IDENTIFICATION

VOCALISATIONS

Sings throughout the year and pairs frequently utter a variety of contact calls. Four main song types are uttered in HK.

Perhaps the commonest call is what is probably a duet.

Other calls include the following.

This vocalisation is not often heard and may be a pair.

DISTRIBUTION & HABITAT PREFERENCE

Streak-breasted Scimitar Babbler is now found through much of HK Island and the mainland New Territories wherever larger expanses of forest and shrubland are present. It is most regularly found and occurs in larger numbers in better quality forest with a well-developed understorey and in closed-canopy shrubland, but it will utilise grassland/shrubland mosaic habitat though perhaps only at higher altitude or where this is adjacent to the higher quality habitats. Thus, it is largely confined to Country Parks and higher altitude areas and is absent from the the Castle Peak range and the lowlands of much of the northwest and northern New Territories as well as developed areas. As yet there are no verified records from any of the offshore islands, though it was recorded from single squares on Lantau in both winter atlas surveys; there is also a single 2020 eBird record from Lantau Peak (eBird 2024).

Much of the current range has been occupied in this century: at the time of the first breeding season atlas survey it was largely confined to HK Island and the central New Territories, with small numbers recorded east of Ma On Shan, and it was on reported from only 2.2% of squares. The first winter atlas survey (2001-05) showed that by then it had spread to the northeast New Territories and Sai Kung and it was found in 6.3% of squares. By the time of the second atlas surveys (2016-19) it was found in 12.9% and 13.7% of squares in summer and winter respectively. However, this increase largely comprised infilling of the range occupied by 2005 with the only significant spread being into the southeast New Territories. There was also a suggestion of a decline in the western part of HK Island. Most of the former closed canopy shrubland there has now undergone succession to forest, perhaps lending support to the suggestion by Carey et al. (2001) that this species prefers closed canopy shrubland to forest.

Streak-breasted Scimitar Babbler appears to be a low density species with a large home range. The highest count, of 20 individuals at Ng Tung Chai on 4 January 2003, remains exceptional and experienced observers rarely encounter more than about four individuals even when spending several hours and kilometres traversing closed-canopy shrubland and forest.

OCCURRENCE

The first accepted record for HK was at Hatton Road, HK Island on 11 and 13 September 1978 (Cooper and Chalmers 1980). This individual was considered at the time likely to be ex-captive, though it was noted that it showed no evidence of having been in captivity. Subsequently, Chalmers (1986) drew a distinction between species that might be occurring in HK in a wild state, which were placed in ‘Category D’, and those for which all records were considered to refer to likely or certain ex-captive individuals (‘Category E’). As a southeast China breeding species with a record of an individual showing no evidence of captivity, Streak-breasted Scimitar Babbler was placed in Category D.

Subsequent records came from HK Island in 1986 and there and at Tai Po Kau in 1988 (the latter being the first observation in the New Territories), after which records became annual with an upsurge in observations on HK Island and the central New Territories in the early 1990s (Carey et al. 2001). Whilst this increase was no doubt genuine, and is, as is discussed above, still continuing, with the benefit of hindsight, it seems likely that Streak-breasted Scimitar Babbler was overlooked to some extent until observers became familiar with its vocalisations, a process that was no doubt greatly aided by visits to forest sites in southeast China from the mid 1980s as is documented by Lewthwaite (1996).

Such speculation aside, the presence of established populations in the central New Territories and on HK Island led to this species being moved to the then Category A of the HK list (Leader 1993) where it remained until the review process undertaken during the preparation of the first Avifauna (Carey et al. 2001) demonstrated that the pattern of colonisation did not accord with it having colonised HK naturally, but rather strongly suggested that both the HK Island and central New Territories populations were derived from ex-captive birds. Accordingly, it was placed on the then Category IIA (then Category C) (Carey et al. 2001), where it remains today.

Indeed, its failure, at least to date, to colonise any of the offshore islands, even those close to the mainland, and the continued pattern of spread in the New Territories during this century provides further support for the conclusion that there is no evidence of its occurring in HK naturally. There are now several recent (since 2015) records from the hills north of Yantian, Shenzhen, whilst on the HK side it is found at Robin’s Nest and between San Kwai Tin and Sha Tau Kok along the boundary with Guangdong, suggesting that the populations may now be continuous. However the wider pattern of distribution in Guangdong indicates that it is more likely that the Yantian area has been colonised from HK rather than vice versa (eBird 2024).

The first reference to the occurrence of Streak-breasted Scimitar Babbler in HK is that of Herklots (1953) who stated that several were seen on the Peak in 1949. No observer was listed, but it was not Herklots himself, as he stated explicitly that he had never seen this species in HK (Herklots 1953). Though this was not mentioned by Herklots, Webster (1975), in reviewing this record, stated that it was not supported by field notes, and treated it as referring to ‘possibly escapes’. In the absence of further details, notably a date or dates and a description by or on behalf of a named observer, it is now considered that this record should be regarded as unsubstantiated and be disregarded.

BREEDING

No nests appear to have been found in HK, though birds have been seen carrying nesting material on 16 March (dry grass) and 17 April. Apparent courtship feeding has been observed on 2 March and ‘courtship display’ on 19 June, whilst a bird carrying food, presumably for young, has been observed on 31 March and family parties observed on 10 April, 2 June and 9 August, suggesting that there is a rather long breeding season and that Streak-breasted Scimitar Babbler may be multi-brooded in HK.

BEHAVIOUR, FORAGING & DIET

Streak-breasted Scimitar Babbler is found in pairs and family parties; pairs foraging and moving together can be found at all times of year, not only during the breeding season. It does not appear to form flocks with more than two or three of its own species but single individuals and pairs frequently join mixed flocks (both small babbler and warbler flocks and laughingthrush flocks). It is not particularly shy and will often approach an observer giving a whistled version of its song; however, it is rather skulking, usually keeping to the forest floor and the lower levels of the canopy. It prefers to search for its presumed invertebrate food in vine tangles and in crevices in tree trunks and larger branches, and at such times it may ascend into the mid-canopy, though usually only briefly.

Diet has been little studied in HK. Leven (2000) found only invertebrates in the two faecal samples that he examined, which accords with its diet elsewhere where it is described as being insectivorous (e.g. Salim Ali and Ripley 1996).

RANGE & SYSTEMATICS

The native range of Streak-breasted Scimitar Babbler extends from the central Himalayas in Uttarakhand, northwest India, eastwards through the Himalayas and throughout south and central China as far north as Sichuan, Shaanxi, Henan, Anhui and Zheijiang. In the south it extends to northern Myanmar, Laos and northern Vietnam. It is widespread on Hainan, but not Taiwan which is occupied by a sibling species, P. musicus (Collar and Robson 2020, Liu and Chen 2021).

There are 12 races; nine of which occur in China. The race occurring in HK has not been confirmed, but photographs appear to match the illustration of the race hunanensis in Liu and Chen (2021) rather than the race stridulus which Cheng (1987) stated occurred in Guangdong and Fujian. However Cheng does not seem to have examined specimens from Guangdong, and whilst photographs on eBird from Guangdong appear to match birds in HK, those from Wuyishan in Fujian/Jiangxi accord with the taxon there being stridulus (eBird 2024), so it seems most likely that birds in Guangdong are in fact also P. r. hunanensis and that this is the race present in HK.

No evidence has emerged to support the suggestion by Carey et al. (2001) that the taxon on HK Island might be different from that in the New Territories; however, there appear to be few published photographs of the HK Island population.

CONSERVATION STATUS

IUCN: Least Concern. Population trend stable.