Bull-headed Shrike Lanius bucephalus牛頭伯勞
Category I. Rare passage migrant and winter visitor to open country habitats and woodland edge
IDENTIFICATION
Dec. 2006, Michelle and Peter Wong.
19-20 cm. Medium-sized shrike with relatively long tail. Fairly large head with bright rufous or rufous-tinged crown and bulbous bill with a pinkish base to lower mandible.
Adult male has rufous crown, black facial mask, white supercilium mainly above and behind eye. Upperparts greyish; wings mostly black, the primaries with a conspicuous white patch at the base. Flanks orange-buff, whitish from throat to belly.
Adult female similar but has browner mask and upperparts with less contrast between crown and mantle, less distinct supercilium and no white primary patch. Underparts heavily vermiculated dark brown.
Dec. 2008, FUNG Hon Shing.
First-year birds have crown and upperparts rufous-brown, a weak mask, extensive barring on underparts and warm buff fringes to wing coverts. Male has white at base of primaries.
VOCALISATIONS
A loud, harsh chatter that is higher-pitched and less harsh than Brown Shrike.
Also, a harsh 'kyew' call similar to its congeners.
DISTRIBUTION & HABITAT PREFERENCE
Favours wide range of open country habitats, especially adjacent to forest edge. Frequently recorded at Long Valley, Ng Tung Chai, Tai Po Kau and Sai Kung. It has been a regular visitor to park-type habitat in urban Ho Man Tin since 2015, and this well-watched locality now provides most records. Bull-headed Shrike was recorded in 0.5% of 1km squares in the 2001-05 winter atlas survey.
OCCURRENCE
Bull-headed Shrike is a scarce passage migrant and winter visitor, mainly occurring from the last week of October to the third week of March (Figure 1). Extreme dates are 8 October 2019 and 1 April 2020.
The weak autumn passage peaks in the last week of October and first week of November, while wintering birds are established by the third week of November. Numbers decline in the second half of December and early January, perhaps indicating some birds move in response to colder weather. Spring passage appears to occur from the second week of February.
Usually occurs in ones or twos, whilst the highest count is three at Ho Man Tin on 7 December 2016. Although it was previously considered to be mainly a late autumn passage migrant, recent records, especially those from Ho Man Tin since 2015, suggest that spring passage was overlooked. Although there were only 22 records to the end of 1998, it has been an annual visitor since 2005. There were records from at least 16 localities in 2017.
The first accepted record of Bull-headed Shrike concerned a male at Mai Po on 23 October 1986 (Lam 1987).
BEHAVIOUR, FORAGING & DIET
Mostly occurs in ones or twos. Courtship behaviour and singing have been observed in February and March. Similar to other shrikes, perches at the top of bushes, on wires and fences or in the lower branches of forest edge trees. Forages on invertebrates including earthworms and wasps. Prey cached at larders.
SYSTEMATICS & RANGE
Of the two subspecies, L. b. bucephalus, which is presumed to occur in HK, breeds in southeast Russia (Ussuriland), northeast China (south Heilongjiang to Hebei and Shandong), Korea, south Sakhalin, south Kurils, Japan (including Ryukyu Islands, Daito Islands and Ogasawara Islands); in the non-breeding season it occurs east to southeast China (Yosef and ISWG 2020, Liu and Chen 2020). Theoretically the little-known taxon L. b. sicarius, which breeds in south Gansu, central China, could also occur.
CONSERVATION STATUS
IUCN: Least Concern. Population trend decreasing.
Figure 1.
Lam, C. Y. (1987). Bull-headed Shrike Lanius bucephalus at Mai Po. Hong Kong Bird Report 1986: 75.
Liu, Y. and Y. H. Chen (eds) (2020). The CNG Field Guide to the Birds of China (in Chinese). Hunan Science and Technology Publication House, Changsha.
Yosef, R. and ISWG (International Shrike Working Group) (2020). Bull-headed Shrike (Lanius bucephalus), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.buhshr1.01
