Earlier this week, the usual morning birdsong was punctuated by a low deep rumble that sounds like a cross between a power drill and a lion. The first time I heard this in the wild, I jumped about a foot; I think there is something primordial in our brains that registers this new noise as an alarm. In any case, once you hear it, you won’t soon forget it.
They’ve done some studies on alligator bellowing in Saint Augustine that finds a correlation between the frequency of the bellow and the size of the alligator, meaning that males can establish territory and dominance without a physical altercation. BBC Earth did a video on the physics of this here.
This “water dance” is the result of such low frequency vibrations that they are undetectable by the human ear, and the vibration then moves up into the throat to produce the audible roar.
As you can see in the video, females bellow or roar too, but they don’t have the infrasonic ability to produce that deep deep sound. We were watching the baby gators at the pond one day, and the mother was hidden under the bank. When the babies began to yelp in alarm, so she roared, sending the group I was standing with into the air to reclaim their golf cart seats!!!
More footage of alligator bellows:
I have been trying to capture an alligator bellowing on video for years. For an animal that makes such a huge noise, they are often hidden in narrow stream passages in the marsh, or just out of my view from roads and pathways. So I was pretty delighted to find this backyard bull vocalizing where I could both see and film him, in great light. I took over three minutes of straight video: here is the uncut version. This particular alligator has one bright yellow scute on his tail, earning him the family nickname of yellow-tip; he has been plying the waters behind our house for at least a decade.
One July morning I was out on the north end of the island and there was a pair of alligators that seemed to be in conversation: as hard as I tried I could only capture the sound. The road vibrated, so they were close, but I couldn’t find them in the marsh or the pond.