We were watching our friendly chicken, Red, drink and my kids asked me “do chickens have saliva, how do they really drink?” I thought about this for a moment, because I love to watch our chickens drink. It’s comical to watch them dip their beaks into the water and then tip their heads back. But as I really thought about this, I wondered if I actually knew the right answer to these questions. So, I decided to do some research. And what shocked me most was that a quick perusal of the internet showed that many other people don’t know the answer either.
At heart, these innocent questions are really more involved than you’d think. Chickens are, after all, a part of our wonderful world of birds, having originated from their wild jungle fowl counterparts. When you look at the bird world, there are lots of different ways that birds drink. It’s not standard, like with mammals.
So what about chickens?
For instance, it has long been thought that hummingbirds suck nectar through their long tongue using it like a straw. Recent research reveals that hummingbirds actually lap nectar. They have a forked tongue that has hair-like extensions that pull in the nectar. When they pull their tongue back, the nectar goes down their throat.Pigeons, on the other hand, have a type of pumping mechanism that sucks liquid up into their throats.
So what about chickens?
For this answer, I turned to the University of Kentucky’s Cooperative Extension Service; they’ve done a great job laying out the digestive system of a chicken. So, here’s the answer to the first question. Yes, chickens do have salivary glands. Since chickens don’t have teeth, they can’t chew their food. The salivary glands do the work of teeth by wetting the food to make it easy to swallow. And their saliva has a special enzyme that starts the digestion of the food immediately. Like us, the chicken uses its tongue to push the wet food to the back of its mouth where it can be swallowed.The answer to the second question is interesting because chickens don’t use a similar process to swallow. A chicken’s tongue, while effective for pushing food back, is not effective for pushing water back. When we swallow, we close our mouths and let our throat do the work. A chicken has to open and close its mouth rapidly while it tilts its head up to get the water to go down its throat. Also, I don’t know if you’ve ever noticed, but chickens have a hole in the roof of their mouth. This is called the choana and it connects to the nasal passages. As the chicken swallows, the choana closes so that water doesn’t come out the nose.
So, next time you watch your chickens drink, you’ll know exactly how the process works. Plus, now my kids have, I’m sure, a much longer answer to their questions than they ever wanted.
Originally posted at Backyard Poultry Magazine.