Dark-sided Thrush Zoothera marginata is a Central and Eastern Himalayan species whose range reaches Yunnan in the west (Gaoligong Mountains) and south (Xishuangbanna). HABITAT & BEHAVIOR Retiring, shy, often found near rocky streams digging in mud, but also in bamboo thickets. Generally non-migratory, with some movement to lower elevations in winter. ID & COMPARISON Cryptically brown, but similar Long-billed Thrush Z. monticola even darker. Primaries reddish-brown and coverts, mantle, and back darker brown. Throat and chin whitish. Faint but discernible crescent on ear covert. Sides scaly, not spotted as in Long-billed. Also smaller than Long-billed. BARE PARTS Bill black, particularly long (but not as long as Long-billed); feet brown; eye-ring white. VOICE Thin whistles; some croaking when flushed. — Craig Brelsford
THE GROUND THRUSHES AND ASIAN THRUSHES OF CHINA
shanghaibirding.com has research on all 10 species in the genera Geokichla and Zoothera in China. Click any link:
Orange-headed Thrush Geokichla citrina
Siberian Thrush G. sibirica
Alpine Thrush Zoothera mollissima
Sichuan Thrush Z. griseiceps
Himalayan Thrush Z. salimalii
Long-tailed Thrush Z. dixoni
White’s Thrush Z. aurea
Scaly Thrush Z. dauma
Long-billed Thrush Z. monticola
Dark-sided Thrush Z. marginata
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.