Ross's Goose x Lesser White-fronted Goose hybrid

Ross's Goose Anser rossii x Lesser White-fronted Goose Anser erythropus hybrid

This bird had been around for a number of years and its identity is perhaps not 100% certain. I think Ross's or Snow Goose involvement is fairly clear and some Anser involvement seems fairly certain too. In most respects Ross's Goose x Lesser White-fronted Goose seems the best explanation.

The small bright pink bill suggests Lesser White-front, although we might expect a Ross's Goose x Lesser White-front to show more white on the forecrown. Many captive and feral Lesser White-fronted Geese are not pure, having some (Greater) White-fronted Goose ancestry - this may be the explanation, or it may simply be that the hybrid shows less white on the head compared to either of its parents. Joern has commented to say that he has seen similarly small amounts of white on the head for Greater White-fronted Goose x Snow Goose hybrids.

Although this bird seems to have a bit of a bulky rear end there doesn't seem to be any convincing evidence for a domestic goose involvement. Joern has pointed out that the wing moult may be contributing to the appearance of a bulky rear end, plus of course it may be over-fed at a site where the public feed bread to the geese.

Some of the previous discussion about this bird noted that it has some black on the cutting edge to its mandibles and a very slight 'grinning patch'. Although still leaning towards Ross's Goose, we felt that this meant that the possibility of Snow Goose involvement was not completely ruled out. Ross's Goose tends to lack black on the cutting edges or a grinning patch, but Joern has now uncovered a number of photos of Ross's Geese that do in fact show these features to some degree. So it seems that this is not a good reason to doubt that Ross's Goose is involved.

Ross's Goose x Lesser White-fronted Goose hybrid (with Greylag Geese), Whitlingham Country Park (Norfolk, UK), 17th January 2011