If you're confused about poultry, perhaps you remember the famous Seinfeld dinner scene in which Mr. Costanza asked the difference between a hen, a chicken and a rooster. Simply put: hens are female chickens, while roosters are male chickens. "Chicken" is the name of the type of bird, while "hen" and "rooster" designate gender. However, the underlying differences between hens and roosters are a bit more complicated.
Hens and roosters do not exhibit signs of their gender until around 6 months of age, at which time the rooster begins to crow. Other telltale signs at this age include differences in feathers, combs, wattles and foot spurs. With roosters, the comb and wattle, which are the fleshy bit on top of the head and the flesh hanging from the throat respectively, are noticeably larger. Unlike hens, roosters have pointy neck feathers, and the spurs at the back of their feet are bigger than a hen's. Finally, hens have the ability to lay eggs with or without the company of a mating rooster.
The easiest way to tell a hen from a rooster is to watch them grow to 6 months, but if you need to know immediately, you can call in a professional gender examiner, also known as a chicken sexer. Using sexing techniques first implemented by the Japanese, chicken sexers employ a variety of tests, including a wing length examination or a test of the chick's internal organs. Amateur chicken sexers can simply flip a coin, as the odds are 50/50 that a chick will be male or female.
In rare incidences, a hen may exhibit gender traits associated with a rooster. Gender changes are the result of an infected ovary in the hen, which creates a hormonal imbalance. As the hen's hormone balance shifts toward more male hormone production, the hen will start to develop rooster traits, including physical appearance changes and, in some cases, even crowing.
Semantics of Gender
To further complicate matters, a rooster or hen's name will change with age. A young female chicken starts out as a chick, then becomes a pullet, and eventually is called a hen after her first birthday. Roosters also start out as chicks, then cockerels, followed by cock or rooster by age 1. However, these names are thrown out in the commercial industry, which immediately calls a chick a hen or rooster around 5 months of age, when sexual activity and reproduction occur. To improve the quality of the meat and lower aggression, some roosters are castrated at birth, resulting in an entirely new name: capon.