brianhstone said:
In the back of my mind I remember something about the extent of white up onto the back - more extensive in northern? Is that right?
BTW twice the size would really stand out, e.g. the size of a Collared Dove if we are talking length. I don't think the northern race is supposed to be that much bigger.
THis is what BWP says i.e. size is diagnostic (but we all know how difficult it can be to estimate in the field) and colour is also different but more subtle.
Taken from the BWP on CD-ROM: copyright Oxford University Press.
Northern and eastern Europe inhabited by nominate pyrrhula, with average wing length of male c. 92•5 (averages of various populations 91•5–94•5, measurements of individuals mainly 89–98). For each sex, virtually no overlap in measurements between nominate pyrrhula and smaller races.
Male pileata from Britain and Ireland about as dark above as europoea, but more diluted dull pink-red below; Female slightly darker and browner above, distinctly so below, especially on flank.
This means that male northern are brighter pink on the underparts and females are paler. No other plumage features are given.