A group of geese is called different names depending upon whether the birds are in the air, in the water, on the ground or on land. When on land, the group is referred to as a gaggle. A group of geese flying in the air is called a skein.
Once the group goes onto water, it is called a plump. Gender or age do not change the terms used for a group of geese. It is common for groups of waterfowl and other birds to have different terms when in different situations. Sometimes different breeds are called by a different name.