Chickens are one of the most common domesticated animals, raised around the world for their meat and eggs. But while we interact with and consume chickens regularly, there’s still much we don’t know about their anatomy and physiology. One question that often comes up is: do chickens have tongues?
Anatomy of the Chicken Mouth
To understand if chickens have tongues, we first need to understand the anatomy of the chicken mouth and throat. Chickens have beaks rather than lips and teeth, which suits their omnivorous diet of grains, insects and vegetation. The beak tapers to a sharp point suited for pecking, grasping and tearing food.
Inside the beak, the mouth cavity serves to manipulate food and guide it down the throat. The mouth itself is fairly small and simple, especially compared to the mouths of mammals. It is lined with mucous membranes rather than cheeks. The upper mouth or palate is rigid, while the lower mouth or tongue (if present; see below) provides some mobility to move food.
At the back of the mouth lie the salivary glands which secrete saliva to begin chemical digestion. The throat begins at the opening of the esophagus which transports food down into the crop and stomach.
Importantly, the mouths of chickens and other birds lack teeth, lips and several other mammalian structures. Already this suggests their tongues, if present, would be quite different than mammalian tongues.
Do Chickens Have Tongue Tissue?
When we look inside a chicken’s mouth, we do see a structure emerging from the lower mouth that resembles a mammalian tongue. There is a fleshy, movable mass of smooth muscle tissue attached at the bottom mouth opening. This tissue, present in all bird species, is sometimes referred to as the “tongue.”
However, there are important differences that suggest calling this structure a real “tongue” may be inaccurate:
- The tissue is entirely made up of smooth muscles rather than the mixture of muscles and mucosa that make up mammalian tongues.
- The structure is rooted much farther down the throat than a mammalian tongue.
- There are no taste buds or ability to sense tastes on this tissue.
- It lacks mobility and cannot really manipulate food around the mouth or throat.
So in terms of both tissue types and functionality, the tongue-like structure in chicken mouths lacks most attributes we associate with tongues. Many ornithology sources thus refer to this simply as the “floor of the mouth” rather than a real tongue.
Chicken Anatomy 101
To understand if chickens have tongues, we first need to understand some basic chicken anatomy.
The Chicken Head
A chicken’s head contains many of the same anatomical structures as other birds and animals:
- Beak – Made up of the upper and lower mandibles which chickens use to pick up food. The beak does not contain any teeth.
- Nostrils – Located at the base of the beak and used for breathing.
- Eyes – Chickens have small eyes on either side of their head. They have good daytime vision but limited night vision.
- Ears – An opening behind each eye leads to the inner ear structure. Chickens don’t have external pinnae (outer ears).
- Comb and wattles – The red appendages on top of the head and below the beak. These are used to help regulate body temperature.
Inside the Mouth
If we peer inside a chicken’s mouth, what anatomy do we find?
- Tongue – Chickens do have tongues! Read on for more details.
- Salivary glands – Glands that produce saliva to lubricate food. Chickens have salivary glands located under the tongue.
- Esophagus – The tube connecting the mouth to the crop and stomach.
So chickens do indeed have tongues. But what do chicken tongues look like and how do they function?
Role of the Chicken Mouth Structure
While chickens and birds lack a true tongues, the muscular floor of their mouths still serves an important function related to eating. As food enters the mouth, this tissue allows the chicken to grasp and position the food farther back towards the throat to be swallowed.
So while small, simple and far less mobile than a human tongue, the tissue does help chickens efficiently transit food from the mouth down into the upper digestive tract. This is likely why it superficially resembles a tongue in gross anatomy.
Functions of the Chicken Tongue
What does a chicken use it’s tongue for? Some key functions include:
Tasting Food
The main function of the chicken tongue is to help the chicken experience tastes and flavors. The tongue contains many small receptors called taste buds that detect chemicals from food and drink. Substances like salts, acids and sugars stimulate the taste buds and the chicken brain interprets these signals as different flavors.
This gives the chicken information about the palatability and quality of food sources in it’s environment. Having a tongue and sense of taste aids chickens in seeking out nutritious food and avoiding toxic or bitter tasting substances. It’s believed chickens can experience the standard sweet, sour, bitter, salty and savory taste sensations just like humans and other animals.
Manipulating Food
Chickens use their beaks and tongues together to grab, manipulate and swallow food. The tongue helps move food around inside the mouth and into position to be swallowed down the esophagus.
Chickens don’t have teeth for chewing or grinding food. But they will use their beak and tongue to break down food into smaller pieces to aid in swallowing.
Swallowing
The chicken tongue contains muscles that enable it to move food toward the back of the mouth and into the esophagus. To aid this process, the tongue depresses and moves in waves which propels the food along.
As food reaches the pharynx area at the back of the mouth, the glottis closes and prevents food from entering the trachea (windpipe). The food enters the esophagus on route to the crop and stomach while the glottis reopens to allow breathing again.
Drinking Water
Chickens use their beak like a ladle to scoop up pools and droplets of water. But it’s the tongue that enables efficient drinking.
As water enters the mouth, the tongue enables the chicken to control the amount of liquid and swallow it efficiently rather than letting the water simply spill back out. This helps the chicken direct streams of water toward the back of the mouth and into the crop for storage and digestion.
Cleaning
Chickens use their tongues to help groom and clean their beaks. By licking the outside of the beak they can remove debris and keep it sharp. The tongue reduces the need for chickens to rub and wipe their beaks on surfaces.
Heat Regulation
The mouth and tongue contains blood vessels that allow heat exchange with the environment. Birds like chickens don’t sweat – instead they use evaporative cooling by panting to keep cool.
The moist surfaces of the mouth and tongue aid this evaporation process when the chicken has it’s mouth open panting. This releases heat and enables better thermoregulation.
Communication
Though not vocal, chickens communicate with visual displays, body language and some contact calls. When very hot a chicken may engage in rapid open mouth breathing.
Seeing the tongue may act as a visual signal allowing other chickens to understand that individuals discomfort. A panting chicken likely needs to find shade and cool down.
Egg Tooth
While developing in the egg as an embryo, all baby chicks grow a temporary spike on their beak called the egg tooth. They use this hard protuberance to peck and crack the shell from the inside when ready to hatch out.
The egg tooth falls off soon after hatching. But while it’s still present, the chick may use it’s tongue to manipulate the spike and continue weakening the shell in preparation for hatching.
So in summary – yes chickens do have tongues and they serve a variety of functions related to tasting food, swallowing, thermoregulation and communication.
Evolutionary Loss of Bird Tongues
Birds are the direct descendants of feathered dinosaurs that survived the mass extinction 66 million years ago. Over the subsequent millions of years of evolution, birds have lost many features present in their dinosaur ancestors, including teeth and tongues.
The modern bird beak serves as both teeth and lips for birds, suited to their high metabolism and largely herbivorous or omnivorous diets. Since their beaks and mouths are so much simpler than dinosaur mouths, a complex and muscular tongue was no longer necessary either.
Thus the fleshy bit of tissue in chicken mouths is likely a vestigial remnants of an ancestral tongue, simplified along with the entire mouth and throat anatomy of birds. Other bird groups like parrots have even lost this vestige, having only a rigid throat structure rather than any fleshy mass at all.
Do Chickens Taste Their Food?
As noted above, the tongue-like tissue in chickens lack taste buds or any oral sensation of flavors. Instead, avian taste perception appears centered higher up in their digestive tract.
Recent research has discovered that birds do have working taste receptors and ability to detect salts, acids, amino acids and other flavor compounds. However, these taste buds are located farther along the digestive tract such as the crop, intestine and liver rather than the mouth.
So birds including chickens can taste their food, but the chemistry of it occurs after swallowing rather than orally as in mammals. This may relate to how rapidly chickens need to eat to stay energized. With only a short time to peck and swallow food, tasting and savoring each bite orally would be inefficient.
This also means tastes may serve a different purpose, such as stimulating gastric reflexes to control food transit through the gut, rather than oral enjoyment of flavors while eating. More research is needed into how avian taste reception really functions and how it differs from mammals.
Do Chickens Have Saliva?
In mammals, saliva is critical for beginning chemical digestion via enzymes, lubricating food for easy swallowing and facilitating taste perception on the tongue. Since chickens and birds lack mammalian-like tongues and oral taste sensation, they were long thought to lack salivary glands as well.
However, microscopic examination of bird mouths has revealed they do have salivary glands in the mouth and throat region. Chemical analysis has identified enzymes like amylase present in chicken saliva as well.
The role of saliva in chickens doesn’t seem geared towards oral food preparation though. Unlike humans producing a mouthful of saliva in response to food, chicken saliva plays a minimal role during eating. This suggests salivation is either a vestigial trait from dinosaur ancestors or serves more basic functions like protecting oral mucosa rather than digesting each mouthful of food on the spot.
Do Other Bird Species Have Tongues?
As dinosaurs evolved into modern birds, anatomical simplification seems to have done away with most avian tongues across all species. The general rule is that no modern birds have complex, protruding tongues akin to mammals and reptiles.
However, there are a few unusual exceptions among some odd bird groups:
- Flamingos have a thick, muscular tongue containing a blood-filled spongy tissue to aid in filter feeding. It resembles a more traditional tongue but is still anchored to the floor of the mouth.
- Some hummingbird species have forked or tubular tongues which protrude slightly past their beak. These may relate to nectar feeding.
- Pelicans have a large, flat tongue divided into two lobes at the tip. This may help scoop fish into their throat pouch.
- Woodpeckers have an unusual tongue structure that wraps up over their skull and can extend out up to 5 inches past their beak. This helps capture wood-burrowing insect prey.
So while 99% of birds lack pronounced tongues, a handful of specialized species do have some strange modifications aiding in certain feeding methods. The tongues of flamingos, hummingbirds, pelicans and woodpeckers push the boundaries of organ simplification in birds.
Interesting Tongue Facts
Beyond basic anatomy and function, the chicken tongue has some other interesting attributes worth noting:
- Chicken tongues are highly vascularized but the surface appears mostly pale pink and devoid of obvious blood vessels unlike the dark reddish hue of many mammal tongues
- Male roosters have slightly longer tongues on average compared to hens
- The cornified stratified squamous epithelium coating chicken tongues undergoes continuous turnover and replacement similar to human epithelial cells
- Studies show chicken tongues average around 0.5-0.7 g in weight depending on breed variety
- Domesticated meat chickens have slightly heavier tongues compared to egg laying breeds due to overall larger body size
- The chicken tongue surface forms the compartment known as the oral cavity which interconnects with additional chambers in the oropharynx and laryngopharynx
- While critical for tasting, chickens don’t possess nearly as many taste buds compared to mammalian species, only around 240 on average
- Scientists have discovered certain species of feather mites that occasionally reside inside the mouths of chickens – definitively proving chickens do indeed have tongues!
- Some linguists hypothesize the word ‘cock-a-doodle-doo’ in rooster calls may have originally been a crude onomatopoeic approximation of the prominent tongue motions seen during crowing
Summary: Vestigial Structures Only
While a few exotic bird species buck the trend, most modern birds including chickens lack a pronounced fleshy tongue. The floor of their mouths house a small mass of smooth muscle which facilitates swallowing, while other structures like their beak and throat have taken over roles like manipulation and taste sensation from ancestral mammal/lizard-like tongues.
So next time you’re eating chicken, Turkey or other poultry, remember they do not have a true tongue inside their mouth! What looks like a tongue is just a muscular food chute, not an organ of taste or speech like our own tongues. Over millions of years of evolution, complex tongues became yet another anatomical casualty as dinosaurs took to the skies as streamlined birds.
