Thanks Mike, I think I’ve got it. If I can summarise
Sulphur-breasted Warbler, phylloscopus ricketti, is the most colourful with all bright yellow underparts including the belly and contrasting black and yellow head pattern
Blyth’s Leaf Warbler (fokiensis), phylloscopus reguloides fokiensis, is the least colourful with all white/grey and no yellow on the underparts and contrasting grey and white head pattern
Goodson’s Leaf Warbler, phylloscopus goodsoni, now a separate species, has a varying amount of yellow on the underparts, some yellow at least on the chin and under-tail coverts and some white at least on the belly, and contrasting dark grey and yellow head pattern.
White-tailed Leaf Warbler and others are for the experts or the photographers.
Is this correct?
So the picture in BoHK&SC is Goodson’s Leaf Warbler?
