Dec 10 2012
Duck Versus Goose
Dear Readers,
A question has been puzzling me for a long time and the answers I’ve found on the Internet are unsatisfactory, so I’m asking you.
What is the difference between a duck and a goose?
Is a duck smaller than a goose? Not always. The Muscovy duck is much larger than a Ross’s goose.
Does a goose have a longer neck or legs? Not always. Consider these black-bellied whistling ducks.
When we see a duck or a goose, intuitively we are able to say, “That’s a duck” or “That’s a goose.”
But how do we know the difference?
Please let me know by posting a comment.
(Credits: mallard silhouette by Vlado on Freedigitalphotos.net, goose silhouette from Shutterstock, Muscovy duck by B.Walker on Wikimedia Commons, Ross’s goose by Alan Vernon on Wikimedia Commons, Black-bellied whistling ducks by Sultry on Wikimedia Commons)
p.s. See the comments! The answer is there!
The difference is social structure. Ducks are seasonally monogamous and form a bond that lasts only through courtship and the initiation of incubation. The male takes no role in raising the young. Geese and swans form strong bonds that last for many seasons (or life) and maintain family units through migration. Whistling ducks are closer to geese than ducks.
Head shape? Geese tend to have a higher forehead and shorter bill. And do all Geese honk?
Hi Kate,
As a geneticist (of bacteria), I was curious about the answers to your question. I found this article on Google Scholar on the systematics of waterfowl http://link.springer.com/article/10.1007%2FBF02424410?LI=true. From their detailed introduction, waterfowl have been classified based on morphology and behavior. DNA analysis is now being used. I haven’t found any discussion of one specific feature that is used so my bet is that there are a number that are used. Several of the articles I found indicated that there is significant cross breeding and not any huge barrier to it. Hope that helps and I really enjoy reading your blog!
Nancy
I always look at the beak. If the beak and the forehead seem to be all one slope, or close to being all one slope, it’s a goose. This make the beak look thick. If there iis a change of angle between the beak and the forehead – this make the beak look thinner – it’s a duck. That’s how I tell ducks from geese. i don’t know if that’s the scientific method, but it works for me.
A goose has a smaller head and shorter bill than a duck relative to its body size. The goose has a longer neck and that protruding kind of lump around vent.