Ravens

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This common raven was found in West Tisbury by Luanne Johnson on Nov. 4. This is the second recorded sighting of the species on the Island. - Ken Magnuson

While the peak of fall migration, long since past, offers the most active birding of the Vineyard year, many of the more unusual avian arrivals on the Island show up at seemingly random times. Such was the case with a common raven, found Nov. 4 by biologist Luanne Johnson in West Tisbury.

Luanne got the word out promptly, and the bird was well seen the next day by multiple observers, and photographed extensively. It has not, to my knowledge when I filed this column, been seen again. The huge crow-like bird represented just the second formal record for this species on the Vineyard; our first one, found and videoed on April 25, 2014, by visiting New Hampshire birders Adam and Rand Burnett, was likewise just a “one-day wonder,” never relocated.

Ravens, in my estimation, likely occurred on the Vineyard, and indeed throughout New England’s forests, prior to the arrival of Europeans. But the species was singled out for persecution by settlers, in part because of a cultural distaste for the raven’s habits as a scavenger, in part because in addition to scavenging, ravens prey (rarely but sometimes) on newborn livestock. The clearing of New England for European-style agriculture may not have helped ravens either; while versatility is their salient trait, they seem most at home in largely forested landscapes.

As a species, ravens retreated to rough country and high elevations. As recently as my childhood in the 1960s and ’70s, they nested sparingly at best in westernmost Massachusetts, and were unusual sights even in the New Hampshire mountains. Powerful fliers, ravens do wander and explore; but prior to the last quarter-century or so, a raven east of the Holyoke Range and the Connecticut River was a great find for a Bay State birder.

No longer so much in conflict with humans, ravens have steadily rebounded since people stopped shooting them, and now breed in all of Massachusetts except the Cape and Islands region. In this context, the sudden occurrence of two closely spaced Vineyard arrivals makes perfect sense. It’s reasonable to speculate that the 2014 bird was a youngster exploring for a potential territory, and the recent bird was a youngster as well, striking out on his own. Expect more; ravens will likely be established as breeders here within relatively few years.

Ravens resemble enormous crows, jet black but with longer, heavier beaks; longer, more pointed wings; and distinctive wedge-shaped tails. Like crows, they are intelligent, opportunistic birds, able to solve problems and exploit a wide range of resources. Their call is much more of a croak than that of a crow, and in flight, ravens spend much more time gliding, even soaring like vultures, than crows do. But size is the salient difference: the largest songbird, the common raven averages about two feet long with a four-foot wingspan. They can exceed four pounds in weight, nearly three times the bulk of the largest crow.

Though social like crows, ravens are much less gregarious, and as breeders, like a lot more elbow room. The Island might support tens or scores of breeding pairs, instead of hundreds (as is the case with crows). Evens so, the prospect of four-pound flying dinosaurs colonizing the Island merits some thought; these are powerful birds, eating pretty much whatever they want, and not often falling prey to other species.

Ravens are, above all, adaptable, and across their vast range (it spans the Northern Hemisphere), ravens in different areas live in dramatically different ways. Ravens descending from New England peaks to reclaim their original range have shed much of their wariness and become very savvy about humans. Our garbage, our agricultural activity, and our road kills would represent rich, easily exploited resources, and might supply a large portion of the diet for a Vineyard raven. (Luanne’s raven was picking insects off a paved road when found, insects likely attracted to the warm road surface.)

But ravens are predators as well as scavengers, preying, quite heavily if the opportunities are there, on small or newly born mammals, reptiles, eggs, nestlings, and even adult birds. They would, therefore, compete against (and maybe occasionally kill) other predators such as skunks, hawks, and owls. One concern, raised in a Facebook discussion of the recent raven, would be their effect on rare species, particularly the already beleaguered beach-nesting terns and plovers. One could easily imagine a raven developing the knack for eating, say, least tern chicks, and just going to town.

How a Vineyard population would choose to live, then, is an open question, ultimately to be decided by the birds themselves when or if they become established here. This column’s view is that our role should be to watch and study, rather than try to preemptively manage or eliminate any population that settles here. Ravens would have effects both negative and positive on both the natural environment and the human one. How these effects would balance out, from the human perspective, is anyone’s guess, but these are wild animals, presumably reclaiming native range and getting here on their own. I’d be happy to see them here.