Rooster Anatomy Guide

You want to learn about rooster anatomy? Smart choice! Having knowledge about the external and internal anatomy of a rooster can help in a number of ways. From discerning a breed to figuring out if a young chicken is male or female, or even talking to a veterinarian about a health problem, knowing basic rooster anatomy is key.

To help you learn more about your male chickens, we have come up with this rooster anatomy guide.

External Parts of a Rooster

Both roosters and hens have some basic anatomical parts that are shared between the genders, such as hackles, wattles, and combs. These features are how you classify a chicken from a duck, for example.

The external parts of a rooster include:

• Comb
• Beak
• Nares
• Eyes and eye rings
• Ears and earlobes
• Wattles
• Hackles
• Spurs
• Hock joint
• Shank
• Toes and talons
• Claw
• Saddle feathers
• Sickles feathers

Chickens, be they rooster or hen, have flight feathers. An axial feather separates the primary feathers from the secondary ones. When a chicken molts, they lose the feathers from the axial outward.

Upper Body of a Rooster

A prominent part of a rooster’s head is the crown, which is the same soft red color as the wattles. There are seven types of combs, including single comb, rose comb, pea comb, buttercup comb, cushion comb, strawberry comb, and V-shaped comb.

Unlike humans and mammals, chickens do not have externally visible ears. Rather, their ears are open holes leading straight to the ear canal that are covered by feathers. The earlobe is a specialized section of skin that varies in color depending on the breed, but the two most common colors are white and red.

The eyeball is enclosed by the eye ring. When a rooster has its eyes open, the eye ring functions much like eyelids.

Here is a video about avian anatomy to help you better understand the topic:

Lower Body of a Rooster

Another part we cannot overlook is the thigh, which is where the upper section of the leg attaches to the body. The lower leg is known as the drumstick, and it connects to the shank at the hock joint. In birds, the hock joint functions much like a human ankle.

Chickens walk on their toes. Most breeds of chicken have three forward-facing toes and one that projects backwards, sometimes called the claw. Some breeds have five toes per foot. Furthermore, some chicken breeds have bare shanks and toes, while others might have feathers covering their legs.

At the base of the tail, chickens have something called the uropygial gland, also known as the preen gland. The chickens use the oils from the gland to keep their feathers healthy and oiled.

Feathers and Skin on Roosters

Chickens use their feathers and skin in a number of ways. Like all birds, chickens have feathers that assist with flight, insulation, protection from the elements, camouflage, and courtship. Roosters tend to have more brightly colored feathers than their female counterparts. They also molt their feathers annually, and the process takes about 8-12 weeks to complete.

Underneath the feathers is skin, and it covers most of the chicken’s body. Like humans, chicken skin serves several functions. The skin that produces feathers has specialized follicles. During molting, old feathers fall out and new feathers grow and push through the skin.

Scaled skin protects the legs and toes. Chickens also have footpads that are thick and tough, protecting them from rough terrain. Roosters and hens have beaks and talons made from hardened keratin, a type of protein. And the comb and wattles? Those are developed by the presence of sex hormones.

Bones, Wings, and Legs of a Rooster

The skeletal system of the rooster is fascinating. Bird bones are a combination of phosphorus and calcium, along with collagen fibers that bind everything together. Bones provide protection and support for the organs and muscles.

Bird bones are split into two categories:

• Pneumatic – These hollow bones connect to the respiratory system with air sacs. Roosters have a hollow skull, humerus, collar bones, and pelvis.
• Medullary – Within these bones, you will find stores of calcium and marrow. The ribs, leg bones, and shoulders all have bone marrow.

Since bird bones store 99% of all calcium in the body and 80% of phosphorus, it is important that chickens receive plenty of sunlight. Vitamin D is the only way for roosters to convert these vital nutrients into something usable. Calcium deficiency isn’t as dangerous for roosters as it is for hens, but it can still lead to a brittle body.

Cage layer fatigue is another issue that stems from lack of exercise and nutrients. Chickens, both male and female, will need freedom, grit, and calcium to recover.

Did you know that the neck and spine of chickens is flexible? The spine alone contains 39 bones. Not only does this lend great shock absorption to the body and head, but it enables a rooster to rotate his head a full 180-degrees.

Roosters also have large sternums. In fact, the sternum is the largest, strongest bone in a chicken’s body. Strong muscles connect the wings to the sternum.

Lastly, roosters have powerful legs. The hip bone and back are fused together, which adds strength and resilience to their bodies and enables quick bursts of speed.

What Do Roosters Have That Hens Don’t?

As with most species of birds, roosters have anatomical features that are not present in hens. These features include sickle tail feathers and hackle feathers. Rooster spurs and wattles tend to be longer than those found on hens. Also, you will notice that roosters have combs that stand erect, while hens have combs that droop.

Internal Anatomy of a Rooster

The internal workings of birds is fascinating, because they are unlike humans and mammals in many ways. At the same time, roosters have a digestive system, nervous system, respiratory system, and other things in common with us.

The organs in a rooster include:

• Brain
• Beak
• Spine
• Heart
• Trachea
• Esophagus
• Lungs
• Kidneys
• Intestines
• Crop
• Gizzard
• Liver
• Testes
• Ureter
• Ceca
• Cloaca

As you can see, there are things on this list that humans don’t have. Let’s discuss these organs in greater detail.

Digestive System of a Rooster

To begin the journey to the center of a rooster’s belly, we must first address the fact that male chickens do not have teeth. No chicken has teeth. Instead, they pick up food with their beak, breaking up the food into pieces small enough to be swallowed.

Once food has been swallowed, it is stored in the crop, an organ that functions like the cheeks of a hamster. Food stays in the crop until it travels to the gizzard. The crop is a tactful organ, used to give chickens a store of food and energy should they be endangered and have to flee.

Within the gizzard, the food is introduced to grit, where it is ground up even further for digestion. From there, the food becomes a digestible mass that passes through to the intestines. Digestive enzymes from the stomach, liver, and pancreas assist in urging the food towards the ceca.

After the food enters the ceca, whatever remains is mixed with water and turned into waste. There are two ceca, one for water reclamation and another for the fermentation of excrement.

Waste then travels to the cloaca or vent, where it is mixed with urinary waste and expelled from the body. Interestingly, male and female chickens both have cloaca that are connected to their reproductive organs.

Respiratory Anatomy of a Rooster

Roosters need to have a strong respiratory system in order to wake the whole neighborhood with a hearty cock-a-doodle-do. In mammals, the diaphragm helps the lungs inflate and deflate. A chicken is different; they have air sacs. Nine air sacs, to be exact, located in the neck.

These air sacs will inflate as air is brought into the body through the nares, which are nostril-like holes in the beak. Nares allow air to move into the trachea, to the lungs, and back out the body.

To breathe, a rooster will first inhale. The air then travels through the posterior air sacs of the neck. At the same time, the anterior air sacs are filling with air from the previous inhalation in preparation for exhalation. As the air coming in moves to the lungs, the exhalation is pushed through the anterior air sacs, up the trachea, and out of the nares.

Rooster Reproductive System

As you might expect by now, the reproductive anatomy of a rooster is very different from how a human male functions. Avian reproductive organs remain inside the bird, including the testes. This is one of the reasons it can be extremely different to sex young chicks and chickens.

Roosters have two testes, located near the kidneys. They are connected to the vas deferens and to the digestive tract, since everything empties through the cloaca. Near the cloaca are two bumps called papillae, which function as the copulatory organ for roosters.

When a rooster mates with a hen, he approaches from behind, performs what is called “the cloacal kiss,” and deposits semen into the hen’s oviduct, where it can remain viable for 30 days. As the hen lays an egg, the sperm fertilize it.

Can You Neuter a Rooster?

Maybe you already have a rooster who rules the yard but want your younger males to have a chance. You can opt to get roosters neutered by a qualified veterinarian. Neutering a rooster is called caponizing. If you ever heard of a capon, it refers to a neutered rooster.

However, you can’t caponize an older rooster, only ones that are still young, between 6 weeks and 3 months old. Caponizing roosters not only stops them from mating with hens but can also make them calmer and less aggressive.

Now You Have Something to Crow About

Hopefully, you have enjoyed this rooster anatomy guide and learned something from it. Birds in general have systems that are very different from the human body, so you need to know the basics if you plan on keeping chickens.

Roosters and hens have a lot in common internally, but on the outside, they look incredibly different. If you are using this guide to figure out a male from a female, keep in mind that roosters often have erect combs and longer wattles. Now go out there and win at some rooster trivia!