Atlantic Canada Goose

The Canada goose has a black head, neck and bill with a white chinstrap, brown back and wings, white under the tail on the rump and a black tail and legs. Sometimes there is a white ring around the base of the neck. The female looks the same, but is about 10% smaller. There are seven subspecies of Canada goose and a goose that used to be considered a Canada goose but is now considered its own distinct species, the cackling goose, which is smaller and itself has four subspecies. It appears that two subspecies of Canada goose are found in Europe. One is the Atlantic Canada goose (canadensis). It is one of the larger subspecies, light colored, with white at the base of the neck which is relatively clear, extending to the back and forming a sharp line with the black neck. The other subspecies is the lesser Canada goose (parvipes), the smallest of the seven subspecies of Canada goose. The lesser Canada goose is of medium size, which helps differentiate it from the smaller cackling goose, which can be as small as a mallard and also has a shorter proportional neck and bill.  The lesser is widely variable in color, with breasts of dark to light gray, and sometimes even brown.

These Canada geese, all in Rudesheim, Germany on the Rhine River, appear to be the Atlantic subspecies. They appear to be a uniform relatively light color and quite large, although I don't have any other geese to compare them against. 

This view shows that the white chinstrap does not connect at the back of the head.

I was a little surprised to find Canada geese in Europe.