How do chickens mate? Have you ever seen your rooster, inexplicably, just seem to attack one of your hens out of nowhere? He may pull out her feathers with his feet while tugging on her comb with his beak. It’s all around seems to be a pretty terrible event. Today we are going to learn why he does that and what it means.
Chickens mate similarly to how many other animals mate. The female, or hen in this case, has an egg that needs to be fertilized. The male, or rooster, has sperm that will fertilize that egg. The rooster will mount over top the hen and push his cloaca to her cloaca, in what is known as a “cloacal kiss” and deliver the sperm. Unlike many animals, there is no penetration from one partner to the other.
If you’ve seen the scene above play out in your flock you, no doubt, have wondered what was going on. It’s a natural part of their life and while you can’t really prevent it you can keep your hens safe from excessive damage.
We know this all sounds scary. But, we assure you, it is all natural and part of the biological way chickens work.
So, how do chickens mate anyway?
The actual act is not too complicated. The rooster will mount then hen and push his cloaca downward while the hen will lift her tail feathers and move her cloaca toward the rooster. They will push their cloacas together while the rooster release sperm from his papilla.
The hen will recieve the sperm into her cloaca which will then travel down the oviduct and stay in the infundibulum until it is time for the yolks to be fertilized. If you are seeing a bunch of new chicken terms, don’t worry, that section is coming up next.
Chicken sexual biology
Both the hen and rooster have different sexual organs, each specific to their intended function.
- Cloaca: you may also know this as the vent. This is the area in which the rooster expels waste as well as secretes sperm
- Papilla: located just inside of the cloaca, this is the exit point from which the sperm enters the cloaca
- Testes: where the sperm is made
- Vas deferens: the tube in which the sperm is delivered to the papilla
- Cloaca: just like the rooster above, hens have a cloaca which is used for waste. It is also used to transfer sperm to an unfertilized yolk
- Follicles: the place in which the yolk is initially produced
- Infundibulum: section of the Oviduct in which the yolk is fertilized. sperm is also stored her prior to fertilization.
- Isthmus: section of the Oviduct in which the shell membrane is added around the egg
- Magnum: section of the Oviduct in which the egg white is placed around the yolk
- Oviduct: a long tract leading from the Ovary to the Vagina in which the egg is fertilized, egg white is added, and a shell is formed
- Ovary: the place in which the egg yolk is initially developed before becoming an egg. a hen will have two; one on each side of the body.
- Shell Gland/Uterus: hard shell is placed around the soft membrane
How it all works
What are the functions of each chicken’s reproductive organs?
The process starts in the rooster’s testes. In the testes you will find seminiferous tubules. Here is where the sperm and semen used for transport is produced. The semen will then travel down through the vas deferens, out the papilla, and into the cloaca.
The hen is a bit more complicated than the rooster. As you may know from reading about how long your hen will lay, hens are born with all of the eggs they will ever be capable of producing.
Things first start in the ovaries. Yolk will start to form in the follicles. This process can take up to 10 days for a yolk to fully form. Eventually, the walls of the follicles will rupture and pass the yolk from the ovary into the oviduct.
The first stop in the oviduct is the infundibulum. It is in the infundibulum that the sperm is stored and used to fertilize the fresh yolk. After passing through the infundibulum, the yolk moves to the magnum where it is wrapped in the egg white.
From the magnum the egg moves to the ithmus. The ithmus is the initial shell membrane is applied to the outside of the egg. This membrane is not the hard shell. It is a soft membrane added prior to the hard shell.
From the ithmus the eggs moves into the shell gland or uterus. This is where the hard shell is added to the egg. Finally, the egg is passed through the vagina and out through the cloaca.
From there you can either incubate the eggs yourself (we personally have had great success with the cabinet in this post) or you can have a broody hen incubate them for you. You can also eat fertilized eggs. It does not change the flavor and is perfectly safe. Here’s how you can tell if the egg is fertilized.
As we described above, roosters can be quite aggressive when they are trying to mate. They are not intentionally trying to harm the hen, but, it is possible. Due to their larger size and weight, with the addition of long, sharp spurs, some real damage can be done to your precious hen.
Not all chicken mating situations are this rough and dangerous. You will need to pay attention to their behavior. But a good, easy to spot sign that things are getting out of hand is if your hens start losing feathers on their back.
The easiest, and most humane, way to fix this issue is to provide your hens with chicken saddles. It may sound funny, but these can be a life saver. They are small pieces of cloth that covers your hen’s back and protects it from the roosters claws and spurs.
You can also get them in different colors and patterns. If you need them, you may as well have fun with them!
Frequently Asked Questions
Here are some of the more common questions we came across while researching for this post.
Q1. Do chickens need to mate to lay eggs?
Chickens do not need to mate in order to lay eggs. Chickens will produce their eggs regardless of the presence of a rooster. If they are not fertilized the hen will just lay unfertilized eggs.
Q2. Does laying an egg hurt a chicken?
The size of the egg and the size of the chicken are what determines whether or not the laying process is painful for a chicken. Typically, they make a lot of noise but it is over rather quickly. Young birds may experience more discomfort than older hens since they are still growing and their eggs may be a bit larger than they would like.
Q3. At what age does a rooster start mating?
Roosters will reach sexual maturity a little more quickly than a hen. Roosters will usually start attempting to mate around 5 months of age. This can vary a month or so in either direction.
Q4. Do Roosters have balls?
Roosters do not have balls, or testes, in the same way mammals do. While mammals have their testes on the outside of their body, a roosters’ testes are internal. Other than that, they are used the same as most other animals in that they produce sperm necesarry for reproduction.
Q5. How do farmers know if a chicken egg is fertilized?
Unfortunately, there is no way to tell if an egg is fertilized without cracking it. If your chickens are breeding, you can probably bet that the eggs are fertilized. The only sure way to tell is to incubate the eggs and see if a chick hatches. If you get a chick the egg was fertilized.
Q6. Do we eat fertilized eggs?
If your chickens are mating, you probably are eating fertilized eggs. Fertilized eggs are safe to eat and are no different than non-fertilized eggs in terms of taste.
Q7. Why do chickens run before mating?
Hens tend to run because roosters can be very aggressive in their mating process. Hens do not need their eggs fertilized in order to lay them so when a rooster starts the mating process then hen may see it as an aggressive attack. At that point their fight or flight instincts kick in and they run.
Q8. Do roosters mate with their mothers?
Animals do not often think of relatives in the same way that people do. So, when a rooster reaches maturity, he will try to mate with any hens in his flock. If his mother is a part of that flock he will not discriminate. This will not typically pose a genetic problem unless he continues to mate his offspring and subsequent generations.
In fact, when intentionally breeding, often times breeders will mate parent to offspring or siblings together to emphasize certain traits. This is called line breeding.
Q9. Why do roosters die after mating?
Roosters do not die right after mating. While their mating process may look intense, it is not so vigorous that they pass away. If your roosters are dying after mating, you may have another problem on your hands.
If you’ve ever wondered about the chicken mating process you now have more information than you probably thought you would get. The actual act can appear to be aggressive, and at times it is, but it is a natural part of chicken life. You can help protect your hen and you can also keep an eye out for when to snatch up some eggs to incubate on your own.
Happy chicken keeping!