A small breeding population of these lives at Colebrook Lake, part of Moor Green Lakes. Snow Geese very rarely visit Britain in their wild state and these are certainly feral. The wild birds breed far into the North-East of Siberia and North America. They are easily told from white domestic geese (which are a much more common sight) by the paler legs and bill, much smaller size and the black 'grin' on the bill. They also have black primary wing feathers, which doesn't appear generally on domestic geese.
1-2: Moor Green Lakes LNR, 08/10/2006.