Masked Laughingthrush Pterorhinus perspicillatus 黑臉噪鶥
Category I. A common resident of anthropogenic and disturbed habitats throughout HK.
IDENTIFICATION
Jul. 2020, Kenneth Lam.
28-31.5 cm. A large, rather lanky, long-legged and long-tailed laughingthrush. Head has an extensive and distinctive black mask, while the upperparts are largely dull grey-brown, slightly greyer on the head and browner on the wings. The tail is a warmer brown, blacker towards the tip of the outer pairs of feathers, which is very distinctive in flight. Underparts largely dull grey-brown, shading to buff on the belly and rufous on the vent. Iris dark brown, bill grey-brown, strong greyish-pink and feet. Noisy and sociable, almost always seen in parties of about five to ten birds.
VOCALISATIONS
Very vocal, parties regularly call together in response to being disturbed or sighting a predator. Characteristic calls are a harsh, strident ‘piuew’ and noisy babbling.
DISTRIBUTION & HABITAT PREFERENCE
Masked Laughingthrush is a common resident breeding species in HK. It is largely restricted to man-made or modified habitats including parks and gardens, villages, active and abandoned farmland, orchards, around fish ponds and even open storage areas. It appears to require some vegetation cover and is, therefore, largely absent from the most intensively developed urban areas, though in such situations it does seem able to make do with the smallest of pocket parks and planting strips as long as there are a few trees or shrubs. It utilises shrubland to some extent, though usually the fringes adjacent to farmland and villages. However, on Po Toi Island, where Chinese Hwamei does not occur, Masked Laughingthrush is common in shrubland throughout the island.
Masked Laughingthrush is widespread throughout the lowlands of HK, its mapped range recorded in the four atlases is almost the obverse of the Country Park boundaries in keeping with its largely occurring in anthropogenic habitats. The exception to this is the dense urban areas of Kowloon where its absence from a number of squares is notable. Numerically, Masked Laughingthrush has its stronghold in the lowlands of the northwest New Territories and, to a lesser extent around Tolo Harbour, both areas where its preferred habitats are widespread. It is present on most of HK’s offshore islands but appears to be absent from the Soko Islands and Tung Ping Chau. Although it was stated to occur on the latter by Carey et al. (2001) there appear to be no verified records.
The range of Masked Laughingthrush appears to have decreased somewhat in recent years: it was recorded in 51.2% of squares in the 1993-96 breeding bird atlas, but in only 44.3% of squares in the 2016-19 breeding atlas, with a similar reduction shown by the two winter atlas surveys (37.2% in 2001-05 and 32.4% in 2016-19). The decline has primarily been on HK Island and, to a lesser extent on Lantau. No doubt this decline is a consequence of habitat changes, as there is now very little of the village and urban fringe habitats required by Masked Laughingthrush remaining on HK Island, whilst on Lantau much of the abandoned farmland that was present in the 1990s has reverted to dense shrubland and young secondary woodland.
Historically, Masked Laughingthrush has been common in HK since the time of Swinhoe (1861). The only suggestion of any change in status comes from Herklots (1953) who considered it to be ‘the common babbler of the scrub-covered hillsides’. That is certainly not the case in recent history. However, Herklots was writing when the hillsides were much more heavily used by people and many of the lower slopes were farmed or grazed, perhaps forming a patchwork of the type favoured by this species. Indeed, Masked Laughingthrush remains very common in its preferred edge habitats as is evinced by a peak count in recent years of 89 individuals at Ho Sheung Heung on 5 February 2018.
OCCURRENCE
Masked Laughingthrush is resident and sedentary and there is no evidence of any movements into and out of HK. However, the HK population is continuous and contiguous with that of Shenzhen and no doubt some interchange occurs. Occasional inter-island movements have been observed in HK: Carey et al. (2001) documented a successful crossing of HK Harbour between Wanchai and Kowloon and an attempt to cross the Sulphur Channel between Green Island and Kowloon which ended with the bird being caught by a Black Kite. More recently, on 9 May 2008, two birds on the southern rocks of Po Toi Island were considered by the observer to be newly-arrived on the island.
BREEDING
Vaughan and Jones (1913) and Herklots (1973) both considered Masked Laughingthrush to be double-brooded with eggs laid from early March to August. Recent observations are similar, with nest-building noted as early as 11 February, newly-fledged juveniles noted from 26 March, nest-building (presumably for a second, or even third, brood) noted again in early and mid-July and dependent juveniles seen as late as 29 August. The rather large, well-constructed, cup nest is made from bamboo leaves and grass or other stems and is placed in bamboos, shrubs and trees at a height of two to ten metres above the ground. Three or four uniform glossy pale blue eggs are laid (Vaughan and Jones 1913, Herklots 1967).
In light of its occurring in parties throughout the year, Carey et al. (2001) speculated that Masked Laughingthrush might have a cooperative breeding strategy but noted that the breeding ecology did not appear to have been studied in HK; this remains the case today. However, in a recent study in central China, Li et al. (2017) showed that it is indeed a co-operative breeder in groups comprising three to six individuals consisting of the breeding pair and one or more retained offspring from previous years as helpers. These helpers were observed to participate in nest-building, incubation and feeding the young; furthermore, groups with a larger number of helpers were shown to fledge larger broods of young.
As has been noted elsewhere in China (Yang et al. 2012), Masked Laughingthrush is a host species for Large Hawk Cuckoo in HK. Single young cuckoos were observed being fed by a Masked Laughingthrush at HK Wetland Park on 31 May 2018 and at Nam Sang Wai on 18 July 2021; on the latter occasion a young laughingthrush was also being fed, suggesting that the young had been raised together.
BEHAVIOUR, FORAGING & DIET
Masked Laughingthrush is a very social species, invariably found in parties of about five to ten birds, which readily make their presence known by foraging in the open or calling loudly from cover. Masked Laughingthrushes are fully at home in anthropogenic landscapes where they are far from shy and are often one of the most conspicuous species. Parties are typically seen foraging noisily in leaf litter on the ground or in shrubs and small trees, though they will ascend, using a characteristic bounding hop, higher in trees when alarmed. Flight appears rather weak and laboured and birds generally only fly for short distances, though as the inter-island movements described above attest, longer flights are occasionally made. It was described as largely insectivorous by Vaughan and Jones (1913) and omnivorous by Herklots (1967), who referred to a diet of insects, snails, grubs and seeds. Leven (2000) considered it to be an insectivore-frugivore with all faecal samples examined containing both seeds and invertebrate remains. Masked Laughingthrush also readily eats bread, rice and other food waste deliberately or accidentally provided by people. Vertebrates, including an Asian Painted Frog Kaloula pulchra (Carey et al. 2001) and a young Changeable Lizard Calotes versicolor, are occasionally captured and eaten, and a Masked Laughingthrush was seen to predate the nest and devour the eggs of a Red-whiskered Bulbul.
RANGE & SYSTEMATICS
Monotypic. Central and southern China north to Henan and Jiangsu and west to central Sichuan and central Yunnan, and northern and central Vietnam (Liu and Chen 2021).
CONSERVATION STATUS
IUCN: Least Concern. Population trend stable.
Carey, G. J., M. L. Chalmers, D. A. Diskin, P. R. Kennerley, P. J. Leader, M. R. Leven, R. W. Lewthwaite, D. S. Melville, M. Turnbull and L. Young (2001). The Avifauna of Hong Kong. Hong Kong Bird Watching Society, Hong Kong.
eBird. 2021. eBird: An online database of bird distribution and abundance [web application]. eBird, Cornell Lab of Ornithology, Ithaca, New York. Available: http://www.ebird.org. (Accessed: 29 December 2023).
Herklots, G.A.C. (1953). Hong Kong Birds. South China Morning Post, Hong Kong.
Herklots, G.A.C. (1967). Hong Kong Birds (2nd ed.). South China Morning Post, Hong Kong.
Leven, M. R. (2000). Shrubland birds in Hong Kong: community structure, seasonality and diet. PhD. Thesis, University of Hong Kong.
Li, S., Z. Cao, G. Li and W. Li (2017). Breeding Ecology of the Masked Laughingthrush Garrulax perspicillatus, a Cooperative Breeder in Central China. Ardea 105(2), 137-144.
Liu, Y. and S. H. Chen (eds) (2021). 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.
Yang, C., W. Liang, A. Antonove, Y. Cai, B. G. Stokke, F. Fossou, A. Moksnes & E. Roskaft. (2012). Diversity of parasitic cuckoos and their hosts in China. Chinese Birds 2012, 3(1): 9-32.