IDENTIFICATION

VOCALISATIONS

The most intense song is that uttered around dawn.

Song uttered in the daytime generally consists of shorter phrases with longer gaps.

Perhaps the most frequently heard call is a sharply downslurred note.

The following is a flight call.

Also gives a quavering trill not unlike Fork-tailed Sunbird.

A variety of calls may be uttered by a foraging flock.

DISTRIBUTION & HABITAT PREFERENCE 

Japanese White-eye is widespread in HK as a breeding species and is almost ubiquitous in winter. As a breeding bird it reaches its highest densities in the secondary broadleaf forest of the central New Territories and HK Island, but it also breeds in fung shui woods around villages, city parks and taller closed-canopy shrubland.

Recorded in 52.7% of 1 km squares in the 1993-96 breeding survey, this was little different at 51.6% in the 2016-19 survey. The main areas of absence are grassland and grassland with shrubs in the western and eastern New Territories and on Lantau. On Tai Mo Shan breeding birds are sparse above 650m altitude and it does not utilise the dwarf bamboo shrubland on the upper slopes. It also appears to be rare on smaller islands at this time. However, flocks of recently-fledged juveniles disperse from the breeding areas as early as mid-May, and these occur in large numbers in mangroves, at the edge of reed beds, in low shrubland and even isolated large trees, especially Chinese Banyan Ficus microcarpa in city streets. The limiting factor is probably the presence of small-sized fruit as this species is almost entirely frugivorous for most of the year.

There appears to have been a significant decline in its winter distribution, however, from 81.1% of 1 km squares in 2001-05 to 67.3% in 2016-19. There was no clear change in distribution, though it seems that urbanization and the decline in area of urban edge habitats may be a factor. It may also be that there is now a smaller immigrant population from the north.

OCCURRENCE

Because of the large breeding population, the extent of immigration in winter is unclear, but it is noticeable that large flocks appear in November in locations where this species is normally scarce, and visible migration is often observed in the early mornings. The highest November counts are 247 at Fanling Golf Course on 26 November 2015 and 244 on 14 November 1993. The largest flocks are usually recorded in midwinter with the highest counts being 341 on Lamma on 27 December 2019 and 315 in southwest Lantau on 18 December 2015. These high counts are similar to those obtained in the 1990s.

The large flocks tend to break up with the onset of the breeding season and spring passage is less easy to discern than that in autumn, but a flock of 25 moving north at approximately 200m altitude above Chek Lap Kok on 25 March 1997 suggests that true northward migration occurs. The highest spring count in the period 1999-2020 is 100, at Po Toi on 7 April and Ho Sheung Heung on 15 April, both in 2013 suggesting unusually heavy spring passage in that year.

Swinhoe’s White-eye was considered abundant by Swinhoe (1861), who found it to be common in the street trees of the new city of Victoria, and all subsequent authors agree with this. This is the most popular cagebird in HK and doubtless some of the birds sold in the markets are caught locally, but there is no evidence of any impact on the population. Indeed, no population or range changes have been detected in HK. Melville (1988) provided preliminary notes on moult.

BEHAVIOUR, FORAGING & DIET

Active passerine that readily forms single-species flocks and also joins multi-species flocks in the non-breeding season. Consumes insects, larvae, small fleshy fruit (Callicarpa longibracteata, Holmskioldia sanguinea, Ilex sp., Mallotus sp., Sapium sebiferum, Zanthoxylum avicennae), seeds, flower buds, nectar (Russelia sarmentosa) and pollen (Rhodoleia championii). Barretto and Barretto (2021) also list the nectar of Tabebuia chrysantha, and Schefflera heptaphylla and Aporusa dioica as sources of food.

According to Dudgeon and Corlett (2004) they are almost entirely frugivorous midwinter, but dependent on insects during the early summer when fruit is scarce. It is one of the three main agents of seed dispersal in HK, the others being Chinese and Red-whiskered Bulbuls.

Flocks are very vocal, while a pre-sunrise song is delivered in the breeding season; daytime song is rarely so intense.

BREEDING

Despite it being a widespread breeding species, there are very few observations relating to breeding activity. Nests have been observed from 21 March to 18 May, while adults bringing food to up to four juveniles have been noted on 5^th (Barretto and Barretto 2021) 17^th and 25 April, as well as on the extremely early date of February 2005 (Wong et al. 2009). Independent juveniles have been seen from 18 April to 10 May.

Herklots (1967) noted that the breeding season stretches from March to August, and that several broods are reared. He stated that small trees and bamboos were chosen as the site of a well-constructed cup slung inside a small fork of a branch or attached to its side. The nest is a small and carefully crafted cup, often placed on the outer part of a horizontal bough surrounded by leaves. Three or four pale whitish-blue eggs are typically laid, and incubation was noted to take ten days.

RANGE & SYSTEMATICS

Ebird range maps indicate it occurs from Liaoning in northeast China south through much of China and Indochina to Singapore, where it is introduced. It is a summer visitor in the north of its range (Wild Beijing 2024).

CONSERVATION STATUS

IUCN: Least Concern. Population trend decreasing.