Sound travels best over water, worst in woods
One of the reasons I posted the article from the beeb. The relevant bit regarding woods is below where whistles are used for communication in the Amazon wich is pretty dense.
Birds tend to be most vocal in the early morning. During the day they are busy hiding or hunting. Unless they issue a warning cry which is nothing like a bird song. And all birds whatever the species take flight or hide and shut up.
But the sounds can also penetrate dense forests such as the Amazon, where hunters whistle to locate each other through the dense foliage. “The whistles are good for fighting against reverberation,” says Meyer.
http://www.bbc.com/future/story/2017052 ... n-whistles
Is your idea that quackers and grunters were domesticated by man, or woman, and through evolution stopped singing?
As for the importance of swans and geese I think the answer lies above in the constellation Cygnus. I wrote previously that Callanish is shaped like a cross or a bird like a swan.
In Plato's Timaeus, Critias tells the story of Atlantis as recounted to Solon by an Egyptian priest, who prefaced the story by saying:
"There have been, and will be again, many destructions of mankind arising out of many causes; the greatest have been brought about by the agencies of fire and water, and other lesser ones by innumerable other causes. There is a story that even you [Greeks] have preserved, that once upon a time, Phaethon, the son of Helios, having yoked the steeds in his father's chariot, because he was not able to drive them in the path of his father, burnt up all that was upon the earth, and was himself destroyed by a thunderbolt. Now this has the form of a myth, but really signifies a declination of the bodies moving in the heavens around the earth, and a great conflagration of things upon the earth, which recurs after long intervals.
The Greeks also associated this constellation with the tragic story of Phaethon, the son of Helios the sun god, who demanded to ride his father's sun chariot for a day. Phaethon, however, was unable to control the reins, forcing Zeus to destroy the chariot (and Phaethon) with a thunderbolt, causing it to plummet to the earth into the river Eridanus. According to the myth, Phaethon's brother, Cycnus, grieved bitterly and spent many days diving into the river to collect Phaethon's bones to give him a proper burial. The gods were so touched by Cycnus's devotion to his brother that they turned him into a swan and placed him among the stars.
By IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg) - , CC BY 3.0, https://commons.wikimedia.org/w/index.p ... d=15406373