IDENTIFICATION

VOCALISATIONS

Brazil (2018) describes a ‘guttural croaking gwa call on taking flight’.

DISTRIBUTION & HABITAT PREFERENCE

In line with its habits at other times of year, Chinese Egrets in HK are mainly recorded feeding on intertidal mudflats and marshes. Since breeding ceased here, most records have been from the intertidal mudflats of Deep Bay, and only rarely are they seen in man-made wetlands around the Bay, such as the gei wai or fish ponds. Also occasionally seen on offshore rocky islets.

OCCURRENCE

Chinese Egret was not recorded until 15 April 1956 (Walker 1958). Until 1962, records occurred from 5 March to 1 July and were largely from Deep Bay. In addition, up to two or three pairs bred at the Yuen Long North and Yuen Long South egretries, with extreme dates being 16 April and 1 July. A high of 11 birds was recorded at the Yuen Long North egretry on 16 April 1960. Increasing disturbance from nearby activities caused the nest site to be abandoned after 1962 (Murton 1972). In 1969 and 1970 two Chinese Egrets were recorded at another egretry close to Yuen Long, but there are no details of the precise location or whether the birds actually bred.

From 1963 to 1983, breeding only occurred at the Yim Tso Ha egretry in Starling Inlet. Each year one or two pairs bred, with breeding activity recorded from 12 April to 27 July. The last nest was recorded in 1982 on A Chau opposite Yim Tso Ha. Although a single bird was seen at Yim Tso Ha on 2 April 1983, no nests were recorded. Between 1963 and 1983 there were also scattered records of one to three individuals at Mai Po, Lok Ma Chau and Tsing Yi.

Records from the Deep Bay area increased after 1984, especially during spring passage when observer activity was higher and access to the intertidal areas improved. The loss of the breeding population meant that Chinese Egret was only seen on passage, and it seems likely that after it ceased to breed, records were submitted more assiduously. After the last breeding record in 1982, it was recorded mainly during spring passage from the last week in March to the first week in June, and since 1999 peak passage has occurred during the second half of April and the first three weeks of May (Figure 1).

In addition, a record count of 23 different Chinese Egrets was made during daily observations at the Mai Po boardwalk from 4 April to 8 May 1998. This may suggest that in spring, single birds or small groups travel along the coast in a slow but continuous migration. Passage appears to cease before the middle of June, and there have been a handful of summer records from 27 June to 14 July. The highest single day count is of nine birds on 4 May 1998.

Since 1994 it has been recorded in autumn from 8 August to 1 November, though in fewer than 50% of years. There were four previous autumn records when Chinese Egret was breeding in HK: 7 November 1971, 3 September 1972, 30 August 1976 and on 20 October 1976. However, these are unsupported by details.

That Chinese Egrets once bred in HK is of interest since it is far from the present breeding populations in northeast Asia around the Yellow Sea. The HK breeding population could have been either a relic of a once much wider breeding range which has now contracted or the temporary opportunistic colonisation of an available site. The former is more likely since La Touche (1931-1934) stated that Chinese Egrets bred in Fujian and northern Taiwan. HK probably lay at the southern limit of its breeding range.

BREEDING

Murton (1972) noted that nesting occurred in mature Banyan and other trees, egg-laying commenced in the third week of April, incubation in the last four days of the month and hatching occurred around 25 May.

BEHAVIOUR, FORAGING & DIET

Murton (1972) described the typical feeding action as ‘rapid dashing to and fro at the tide’s edge’, with the wings ‘raised over the back and…half spread, while at frequent intervals…flapped or flicked back and forth; at the same time (makes) rapid and repeated stabs at the water’.

Generally, forages and roosts separately from Little Egret. Roosting birds can be seen in mangrove or in ponds and gei wai in Mai Po NR. Birds are occasionally seen on diurnal migration over the sea and also resting on rocky islets, all between 10 April and 26 May.

RANGE & SYSTEMATICS

Monotypic. Breeds along on offshore islands of the Vladivostok area where the borders of China, Russia and North Korea meet, the Korean peninsula and northeast and east China; occurs in non-breeding season from Vietnam and peninsular Malaysia south to Indonesia and the Philippines (Martínez-Vilalta et al. 2020). In China a migrant and summer visitor to east and south coastal provinces (Liu and Chen 2020), including Hainan where it is a scarce non-breeding visitor in spring and early winter (Lewthwaite et al. 2021).

CONSERVATION STATUS

IUCN: VULNERABLE. Small population that is declining due to reclamation of tidal mudflats, estuarine habitats and offshore breeding islands for industrial development and aquaculture.