IDENTIFICATION

VOCALISATIONS

The typical call heard (often near the roost) is a whinnying whistled note that falls in pitch and ends with a trill.

May also give a dry throaty, plaintive call and a modulated rattle, including when squabbling, both reminiscent of large gulls.

DISTRIBUTION AND HABITAT PREFERENCE

Black Kites are widespread throughout HK and are found in a wide variety of coastal and inland habitats, including small islands, inshore waters, marine coasts, intertidal mudflats, fish ponds, reservoirs, landfills and grassy hillsides at all altitudes. They are conspicuous in the urban areas around Victoria Harbour all year.

OCCURRENCE

Present all year, with numbers highest in the autumn and winter months when the local population is supplemented by migrants from the north.

Surveys have previously indicated that numbers at roost sites peak in December and January, then fall by March and remain at relatively low levels from June to September, before rising again in October when migrants arrive from the north. This pattern is corroborated by the results of a weekly census carried out at the former Kai Tak airport between March 1974 and December 1979 (Melville 1980a) which showed a significant drop in numbers at the end of March, when wintering birds departed, and a subsequent increase in the last week of October on their return. Similarly, in Deep Bay, where this species is very scarce in summer, data from coordinated monthly counts during 1993-1997 gave peak totals of 137 to 186 for November to February, but no more than 90 for March.

Humphreys (1960), Bovey (1972), Melville (1976) and Carey (1996) detailed results of roost counts at various times of year. The highest such counts were 1,150 at Stonecutters and 150 at Magazine Gap, totalling 1,300, on 30 December 1959 (Humphreys 1960b) and 250-300 at Stonecutters and 970 at Magazine Gap totalling 1,220 to 1,270 on 15 January 1995 (Carey 1996d). Thus, no significant change since 1959 was evident in the size of the wintering population, though there had been a shift in the preferred roost site.

The summer population, however, appears to have declined since 1970, though it should be noted that roost-sites have received less coverage in the summer months and data are limited. Recoveries or sightings of ringed or marked birds indicate that locally reared birds do not move out of Hong Kong in their first winter (Melville 1980b).

The traditional roosts at Stonecutters and Magazine Gap are known to have been used in the 1930s (Hutson 1930e) and possibly earlier (Vaughan and Jones 1913). The shift from Stonecutters to Magazine Gap noted above began in the 1970s and appears to have been accelerated by reclamation and development of Stonecutters in the 1990s (Carey 1996d). Night-roosts have also been recorded at Tai O, Ma Wan and Ma Lam Wat (Hebe Haven), while day-roosts of 50 to 164 have been reported at Deep Bay, Kowloon Reservoir, Shuen Wan and Junk Island.

No change in status is indicated in the literature. It was described as common in HK by Swinhoe (1861), and as a common resident whose numbers were greatly increased in winter by Kershaw (1904), Vaughan and Jones (1913), Hutson (1930e) and Herklots (1953). Partly due to the bird strike hazard it poses, this species has been relatively well-studied in HK (e.g., Melville 1977, 1980a,b, Carey 1995).

BREEDING

Typically nests in large trees in HK, usually pines or firs but also other species, though nests on rocks have also been noted (Vaughan and Jones 1913, Herklots 1967); one such was about three metres above the sea on a large rock on an island of The Brothers in 1996. The current over-summering population is thought to include around 30 breeding pairs.

Whilst nest-building and twig-carrying is noted from October to April, most breeding records indicate that incubation occurs from late March, with hatching in April or May.

BEHAVIOUR, FORAGING & DIET

The most frequently noted dietary items are dead fish. Other foods items reported are offal and snakes (Hutson 1930), winged termites (Galsworthy 1990), frogs and young, sick or injured birds. The predation of a Masked Laughingthrush bold enough to attempt to fly across a sea-channel near Green Island was unusual (Chalmers 1988). Birds have also been observed scavenging at sewage outfalls (Melville 1977), searching opportunistically at hill fires and even ‘following the plough like a rook (Corvus frugilegus)’ (Kershaw 1904).

Roosts communally at night at traditional sites in trees or large shrubs. The main roost site is Magazine Gap on HK Island and, formerly, Stonecutters, though increasing development there appears to have made it less attractive. Other roosts have been recorded at Tai O (Lantau) and Sai Kung harbour. The location of daytime roosts is related to foraging locations and generally involves fewer than 15 birds. Forages singly or in loose groups. In autumn juveniles may be seen ‘playing’ aerially with plastic wrapping or similar.

RANGE & SYSTEMATICS

Widespread across Africa, Europe, Asia and Australia. Summer visitor to Europe, north Africa, Russia, Central Asia, Mongolia and north China, but present all year south of these areas with numbers in Africa and Asia supplemented in the non-breeding season by migrants from the north. In China occurs throughout the country away from high plateau areas with the northernmost populations leaving before winter (Liu and Chen 2020). Declining in numbers as a passage migrant through the Beijing area (Birding Beijing 2022).

Polytypic, with M. m. lineatus breeding from Siberia to Japan to Indochina and India, including HK. Elsewhere, M. m. formosanus breeds in Taiwan and Hainan, the nominate breeds from Europe and north Africa to Central Asia and M. m. govinda occurs from Pakistan and India to the Malay peninsula and Indochina. The remaining taxon, M. m. affinis, breeds in the Lesser Sundas and Australia.

CONSERVATION STATUS

IUCN: Least Concern. Population trend stable.