Long-tailed shrike | |
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L. s. erythronotus
at (Mangaon, Maharashtra, India) |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Family: | Laniidae |
Genus: | Lanius |
Species: | L. schach |
Binomial name | |
Lanius schach Linnaeus, 1758 |
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Subspecies | |
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Rough distribution of key forms |
at (Mangaon, Maharashtra, India)
The long-tailed shrike or rufous-backed shrike (Lanius schach) is a member of the bird family Laniidae, the shrikes. They are found widely distributed across Asia and there are variations in plumage across the range. The species ranges across much of Asia, both on the mainland and the eastern archipelagos. The eastern or Himalayan subspecies, L. s. tricolor, is sometimes called the black-headed shrike. Although there are considerable differences in plumage among the subspecies, they all have a long and narrow black tail, have a black mask and forehead, rufous rump and flanks and a small white patch on the shoulder. It is considered to form a superspecies with the grey-backed shrike (Lanius tephronotus) which breeds on the Tibetan Plateau.
The long-tailed shrike is a typical shrike, favouring dry open habitats and found perched prominently atop a bush or on a wire. The dark mask through the eye is broad and covers the forehead in most subspecies and the whole head is black in subspecies tricolor and nasutus. The tail is narrow and graduated with pale rufous on the outer feathers. Subspecies erythronotus has the grey of the mantle and upper back suffused with rufous while the southern Indian caniceps has pure grey. A small amount of white is present at the base of the primaries. The bay-backed shrike is smaller and more contrastingly patterned and has a more prominent white patch on the wing. The sexes are alike in plumage.
The genus name, Lanius, is derived from the Latin word for "butcher", and some shrikes are also known as "butcher birds" because of their feeding habits. The specific schach is an onomatopoeic name based on the call. The common English name "shrike" is from Old English scríc, "shriek", referring to the shrill call.
A number of subspecies are noted within the widely distributed range of this species. Stuart Baker in the second edition of The Fauna of British India considered Lanius schach, Lanius tephronotus and Lanius tricolor as three species. He considered nigriceps as synonymous with tricolor and included erythronotus as a race of schach. Other treatments were proposed by Hugh Whistler and N B Kinnear where tephronotus was considered a subspecies of schach and nigriceps and nasutus grouped together. Another treatment considered tricolor as a subspecies of L. tephronotus. It was subsequently however noted that tephronotus and schach co-occurred in the Kumaon region and so the two were confirmed as distinct species. Molecular distances also indicate that they are distant enough. The erythronotus group have a grey head which continues into the back with a gradual suffusion of rufous. The westernmost population from Transcaspia named by Sergei Buturlin as jaxartensis and said to be larger, is not considered valid. A very light grey form from western dry region of India named by Walter Koelz as kathiawarensis is also considered merely as a variant. In southern India and Sri Lanka, subspecies caniceps, is marked by the rufous restricted to the rump, light crown and the pure grey on the back. Biswamoy Biswas supported the view that nigriceps (having upper mantle grey and lower mantle rufous) was a hybrid of tricolor and erythronotus.