There are lots of reasons you may want to know whether you’ve got male or female ducks or ducklings. In this article, you’ll find out how to definitively tell boy and girls ducks or ducklings apart!
Entering the search query “how to sex a duck” into Google sounds like something that could land you on an FBI watch list. Fear not. When we use the terminology “sexing a duck,” we’re referring to how you can distinguish between a male vs female duckling or duck, nothing nefarious. And, no, we won’t tell the FBI on you for reading this article.
Sex vs gender: what’s the difference?
First, a point of clarity: “sex” refers to reproductive organs. “Gender” refers to a critter’s sexual identification, e.g. primarily a function of the brain. Confusingly, these terms are often used interchangeably even though they’re quite different, biologically speaking.
Complex organisms are indeed complex, ducks included. And complex biological organisms don’t always line up into neat binary categories, ducks included.
For instance, our female ducks regularly have sex with each other. They also have sex with our drake. Ducks are not known for their sexual discretion, so don’t be alarmed when you see these behaviors in your mature ducks.
Humorously, our duck Mary seems to actually think she’s a drake. She’ll regularly challenge our drake, Sir Winston Duckbill, to a duel. She often wins, sending Winston running for his life.
Mary (who we now jokingly call Marty) even has the secondary sex characteristics of a drake: green head during nuptial plumage, orange feet, and curled drake tail feather. What the heck?
Turns out due to prolific egg laying in years past, Mary/Marty experienced ovarian damage. With non-functioning ovaries, her body stopped producing the hormones that made her female, so she started to revert to the default sex in ducks, which is male.
Mary’s sex is female, based on her reproductive organs and chromosomes. What’s her gender? We have no idea. She’s not saying and she doesn’t seem to care — nor do her flockmates.
Thankfully, when it comes to sexing ducks (or ducklings), most cases aren’t nearly as difficult as Mary/Marty. We’ll teach you how!
How to sex mature ducks
Let’s start with the easy part: sexing 6+ week old ducks:
Method 1. Vocalization check
If you’ve ever raised ducklings, you know they mature incredibly quickly. In fact, they look like miniature adults after about six weeks. At that point, you can start to tell the difference between male and female ducks using your ears.
That’s because real duck men don’t quack. Instead, drakes make more of a low, raspy blurp-blurp-blurp sound. A drake could talk as loud as it wanted in your backyard and would likely be unable to let your neighbors in on the conversation — unless you have particularly nosy neighbors.
Only female ducks make the distinctive (and loud) duck vocalizations that you think of with ducks: quack-quack-quack. Granted they actually have a far more varied and nuanced vocabulary than “quack.” When a female duck wants to be heard, your entire neighborhood will know about it.
Vocalizations are an easy way to sex either:
a) Young 6-10 week old ducks who haven’t yet earned their distinctive adult plumage. (*Watch the video “Duckling vocalizations: 12 Days old to 6 weeks old” in our How to raise ducklings guide.)
b) Monomorphic breeds like American Pekins who have nearly identical plumage regardless of their sex.
Method 2: Plumage and other physical features
Feather coloration – For older, mature ducks with dimorphic plumage (e.g. the males look different than the females), the easiest way to sex them is to look at their feathers. Drakes of most mallard-derived breeds have gorgeous green-iridescent head plumage for a large part of the year (nuptial plumage), until they go into their eclipse plumage when they look far less showy.
Female ducks within these breeds do not have green heads. However, for other breeds like Pekins (which are all-white), this distinction does not help in sexing.
Drake feathers – While in their nuptial plumage, drakes also have “drake feathers,” a few curled feathers on the top side of their tail.
Female ducks do not have curly drake feathers on the tops of their tails.
Other physical features – Finally, some breeds — like our Welsh Harlequins — also have other physical differences at maturity. For instance, our Welsh Harlequin drake has bright orange legs and a yellow/orange bull, whereas our females’ legs are more dark grey/green in color as are their bills. These physical distinctions are not universal to all breeds of ducks.
Using the distinctions detailed above (vocalizations, plumage check, & other breed-specific sex differences), you should be able to sex a duck that’s 6+ weeks old. If you’re trying to sex a monomorphic breed, there won’t be a green head to go by, but the voice and possibly the drake feather (if they’re in nuptial plumage) will indicate their sex.
How to sex ducklings
Now comes the harder part: sexing those adorable little duckling fuzzballs that all look nearly identical.
Methods: Down color vs bill color vs vent sexing
In some duck breeds, there are subtle differences in down coloration between male and female ducklings. There are too many breeds and too much variability (or lack of variability) to list here. Plus, this method is not going to help you definitely sex ducklings.
As for bills: in very young Welsh Harlequin ducklings (days 1-3), a pinkish colored bill with a dark tip likely means female, whereas a darker bill likely means male. However, this method is not definitive either and only applies to one breed of duck.
The only 100% definitive way to sex ducklings of any breed is vent sexing, also called vent checking. However, it’s critical that you know how to do vent sexing safely and correctly before you give it a try. And as John Metzer of Metzer Farms says, vent sexing is best done on 1-2 day old ducklings — after that, it’s more difficult.
Warning: you can permanently injure your ducklings with improper vent check
Before we dive into the how to’s of vent sexing, we need to issue a very clear warning. If a vent check is done incorrectly with too much force or for too long a duration, you can permanently injure your ducklings. Those little parts are quite delicate!
Thus, if you don’t know how to conduct a proper vent check, please do not proceed. Let an expert — such as an avian vet — conduct a vent check for you and possibly teach you how to do it for future reference.
Vent sexing instructional video
There are also excellent online instructional videos about how to sex ducklings. We’d highly recommend watching this Metzer Farms’ video about vent checking before you consider doing the procedure yourself:
*For reference, Metzer Farms sexes tens of thousands of ducklings per year, so they likely have more experience sexing ducklings than anyone else out there.
How to vent sex ducklings:
A duck’s anal vent, aka cloaca, is where their reproductive organs reside. However, in ducks/ducklings, neither the male penis nor the female vagina is visible with a mere surface inspection. Hence the need for a deeper look…
When doing vent sexing, you’re NOT trying to pop the [potential] drake’s penis out by pushing on the area around the vent. Instead, holding the duckling upside down in one hand, use the fingers of your other hand to gently pull back (not pushing or applying pressure) on either side of the vent in order to open the vent and expose the reproductive organs below.
Note: Your first time out, this process may be easier with two people — one to securely hold the duckling, the other to do the penis hunting (ha!).
If you spot a drake penis (which looks like a small, light-colored worm), you’ve got a male. No penis = female.
If you’re vent sexing a bunch of ducklings, you should end up with about a 50/50 ratio of males to females. If not, you’ve likely not been very accurate your first time around. If so, don’t feel bad – it takes a lot of practice to get really good at vent sexing.
Post-sexing: what next?
If you want to keep track of your male and female ducklings after sexing them, you can either:
a) separate them into separate flocks immediately after sexing, or
b) keep both sexes together, but place a zip tie around the ankles of one of the sexes, clipping off the excess tie.
Warning: If you use zip ties, you have to pay very careful attention as the ducklings’ ankles grow so you don’t end up cutting into the skin with the ties. Remove and replace zip ties as your ducklings grow.
For backyard or pet duck parents, we recommend either not having any drakes or having no more than 1 drake per every 3-4 females. Or if you’re not interested in eggs and are instead interested solely in having good pet ducks with lower potential for medical problems, having a small, all-drake flock could be a good choice for you.
Read more on this topic in our article: Should I get male or female ducks… or both?
Now you know how to sex male and female ducklings and ducks, regardless of their age or breed!
Get quacking on other helpful duck articles:
- How to build a self-cleaning duck pond
- 17 tips to keep your ducks safe from predators
- How to build a long-lasting predator-proof duck coop and duck run
- How to choose the best duck breeds for you (with breed rankings)
- How to hatch duck eggs: complete guide
- What to feed pet or backyard ducks to maximize their health and longevity
… and more helpful duck articles from Tyrant Farms.