Why Do Birds Lose Their Teeth?
What do birds have instead of teeth?
Do birds chew their food?
How do birds eat?
Do birds swallow food whole?
Do birds eat until they are full?
Bird Tooth FAQ
Have you ever wondered why hens have so few teeth? A close inspection of the bird’s mouth and digestive system may reveal some surprises, but it won’t reveal any teeth. Instead, birds have evolved complex beaks, digestive systems and behaviors that make feeding possible.
Birds don’t have true teeth, but there have been times in their evolutionary history when they did. Since then, bird beaks have evolved into a stunning array of shapes and sizes, unique to each bird species. Surprisingly, the gene for tooth growth is still present in modern birds. Scientists have demonstrated this by manipulating the genes of chickens and producing a mutant poultry with a beak full of teeth.
We don’t know why modern birds lose their teeth, but it may have something to do with weight loss and shorter hatch times. Tooth loss apparently works for the birds, as their specialized beaks and digestive systems are now able to thrive. The richness and diversity of birds seen today is a testament to this.
The beaks of some modern birds do have structures that look very much like teeth. For example, geese have sharp serrations on their teeth and tongue for cutting grass and plants. These structures are called tomia, and they do perform some of the functions of teeth. However, Tomia are not teeth because they lack dentin, enamel, and other tissues of real teeth.
Read on to learn more about why birds don’t have teeth, and how they survive without them.

Close-up of the goose’s beak where you can see the tomia
Why Do Birds Lose Their Teeth?
Birds are believed to have evolved from dinosaurs about 150 million years ago. At the time, dinosaurs had teeth, which were passed on to early birds.
However, research shows that birds lost their teeth about 100 million years ago. We don’t know why birds lost their teeth millions of years ago, but some interesting theories have been proposed.
Read on to learn about some of the possible reasons why evolutionary birds lose their teeth.
One of the most obvious reasons birds lose their teeth is to lose weight. Birds exhibit many other weight-loss strategies that are important for flight. Teeth are heavy, a strengthened skull and strong muscles needed for chewing are equally important.
This theory may be partly true, but certainly not entirely. We know this because many early birds had both teeth and the ability to fly.
Another intriguing theory about why birds lose their teeth has to do with the development of young birds. The idea is that since the teeth take a long time to grow and develop, they increase the amount of time the egg needs parental protection and incubation.
By losing their teeth, the birds may have improved egg and parent survival.

Red-breasted merganser – ducks also have tomia, which helps in mowing grass and plant matter
What do birds have instead of teeth?
The beaks of birds are often highly specialized for their diet and behaviour. There are tons of different banknote shapes, including some pretty eye-catching shapes and sizes. Some birds have tooth-like structures in their beaks, these are called tomia.
For example, geese have serrated tomia in their beaks that help them chop down the grass and plants that feed on them. Falcons have a pair of tomia on their upper jaws, which they use to kill prey.
Hatchling birds also have a structure called an egg tooth on their beaks. Egg teeth are not real teeth at all, but sharp, hardened spots that a newly hatched bird uses to break free from the eggshell.

Closeup of a chick American robin with visible egg teeth
Do birds chew their food?
We chew our food to start the digestion process and make our food easier to swallow. Birds don’t have teeth and strong jaw muscles, so how do they chew their food? To answer this question, we first have to look inside the bird’s body, not its beak.
Birds that eat hard food like seeds must have some way of breaking down the food and making it more digestible. The process starts with the crop, a food storage organ.
Food is not digested in the crop, but softens slightly in storage. Food passes from the crop into the stomach, where highly acidic digestive juices begin to break down the food. This softened food then goes into the gizzard, where it is “chewed.”
The bird gizzard is a powerful organ lined with a tough, rough tissue called the gizzard. Food is crushed in the gizzard with the help of small stones and gravel that the bird swallows.

Close House Wren Eating Bugs
How do birds eat?
Birds use their beaks, tongues, and gravity to gather food and maneuver it into their digestive system. They don’t have hands like we do, so their special bills are used with amazing dexterity.
How birds swallow their food whole is very important in preventing choking. For this reason, piscivorous birds like kingfishers usually swallow their prey’s head first.
Birds will usually pick up a small piece of food and throw their head back to swallow it. Most birds swallow their food whole, but seeds often need to be crushed and large animal prey need to be torn into strips.

Male American Goldfinch eating seeds
Do birds swallow food whole?
Birds feed on a variety of different food sources, from liquid nectar to tiny seeds, large fruits, and animals larger than themselves. Each of these diets requires a different strategy for animals without teeth!
Most toothless birds get by by focusing on food sources they can swallow whole. However, some birds, such as parrots and raptors, are able to crush and tear their food into manageable portions that can be swallowed.
This ability is indeed important for birds that eat large prey, but the ability to tear food is just as important for birds that eat grass or large fruits.

Bald eagle tearing up salmon
Do birds eat until they are full?
Birds require a surprisingly large amount of food each day. Smaller birds tend to require more food than larger birds, typically thirty percent of their body weight per day!
Birds need so much food because their body temperature is naturally high and requires a lot of energy to fuel their flight. Birds don’t give up a meal when they’re not full, and store excess food in their crops until they’re digested.

A pair of male and female western bluebirds feeding on seeds
Bird Tooth FAQ
Do chickens have teeth?
Chickens have relatively unprofessional beaks that are specialized for picking up seeds, insects, and other small things. Chickens have no teeth. They use powerful gizzards to grind their food.
Do crows have teeth?
Ravens have no teeth. These clever birds have a large “universal” bill, which they are able to use in a variety of ways. In fact, studies of New Caledonian crows (Corvus moneduloides) have shown that their beaks are at least partially adapted to tool use.
Do parrots have teeth?
Parrots have a pointed and powerful beak, which makes up for their lack of dentition. Their bills are highly specialized, designed for crushing and processing food and helping birds climb.
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I am broadly interested in how human activities influence the ability of wildlife to persist in the modified environments that we create.
Specifically, my research investigates how the configuration and composition of landscapes influence the movement and population dynamics of forest birds. Both natural and human-derived fragmenting of habitat can influence where birds settle, how they access the resources they need to survive and reproduce, and these factors in turn affect population demographics. Most recently, I have been studying the ability of individuals to move through and utilize forested areas which have been modified through timber harvest as they seek out resources for the breeding and postfledging phases. As well I am working in collaboration with Parks Canada scientists to examine in the influence of high density moose populations on forest bird communities in Gros Morne National Park. Many of my projects are conducted in collaboration or consultation with representatives of industry and government agencies, seeking to improve the management and sustainability of natural resource extraction.