By: Ally McEntire
The calls of the baby gator in the Holliday lab got me thinking about alligator vocalizations. On a whim, I decided to look this up and found a little more than I had bargained for. Alligators and other crocodilians have a different vocal structure than any other reptile, amphibian or bird– all nearby relatives. Their vocal structure is actually quite similar to that of mammals. Instead of a syrinx like birds have, which involves air passing through the trachea while it vibrates at different rates; they have vocal folds—a larynx—just like humans.
This article details a study done on live juvenile crocs to study their vocalizations. It discusses a number of very specific things like sexual dimorphism in calls and amount of time the noises lasted. What I find more interesting than all of that is that their vocal structure is so unique. Even though they are evolutionarily related to these 3 other branches, their system of making noise is not really like any of their closest relatives. Basically, they have vocal folds, which contract and/or relax when the gator breathes out, like mammals.
This made me want to find out more about the ancestral line, if the present one is so estranged. Would other archosaurs resemble birds, lizards or crocs more closely? I’m not sure there’s a way to know this, considering the vocal cords are a soft tissue, and therefore incredibly difficult to preserve. But, if there were tissue attachments that could be identified, I think it’s something worth looking into.
Also, if you’re curious to hear our captive alligator making his own vocalizations, check Romer out here: