small goose dilema

this bird is accompanying the Humber Barnacle Goose flock at Alkborough; I assumed that it was the same Barnacle x Cackling? Canada hybrid that I photographed with the Barnies in January 2013 nearby but it seems to have less white over the bill though its head was down in almost all photos; could it have lost that feature over 3 moult cycles?
The pattern and tones of the coverts surely mean it is a hybrid but could it be a Greater Canada x Barnacle or is it certainly a Cackling x Barnacle; size would seem to suggest the latter but is t that certain? and if it has Cackling Goose input then where from as there has never been a known Cackling Goose on the Humber -- really bad heat haze yesterday so nothing very sharp -- bottom 3 shots are of the bird in 2013 --