The elusive shrike strikes again
In all my life, I have observed just two shrikes. Both observations were memorable; I've written about them before. In both instances, the shrikes were being what they're known to be and doing what they're known to do; that is, being predators and displaying predatory behavior. The experiences were fascinating, to say the least.
My first shrike observation was of a bird that plummeted into a patch of tall grass and then flew to a nearby hawthorn tree with a vole in its beak. I watched in amazement as the bird impaled the newly captured vole onto a thorn and began to feed on the furry mammal.
My second observation occurred while deer hunting. My son and I shared the experience, in amazement, as we watched a shrike chase a downy woodpecker from a nearby woodland into a clearing where we happened to be.
Both birds were in flight, but the shrike overpowered the woodpecker and forced it to the ground where it promptly killed the downy with two quick blows with its beak behind the woodpecker's head. We were thrilled to have witnessed the act.
Minnesota is home to two species of shrikes. My bird sightings were more than likely northern shrikes. The other species of shrike, the loggerhead shrike, is much rarer. Loggerheads are slightly smaller than northern shrikes, and it is only the northern shrike that occurs in Minnesota the year around. Loggerheads occur here only in the summertime.
Northern shrikes are about 10 inches long, which is about one inch longer than loggerheads. Northerns also have longer and more hooked bills than do their loggerhead cousins. The bills of these two species of shrikes are the only features resembling that of raptors -- birds we typically think of when birds of prey are mentioned. Shrikes do not possess strong feet and sharp talons like owls, hawks, falcons and eagles do.
Shrikes are non-dimorphic; that is, both sexes look alike. Furthermore, both loggerhead and northern shrikes have similar markings. The adults of the two species sport solid black masks across their eyes that extend along the sides of the head. They are grayish in overall color, have black tails and share similarly patterned dark wings with white wing patches that are visible when in flight.
Shrikes prefer hunting solo. Scanning the ground for prey from treetop vantages, a shrike will suddenly dive, flying low and just above the vegetation, as it prepares to attack. Prey is captured by dropping on top of the quarry, just like what my son and I observed when the shrike overtook the downy woodpecker, and when I saw the shrike fall into the grass and capture a vole.
But shrikes also feed on prey less difficult to catch. Beetles, grasshoppers, caterpillars, wasps, crickets and other invertebrates are thought to make up about a quarter of a shrike's diet. The other three-quarters of its diet, particularly in the wintertime for northern shrikes, consists of larger prey such as mice, voles and lemmings, in addition to birds as large as blue jays and grosbeaks.
Since shrikes cannot securely grasp their prey with their feet to make feeding easier, the birds will commonly impale or wedge their food onto thorns of woody and herbaceous plants, or on the barbs of barbwire fences or into cracks of branches and bark. Their hooked bills do the rest of the work as they tear off small bits to swallow. Like owls, shrikes regurgitate tiny pellets of undigested parts such as hair, exoskeletons of insects and bones.
Interestingly, in just the past few weeks, two readers have notified me about observing shrikes in their own backyards. Like my shrike sightings, both reports appear to be of northern shrikes. The first observation was reported by Tanya Ekstrom of Cass Lake. She telephoned me and left a message. She excitedly told me about watching and photographing a shrike near her bird feeders. One of her photos accompanies this column.
To keep their shrike happy, her husband, Bob, placed some carrion in a tree. The shrike took advantage of the offering and, at last report, was still being observed by the Ekstroms as it feeds on bits of meat. I was also told that the chickadees aren't too pleased about the shrike being around!
Another reader, Darrel Lillquist, also from Cass Lake, wrote to tell me about a northern shrike that showed up at his backyard. He had just tossed a dead mole onto the snow near one of his sunflower feeders and had planned to dispose of the animal later, but had forgotten about it.
Later on, after remembering the mole, he looked through the window of his house and saw a shrike in the lilac bushes, then on top of the support pole of his feeder. Seconds later he watched the shrike drop to the snow, capture a mole and begin beating the animal with its beak.
After killing its prey, the shrike picked up the rodent and flew to the woods with it. Twice more Darrel watched the shrike attempt to capture other prey, but it wasn't successful. Darrell wrote about his shrike, ". . . it stayed around for a couple days and then disappeared. So did the mole problem."
Indeed, as my friends Tanya, Bob and Darrel have come to learn, shrikes are as much intriguing as they are mysterious. As many bird enthusiasts will attest, including yours truly, seeing a shrike is a rare and pleasurable experience.
Superficially, just by looking at them anyway, most people would never guess the shrike to be the hunter and predator that it really is. Not especially imposing at all, the shrike is no more than a mid-sized songbird, but with the temperament and skills of a raptor.
Shrikes, and searching for shrikes, provide one more reason to get out and enjoy the great outdoors.
Blane Klemek is the Bemidji area assistant wildlife manager, DNR Division of Fish & Wildlife. He can be reached at firstname.lastname@example.org.