Eastern Buzzard Buteo japonicus 普通鵟
Category I. Common autumn passage migrant and winter visitor, scarce in spring. Occurs in widespread areas of Hong Kong in most non-urban habitats.
IDENTIFICATION
Nov. 2020, John and Jemi Holmes. Juvenile.
47-59 cm. Medium in size and compact with broad wings and tail shorter than width of wings. Soars with spread tail and wings in shallow V-shape. Juveniles such as this bird have a diffuse darker trailing edge to the wing, while adults have a distinct broad black trailing edge.
Dec. 2016, Kinni Ho.
Brown above with barred flight and tail feathers and pale inner webs to the dark-tipped primaries.
VOCALISATIONS
A whistled downslurred ‘pseeeooo’.
DISTRIBUTION & HABITAT PREFERENCE
Eastern Buzzard occurs in or over a wide variety of habitats at all altitudes, including marshes, fish ponds, active or abandoned agricultural land, woodland (occasionally), shrubland-grassland, grass-covered hillsides, golf courses, city parks and urban habitats. It is widespread in the New Territories and is also irregularly reported from Kowloon, HK Island and offshore islands.
Records during the period indicate that while no change can be inferred in either numbers occurring in HK as a whole or specifically in the Deep Bay area, there was a substantial fall in the proportion of records from urban areas of Kowloon and HK Island, from approximately 24% before 1980 to 3% during the second half of the 1990s. This was presumably due to the loss of suitable urban fringe habitat.
OCCURRENCE
Common Buzzards are recorded from October to April (Figure 1). Highest numbers are reported during autumn passage from the last week of October to the third week of November. The wintering population remains stable from the last week of November to the third week of February, after which there is a gradual decline through March and April. Extreme dates are 2 October 2017 and 10 May 2008, though the latter is 16 days after the next latest.
Most reports are of up to seven birds, with an exceptional 19 at Long Valley on 6 November 2016 being the highest count. The highest counts since 1999 are higher than the period prior, but this is likely due to increased observer activity. Migrating flocks of up to seven birds have been noted in autumn.
The earliest record is of two seen on HK Island by Swinhoe (1861); it was considered a regular winter visitor by Vaughan and Jones (1913), Aylmer (1932) and Herklots (1953).
BEHAVIOUR, FORAGING & DIET
Prey items reported include grasshoppers (Williams 1933), rats and birds (White-breasted Waterhen, Masked Laughingthrush, Oriental Turtle Dove, Domestic Pigeon and a duck).
Commonly seen soaring over a variety of habitats in autumn in particular. Roosting birds can be seen on tall lights over highways (e.g., Tolo Highway) by day and night.
RANGE & SYSTEMATICS
Breeds from southeast and east Siberia south to Sakhalin, north Mongolia, north China, Ussuriland and Japan; winters in South Korea, south China west to the Himalayas and south to northern Indochina and parts of southeast Asia, while birds in Japan are resident (Kirwan et al. 2022). In China a summer visitor to the northeast and winters south of a line from southeast Tibet to Liaoning (Liu and Chen 2020).
Polytypic, four subspecies recognised of which B. j. burmanicus breeds from southeast Siberia and north Mongolia to northeast China, Korea and northeast Siberia, and presumably winters in south China, including HK. Nominate japonicus breeds in much of Japan, while the remaining two subspecies are resident on southern Japanese islands.
CONSERVATION STATUS
IUCN: Least Concern. Population trend unknown.
Figure 1.
Aylmer, E. A. (1932). The birds of Hong Kong. Part IX. Order Accipitres (Falcons, Kites, Buzzards, Eagles, Hawks, etc.). Hong Kong Naturalist 3: 3-5.
Herklots, G. A. C. (1953). Hong Kong Birds. South China Morning Post, Hong Kong.
Kirwan, G. M., K. Nagai, C. Hansasuta, and J. S. Marks (2022). Eastern Buzzard (Buteo japonicus), version 2.0. In Birds of the World (G. M. Kirwan and B. K. Keeney, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.combuz6.02
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.
Swinhoe, R. (1861). Notes on the ornithology of Hong Kong, Macao and Canton, made during the latter end of February, March, April and the beginning of May 1860. Ibis 1861: 23-57.
Vaughan, R. E. and K. H. Jones (1913). The birds of Hong Kong, Macao and the West River or Si Kiang in South-East China, with special reference to their nidification and seasonal movements. Ibis 1913: 17-76, 163-201, 351-384.
Williams, M. Y. (1933). Notes on Hong Kong birds. Hong Kong Naturalist 4: 88-89.
