Relatively difficult to identify, geese are perhaps best known for their migration, being harbingers of both summer and winter. Geese live comfortably at the intersection of water and land, eating a vegetarian diet of grasses, seeds, roots, berries, and aquatic plants. Unlike many birds, geese pair-bond and mate for life, building a simple nest in the ground and lining it with down. Depending on their species, geese lay a clutch of four to nine eggs, and fledglings remain grounded for forty to seventy-three days. Geese molt once a year after the breeding season; during this period the bird is unable to fly for four to five weeks.
Physical Characteristics of Geese
Geese are medium- to large-sized birds, between the size of ducks and swans. They have long necks and short legs in the center of their bodies. Because of this leg placement, geese do not waddle as much as other waterfowl when moving about on land. Their feet are webbed, which enables them to swim rapidly. The bills of geese have serrations on the mandibles called lamellae; these are useful, because most geese gather some of their food while submerged. Because the bill is equipped with a horny covering at the tip of the upper mandible and because of the curved shape of the bill, geese can easily clip grasses, grains, or other foods. Most species of geese are blackish in color, although many species have considerable white markings in their plumage, often restricted to their bellies or lower tail coverts. Even though each species has distinguishing physical characteristics, it is often difficult to identify a particular species in the field. Even Canada geese, which are probably the easiest to identify with their white chin straps, can be a source of frustration for bird watchers attempting to distinguish between the dozen or so subspecies of Canada geese. Male and female geese of each species resemble each other.
Thanks for description - Animal life club