You tell a young Khaki Campbell duck's sex most reliably at home by voice first, then by the curled drake feather and head colouring as the bird matures. Khaki Campbells are a khaki-brown laying breed with subtle plumage differences, so behaviour and sound beat guesswork from down colour in the first weeks.
Listen to the voice of a young Khaki Campbell first
Voice is the earliest dependable clue in a young Khaki Campbell because the two sexes sound strikingly different once the duckling voice breaks. A female develops the classic full quack: loud, clear, and unmistakable when she is picked up, calls to the flock, or announces food. A male keeps a much quieter, hoarse, rasping whisper, more like a breathy croak than a quack, and he never produces the female's ringing call. Listen to birds individually rather than in a chorus, since one confident female can make a whole pen sound female. Handle each duckling calmly and briefly, in the same way, and compare, because a stressed bird may stay silent while a relaxed male's rasp is obvious. Repeat over several days before deciding, as young voices change quickly while they mature.
Watch for the drake feather and Khaki Campbell colouring
Plumage confirms a Khaki Campbell's sex later, when the male's curled drake feather appears as a small upturned curl of feathers just above the tail. That curl is absent in females and is one of the clearest visual signs in ducks generally, but it only arrives as juvenile plumage gives way to adult feathering, so its absence in a very young bird proves nothing. Colour helps in this breed too: a maturing Khaki Campbell drake typically shows a darker, olive or greenish-toned head and neck against a lighter body, while the female stays a more even, plainer khaki brown overall. Bill tone can differ subtly between individuals, so treat it as a supporting hint alongside voice and feather, never as the deciding test on its own. Photograph each bird as signs emerge if you are sexing a group, because several similar khaki youngsters are remarkably easy to mix up between checks.
What not to try when sexing a young duck
Vent sexing is the method to leave alone with a young Khaki Campbell, because it involves everting a duckling's vent to look for tiny differences and in untrained hands it can injure a small, struggling bird. Hatcheries use trained sexers working quickly on day-old birds; that skill does not transfer from a video to a kitchen table, and an injured duckling is too high a price for an early answer. Behaviour is also unreliable at this age: mounting games, following, or boldness appear in both sexes among youngsters and settle nothing. Size misleads too, since Khaki Campbell drakes and ducks overlap enough that the biggest youngster in a brood is not automatically male. If you bought birds as sexed and the voices later disagree, raise it with the breeder calmly and early rather than assuming your ears are wrong.
When certainty matters for a Khaki Campbell duck
Certainty about a Khaki Campbell's sex matters most for breeding plans, flock balance, and local rules on keeping drakes, so match the method to the decision. For a laying flock, one unnoticed drake is mostly a surprise rather than a disaster, but too many drakes among few females leads to relentless chasing and stressed ducks, which is why a headcount by sex belongs in your flock plan. Once voice and feather agree, mark the bird in whatever way you already identify individuals, such as a leg ring you are confident fitting, and note the date you decided and the signs you used. If a bird remains genuinely ambiguous well past the age its siblings declared themselves, a vet or an experienced waterfowl keeper can examine it safely. Keeping that settled result in KinsLe on the duck's Pet Passport means the sex, and the signs behind it, stay with your Khaki Campbell's records instead of in your memory.