Alstrom’s Warbler, Phylloscopus soror, breeds in China and winters from southwestern China into Indochina. In Hong Kong it is a passage migrant in autumn and early winter.
A complete yellow orbital ring surrounds the eye. The forehead and forecrown are greenish, the underparts are yellow, and the flanks are greenish; the wingbar varies in appearance.
In Hong Kong it is a scarce passage migrant in autumn and early winter, using wooded areas. It forages unobtrusively in the understorey and may make short flights to catch insects.
An extinction-risk assessment has not been added yet.