You’ve probably noticed tooth-like structures on some birds’ beaks and are wondering whether these are teeth indeed, right?!
We must reveal the truth – no modern bird has teeth! However, this doesn’t mean they never had them!
If you want to learn more, keep reading, as we’ve prepared some interesting details for bird enthusiasts! You’ll also discover how birds chew their food without teeth!
Why Don’t Birds Have Teeth?
Modern bird species do not have teeth. However, they weren’t always toothless. Studies show that until around 101 million years ago, birds had dentin (the substance teeth consist of).
However, at that time, the process of losing their teeth was already in motion, as the first step happened around 116 million years ago when birds started losing the enamel (a substance that protects the teeth).
During this process, birds basically replaced their teeth with beaks. However, there is much more yet to be discovered about the topic, as researchers are still unsure why this happened.
Some hypotheses include that birds lost their teeth to be able to fly more easily, as no teeth equaled less weight. Other scientists, however, confirm this might have been one of the reasons, but it’s highly likely not what stands behind the loss of teeth in an entire group of animals.
Moreover, the Archaeopteryx, often considered the world’s first bird, could fly well before birds started losing teeth, indicating there’s little connection between the two.
Other theories are concerned with the purpose of teeth in birds. First, some scientists believe that beaks serve better purposes. Secondly, birds have a gizzard that breaks down the food birds ingest, so using teeth to chew would be pointless. Moreover, it would be a waste of energy.
Some studies show that birds might’ve lost their teeth because teeth development is associated with a longer egg incubation period, which decreases the chances of survival and causes much stress to the parents, thus leading to body weight loss and further health issues.
As such, while we’re sure that no modern birds have teeth, it’s difficult to confirm why they lost them over time.
What Do Birds Have Instead of Teeth?
You’re probably wondering why some birds like geese look like they have teeth , right?! Well, some species do have teeth-like structures, but they’re not actual teeth.
In fact, they’re called tomia and are often defined as the mandibles’ cutting edges. These are highly specialized structures that facilitate food handling.
For example, birds that primarily feed on seeds have specialized ridges that help them cut through a seed’s outer shell. They are located in their tomia.
Some birds of prey, falcons, for instance, have a sharp “tooth” along their upper mandible that helps them rip prey apart. Scientists often refer to it as a “tomial tooth.”
Other birds, like kites, have more similar projections (tomial teeth) that facilitate insect and lizard feeding.
Furthermore, the tomia of fish-eating birds have sawtooth serrations along them. This aids the birds in handling slippery prey.
Insectivores or snail-eating birds have short bristles along their tomia.
A quarter of all hummingbird species have similar serrations on their bills, which are believed to help them hold insect prey, but also to easily cut through waxy or long flower corollas.
How Do Birds Chew Their Food?
Now that we set all the technical details apart, the first question you’re probably asking yourself is, “How do birds chew their food?”
We use our teeth to chew – it would be impossible to eat and swallow food otherwise, right?! If birds don’t have teeth, how do they chew and swallow their food sources?
The thing is that birds don’t actually chew their food. Well, there is some breaking down involved, but it doesn’t happen in the mouth, which is why we must discuss their digestive system as a whole to understand the process.
Birds usually swallow the prey whole, although some may use their beaks to tear prey apart if it’s too large. Insectivorous birds have specialized saliva used to stick prey together. This way, they can swallow the insects more easily.
Afterward, it reaches the crop, where food is stored for later digestion. If the bird doesn’t have a crop, the food will directly go through to the next digestive step – it reaches the bird’s stomach to be broken down.
A bird’s stomach consists of two chambers – the proventriculus and the gizzard. The food first arrives in the proventriculus, which secretes acids that help break down the food.
Then, the prey arrives in the gizzard, which consists of tough muscles that grind and digest the food. Sometimes the process is facilitated by various items birds ingest – sand, grit, or pebbles.
In short, birds do not chew their food – the gizzard does it for them!