Claudia’s Leaf Warbler Phylloscopus claudiae is a Chinese breeding endemic (eastern Tibet, western Sichuan, and southern parts of Gansu, Shaanxi and Shanxi; disjunctly in Hebei); non-breeding southern Yunnan, also India and Southeast Asia. HABITAT & BEHAVIOR Broadleaved, coniferous, and mixed forests, in summer between 1500-3700 m (4,920-12,140 ft.), in winter below 1500 m (4,920 ft.). Feeds at all levels of forest, from upper canopy to undergrowth. Very agile; often hangs upside down on branch, like a tit, and creeps along branches and tree trunks like a nuthatch. In breeding season, slowly flicks wings one at a time in territorial display. ID & COMPARISON Very similar to Blyth’s Leaf Warbler P. reguloides and Hartert’s Leaf Warbler P. goodsoni. Mid-sized leaf warbler with boldly patterned head and two wingbars. Long supercilium, yellowish before eye, whiter behind it, extends to nape, joined below by blackish eye-stripe and above by blackish posterior crown sides. Above crown sides, yellowish-olive median crown-stripe, turning yellowish-white posteriorly. Yellowish ear coverts with indistinct greyish mottling. Upperparts olive-green, with yellowish-white tips to greater and median coverts forming two distinct wingbars. Brownish-black tail edged olive-green above, with narrow white edges to inner web of outer rectrices. Underparts mainly white with slight yellow and greyish streaking; pale yellow vent and undertail coverts. Kloss’s Leaf Warbler P. ogilviegranti is slightly smaller and yellower overall, notably on supercilium, ear coverts, and median crown-stripe; note that underside of tail in Kloss’s is white. Kloss’s flicks wings quickly and simultaneously (this character should be used with care outside breeding season). Eastern Crowned Warbler P. coronatus has single weak wingbar, a fainter crown-stripe and crown sides, and yellower vent and undertail coverts. BARE PARTS Bill blackish-grey above, orange-yellow below. Feet yellowish-grey. VOICE Tit-like pit-chew call, often doubled or ending with a clearer note. Song 1-2 introductory whistles followed by 7-9 faster, lower-pitched notes, reminiscent of a sunbird, or 2 to 3 repeated tones in a cyclical pattern, reminiscent of Coal Tit. — 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.