Guide to selected species of:
Birds of the Boreal Forest
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 | Perching Birds
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Northern Shrike
Lanius excubitor
An estimated 90% of the North American population of Northern Shrike breeds in the Canadian boreal forest. A predatory songbird, the Northern Shrike breeds in open deciduous or coniferous woodland, taiga, thickets, bogs, and scrub. The Northern Shrike is known for its unique behavior of impaling its prey of small birds, mammals and insects on thorns and barbed wire fences; hence its preference for nesting near areas containing such objects. The majority of Canada’s breeding population migrates southward into southern parts of Canada and the northern United States, but these movements are notably variable in extent from year to year and probably depend on prey availability. Populations are probably stable, but forest regeneration, urbanization, and intensive farming, which now dominate many landscapes once favored by shrikes, will probably cause local declines.
Description:
9-10 1/2" (23-27 cm). Robin-sized. Pale gray above, white below, with faint barring on underparts, and bold black mask ending at bill. Black tail with white edges. Stout, hooked bill. Immature is browner. Usually seen perched atop a tree in the open. Loggerhead Shrike is shorter-billed, with black mask that crosses forehead.Habitat:
Open woodlands and brushy swamps in summer; open grasslands with fence posts and scattered trees in winter. Nesting:
4-6 pale gray eggs, spotted with dark gray and brown. Nest a large mass of twigs, lichens, moss, and feathers, usually in a dense conifer. Range:
Breeds from Alaska across northern Canada to Labrador, south to northern British Columbia. Winters irregularly across northern tier of states south to northern California, Kansas, and Pennsylvania. Also in Old World. Voice:
Mixture of warbles and harsh tones with a robin-like quality. Discussion:
The Northern Shrike sits quietly, often in the top of a tree, before swooping down after insects, mice, and small birds. It kills more than it can eat, impaling the prey on a thorn or wedging it in a forked twig. On lean days it feeds from its larder. Like other northern birds that depend on rodent populations, the Northern Shrike's movements are cyclical, becoming more abundant in the United States when northern rodent populations are low. Sometimes they hunt from an open perch, where they sit motionless until prey appears; at other times, they hover in the air, ready to pounce on anything that moves. |
