Xen- (prefix): Foreign or other. As in: 1  Xenoantigen -- An antigen that is found in more than one species.  Xenograft -- A surgical graft of tissue from one species to an unlike species, genus or family.
Diet. Snow Geese feed almost exclusively on plant material. During the breeding season, they eat many seeds, leaves, and roots of aquatic vegetation. The very young birds feed on invertebrates. Berries become more important in the fall. In winter, waste grain from agricultural fields has become a primary food source.
Geese eat grass by grabbing the blade with their bill then tearing it from the ground. In some areas, there are laws against humans feeding geese. While it can be fine in moderation, geese that humans feed too much may start to rely on them instead of finding their own food.