Eastern Olivaceous Warbler Iduna pallida elaeica is a very uncommon breeder in extreme western Xinjiang. HABITAT More wooded than Sykes’s Warbler I. rama. ID & COMPARISON Greyish above and whitish below, with dark loral line, short white supercilium (often absent behind eye), and broken white eye-ring. Pale edges to tertials and secondaries often form sign of a wing panel. Secondaries sometimes tipped white (never so in Sykes’s Warbler). Very similar to Sykes’s Warbler and Booted Warbler I. caligata. Distinguished most readily from Sykes’s Warbler by the former’s regular downward tail movements, also by slightly larger size, longer bill, lack of bare bill base and wing panel, longer primary projection, slightly greyer upperparts, and distinctive song. Sykes’s rarely dips its tail, instead flicking it nervously in all directions. Square-ended tail with white sides, tail movement, slightly finer bill (with broad base), and greyer upperparts distinguishing features against Blyth’s Reed Warbler Acrocephalus dumetorum. VOICE Song slow, monotonous, scratchy tones performed in a cyclic pattern. Calls tjuck, fast zet-zet-zet, and somewhat subdued rolling tjrrrr, similar to Eurasian Tree Sparrow. — Craig Brelsford
THE REED WARBLERS OF CHINA
shanghaibirding.com covers most of the species in China in the family Acrocephalidae. Click any link:
Great Reed Warbler Acrocephalus arundinaceus
Oriental Reed Warbler A. orientalis
Clamorous Reed Warbler A. stentoreus
Black-browed Reed Warbler A. bistrigiceps
Moustached Warbler A. melanopogon
Sedge Warbler A. schoenobaenus
Speckled Reed Warbler A. sorghophilus
Blunt-winged Warbler A. concinens
Manchurian Reed Warbler A. tangorum
Paddyfield Warbler A. agricola
Blyth’s Reed Warbler A. dumetorum
Eurasian Reed Warbler A. scirpaceus
Thick-billed Warbler Arundinax aedon
Booted Warbler Iduna caligata
Sykes’s Warbler I. rama
Eastern Olivaceous Warbler I. pallida
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.