first-winter flavas

clearly need to do some swatting on these-- up to 15 on a local field of late with a large range of variations from full adult yellow, males to this grey bird with yellow restricted to undertail coverts; had one this morning with brownish toned uppers, whitish super and underparts down to yellow vent and undertail coverts -- also a strong call heard from an unseen bird but not recorded in the rain -- need to get back if it fines up later -- rubbish heavily cropped shots here