Do Birds Have Teeth?
In short, no birds do not have teeth, however as we look into this fascinating subject further, we’re sure you’ll agree that birds have developed an interesting way to masticate their food. To fully understand why birds no longer have teeth we will need to travel a long way back in time. According to the latest research, birds had teeth but they exchanged teeth for beaks over 100 million years ago.
Why Do Birds Have Beaks?
There are such a variety of shapes, sizes and colours of bird beaks on the planet. All with differing jobs to do depending on the type of bird and their particular dietary needs. Interestingly birds are not the only creatures with beaks.
There has been a study recently published that examines the evolution from teeth to a beak in birds spanning the ages back to the birds ancestor -the dinosaur. Researchers from the University of California discovered that the transition from teeth to beak happened at around the same time. They also discovered that the gene responsible for teeth suppression in birds is the same gene responsible for beak growth.
After painstaking studying of fossils they discovered that there are early birds in the fossil collection like that of the Ichthyornis – an extinct type of “fish bird” dating from the late cretaceous period of North America that have teeth at the back of their mouth and the beginnings of a beak at the front. They have also pinpointed the first step in the removal of teeth (the loss of enamel) to around 116 million years ago. They have discovered how birds exchanged teeth for beaks, but not why.
Birds With Teeth
Science has also been able to identify the mutations necessary to cause this transformation and in 2006 they managed to reverse the process. They manipulated the genes of a chicken and the bird actually grew teeth. Many have theorised that birds ditched the teeth to make them lighter and allow them to fly. However, there have been numerous archaeological discoveries of the fossils of Archaeopteryx, which is widely recognised as the first bird as we would recognise it.
Archaeopteryx definitely could fly, had feathers and a full mouth of teeth. Even if you considered this one bird type to be the exception to the rule, the loss of teeth to allow flight still doesn’t hold up. There are many mammals that fly but have teeth, bats for example.
Birds Have A Fast Incubation Period
Studies have been carried out as to why many creatures appeared to ditch teeth at around the same time, many dinosaur eggs took in excess of 6 months to hatch. With most of this time waiting for teeth to develop, something that would make the parent birds vulnerable for long periods of that incubation period. Creatures are tough as the T. Rex could defend their eggs without fear of becoming someone else’s dinner, but small birds didn’t have that luxury.
Many scientists now theorise that this extended incubation time to vulnerability scale was reason enough for the evolutionary change from teeth to beak. A shortened incubation time would reduce the amount of time the eggs or parents were vulnerable to predators, diseases or natural disasters.
Feasible But Does It Hold Water?
This theory does sound feasible, as birds only incubate for around 12 to 14 days, but other creatures that have no teeth and have a beak have far longer incubation times. Take the turtle for example, they have beaks instead of teeth and yet the eggs have an incubation period of between 42 to 112 days (depending on the type). Of course turtles lead completely different lives to birds so their change from teeth to beak might have very different reasons. Clearly more study is needed , but it is an interesting theory.
The Egg Tooth
To make things even more of a mystery, many species of bird embryos develop what is known as an egg tooth. This is a hard tooth – like growth that is present on the upper beak in birds that is used to break out of the egg. It then falls off some days later in some birds and absorbs back into the beak in others.
Just to add some confusion to the mix, some birds like geese have serrated tooth-like appendages along the edges of their beaks, these cutting edges have been given the name tomia by scientists and if they have the teeth-like serrations these are called tomia serrata (which means serrations on the tomia).
The geese and other fish eating birds seem to have developed these serrations as an aid to hold and eat slippery, wriggling fish. So it’s almost a case of evolution re-inventing the wheel – They went from having teeth, developing beaks at the expense of losing teeth, only to develop tooth-like serrations on their beaks.
Other birds like some birds of prey also have these serrations on their tomia to help sever their prey’s vertebrae.
How Do Birds Without Teeth Digest Their Food?
We have been told from a young age to chew our food properly to prevent indigestion, so how do birds chew their food? The scientific term for chewing up food is mastication, or as a verb, the word is masticate.
“to grind or crush (food) with or as if with the teeth : CHEW”
So how do birds, without teeth, masticate (or chew) their food? It turns out they swallow their food whole, and it is then ground up by a muscular organ in their stomach called the gizzard, which then allows them to digest their food.
Birds have 2 parts to their stomachs; the first part (that we have too) is called the proventriculus (glandular) stomach and is where enzymes that begin the digestive process are secreted. The second part of a bird’s stomach is the gizzard or muscular stomach. In some bird species the gizzard is very thick, these birds include emus, ducks, turkeys and quail. The majority of these birds eat hard items like nuts and seeds.
They also pick up small stones, grit and sand which stays in the gizzard and helps to “chew” their food. The thick, strong muscles of the gizzard along with the gravel, stones and grit help to crush the food into smaller digestible pieces.
All birds have a gizzard but the types of birds that eat easily digestible foods like fruit, soft bodied insects or nectar have a much smaller and weaker gizzard.
Frequently Asked Questions
No birds have teeth, they appear to have exchanged their teeth for beaks 116 million years ago.
Yes, all birds are toothless, some have serrations on their tomia that appear something like teeth but they are not teeth in the true sense of the word.
Teeth are absent in birds because for some reason in prehistoric times, they swapped their teeth for beaks. There is a theory that this was done to speed up egg incubation times but more research is necessary before this can be proven.
Birds stopped having teeth somewhere around 100 million years ago, scientists believe.
Some species of birds have egg teeth, which enable the chick to hatch quicker, and drop off a few days after they have hatched.
No, turtles don’t have teeth.
No birds do not have teeth in their throats. Some birds have gizzards (second stomachs) that are strong, muscular areas where their food is crushed into digestible pieces.
Some dinosaurs are known to have had beaks.
Birds can lose their beaks or get them damaged. It can be hard for birds to survive if they have no beak or their beak is damaged.