Family Bush-warblers (Scotocercidae)

Least Concern

Aberrant Bush-warbler (Horornis flavolivaceus)


French: Bouscarle jaune et vert German: Olivseidensänger Spanish: Cetia verdiamarilla

N[eornis]. flavolivacea


, 1845,



Hitherto treated as two species, with races stresemanni, alexanderi, weberi, intricatus and oblitus under a narrower H. flavolivaceus and the remaining races grouping under “Sunda Bush-warbler” H. vulcanius. Molecular evidence, however, places races intricatus and oblitus as closer to latter grouping#R, but morphologically they remain near-indistinguishable from other taxa in former grouping#R; lumping the two species thus seems appropriate and is consistent with the monophyly detected in these taxa#R. Birds from S China (Sichuan, W Yunnan) described as race dulcivox (which has been treated as synonym also of H. fortipes davidianus), but type specimen lost; probably inseparable from intricatus. Form described as “Phylloscopus subaffinis arcanus”, based on three specimens from W Nepal (in Jan and Apr), now considered synonymous with nominate race of present species. Fourteen subspecies recognized.

Subspecies and Distribution
  • H. f. flavolivaceus (Blyth, 1845) – Aberrant Bush-warbler – Himalayas from NC India (E Himachal Pradesh and Uttarakhand) E to S China (SE Xizang).
  • H. f. stresemanni (Koelz, 1954) – Garo and Khasi Hills, in NE India (Meghalaya).
  • H. f. alexanderi (Ripley, 1951) – hills of extreme NE India (E Nagaland, Manipur and Mizoram).
  • H. f. weberi (Mayr, 1941) – Chin Hills, in W Myanmar.
  • H. f. intricatus (E. J. O. Hartert, 1909) – Perplexing Bush-warbler – N & E Myanmar, S China (Sichuan E to SW Shanxi and S Shaanxi, S to W & N Yunnan); some birds winter S to NW Thailand.
  • H. f. oblitus (Mayr, 1941) – N Laos and NW Vietnam.
  • H. f. sepiarius (Kloss, 1931) – N Sumatra.
  • H. f. flaviventris (Salvadori, 1879) – C & S Sumatra.
  • H. f. vulcanius (Blyth, 1870) – Sunda Bush-warbler – Java, Bali and Lombok. Probably this race on Sumbawa (Gunung Tambora#R).
  • H. f. kolichisi (Johnstone & Darnell, 1997) – Alor.
  • H. f. everetti (E. J. O. Hartert, 1898) – Timor. Probably this race on Wetar#R#R.
  • H. f. banksi (Chasen, 1935) – NW Borneo.
  • H. f. oreophilus (Sharpe, 1888) – Mt Kinabalu, in N Borneo.
  • H. f. palawanus (Ripley & Rabor, 1962) – S Palawan (Mt Mantalingajan), in SW Philippines.
  • Descriptive notes

    12–13·5 cm; 6–10 g. A medium-sized bush-warbler with short, rounded wings. Nominate race is yellowish olive-green above, with pale yellowish supercilium,... read more


    Song of Aberrant Bush-warbler group a short series of thin rising notes followed by longer whistle... read more


    Bushes, tall grass clumps, dense bamboo thickets, ferns and scrub (including Lantana scrub... read more

    Food and feeding

    Food items not well known, presumably invertebrates and larvae; Sunda Bush-warbler group recorded taking small invertebrates and larvae;... read more


    Poorly known. Season May–Aug (Aberrant Bush-warbler group) or Feb, Apr, May, Jul, Aug, Oct and Dec (Sunda Bush-warbler group). Nest a... read more


    Altitudinal migrant; post-breeding descent to lower elevations; resident in Indonesia and Sundaland... read more

    Status and conservation

    Not globally threatened (Least Concern). Common to fairly common in Himalayas; common in NE Indian hills. Uncommon in China; fairly common in Myanmar and N Indochina;... read more

    Recommended citation

    Clement, P. & Kirwan, G.M. (2019). Aberrant Bush-warbler (Horornis flavolivaceus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 7 December 2019).