It is always thrilling to see a shrike, even in bloody encounters. We once came upon one on a Sunday morning as we arrived home from church. The predator was pursuing our male cardinal around in the shrubs adjacent to the birdfeeder. Wings were fluttering, feathers flying. When the red bird whipped past me, I had never seen a cardinal fly so fast. By then, I was waving my arms and yelling; the commotion derailed the shrike just enough for the cardinal to escape.
Minnesota ornithologist T.S. Roberts called shrikes “bold and courageous;” Cornell University, “burly” and “bull-headed.” On the recent Christmas Bird Count (CBC) I realized that in the field, shrikes present themselves in two different ways: one either spots them perched on the top of a small tree, or sturdy weed, a “look-out post”; or, one sees first a commotion in the bushes and then a scattering of small birds, fanning away from the predator.
Northern Shrikes are winter visitors to Minnesota, appearing erratically. Some years the CBC records many shrikes; others, none, although there are “invasion years” when many are seen. The birds have no record of breeding within the state. In North America they nest in the high north of Canada on the edge of the boreal forest/tundra. There, dwarfish brushy trees edge open areas, good habitat for many of the small mammals—mice, voles, shrews and lemmings—that make a meal for a shrike. (The similar-looking Loggerhead Shrike does breed in Minnesota, although it is classified as a state Endangered Species.)
Northern Shrikes are also notorious for preying on small songbirds. In The Birds of Minnesota, Dr. Roberts noted that in Minneapolis, the non-native House Sparrow was a frequent target. He added that he had heard of a shrike entering a house through an open window and attacking a caged bird. A shrike subsists wholly on animal matter. Over half of their calories come from birds and small mammals; grasshoppers, caterpillars and other insects comprise the rest. Northern Shrikes are circumboreal. Eurasian shrikes also catch lizards, snakes and frogs.
Northern Shrikes are infamously called Butcher Birds, not because they are notably gory, but because they often hang the carcasses they kill on thorns, as a butcher would a beef carcass. This saves them for a later meal. Research also shows it is used to mark territory or attract a mate.
The natural history of shrikes is well- known for a species nesting so far from human development, an indication of a long, on-going fascination with this singular predatory songbird. Seeking the forest/tundra interface, shrikes place their nests in shrubs or small trees in a fork near the trunk, about eight feet from the ground. The female builds the nest and incubates the eggs; both parents bring food to the nest to feed fledglings. The male caches food near the nest to display his prowess as a provider. If the female deems it insufficient, she signals her displeasure with special calls and displays.
When shrike nestlings fledge, they may remain together and have been known to migrate together. Alternatively, the parents divide up the brood, some fledglings staying with the female and the others tended by the male.
Shrikes have a variety of vocalizations—songs, calls, chatter. Both sexes sing, often in flight. A mated pair will sing duets. The variety of sound is reminiscent of another “bully boy” of the bird world—the blue jay. Characterizing the sounds as “Shrill” “harsh” “low-pitched” and “complaining” as iBird does is just an indication of the varied life of this unusual bird.
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