Northern shrike
| Northern shrike | |
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| Species: | L. borealis
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| Binomial name | |
| Lanius borealis Vieillot, 1808
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6 sspp, see text | |
The northern shrike (Lanius borealis) is a large songbird species in the shrike family (Laniidae) 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 first described by French ornithologist Louis Jean Pierre Vieillot in 1808. In the 19th century, North American ornithologists considered as a distinct 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 the sinking of the two into Lanius excubitor.[1]
In a 2010 study of mitochondrial DNA, Olsson and colleagues found that the northern shrike was most closely related to the southern grey shrike (Lanius meridionalis), and the two formed a clade along with the Chinese grey shrike and loggerhead shrike.[2]
Subspecies
East Eurasian group
- Lanius borealis sibiricus – eastern Siberia to northern Mongolia
- Browner above than excubitor, distinct but delicate banding below. Some white on primary bases only.
- Lanius borealis bianchii – Sakhalin and possibly southern Kuril Islands
- Smaller and paler than sibiricus, banding below pale and indistinct. Some white on primary bases only.
- Lanius borealis mollis – Russian Altai Mountains, north western Mongolia
- Browner than sibiricus above, banding below well-developed. Little white on primary bases.
- Lanius borealis funereus – Tian Shan and western China
- Large; quite dark and brownish, below bluish-grey with almost black banding. Little white on primary bases.
North American group
- Lanius borealis borealis – Hudson Bay region of Ontario and Quebec
- Similar to excubitor, but darker with faint barring below. John James Audubon called this subspecies the great American shrike in his book Birds of America.
- Lanius borealis invictus – northern Alberta west to northern Alaska, perhaps also Chukchi Peninsula region in extreme north east Siberia
- Larger and paler than borealis, paralleling homeyeri compared to excubitor.
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.[3]
Distribution and habitat
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.[4]
Feeding
Northern shrikes often sit on tall poles and brnaches surveying for food.[5]
References
- ^ Miller, Alden H. (1930). "The Status of Lanius borealis as a Species" (PDF). Condor. 32: 163–64.
- ^ Olsson, Urban; Alström, Per; Svensson, Lars; Aliabadian, Mansour; Sundberg, Per (2010). "The Lanius excubitor (Aves, Passeriformes) conundrum—Taxonomic dilemma when molecular and non-molecular data tell different stories" (PDF). Molecular Phylogenetics and Evolution. 55 (2): 347–357.
- ^ Dunn, Jon Lloyd; Alderfer, Jonathan K. (2006). National Geographic Field Guide to the Birds of North America. National Geographic Books. p. 312. ISBN 9780792253143.
- ^ Atkinson, Eric C. (1993). "Winter foraging and diet composition of Northern Shrikes in Idaho" (PDF). Condor. 95 (3): 528–35.
- ^ Atkinson, Eric C.; Cade, Tom J. (1993). "Winter foraging and diet composition of Northern Shrikes in Idaho" (PDF). Condor. 95 (3): 528–35.