Wild Side: Spring orioles

Spring songbird migration on Martha’s Vineyard is a highly variable phenomenon from year to year. Sometimes, about all that happens is that our breeding birds gradually filter in, set up shop, and start nesting. Other years, though, the vagaries of bird movement result in a steady stream of unusual arrivals.

While surely not the best spring on record, 2023 has established itself as one of the more productive migrations in recent years. Between mid-April and mid-May, rare or uncommon birds here included yellow-throated, prothonotary, hooded, bay-breasted, and cerulean warblers (the last of these, quite rare here, beautifully documented); white-eyed vireo; a couple of blue grosbeaks; a veritable torrent of indigo buntings; multiple blue-gray gnatcatchers; at least two veeries; and several purple martins.

While they generate less excitement, our normal breeding birds seem to be having a good spring as well. I have only impressions, not hard data, to offer, but it seems like many species arrived in unusually large numbers. Whether all these birds remain to breed is still an open question; many may be unable to establish territories, and will opt to move farther north. But for the moment, the Island seems unusually well equipped with catbirds, orioles, great crested flycatchers, and towhees.

Rare vagrants are all fine and well, but it’s these common breeding birds that really raise the standard of living here in spring. And if I had to pick one species that brightens the season, it would be the loud, garish, sometimes pugnacious Baltimore oriole.

The abundance of this species is often under-appreciated: The Baltimore oriole tends to be a treetop species, spending most of its time well above the ground, and both males and females are adept at staying hidden in foliage. But if you cultivate the knack of noticing this species in flight at a distance, or especially if you learn its vocalizations, you’ll realize that the species is nearly inescapable on the Vineyard.

Orioles like edge and semi-open habitat; the Baltimore oriole is not a species you tend to find in the middle of closed-canopy oak woodland, which dominates substantial parts of the morainal sections of the Island. But in other habitats, ranging from residential neighborhoods to woodland edges and clearings, the clear, whistled song of this species is a major part of summer’s soundtrack.

It’s a song you must learn to recognize by tone quality. Each bird has a repertoire of several distinct melodic patterns, and so trying to recognize the pattern of notes given by this species won’t help. But the ringing quality, once you learn it, is evident even from a single note. Both sexes, when agitated, also give a highly distinctive chattering call that may last anywhere from a fraction of a second to three seconds or so.

But of course it is the plumage of this bird that attracts the most admiration. Males are black on the head, back, and wings, but orange, orange, orange on the breast and belly — the kind of orange that sears your retina. It’s a wonderful thing to see after the gloom of winter, and the sight of a male oriole never fails to lift my mood. Females and immature birds, which will be in evidence by mid-June or so, show a similar pattern, but with a muted orange.

Equipped with a long, sturdy, and fine-tipped beak, an oriole enjoys a varied diet. Especially when feeding growing young, they take huge quantities of insects, with a special fondness for caterpillars and other larvae that they winkle out of flowers and foliage. But the species is also notoriously fond of fruit, berries, and even sweets like jam or jelly; putting out split oranges is a time-honored way of attracting orioles to your yard.

Orioles weave pouchlike nests from grasses and fiber. Typically these hang from the end of a branch up high in a deciduous tree. Despite their placement, though, oriole nests can be well concealed, and it is often not until the leaves drop in fall that I learn the exact placement of the nests of our local orioles. Like other songbirds, orioles often build multiple nests, only using one for egg laying; the extras are either rejected for some reason clear to the birds or, perhaps, are decoys built to confuse potential nest raiders.

Survey data show a complex story for the status of this gorgeous songbird. Numbers recorded in breeding bird surveys are trending steadily downward across the bird’s range, which may reflect problems either in the breeding range or on the wintering grounds. The Massachusetts Audubon Society’s state breeding bird atlas project, though, showed the Baltimore oriole occupying more habitat (though perhaps not actually increasing in numbers) between the 1970s and 2011. And perhaps reflecting milder winters, reports of orioles lingering into and even through the winter in the U.S., far north of the core wintering grounds in the Neotropics, have steadily increased in recent decades.

In any case, keep your ears and eyes open for signs of this beautiful species. It’s the avian essence of summer on the Vineyard.