The Ameraucana breed of domestic fowl, more commonly called the Americana, is an attractive fowl, whose ancestors originated from South America. Although the Americana looks different from other chicken types, sufficient differences exist between the mature roosters and hen for the two birds to be told apart. Breeders can determine the sex of their adult birds by examining both the physical characteristics and observing the behavior of the two birds.
Look at the size of the adult birds. Roosters are larger than hens, which are visibly short and squat birds.
Examine the tuft of flesh on the bird's heads. This is termed a comb and will be larger on the mature rooster than on the mature hen. The color of this fleshy comb will normally be more intense in the rooster.
Look closely at the feathers of the mature birds. The bird with the longer feathers, particularly on the tail, is the rooster. From a distance, the rooster's longer tail feathers are easily noticeable. If you look closely enough, you will notice that most of the feathers on the rooster are proportionally longer than those of the hen.
Examine the feathers on the bird's necks. The rooster has long and thin neck feathers while those of the hen are rounded.
Weigh the birds. The adult rooster will weigh approximately 6 1/2 lbs. The adult hen will weigh approximately 5 1/2 lbs. Even if the weights you get are not exactly the same as these figures, the mature rooster will typically weigh about 1 lb. more than the mature hen.
Listen to the birds vocalize. Although both Americana roosters and hens are relatively quiet birds, the rooster will crow, particularly around sunrise. Do not use this criterion as the sole means of differentiating between the sexes, as select hens may vocalize in the early morning, particularly in the absence of a rooster.
Observe the behavior of the birds. The outgoing bird will be the rooster. The rooster will display by strutting around the coop or farm, while hens will tend to keep to themselves. The aggressive birds are roosters. This aggression is often displayed towards other chickens. Roosters are generally friendly towards people and move around much more than hens do.
Wait to see which bird lays eggs. If you are watching egg laying, you can be absolutely certain that you are looking at a hen.