The rooster is the male chicken and it engages in various rituals and courtship processes to impregnate the female chicken, or hen. Surprisingly, this is quite an involved process and their reproduction is quite different from mammalian reproduction. The most noticeable difference being that chickens lay eggs.
The breeding season for chickens is typically during spring and early summer. The common courtship ritual is the rooster doing a “dance” around the hen. He will drag his wing in a circle around the hen. More often than not the hen will walk off, and the rooster will chase her down and mount her beginning the insemination process.
Another ritual involves the rooster’s cunning. The rooster is a clever animal and when he feels the need to impregnate a hen, he will lead the hens out to food, which is typically grain. He does this by clucking in a high pitch. The rooster then allows the hens to feed first. While feeding, the rooster will surreptitiously climb onto the back of the chosen hen and begin the insemination process.
Roosters do not have a reproductive organ that is similar to the penis. Instead, they have an opening called the cloaca. It is not visible, but it is something akin to a sperm glob. The rooster moves his cloaca near the hen’s cloaca (females have a similar opening) and he deposits his sperm inside the hen’s cloaca.
Placing the sperm blob inside the hen’s cloaca fertilises the egg yolk that sits inside the hen’s cloaca. The hen ovulates every 24 to 48 hours. Once the sperm is inside the egg yolk, the shell membrane emerges and it begins to harden around the yolk. The hen will lay the egg within about 24 hours after the ovulation occurs. An egg will emerge regardless of whether it was fertilised. It is good to keep a rooster around up to six hens to increase the likelihood of fertilisation.
Typically, roosters have their own “broods,” which is a grouping of hens that he tends to fertilise with regularity. There may a few broods within a chicken coop and this can cause competition among the roosters. If another rooster approaches another rooster’s brood, the rooster will protect the brood by pecking at the rooster and jumping upward and on top of the rooster, using its feet to cause damage.
It takes anywhere from 21 to 24 days for the eggs to hatch. Unfortunately roosters can engage in infanticide, killing the newborn chicks. It is important to remove the newborn chicks from their parents after they are two days old. The parents, especially the roosters can peck at the chicks when they are young.