Grey-backed shrike

The grey-backed shrike was first described in 1831 by Nicholas Aylward Vigors as L. tephronotus collected near Darjeeling, India. It is closely allied with L. schach, and formerly treated as conspecific, but differs in morphology; moreover, the two species are largely sympatric and, although race lahulensis sometimes considered to represent a hybrid population between them, there is no definite proof of interbreeding. Two subspecies (L. t. lahulensis and L. t. tephronotus[2]) are recognized.[3]

In China

The species is 21–25 cm long and weighs 39-54 g. It is a shrike with long tail. The nominate race has black lowermost forehead (just over base of bill) and facial mask through lores and eye to rear ear-coverts; crown to nape and most of upperparts dark grey, small rufous rump patch; upperwing black, most wing-coverts, secondaries and tertials fringed pale rufous to whitish, sometimes tiny white patch at base of primaries (often lacking); tail chestnut-brown, tipped buffish, outermost pair of rectrices light brown; throat and undertail brownish-grey; iris dark brown; bill black or dark green; legs dull black or dark green. Sexes very similar. Juvenile is browner above than adult, with less marked brown (not black) facial mask, horn-colored lower mandible, has crown finely barred, upperparts and much of underparts heavily barred dark brownish. Race lahulensis is smaller and weaker-billed than nominate, also much paler, brownish-grey above, with rufous lower back and rump, white primary patch usually slightly larger and more visible, tail sometimes blackish (not brown).[3][4]

Voice: Rough, breathing-like call.[4] Territorial call described as harsh zzert-zzert..., tchert-tchert... or tzert-tzert...; repertoire includes also a repeated ktcht-ktcht-ktcht given at dusk or as alarm. Breeding song subdued and musical, with mimicry of other bird calls lasting several minutes.[3] Voice seems to be similar to that of L. schach.[3][4]

In China

The grey-backed shrike has two subspecies. L. t. lahulensis (Koelz, 1950) breeds from north Kashmir east to central India (Uttar Pradesh), and southwest China. L. t. tephronotus (Vigors, 1831) breeding range extends from Nepal east to northeast India (Arunachal Pradesh), and center and south China (southern Gansu, Ningxia and eastern Shanxi south to southeast Qinghai, south and east Xizang, southeast Yunnan and central Guizhou); non-breeding distribution stretches south to Bangladesh, Myanmar, Thailand and Indochina.[3][5]

Breeds at high elevations in forest clearings, plateau plains and mountain meadows dotted with small trees or fairly large bushes; to at least 4500 m in Nepal (becoming common from 2700 m upwards) and in south China (Yunnan). Post-breeding habitat in Sichuan (south China) either young open coniferous stands with forest clearings dominated by bushes, or pastures at higher elevations; at lower altitudes occurs in extensive agricultural valleys near human settlements. On non-breeding grounds in valleys and plains found in variety of habitats, including gardens and abandoned cultivation.[3]

Grey-backed shrikes preferred sites close to human settlements, because these habitats offered a better foraging substrate and places safe from large predators.[9] They appears to be naturally common across a widespread area and there is no evidence of them being globally threatened.[3] But this species is more at risk if their habitats are altered by changes in land management activities,[6] and high-elevation habitat considered more secure than lower-lying ones.[3]

The grey-backed shrike has an extremely large range and appears to be naturally common across a widespread area.[3] The population trend appears to be stable, and hence the species does not approach the thresholds for vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.[1][10]