By the form at the bottom of 'English Version' on my Homepage I regularly receive mail from readers. Often these are students that request information for their paper on dolphins. Usually this is available in literature or can be found elsewhere on my or other dolphin websites. As I do not want to do clerk work I leave them to their job, so I can do mine.
However sometimes, something comes in that is interesting. Like the information responding to a remark I made about Cetaceans swimming in a desert as they lack drinking water (DA 19, 2003). The response to this I put in an Extra Edition, August 16 2003 and it kicked of a truly prolific relationship.
This time I received an e-mail from Roland Cools, about the way dolphins might communicate their observations. As the source he mentions the Avatar course by one Harry Palmer:
'Dolphins emit a sound wave that is reflected. When it comes back they emit a new sound wave that collides with the incoming one, so both interfere. This interference pattern produces a sound, which is interpreted by the dolphin as a three dimensional image of the observation.'
Attentive readers of my website may recognize this information. In DA 1, 2003 and in DA 15, 2003 I have investigated this theory and displayed a few photographs of vibrations in the water near Dusty's head.
Harry Palmer, by mouth of Ronald, continues by asserting that instead of the usual sonar sounds, the dolphin might send the interference pattern of his observation to another dolphin.
This includes the assumption that dolphins communicate by sonar. Though they must hear the echo's of each others sonar and may be able to interpret each others reflections its use will be virtually limited to the location from where it was originally emitted. Besides, dolphin do communicate already by whistles, clicks and weird sounds.
The attribution of fantastic-realistic qualities to dolphins contrasts acutely with their actual behavior. A few days ago Dusty played all afternoon with two empty bottles that were tied together with a rope. She towed them with a pectoral fin and sometimes even with her dorsal fin. She left them to float until someone wanted to pick them up and then snatched it away. A nifty little game that nicely portrays her cunning. But would she be able to transmit her locations to other dolphins with the same precision? Bottles merely move on the waves or ascend in a more or less straight line. Prey fish on the contrary are much more lively. Apart from the location issue, she would have to be able to reproduce the sound pattern she receives. This would then have to be deciphered by the receiver. If the receiver is not familiar with the target at stake this seems out of the question.
Which ever way I approach this theory of remitted data composition, it seems tragically defective. It would, however, be typical dolphin if there would be some kind of a surprise in here.