at work and often competent: Crows, gulls, harriers, night herons, and skunks lead the list of consumers. Spring storm washovers by ocean waves often destroy the first nesting attempts or kill the eggs by soaking them.
Killdeer
The killdeer (Charadrius vociferus) is known for its spectacular distraction displays to fool predators (including humans) by feigning a broken wing and dragging it pitifully on the ground until a safe distance away from its eggs or young. While they may be found feeding or resting in a tidal zone, they don’t need to be near the ocean and they actually prefer upland habitat – open grasslands, gravelly areas, and plowed fields, such as Katama’s agricultural land – for nesting and raising young.
Their body plumage patterns are high-contrast. However, like a lot of strongly marked birds, the breakup of silhouette by distinct design allows the bird to disappear against many backgrounds. First you don’t see them, then maybe you do. Picking out an unmoving killdeer in a field of plowed farmland is an acquired skill.
Spotted sandpiper
The spotted sandpiper (Actitus macularius) frequents the littorals of fresh and brackish waters and is sometimes seen bobbing along the edges of the great ponds, Squibnocket Pond, freshwater ponds along the north shore, and occasionally at the ocean where there are rocks. This seven-inch-long sandpiper is a monochrome buff-brown with a weak, whitish wing stripe, and it is white below with dark spots in its breeding plumage. As with many relatively plain birds, there are beautiful and refined details in the plumage when seen up close.
When plumage and structural details are out of range, other attributes make for easy identification at a distance: their habitat preference; their body language, which includes a constant and distinctive teetering; their in-flight call; and a flutter-and-glide flight usually low over the water, with stiff, shallow wing beats. Also of note, in terms of behavior, spotted sandpipers are often polyandrous: The guys raise the brood, and one female may produce separate clutches with different males.
Confirmed nesting records for this species, which used to be more widespread, are hard to come by. Locations on Noman’s Land and along Tisbury Great Pond are cited in the published census. A casual survey of active on-Island birders produced no recent claims of actual nest discoveries. Most speculation about nesting sites derives from sightings of youngsters in the summertime and focuses on the Squibnocket area, the fresher upper reaches of the great ponds, and those north-shore freshwater ponds.
American woodcock
If the oystercatcher is the most outrageous shorebird on the beach, then the woodcock (Scolopax minor) is the most outrageous shorebird off the beach. It is a denizen of bogs, thickets, and the leaf litter of the forest floor. The problem is finding one – though they are known to nest here and there on the Island. You will not find them at the beach or in the tidal zone where other shorebirds dwell. They are secretive, to the point that you have to almost step on them to provoke them to flight, and they are so cryptically feathered that it is nearly impossible to spot them unless they do fly, when their exit is explosive. When they walk, the gait is a slow, rhythmic bounce – more like a chameleon than a bird. Appearing much like a cross between a grouse and a sandpiper, this bird is short-winged, short-legged, very long-billed, and round like a soft football, with extra-large eyes set fairly high on its head. The long bill is for sensing and grasping earthworms deep in the soil, so the woodcock, also known as a timberdoodle, prefers moist and penetrable soils to find its meals.
The male woodcock can arrive on the Vineyard in the spring almost anytime from March on. He will seek out an open field bordered by scrub or forest and use this spot to begin his dance and launch his wondrous aerial display antics to attract a mate. These display flights are nocturnal, beginning just as the last light fades in the west on a clear night, or at dawn. The performer makes a distinctive peent sound at ground level as he prepares for the flight. He heads upward in broad spirals until out of sight, his wings making a twittering sound as he rises. From way on high, he then dives steeply and zigzags to earth as specialized feathers in his wings produce a third distinctive sound, a sharp chirp. The chirping ceases and there is dead quiet as the woodcock glides on silent wings back to his departure point out in the open field to resume the dance again. This performance is enthralling to observe, since the different sounds, once learned, tell you what he is doing just by listening in the dark.
