Ask the Swan Specialist

How to Tell a Swan Male From Female
By:The Regal SwanŽ
Date: 21 May 2006
In Response To: male or female? (natalie dutfield)

Dear Ms. Dutfield:

A very good and common question. Usually, you can tell male swans from female swans due to the following:

The male will have a larger knob (the bump on the bill) than the female. He will usually be larger, although this appearance can be deceiving if the food supply is not that great. Obviously, with weight loss, the male will also look small. Finally, there is no doubt during mating season the gender of the swans. The males will puff up at the least amount of agitation and will be ferociously defending his territory from any perceived intruder. His wings will be held higher and his neck will ride farther back on the wings as he goes through the water (busking) while creating a large wake as he moves in the water. If he is really upset, his neck will be even farther back onto the wings. Even more obvious is mating behavior, except that males will mate with males and females will mate with females if the opposite gender is not available.

Females will exhibit territorialism, but usually leave it to the males to defend. However, we have seen females actually egg on (no pun intended) a fight so that the male can remove an intruder from her "universe" just to have them removed!

You cannot tell just by looking if a female swan is "pregnant". You would have to conduct a physical examination to see if egg development is in progress or conduct possible hormone testing. At this point in time, there is very limited knowledge regarding bird hormone levels, much less a swan's normal hormone levels. It is for this reason, that our research team will begin testing swan hormone levels in the next month to provide veterinary medical personnel with a baseline knowledge of swan hormones.

Our best guess without seeing the swans, is that the swan is eating very well. If the swans just flew in from the migratory path, they would have lost a good percent of body weight during the migration. Once they find a suitable food source, they quickly regain their weight and this might be why you are just now noticing the weight difference. This is why we would be only guessing without seeing your swans, observing their behavior or physically examining the swans to ascertain the gender.

We hope that this information is of benefit. The Regal SwanŽ

> hi i was just wandering if you would be able to reply back via email
> for me wiv the answer to this quiestion? where i live there is a lake
> right in front of my house and along with geese, mallards and others
> there are 2 swans, they seem really friendly and love coming up to
> you when your feeding them. up intill recently i always thought that
> the small looking one with the smallest bump on the nose was the
> female and the biggest was the male, but the biggest one now looks
> pregant and its really confusing me which ones what sex????? please
> email back. yours faitfully miss natalie dutfield

Messages In This Thread

male or female? -- natalie dutfield -- 20 May 2006
How to Tell a Swan Male From Female -- The Regal SwanŽ -- 21 May 2006