IDENTIFICATION

VOCALISATIONS

Utters a slightly buzzing ‘zrrak’ call, sometimes run together in a decrescendo.

DISTRIBUTION & HABITAT PREFERENCE

Oriental Dollarbirds are widespread on lightly-wooded hillsides, but they also occur in forests and forest edges. They are reported most frequently from the central and eastern New Territories, the western New Territories at Tai Tong and Lung Kwu Tan and from western parts of HK Island and at Ho Man Tin in urban Kowloon. There are also regular reports from Lantau and other offshore islands, especially Po Toi.

OCCURRENCE

Oriental Dollarbird is a fairly common and widespread spring and autumn migrant (Figure 1). Extreme dates are 25 March and 5 June and 24 August and 28 November. Two summer records outside the main migration period involved singles at Po Toi on 3 July 2008 and at Wonderland Villas on 18 June 2018.

In spring, most reports fall between mid-April and mid-May with a peak in the last week of April and the first week of May. In autumn, the majority of records occur from the second week of September to the second week of October with a peak in the final two weeks of September. Reports mainly refer to single birds or to several birds in the same general area; double-digit counts are uncommon. The highest single-site count in spring remains 16 at Tai Po Kau on 21 April 1988; the highest autumn count is 28 at Tai Tong on 15 September 2019. Overall, numbers are higher in autumn than in spring with 60% of records occurring in autumn compared with 40% in spring.

The estimated total number of birds each year during 1988-2005 averaged 32, but there has been an increase since (Figure 2), with total numbers of over 50 each year, rising to triple-digit counts in 2019 (132 birds) and 2020 (176 birds). This increase in records, particularly in autumn, probably reflects a rise in observer activity.

Between 1958 and 1978 autumn migration regularly extended to the end of November, but in the 1980s this ceased to be the case, with the last November record being of two at Shek Kong on 5 November 1989. The only November records since then concern one at Shek Kong catchwater on 5 November 2018 and one on Po Toi on 18 November 2021. This may reflect a decline in the breeding population in Japan, which was described by Brazil (1991) as ‘once much commoner’.

Prior to 1958, the only reports of this species were of small numbers in spring and autumn (Vaughan and Jones 1913) and up to eight in October (Hutson 1931, Walker 1958) and April (Dove and Goodhart 1955).

BEHAVIOUR, FORAGING & DIET

Most food is taken in aerial sorties from look-out perches such as bare branches, the tops of bare trees and service-wires. Food items recorded are insects, including winged ants, beetles and ‘stink-bugs’ Pentatomidae (Hutson 1931). One was observed eating a dragonfly at Tai Po Kau Headland on 17 September 2005.

Birds may flock together to roost: 15 were seen perched in bamboo at Nam Chung late afternoon on 20 April 2009, and 15 were counted arriving to roost at 6.00 p.m. at Ng Tung Chai on 18 September 2007.

SYSTEMATICS & RANGE

Apart from a disjunct population in southwest India, Sri Lanka, and the Andamans, Oriental Dollarbird occurs from Nepal east to Korea and Japan, and south through southeast Asia, Indonesia, Borneo and the Philippines to New Guinea, and north & east Australia (Fry and Boesman 2020).

E. o. cyanocollis breeds in Nepal, northern India and Bangladesh east to eastern China, southeast Siberia, Korea and Japan; it winters south to southeast Asia and the Greater Sundas. In China it is a passage migrant and/or summer visitor south of a line from Yunnan to the northeast provinces (Liu and Chen 2020).

CONSERVATION STATUS

IUCN: Least Concern. Population trend decreasing.