Buff-throated Warbler Phylloscopus subaffinis breeds from southeast Qinghai across much of southern China to Zhejiang. Non-breeding at lower altitudes in breeding range and from southern Yunnan east to Fujian. HABITAT Breeds on open hillsides with scrub and in montane forests, generally at lower altitudes (1800-3600 m [5,910-11,800 ft.]) than Alpine Leaf Warbler P. occisinensis. Non-breeding to 200 m (660 ft.). ID & COMPARISON Very similar to Alpine Leaf Warbler. Distinguished by overall duller coloring and more nondescript appearance, shorter and usually darker bill, and longer tail. Generally less green hues in upperparts and no bright lemon hues in underparts, being more greyish-brown above and buffish-yellow below. Also has more buffish-yellow supercilium that may be diffuse before the eye, unlike brighter yellow supercilium of Alpine, which is often whiter behind the eye; a duller eye-stripe; and slightly darker ear coverts. Sulphur-bellied Warbler P. griseolus is colder grey-brown above, has more distinct head pattern, different coloration on underparts, greyish-white edges to flight feathers, longer and stronger bill, and slender appearance more reminiscent of Dusky Warbler P. fuscatus. BARE PARTS Bill blackish-brown above, yellow below, usually showing extensive dark tip (sometimes only yellow at base); feet dark brown or brownish-yellow. VOICE Call a cricket-like chirrup; song a simple trill similar to Alpine Leaf Warbler, but softer, slower, and higher-pitched, and lacking introductory chep call note. — Craig Brelsford
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.