If you don’t regularly visit the farm or the chicken coop, you may find yourself visiting the cackling, cacophonous little birds and wondering, “Is a rooster a chicken? How can they mate if they’re different?”
In agriculture, especially poultry farming, the term “rooster” is used to describe a sexually mature chicken, usually kept by chicken breeders. So yes, a rooster is a chicken.
Additionally, an article from Perdue University describes a newly hatched chicken as a chick, a young female chicken as a pullet, a young male chicken as a rooster, and castrated males as a capon, and an egg-laying female chicken as a hen.
Identifying an Adult Female vs. an Adult Male Chicken
As chicks mature, chicken breeders use a number of visual characteristics to distinguish roosters from adult hens.
The most distinguishing features between them are the cock’s combs and wattles: flaps of skin that indicate high testosterone levels and can also signal that the rooster is ready to take on male rivals. Most rooster breeds have a bright red comb for maximum visibility.
Other common indicators include leg muscle development and feather orientation. When ready to lay eggs, most adult female chicken breeds develop thicker legs with short, blunt claws. Meanwhile, roosters of the same breed tend to retain long legs with sharp claws on their feet for defense.
Chicken feathers are generally soft and fluffy all over the body, while rooster feathers are coarser and more exaggerated. Hens retain short, rounded hackle feathers throughout their lives, while most male chickens develop long, graceful hackle feathers along the edge of their backs.
Then there are the long saddle feathers, which surround the tail and point backward or fan out, making the rooster appear larger to enemies.
Can female chickens change sex?
Miss Lucille was a sweet little pullet (fry) who found a cozy home in Kristi Allen’s (not her real name) Powder Springs, Georgia, backyard chicken coop. At first, all seemed to be status quo with the young Treasure Chest-Leghorn cross.
After observing her for a while, however, Allen noticed that Miss Lucille was growing a comb. Although both sexes of the breed can have them, Allen’s instincts told her that something might not be quite right, so she sought the help of a local farmer. Allen recalls:
“The farmer did all the checks to confirm that Miss Lucille was a ‘miss’. She had no long saddle feathers [pointy feathers at the base of the tail]no aggression, did not jump or react in the presence of all the hens and roosters, and when put back in the farmer’s hand she stuck her legs straight out and just lay there. It’s all old tricks to identify adult roosters, since there is no definitive way to know until they mount another hen or crow, short of lab testing.”
Miss Lucille had “failed” the rooster test. However, Allen later came home to find a mess of feathers in the backyard, an unusual occurrence since female chickens usually don’t molt until around 18 months. She also began to exhibit more aggressive behavior.
“She started acting more temperamental, but I put that down to her molting, which can be quite uncomfortable for chickens,” she says. “I was concerned about her health.”
Growing saddle feathers
While there were certainly strange things happening in Miss Lucille’s world, none of them were a threat to her health. When her feathers did grow back, they were pointed saddle feathers, which was a sign of her transition to a mature male chicken. Her neck and tail feathers had also undergone some major changes.
“She went from a typical hen to a rooster with beautiful, long tail feathers and pointed hackles. Her gait changed and she was definitely at the top of the pecking order,” Allen said.
After further discussion, it was advised to wait and see. One farmer told her, “Just because she looked like a rooster now, didn’t mean she was one. I had to wait until she crowed or jumped on one of the chickens.”
Ironically, Miss Lucille became more gentle and friendly. “But then her comb grew bigger and redder. For every hint that she might still be a ‘she,’ there was another that indicated she was a ‘he,'” she says.
Finally, around 5 months of age, the irrefutable proof came: the rooster was literally crowing. “Every day, the crowing got louder and louder. It was official that Miss Lucille was now Mr. Lucille,” Allen says.
“And to his credit, he took the role wonderfully. When the girls were low on water, he would crow and let me know I had to go. He would lead the group to the rest home at night. He would wake us up early every morning with his song.”
How do hens become male chickens?
Spontaneous sex change, such as in the case of Mr. Lucille, is extremely rare. In fact, a study from Bangladesh found that only 28 of 3,000 adult female chickens monitored underwent sex change.
The exact cause of this phenomenon isn’t yet clear, but there are some prevailing theories, according to Drew Benson, assistant professor of poultry science at the University of Georgia.
“Current evidence indicates that sexual differentiation in birds is a combination of direct genetic and hormonal mechanisms,” he said by email, noting that most cases of spontaneous sex change in birds, such as Mr. Lucille’s, are likely related to changes in the action of sex hormones, such as estrogen.
“The right ovary and fallopian tube [tube through which the chicken eggs pass from the ovary] regression during embryonic development, leaving the hen with only one functional ovary, the left one. If the left ovary is removed or becomes dysfunctional due to disease, the regressed right ovary can form an ovotestis,” he explains.
The hypothesis is that estrogen activity suppresses the development of the right gonad. However, when the ovary does not secrete estrogen, the medullary tissue in the rudimentary right gonad changes into an ovotestis, a testis-like structure.
“The ovotestis starts secreting androgens that masculinize the female bird,” he says, noting that the lack of estrogen changes the bird’s plumage and that the increased testosterone causes crowing and the growth of head ornaments, such as the wattle and comb.
Scientists aren’t sure why this happens. Benson says it’s fairly common for ovarian disease to cause ovarian dysfunction, but spontaneous sex reversal is much less common. “You can’t just remove an ovary from a chicken and cause spontaneous sex reversal,” he says. “In fact, the exact mechanism underlying sex determination in birds has yet to be solved.”
Being the boss of the cage
So what’s an owner of a rooster-turned-hen, like Allen, to do? “Embrace the fact that you have a rare hen, as many hens will not undergo this transformation after a decrease in ovarian hormone production,” Benson says. “The newly transformed hen will no longer lay eggs, so you will need to get a new hen if you want to produce eggs.”
However, Allen had to outsource Mr. Lucille to another rooster enthusiast when the crowing got out of hand. “We have a neighborhood behind our house, and while we’re lucky enough to have male hens on our property, we didn’t think he was a great neighbor,” she says. “While I miss him, I don’t miss the early alarm. And I’m glad he’s out there where he can do his thing.”
Now that’s interesting
The pecking order is real—and sometimes mean. The most aggressive hen will claim the top spot, pecking when necessary to get his point across. His chief status helps him get the best roost or roost and priority access to food and water, while acting as a protector of the flock. If an adult male hen is present, he will usually be the chief. All the hens tend to the eggs and newly hatched chicks and pullets, while the rooster watches the flock in the backyard for threats. An adult male hen usually shows more aggression because he must be ready to fight off predators or other roosters at a moment’s notice.
Original article: Is a rooster a chicken? Can a chicken become a rooster?
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