Every once in a while, something unexpected happens. Like hearing a manta ray let out a battle cry and then being headbutted by it. Twice.
Some background: I was swimming in the Indian Ocean the other day, south of Sri Lanka, following a lone manta ray that was feeding on plankton.
The manta was behaving exactly as I expected, alternating one wing flip with the other to keep its body parallel to the ocean surface as it swam. The fish wasn't in any particular rush, which meant I was able to keep up without undue effort.
Given the nice colour of the water and the seemingly carefree attitude of my winged friend, I decided to try to photograph the manta from behind to show its wingtips protruding from the water…a perspective you don't see too often with manta ray pictures.
We swam along together for quite some time, manta enjoying the nice day while dining on fresh plankton, me snapping away, trying to get the perfect composition and lighting. Everything was just peachy.
Until that is, I heard a loud noise…a brief, punctuated, scratchy, high-pitched screech. It was loud enough that I initially thought it was a boat engine, or perhaps some other mechanical device.
But I didn't have time to lift my head out of the water to check, as the manta flipped one wing down, banked a hard right, then swam directly at me. Given our proximity, I only had fractions of a second to react…jerking my body backward as the manta brushed by.
The cogs of my brain processed the split-second encounter, and I concluded that the manta may have reacted to the sudden noise. I had certainly been taken by surprise…first by the sound, then by the sight of an oncoming manta.
Anyway, we picked up where we left off…manta feeding, me snapping. In hindsight, I should've looked up to search for a possible source of the sound, but I was 100% focused on keeping up with the manta.
All was good again, until a few minutes later, when I heard the sound again. This time, I watched the manta execute a barrel roll, swim toward me, and finally…headbutt me. Bonk!
As befuddled as I was, I managed to ball up and avoid the full brunt of the manta attack, taking the impact on my left elbow. Satisfied with its marksmanship, the manta sauntered off to continue feeding, behaving as if nothing untoward had taken place.
It's difficult to describe the sound in words, so this is my best impression of it:
It's not a perfect impression, but pretty close. The real sound was much louder, and somewhat longer.
I'd like to use the word "vocalise" to describe what the manta did, but I have no idea how the manta made the sound. I know these fish don't have vocal chords, but I'm 100% certain that the sound came from the manta, because it happened twice in association with the barrel roll + attempted body slam manoeuvre. There was also another person in the water who observed and heard the same thing.
This might be the first documented case of "manta burn"
I've searched the net to see if there are any other references to manta rays emitting sounds, but haven't come across anything yet. If you've heard a manta "vocalise" before, or know something about this topic, please get in touch!
Update 27 July 2011: Captain Craig of MV Golden Dawn just sent me the text below. He reports hearing a large female manta make a loud noise at the manta cleaning station in Milne Bay:
While diving with five mantas the other day at Gona Balabala, I was sitting on the sand at the manta rock watching a large female being cleaned.
Another manta approached in close to the first manta, so she started to move off slowly. The other closed right in on her, and they started to move together in close formation, coming past me and then up and over, turning directly towards me. Just as she completed the turn, her mouth closed and she made a loud squeaking noise, like the one you talked about.
To me it looks like she made it with her mouth by grinding the upper and lower jaw together!!! It looked as if she moved her mouth slightly sidewards. The result was that the second manta broke formation, and the large female manta passed by me with no further noise or action.
That's it..quite remarkable. I wouldn't have taken note of it or believed it was the manta that made the noise if we hadn't had the conversation when you were here. You know I have those ear muffs with dry ear pockets around my ears, so the sound was clear and came from the manta direction.