Deasbaireachd:Breac an t-sìl
I think this is wrong and not helpful. There are three species that can be clearly distinguished visually and birders would never confuse them.
The two smaller species are the yellow one M. flava and black-and-white one M. alba; the latter occurs in two forms; one of which has a lot more black. I think flava=yellow=buidhe and alba=an-t-sìl and yarrelli=glasag. M. cinerea=grey is quite a bit bigger =breacan-baintighearna.