This tiny warbler is prone to vagrancy as far as western Europe in late October and November, despite a 3000km distance from its breeding grounds. For example, this species occurs in late autumn in Great Britain regularly enough that it is not classified as rare there.
This is one of the smallest warblers, and shares greenish upperparts and off-white underparts with typical leaf warblers. However, this is a little jewel of a bird, with prominent double wing bars, supercilia and crown stripe, and a lemon-yellow rump.
The closely related southern species, Lemon-rumped Warbler, P. chloronotus, and Gansu Leaf Warbler, P. kansuensis, move to lower latitudes in winter, but do not migrate long distances.
This bird is named after the German zoologist Peter Simon Pallas.