The start of the new year coincides with the closest we ever come to a true pause in the movement of birds through our region. Fall migration has ended, though a few disoriented individuals or stragglers may still be wandering. And the first inkling of spring migration, in the form of incoming red-winged blackbirds or northbound ducks, is still a month or so in the future.
But there is no such thing as true stasis in the bird world, and indeed, the first days of January are as good a time as any to hope for the arrival of our most interesting avian visitors. A good example would be the dovekie, a tiny but incredibly hardy seabird that is rarely seen on the Vineyard, but has lately put in an appearance.
Dovekies are members of the auk family (the European name for the same species is “little auk”). Like other auks, the dovekie is strongly associated with oceanic habitats: sea cliffs in Greenland, Iceland, northernmost Europe, and arctic islands during the breeding season, and cold Atlantic waters, generally north (sometimes far north) of the 42nd parallel in winter. [Martha’s Vineyard Airport is at 41.39 degrees N.]
Abundant birds, dovekies are estimated to number in the millions. But their maritime lifestyle keeps them in remote regions and, usually, far from land except when they’re nesting; it’s easy for a Vineyard birder to go for years without seeing one. But photos have recently been taken of dovekies at Menemsha, Lambert’s Cove, and Vineyard Haven harbor, and a dead one was found on land at Cedar Tree Neck. A spate of other sightings in southern New England suggest that this may be a good year for finding this odd bird.
Like many other kinds of seabirds, dovekies are subject to being driven far off course by storms. When coastal storms coincide with a robust movement of dovekies, hundreds of these birds may be blown far inland, where many or most perish from exhaustion, starvation, and an unfortunate inability to get airborne once they’ve landed on a hard, flat surface.
But storms don’t account for all the wanderings of this species. Dovekies have turned up many hundred of miles south of their normal wintering range, often with no indication that bad weather accounted for their occurrence. And sometimes mass movements of these birds have been observed from coastal vantage points under fine conditions. However they gain it, dovekies obviously have a sophisticated understanding of geography and are capable of prodigious movements in search of resources.
Black-and-white, barely eight inches long and a foot across the spread wings, and weighing in at about six ounces, a dovekie is about the size and build of a mourning dove missing its long tail feathers. Like all the auks, a stocky family, dovekies are marginal aerialists, able to keep aloft only through comically frantic wing-beats. Nesting on sea cliffs, they take off by plunging toward the water to build air speed, and taking off from water requires a long take-off run.
But in the water, it’s another story. Dovekies, like all the auks, spread their wings to “fly” underwater and a dovekie can dive to more than 100 feet and stay submerged for several minutes if it feels the need. In effect, they’ve followed the same evolutionary route of the penguins, only not quite as far: auks retain the ability to fly, but their true home is in saltwater. It’s hard to believe, but millions of these tiny birds survive winter on the frigid waters of the North Atlantic each year, often without ever setting sight on land.
One secret to the success of the dovekie is probably the dietary preference of this species. They are known to feed primarily on plankton, especially the tiny but not truly microscopic arthropods that make up the lower rungs of the marine food chain. Focused on a plentiful and widespread food supply, dovekies may have an advantage over their larger relatives, most of which focus on fish — a less evenly distributed and less dependable food source.
Oddly, the birds recently photographed on the Vineyard were feeding on Atlantic silversides, schooling fish that range up to about five inches in length. This food choice is hardly unprecedented in dovekies, which are opportunistic and frequently include small fish in their diet. But the presence of these birds inshore, and in areas rich in bait fish, make one wonder whether something has happened to the offshore plankton supplies that would normally be sustaining these birds.
How long the species will linger here is anyone’s guess and hopefully at least one will stay for this weekend’s Christmas Bird Count! But Island birders are happy to have an opportunity, however brief, to search for this hardy, mysterious bird.