Who’s the assassin? Did you see, in the police line-up, among the hawks and snakes and foxes and weasels and owls, one that didn’t seem to belong?
A little songbird, no bigger than a robin, wearing a black mask? No, it couldn’t be, and yet…that cruel little downturn of the beak…
One of our oddest predators, the shrike is more closely related to the harmless jays and vireos than to hawks and falcons. Its name is related to the word “shriek,” but whether that’s the sound it makes or that of its victims, no linguist can say. While the bird’s close relatives eat plenty of insects, the shrike itself preys on larger game: rodents, lizards, and, amazingly, other birds. Lacking the powerful legs characteristic of other raptors, the shrike has evolved a strong, hooked bill used (along with its feet) to catch and kill its unfortunate victim
Photo by Dave Menke
But the atrocity doesn’t stop there! Food is at a premium, and the bird must capitalize on every hunting opportunity. As a result, the shrike frequently kills, if possible, more than it can eat at one sitting, storing the leftovers by impaling them on a thorny branch or a strand of barbed wire. This gruesome cache is given an unusually vivid technical name: “the larder.” The practice seems barbaric, like exhibiting heads on spikes along London Bridge. For shrikes, too, that exhibition itself may even serve a purpose: to woo their mates, male Loggerhead Shrikes have been known to pile up multiple corpses in a larder and then garnish them with an assortment of beaks and feathers. A grim courtship offering, one that might win over a Lady Macbeth.
A Loggerhead Shrike's "Larder"
Other than speed, agility, and surprise, the shrike has another trick up its sleeve, one not often observed: it sings like a Siren. Not an ambulance’s—no, like the Sirens of Greek myth, whose uncanny human voices were so mesmerizing, mariners would change course the better to hear them…only to be wrecked on their rocky island and subsequently devoured. The shrike, not known for its singing, sometimes imitates the calls of other birds in order to draw them in. Such behavior has been known for hundreds of years. The Boke of St. Albans (1486), an early English compendium of hunting-related information, contains this lovely passage about the Northern Shrike:
“She will stand at perch upon some tree or poste, and there make an exceedingly lamentable crye and exclamation…all to make other fowles to thinke that she is very much distressed and stands in need of ayde; whereupon the credulous sellie birds do flocke together at her call. If any happen to approach neare her, she…ceazeth on them, and devoureth them (ungrateful subtill fowle) in requital for their simplicity…”
Northern Shrike, Scanning for Supper
Photo by Sharon Harvell
The credulous sellie birds. Can you blame them? The silhouette of a shrike overhead hardly looks predatory. Other than that subtle beak, what’s in its shape to distinguish it from other insectivorous birds? Why should the titmouse or the goldfinch instinctively react with alarm? Many stories of “shrike attacks” contain this common element: the birds being chased seem, initially, not to take the chase very seriously! And this—for the quarry, at least—spells trouble. Perhaps the shrike, even tens of thousands of generations after splitting off from the rest of its peaceable passerine family, is still profiting from its mask, from being a wolf in sheep’s clothing.
First-year Northern Shrike
Photo by Nigel "Winnu"
Nevertheless, a shrike’s presence is often announced by a synchronized panic of a songbird flock, all fleeing to the nearest cover in a dense hedge or rhododendron. Listen for the “seet, seet” alarm calls of your local chickadees and nuthatches, an early-warning system alerting each other (and you, too!) that danger’s been spotted. (You can sometimes hear similar calls, though somewhat less urgent, when you yourself walk out to the birdfeeder.) Wherever you are in the Continental 49 (south of Fairbanks, at least), there’s a chance of a shrike visitation at your birdfeeder this winter, and it’s not coming to dine on sunflower seed!
The Northern Shrike (Lanius excubitor: meaning, “the watchful butcher”) winters as far south as Maryland, Iowa, and, in the West, even New Mexico. It’s an irruptive migrant, meaning that its annual movement south each fall is tied to the abundance of food near the breeding grounds. In “good” years (that is, good for bird-watchers), when food is scarce to the north, many shrikes are forced to seek their fortune further south; other winters, just a handful will show up in any given region. The Loggerhead Shrike (Lanius ludovicianus), a smaller and more southerly species, is less migratory through much of its range. Both tend to perch in conspicuous places, often on the tip-top branch of a leafless tree or bush in rather open surroundings. This winter, keep an eye out for its long-tailed silhouette, flashing black-and-white wings on takeoff: it’s a more subtle, more wonderfully foul fowl than it seems.
Photo by Henry Walters
Henry Walters is a naturalist, a teacher, and a falconer. He lives and writes in a cabin in southern New Hampshire on a 1,700-acre tract of conservation land, of which he acts as steward. His poems, essays, and translations have appeared or are forthcoming in a number of print publications, including The Old Farmer's Almanac. He is the co-founder of the Harriers, a club for young birders throughout New Hampshire (nhyoungbirders.org), and as a seasonal naturalist for the New Hampshire Audubon during the fall hawk migration, his writing appears on the blog (www.hawkcount.org) for Pack Monadnock Raptor Migration Observatory. A book of poems, Field Guide A Tempo, will be published in the fall of 2014.