Yellow-bellied Bush Warbler Horornis acanthizoides acanthizoides in China breeds in high country from Qin Mountains to western Yunnan and disjunctly from southern Anhui to Wuyi Mountains, Fujian. Also concolor Taiwan. HABITAT & BEHAVIOR Breeds in misty evergreen forests with thick understory of dwarf bamboo, on mainland above 1850 m (6,070 ft.), Taiwan above 2500 m (8,200 ft.); lower in winter. Energetic and elusive in thick undergrowth. Song best indicator of presence; but when silent difficult to separate from Brown-flanked Bush Warbler H. fortipes. ID & COMPARISON Belly, flanks, and undertail coverts pale yellowish. Chin, throat greyish-white, grading into buff and yellow. Greyish smudge on breast sides may sometimes suggest faint breast band, as in Brown-flanked Bush Warbler. Rufescent brown from head to tail, most rufescent on wings and base of tail, but rump and lower back have more olive tinge. Supercilium well-marked, white. Greyish-black eye-stripe distinct before eye, more diffuse behind. White part of eye-ring visible below eye. Cheeks grey. Brown-flanked slightly larger and darker and has less well-defined supercilium. Adult Brown-flanked lacks obvious yellow underparts. Juvenile Brown-flanked has yellowish underparts but is more drab, lacks contrast to whitish throat, and is more olive on flanks and upperparts. Aberrant Bush Warbler H. flavolivaceus is larger and has short, simple song, more uniformly yellow underparts, and more olive upperparts. BARE PARTS Bill dark brown to greyish-black with yellowish base to lower mandible. Feet brownish-yellow. VOICE Song remarkable, a series of ascending see notes lasting 10–15 seconds and climaxing in a long, descending trill of 30–40 seconds. Song sometimes preceded by a shuttling call a few seconds long that may be repeated several times. Contact call an electric chet. Hume’s Bush Warbler H. brunnescens has similar but shorter song (usually no trill). Brown-flanked Bush Warbler has explosive song chee wichew. — Craig Brelsford
THE CETTIID WARBLERS OF CHINA
shanghaibirding.com covers most of the species in China in the family Cettiidae. Click any link:
Yellow-bellied Warbler Abroscopus superciliaris
Rufous-faced Warbler A. albogularis
Black-faced Warbler A. schisticeps
Mountain Tailorbird Phyllergates cuculatus
Broad-billed Warbler Tickellia hodgsoni
Japanese Bush Warbler Horornis diphone
Manchurian Bush Warbler H. borealis
Brown-flanked Bush Warbler H. fortipes
Hume’s Bush Warbler H. brunnescens
Yellow-bellied Bush Warbler H. acanthizoides
Aberrant Bush Warbler H. flavolivaceus
Grey-bellied Tesia Tesia cyaniventer
Slaty-bellied Tesia T. olivea
Cetti’s Warbler Cettia cetti
Chestnut-crowned Bush Warbler C. major
Grey-sided Bush Warbler C. brunnifrons
Chestnut-headed Tesia C. castaneocoronata
Asian Stubtail Urosphena squameiceps
Pale-footed Bush Warbler U. pallidipes
ACKNOWLEDGEMENTS
Daniel Bengtsson served as chief ornithological consultant for Craig Brelsford’s Photographic Field Guide to the Birds of China, from which this species description is drawn.
