Streaked Shearwater Calonectris leucomelas 白額鸌
Category I. Passage migrant mainly in spring through coastal waters.
IDENTIFICATION
Mar. 2023, Paul Leader.
Large shearwater, brown above, white below, mottled head and pale bill; some dark markings on underwing coverts and dark underside to tips of flight feathers. Rather languid flight on slightly bowed wings.
VOCALISATIONS
Vocal at colonies but not in the non-breeding season.
DISTRIBUTION & HABITAT PREFERENCE
Nearly all records have occurred in offshore waters to the south and east of HK. The exception is one at Mai Po NR on 9 April 2012. Sick or weak storm-blown birds are occasionally picked up close to shore.
OCCURRENCE
Based on current evidence, Streaked Shearwater is largely a passage migrant, uncommon in spring and scarce in autumn. The earliest record is of a bird taken into care on 4 March 2005, with the next being eight off Po Toi on 6 March 2015. Figure 1 indicates that most birds are recorded from the third week of March to the last week of May, with the latest occurring on 1 June 1986. Summer records have occurred in on 23rd and 26 June and on 21st and 23 August. Otherwise, the earliest on return passage occurred on 17 September 1993 and the latest on 27 October 2016.
Most records are of up to 13 birds, but the highest is 95 in southern waters on 21 March 2020, suggesting that in some years at least larger numbers may occur offshore.
BEHAVIOUR, FORAGING & DIET
May occur in flocks on or over the sea.
RANGE & SYSTEMATICS
Monotypic. Breeds on islands from Hokkaido south through Japan and Korea to Taiwan; winters in western Pacific as far as southeast Australia (Carboneras et al. 2020). In China considered a summer visitor to coastal areas of the East and South China Seas (Liu and Chen 2020), though the pattern of occurrence in HK suggests this may not be the case this far south.
CONSERVATION STATUS
IUCN: Near-threatened. Population trend decreasing.
Figure 1.
Carboneras, C., F. Jutglar, E. de Juana, G. M. Kirwan, and C. J. Sharpe (2020). Streaked Shearwater (Calonectris leucomelas), 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.strshe.01
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.
