What’s The Difference Between A Duck And A Goose?
Ducks and geese, along with swans, are birds that belong to the family Anatidae. It is a large family with members found on all continents except Antarctica, and in a diverse range of habitats.
Currently there are 174 species distributed across 53 genera although there is some uncertainty over the classification of about 15 species.
Ducks and geese share many traits. They typically have webbed feet, relatively short wings, and a broad, flat bill. The offspring of both imprint on the first thing they see after hatching which can sometimes include inanimate objects.
The main way scientists differentiate between ducks and geese is from the number of bones in their neck. Ducks have 16 bones or fewer in their necks while geese have between 17 and 24. This means that in general geese have longer necks than ducks.
However, there are some other differences which can help you identify ducks and swans, although in some cases there are overlaps.
Size and shape
Geese are generally larger and more muscular than ducks and have a more elongated body. Ducks tend to have shorter legs which are set further back on their body. Both have webbed feet except for the feet of the Hawaiian nene goose which are only partially webbed, and the webbing on the feet of geese is often more prominent than those on the feet of ducks.
Bill
Ducks have a broad, flat bill which reaches to about eye level and with nostrils that are positioned high up. They use their bill to forage for snails, crustaceans, fish, worms, and aquatic vegetation both in water and on the ground. Geese have shorter, humped shaped bills with a notch that can reach the top of their heads and with nostrils that are positioned further down. They tend to be herbivores and use their bill to graze on the ground.
Colour
True geese tend to be grey, white, or brown, and can be divided into two groups: pale-breasted geese and dark-breasted geese. They all have pink, orange, or yellow bills and legs. Geese are not sexually dimorphic which means there is little difference between males and females although ganders tend to be slightly larger although size is not a reliable indicator of sex.
Ducks have much more varied plumage and can show significant sexual dimorphism with the drakes being much more brightly coloured than the female, sometimes showing iridescent or metallic feathers.
Can ducks breed with geese?
Although waterfowl crossbreed more often than any other family of birds with records of more than 400 hybrid combinations, a duck cannot breed with a goose.
Different species of ducks and geese breed with each other with mallards being the most common duck to mate with other species. Mallards have been known to breed with pintails, black ducks, wigeon, shovelers, gadwalls, and teal.
When two different species mate, they tend to produce infertile offspring, although when mallards breed with their closest relatives they produce hybrids that are fully fertile, and ruddy ducks interbreed with white-headed ducks to produce fertile hybrids which has led to the decimation of the white-headed duck population.
Many duck and geese hybrids find it difficult to attract mates as they don’t have the physical and behavioural characteristics such as showy plumage or the ability to perform courtship rituals for successful pairing.
What about the sheldgeese?
The sheldgeese along with the shelducks belong to the sub-family or tribe Tadorninae. They are mostly found in the Southern Hemisphere, except for the common shelduck and the ruddy duck.
They have short bills, a goose-like build, an upright stance, and long legs which gives them an appearance somewhere between a goose and a dabbling duck. The smaller birds are called shelducks or sheldrakes, and are more aquatic and omnivorous, while the larger members of the tribe are called sheldgoose and are essentially vegetarian and spend more time on land.
Some of them, such as the Egyptian goose and the blue-winged goose, have a name that suggests they are geese. However, molecular data shows that sheldgeese as well as shelducks are ducks and the names are misnomers.
