In China, Ashy-throated Warbler Phylloscopus maculipennis maculipennis uncommon resident southeastern Tibet, western Yunnan, and southwestern Sichuan, and virens possibly in Ngari Prefecture, western Tibet. HABITAT & BEHAVIOR Breeds in oak and conifer forests with thick rhododendron undergrowth, between 1800-3500 m (5,910-11,480 ft.); in winter in moist lowland forests, down to 600 m (1,970 ft.). Usually in canopy, foraging actively and flicking wings and tail. ID & COMPARISON Has unique combination of small size; grey face, throat, and breast, and contrastingly bright-yellow underparts below breast; long, broad, greyish-white supercilium; and white outer tail. Has greyish-white crown-stripe extending to center of nape, two yellowish-white wingbars, pale yellow rump, dark grey eye-stripe, grey crown sides and nape, and bright-green mantle, back, and scapulars. Flight feathers dark brown; white tips to tertials. Tail blackish-brown, with white on outermost tail feathers visible when tail flicked. All other close relatives have much more uniformly yellow underparts. Additionally, Sichuan Leaf Warbler P. forresti and Lemon-rumped Warbler P. chloronotus lack white in tail and have a yellowish crown-stripe, and Buff-barred Warbler P. pulcher has orange-buff wingbars and a more yellowish supercilium. BARE PARTS Dainty bill black with yellowish basal half of lower mandible; feet yellowish-brown. VOICE Song a fast, jumpy whistle of five high notes, the last lowest in pitch; also a slower “teach-you teach-you.” Call a thin, high-pitched “swit.” — 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.