Learn how birds evolved to rely on their beaks, not teeth, to eat, and how their digestion differs from the way humans and other mammals process food.
This Is Why Birds Do Not Have Teeth
How frequently have you thought about birds’ beaks lately? Unless you’re an ornithologist, probably not often. Then again, if you are thinking about birds consume their food, you might wonder, do birds have teeth? It’s a question with more complexity than you might think. Here’s what you should know about bird beaks, bird “teeth,” and how the way birds eat differs from how we humans do the same.
Do Birds Have Teeth?
The simple answer is as follows: “Not unless you go about a hundred million years back,” Dr. Lina Rifai, associate professor of vertebrate biology at Indiana University-Kokomo, says. She explains that while birds can have tooth-like structures, they don’t translate to what we’d consider teeth, and they’re not used for what we use teeth to accomplish.
“Fish-eating birds need to be able to hold on to slippery fish, so they have serrations on the edge of their beak,” Lina says. “Seed-eating birds have ridges that help them cut into seeds. Falcons and kestrels have a triangular notch at the edge of their beak to help them kill prey.”
For those who have seen mildly nightmarish photos of geese on social media with what looks like teeth inside their beak, Lina breaks it down. “Geese always look terrifying because they have toothlike structures that look like teeth, but they’re hard cartilage structures in or on the side of the beak.”
According to Lina, they’re hard cartilage structures meant to help geese tear off vegetation. Think of how frequently you’ve seen Canada geese eating grass in parks; from that perspective, those frightening-looking not-teeth serve a purpose.
How Do Birds Eat Without Teeth?
Again, a simple answer: Teeth aren’t necessary. Lina highlights that we, as mammals, are unique because we chew our food. Birds don’t need to do that. Instead, they use the strong, muscular portion of their stomach, called a gizzard, to break down their food in the way that we use our molars. “That’s why some birds will have stones that they ingest, such as doves — they use that in the gizzard to grind up food,” Lina says.
When it comes down to it, it seems teeth just weren’t an evolutionary necessity for birds. While Lina says scientists have discovered the specific gene that codes for teeth in them, it takes more energy than it’s worth for a bird to grow teeth in the wild. Their beaks and stomachs are enough to serve that purpose, so birds didn’t need to grow teeth and could hatch faster. Some also believe teeth added weight when flying, so birds evolved to get rid of them.
For Lina, that lack of chompers is a good thing. “I always say when I band birds that it’s bad enough that they have beaks,” she says. “I’m glad they don’t have teeth, as well.”
About the Expert
Dr. Lina Rifai is an associate professor of vertebrate biology at Indiana University-Kokomo. She earned a Ph.D. in behavioral ecology from the University of Louisville.
Sources
- Cornell Lab of Ornithology, “Do Birds Have Teeth?“
- National Audubon Society, “How Birds Lost Their Teeth“
