Facebook is a wonderful tool for sending me weird questions. For instance, a friend in Portland just messaged me, asking if it was possible that he had seen a robin kill and eat another robin.
I’d never heard of such a thing, but the world is full of things that hypothetically exist yet have never been seen, such as gravity and the president’s tax returns. So I searched the Internet to see if I could find the facts, or even alternative facts that would support the possibility that robins would eat each other. Nada.
True predators require tools, such as bills designed to tear flesh. The bill of a robin can’t even dismember an earthworm or chew a crabapple. Both are swallowed whole. Robins might fight over territory, but it’s more like a boxing match than a knife fight, and the loser isn’t dinner. I suspected the real culprit was the one songbird in Maine that would eat another songbird – a northern shrike.
Shrikes are about the size of a blue jay or mockingbird. In fact, it resembles a mockingbird with a black mask. The wings are black with white wing patches.
The shrike name is derived from an old English word that is also the root for the word shriek. Many shrikes are known for their shrill cries. The shrike’s ornithological name, Lanius Excubitor, reflects its common nickname, the butcher bird. It preys on small birds, mammals, and insects, often impaling a meal on a thorn or barbed wire so that it can finish it later.
There are 31 species of shrike worldwide, but only two in North America. Loggerhead shrikes are well distributed through most of the southern United States, but rarely wander as far north as Maine. Northern shrikes breed in the taiga and tundra regions from Alaska to Labrador, and a few wander south each winter.
For the last couple of years, shrikes have been very few. Like most Canadian visitors, shrike incursions can vary greatly from winter to winter. I saw none last year, and only one the year before. But three years ago, I enjoyed a dozen sightings. So far this year, I’ve tallied two, including one that I spied in a treetop next to the highway north of Bangor Mall last week.
Northern shrikes may be unusual here, but when they’re around, they’re not hard to see. They habitually sit at the very tippy-top of trees, where they can watch for prey. That’s the behavior that always catches my eye. They will perch there even on a windy day, swaying in the breeze, holding on for dear life. They should worry about becoming hawk food, yet they are fearless. They probably figure that if they are nimble enough to snatch a chickadee, they are agile enough to dodge a hawk.
In the bird world, agility requires short wings and fast flaps. The northern shrike has a funny flight that consists of rapid flutters punctuated by brief glides. Few other species share this erratic, undulating flight pattern. Perhaps 90 percent of the time, I spot shrikes sitting in treetops, but I discovered my first shrike this winter when I noticed a bird fluttering in shrike-like style.
Shrikes are, indeed, songbirds. It’s a pity that they don’t sing here. They are surprisingly musical. I’ve heard only two in my life. One was on its breeding territory in northern Manitoba. The other was a male near Bangor Mall that happened to stay later in spring than normal. He was practicing his aria before migrating home to the tundra.
And shrikes are, indeed, predators. Years ago, I watched a shrike chasing house sparrows around the McDonald’s in Brewer. In fact, when house sparrows were brought from Europe in the 1870s and introduced to America, a sharpshooter was hired to protect them on Boston Common. He killed 50 shrikes that winter.
Shrikes do not have talons, as hawks do. They strike their prey with a body slam, then use their hooked, razor-sharp bills to quickly snap the bird’s neck — Nature’s way of being simultaneously cruel and humane. Their feet can carry prey, but not tear flesh, so shrikes are confined to using their bills to tear off bites.
Four years ago, I watched a shrike catch a mouse. I figured he would alight on a tree branch and chow down. Instead, he hid in the bushes to enjoy the meal. I realized that he didn’t want to be seen and risk having his dinner stolen. They’re clever birds, too.
Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. He developed the Maine Birding Trail, with information at mainebirdingtrail.com. He can be reached at firstname.lastname@example.org.