Northern shrike
The northern shrike is a large songbird species in the shrike family native to North America and Siberia. Long considered a subspecies of the great grey shrike, it was classified as a distinct species in 2017. Six subspecies are recognised.
Taxonomy
The northern shrike was formally described by the French ornithologist Louis Pierre Vieillot in 1808 under its present binomial name Lanius borealis. In the 19th century, North American ornithologists considered it as a separate species from the great grey shrike, while European authorities held them to be the same species. American ornithologist Alden H. Miller investigated differences between the Siberian and Alaskan populations in 1930 and could find no consistent differences, hence he recommended combining the two into Lanius excubitor.In North America, this and the related loggerhead shrike are commonly known as butcherbirds for their habit of impaling prey on thorns or spikes. A folk name from Michigan is winter butcherbird. The Vuntut Gwitchin First Nation people of Old Crow, Yukon call it Tzi kwut go katshi lyi. As a passerine, or song bird, it has no talons. It has the hooked beak of a raptor.
A 2010 study of mitochondrial DNA found that the northern shrike was most closely related to the Iberian grey shrike, the steppe grey shrike, and the two formed a clade along with the Chinese grey shrike and loggerhead shrike.
Subspecies
East Eurasian group- Lanius borealis sibiricus – eastern Siberia to northern Mongolia
- Lanius borealis bianchii – Sakhalin and possibly southern Kuril Islands
- Lanius borealis mollis – Russian Altai Mountains, north western Mongolia
North American group
- Lanius borealis borealis – Hudson Bay region of Ontario and Quebec
- Lanius borealis invictus – northern Alberta west to northern Alaska, perhaps also Chukchi Peninsula region in extreme north east Siberia
Description
The loggerhead shrike can be distinguished from the northern shrike by its smaller size, darker grey plumage and larger black face mask that covers the eye completely. It also has a shorter bill with less prominent hook. Their calls are similar.Measurements:
- Length:
- Weight:
- Wingspan:
Distribution and habitat
The northern shrike breeds in taiga and tundra from Labrador west through Alaska to western Siberia, and south to extreme northwestern China, northern Mongolia, and James Bay. It breeds in forest edge habitats wherever suitable trees or shrubs are present and has nested in white spruce, black spruce, felt-leaf willow, mountain alders, and poplars. The northern limit of its breeding range is defined by the presence of 1-2 meter high shrubby willows.Northern shrikes are irruptive in the non-breeding season. Some stay year-round in this breeding range, but most move south depending on the severity of the winter, food supply, and competition from other shrikes. They will go as far south as northeastern China and Japan in Asia and irregularly as far south as New Mexico, Kansas, Illinois, Ohio, Pennsylvania, and New Jersey. On their wintering grounds, they prefer open country, including forest edges, prairies, agricultural land, savannas, and coastal marshes.
Observations of wintering habitats in Idaho suggest suitable wintering territories are in demand, as northern shrikes that died in a particular area were quickly replaced.