Posted: Mar 06, 2016 4:10 pm
DavidMcC wrote:The_Piper wrote:The other explanations of it being a territorial behavior or adding to an aggressive display seem more plausible.
The stoner chimps.
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I agree, and you are probably right, but there would then have to be an audience for the stone-throwing. Unfortunately, the OP article doesn't mention whether there was such an audience.
An audience for the behaviour of a social animal is obviously crucial, so it is unfortunate that the article seems to have been written by someone who doesn't understand that.
I don't think it's crucial for there to be another chimp close by, it could be done just in case there is one within earshot distance. Though the article and video are unclear. In the last segment of the video there is another chimp present, who appears to run away when the chimp at the tree hoots and screams. If there is wider and more lengthy footage it would be helpful to us.
The behavior of the one with the baby on it's back is compelling that it could be ritualistic. Or, it just decided not to make a lot of noise at that time.
Again with my red squirrel references, they will call out with a rattlesnake call (apparently) with or without another squirrel being nearby. (Of course red squirrels are vastly different from chimps and are solitary not social.)
I'm sure the researchers know a lot about chimp behavior and about these specific chimp populations.