The Tongue of a Heron

On one of my outings this year, I encountered a Great Blue Heron. Often one sees a heron standing still and regal, elegantly waiting for the moment to strike at an unsuspecting victim in the water at its feet. Not this one. It stood on the edge of the Goffle Brook, opening and closing its mouth. I took my photos, as I usually do, in the heat of the moment and while the constant mouth movements did seem a bit unusual, I didn’t think too much about it until after I got home and took a look at the photos.

Once I had the photos on a computer where I could zoom in, I took a really good look at the Heron’s mouth. And that was when I noticed how weird its tongue looked. Usually we think of tongues like our own, a relatively smooth, flat muscle. Not the Heron’s tongue. While the tip was long and thin, the farther back into the bird’s mouth it went, the more grooved and angled it seemed to become. Besides the angles, it had more than one section that was raised, with curves and edges going in several directions. I found the irregular shape interesting and began to wonder why it was formed in such a way. So I decided to do a little research into why a Heron’s tongue is shaped the way it is.

It turns out that not only do birds have tongues that are very different from those of a human, they actually can have very different types of tongues from other birds. The type of tongue a bird has, just like the type of bill or beak, is directly related to what they eat and how they eat it. Nectar collectors like hummingbirds have tongues that differ from woodpeckers or fish eating birds. This is because birds do not have teeth, and therefore their tongues need to take on extra functions that a human tongue would not. Another big difference from human tongues is that most bird’s tongues are not involved in their vocalization or sound making. However, birds do have taste buds, though far fewer than humans. The exact amount of taste buds differs greatly by bird species.

Many fishing birds have tongues with hooks or spikes to help contain their captured fish. But a Heron’s tongue is different from other fish eating birds, like Cormorants or Pelicans, because it also eats amphibians, reptiles, insects and small mammals. Unlike woodpeckers and other birds with long tongues, Herons’ tongues are attached below the mandible bone and are more limited in the their movement. However, this is to their advantage, as it allows more room in their mouth for them to swallow large items. Herons swallow fish and other food whole, and sometimes they regurgitate up to a dozen fish when they are feeding young. So what they need is a tongue that won’t get in the way. Their tongues are shaped not only to allow fish to be swallowed whole, but also to be turned in the bird’s mouth and eaten head first. So now when I see the pink on the inside of a bird’s mouth, I think I will pay a bit more attention. Bird tongues turned out to be much more complicated and interesting than I expected and they can tell the bird watcher a lot about a species, if you know what to look for.

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