Upperwing has pale greyish-white primary bases and often pale rufous or yellowish-brown forewing, paler than dark grey flight-feathers.
翼上初级飞羽呈现灰白色，翼前缘经常为淡棕色或黄棕色，比飞羽的深灰色要浅。
Upperwing has pale greyish-white primary bases and often pale rufous or yellowish-brown forewing, paler than dark grey flight-feathers.
翼上初级飞羽呈现灰白色，翼前缘经常为淡棕色或黄棕色，比飞羽的深灰色要浅。
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