Martens’s Warbler Phylloscopus omeiensis 峨嵋鶲鶯
Category I. Rare winter visitor to closed-canopy woodland and shrubland.
IDENTIFICATION
Jan. 2013, Michelle and Peter Wong.
11-12 cm. Orbital ring yellow and unbroken (may be diffuse above rear of eye), median crown stripe pure grey (though rarely forehead can be green), blackish lateral crown stripes usually distinct on forecrown, lower border of lateral crown stripe grey, ear coverts and lores green, upperparts yellowish-green, underparts variable but often dull yellow (can be bright) with variable pale greenish suffusion on breast side and flanks, wing bars usually lacking but can be present on greater coverts, bill relatively short and thin (Leader and Carey 2016, Alström 2020).
Differs from similar Bianchi’s Warbler by purer grey median crown stripe, blacker lateral crown stripes reaching closer to bill, brighter upperparts, more saturated yellow underparts and on average less distinct wing bar. Differs from even more similar Grey-crowned Warbler by smaller bill, slightly less distinct head pattern, more often a pale wing bar and complete orbital ring (Alström 2020). Call diagnostic (see below).
VOCALISATIONS
The call is ‘chik’ most similar to Grey-crowned Warbler but much thinner (as it is monosyllabic), less slurred and slightly higher in pitch. The same note presages most strophes in full song.
DISTRIBUTION & HABITAT PREFERENCE
Occurs in closed-canopy woodland or shrubland.
OCCURRENCE
One of the rarest ‘goldspec’ warblers in HK.
2013: one at Pak Sha O from 5 January to 26 February (Carey 2015), one at Aberdeen CP on 19th and 22 January and one again at Pak Sha O from 28 December to 14 January 2014 (presumed same as previous winter).
2014: singles at Sha Lo Tung on 18 January, Cheung Chau during 15-21 February and Ng Tung Chai on 15 February.
2017: one on Cheung Chau during 30-31 October and on 22 November.
2019: one at Ho Pui Reservoir from 27 January to 4 February.
2020: one at Lau Shui Heung on 30 January.
Lack of knowledge regarding field identification of members of the ‘golden-spectacled’ group of warblers means only in-hand records before 2002 can be assigned to species.
BEHAVIOUR, FORAGING & DIET
Forages unobtrusively in understorey when it takes short flights to catch insects; has a rather horizontal posture much of the time. Can be quite vocal, uttering its unremarkable call irregularly for long periods.
RANGE & SYSTEMATICS
Monotypic. Known to breed only in China in north Yunnan, Sichuan, Shaanxi, Hubei, Guizhou and probably south Gansu; winters southeast Asia (Alström 2020), probably including Yunnan.
CONSERVATION STATUS
IUCN: Least Concern. Population trend stable.
Alström, P. (2020). Martens's Warbler (Phylloscopus omeiensis), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.marwar4.01
Carey, G. J. (2015). Martens’s Warbler Seicercus omeiensis at Pak Sha O, Sai Kung. The first Hong Kong record. Hong Kong Bird Report 2013: 278-280.
Leader, P. J. and G. J. Carey (2016). The identification of Seicercus warblers in Hong Kong. Hong Kong Bird Report 2014: 322-333.
