Shrikes (/ʃraɪk/) are passerine birds of the family Laniidae. The family is composed of 34 species in two genera.
The family name, and that of the largest genus, Lanius, is derived from the Latin word for "butcher", and some shrikes are also known as butcherbirds because of the habit, particularly of males, of impaling prey onto plant spines within their territories. These larders have multiple functions, attracting females and serving as food stores.[1]
The common English name shrike is from Old Englishscrīc, alluding to the shrike's shriek-like call.[2]
Taxonomy
The family Laniidae was introduced (as the subfamily Lanidia) in 1815 by the French polymathConstantine Samuel Rafinesque. The type genusLanius had been introduced by Carl Linnaeus in 1758.[3][4]
As currently constituted the family contains 34 species in four genera. It includes the genus Eurocephalus with the two white-crowned shrikes.[5] A molecular phylogenetic study published in 2023 found that the white-crowned shrikes were more closely related to the crows in the family Corvidae than they are to the Laniidae and authors proposed that the genus Eurocephalus should be moved to its own family Eurocephalidae. The cladogram below is based on these results:[6]
Most shrike species have a Eurasian and African distribution, with just two breeding in North America (the loggerhead and northern shrikes). No members of this family occur in South America or Australia, although one species reaches New Guinea. The shrikes vary in the extent of their ranges, with some species, such as the great grey shrike, ranging across the Northern Hemisphere; to the Newton's fiscal, which is restricted to the island of São Tomé.[7]
They inhabit open habitats, especially steppe and savannah. A few species of shrikes are forest dwellers, seldom occurring in open habitats. Some species breed in northern latitudes during the summer, then migrate to warmer climes for the winter.
Description
Shrike on a Winter Tree, silk painting by Li Di (李迪). China, Song dynasty, 1187 AD
Shrikes are medium-sized birds with grey, brown, or black-and-white plumage. Most species are between 16 cm (6.3 in) and 25 cm (9.8 in) in size; however, the genus Corvinella, with its extremely elongated tail-feathers, may reach up to 50 cm (20 in) in length. Their beaks are hooked, like those of a bird of prey, reflecting their carnivorous nature; their calls are strident.
Male shrikes are known for their habit of catching insects and small vertebrates and impaling them on thorns, branches, the spikes on barbed-wire fences, or any available sharp point. These stores serve as a cache so that the shrike can return to the uneaten portions at a later time.[8] The primary function of conspicuously impaling prey on thorny vegetation is however thought to be for males to display their fitness and the quality of the territory held to prospective mates.[9] The impaling behavior increases during the onset of the breeding season.[10] Female shrikes have been known to impale prey, but primarily to assist in dismembering prey.[11] This behaviour may also serve secondarily as an adaptation to eating the toxic lubber grasshopper, Romalea microptera. The bird waits 1–2 days for the toxins within the grasshopper to degrade before eating it.[12]
Loggerhead shrikes kill vertebrates by using their beaks to grab or pierce the neck and violently shake their prey.[13]
Shrikes are territorial, and these territories are defended from other pairs. In migratory species, a breeding territory is defended in the breeding grounds and a smaller feeding territory is established during migration and in the wintering grounds.[7] Where several species of shrikes exist together, competition for territories can be intense.
Shrikes make regular use of exposed perch sites, where they adopt a conspicuous upright stance. These sites are used to watch for prey and to advertise their presence to rivals.
Shrikes vocally imitate their prey to lure them for capture.[14] In 1575, this was noted by the English poet George Turberville.
She will stand at perch upon some tree or poste, and there make an exceedingly lamentable crye. . . . All to make other fowles to thinke that she is very much distressed. . . whereupon the credulous sellie birds do flocke together at her call. If any happen to approach near her, she. . . ceazeth on them, and devoureth them (ungrateful subtill fowle).[15]
Breeding
Shrikes are generally monogamous breeders, although polygyny has been recorded in some species.[7] Co-operative breeding, where younger birds help their parents raise the next generation of young, has been recorded in both species in the genera Eurocephalus and Corvinella, as well as one species of Lanius. Males attract females to their territory with well-stocked caches, which may include inedible but brightly coloured items. During courtship, the male performs a ritualised dance which includes actions that mimic the skewering of prey on thorns, and feeds the female. Shrikes make simple, cup-shaped nests from twigs and grasses, in bushes and the lower branches of trees.[8]
^ abcYosef, Reuven (2008). "Family Laniidae (Shrikes)". In Josep, del Hoyo; Andrew, Elliott; David, Christie (eds.). Handbook of the Birds of the World. Volume 13, Penduline-tits to Shrikes. Barcelona: Lynx Edicions. pp. 732–773. ISBN978-84-96553-45-3.
^ abClancey, P.A. (1991). Forshaw, Joseph (ed.). Encyclopaedia of Animals: Birds. London: Merehurst Press. p. 180. ISBN1-85391-186-0.
^Yosef, Reuven; Whitman, Douglas W. (1992). "Predator exaptations and defensive adaptations in evolutionary balance: No defence is perfect". Evolutionary Ecology. 6 (6): 527–536. doi:10.1007/BF02270696. S2CID23312866.
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