Shakespeare portends the assassination of Caesar (an unnatural act, if you’re into the divine right of rulers) by Casca’s reporting, “yesterday the bird of night did sit even at noonday upon the marketplace, hooting and shrieking.” Likewise in Macbeth, the imminent murder of King Duncan is marked by a cry in the night: “It was the owl that shrieked, the fatal bellman.” Think how many movie scenes you’ve seen in which an owl’s sudden hooting scares the daylights out of innocent little kids sneaking into a spooky situation. Owls get a bad rap, mostly for their associations.

There are perhaps two exceptions. The tiny saw-whet owl gets a pass because it’s not much bigger than a robin and really cute. Almost nobody knows anymore the noise of a file whetting the teeth of a crosscut saw. This little guy imitates it pretty well. You may remember an animated cartoon character named Gerald McBoing-Boing; his noises are pretty close, too.

The other owl, one that attracts a lot of attention in New England mainly because of its exotic origins, rarity, and large size, is the snowy owl, Bubo scandiacus. It normally lives and breeds north of 60 degrees north latitude – the southern boundary of what used to be called the Northwest Territories of Canada. It’s the official bird of the Province of Quebec. As a small boy, I got my monthly haircut sitting in a chair facing a huge lithograph of Custer’s Last Stand and, beside it, a poster advertising White Owl Cigars, in which scandiacus perched owlishly on a cheap cigar.

The Arctic tundra is the natural and preferred habitat of the snowy owl, and as long as it can satisfy its need for the equivalent of about 1600 lemmings a year, it stays there. Ookpik, the Inuit call it. Now and then its natural food source is diminished by one factor or another, and it goes looking elsewhere. It’s nomadic, anyway, and travels far and easily. When it migrates for the winter, we see it in the fields – like Logan Airport, where there’s a dangerous number of them this year – watching for prey. It’s a sit-and-waiter, rather than a searcher, like the hawks.

Their arrival invariably makes the front page of local papers. When we first moved to Hanover in the 60s, the big barn of the former Garipay Farm in Hanover was still standing beside Reservoir Road. For some years its distinctive cupola attracted a snowy owl, which peered at the Valley News photographer on at least one slow news day each winter.

Snowy owls were sought after, 100 years ago, as decorative pets in stores and shops; they spent their lives on perches with an ankle shackled. Formidable fliers that they are, there was no fate much worse for them. I’m delighted that it’s been many decades since I’ve seen one in that situation. One of my favorite poems as a kid was a chestnut named “The Owl-Critic,” by New Hampshire-born poet James T. Fields. I’m astonished to see it’s posted online. It’s a tale of a young critic of a terrible taxidermy job on a white owl that turns out to be alive.

Harry Potter’s magical communication system is a snowy owl named Hedwig, who suffers so many indignities in the course of her duties it’s a wonder she’s still alive, or hasn’t resigned.

Snowy owls are being spotted in New England again for the third winter straight. They’re often referred to as “invaders,” as if they didn’t belong here – much the same way, I suppose, the native Americans thought of our Puritan forebears. We’ve seen them all over, from the Parker River Wildlife Refuge in Massachusetts to open stubble fields in the glacial hills of Central New York. They like to perch where they can see all around them with their 270º head-swiveling ability.

Paddling through the barrenlands on Victoria Island at 71 degrees north, my friends and I were intrigued by little earthy mounds a few rods apart along the riverbank. They had vegetation on them, too, unlike the surrounding soil. Turned out they were snowy owl nesting sites and hunting platforms. Many decades of use had built the mounds of tiny bones, pebbles deposited by the owls, and their droppings, which encouraged the greenery.

We paddled through the semidarkness all one night and, on a high bank above us watched an irresistible drama. A large snowy owl hovered ominously, trying to grab a Canada goose gosling from a little flock of perhaps half a dozen, while the frantic parents squawked and flapped at the owl whenever it dipped down for another pass. Our natural human impulse was to yell, “Shoo!” at the owl, and perhaps race up the bank to save the day. But there was nowhere for dozens of miles for the geese to hide – not a stick of wood, let alone a thicket – and nothing we could have done to affect the outcome of the attack. As we looked up, watching, the birds passed out of sight behind the top of the bank. We saw the owl’s wings for a couple of seconds, and then even the sound of the confrontation was lost. We paddled thoughtfully for a while, rooting wordlessly for the little geese behind us. But we were predators ourselves, just like the owl. I think of him and his constant search for food whenever I see one of his relatives down here on their never-ending hunt.