Corvids

A mention of an interesting event that I observed last weekend.  On Saturday afternoon I was outside clearing out the greenhouse and doing a few other autumn garden jobs, when all of a sudden there was the noise of a great assembly of crows and jackdaws in the big oak tree to the north of our garden.  To me it seemed like a major argument, perhaps even a battle, with the birds wheeling about in numbers.  I am pretty sure I could hear magpies too, though I couldn't actually see them. I know crows and magpies will fight, and perhaps that's true for jackdaws as well;  anyway, I really can’t be sure what provoked this, but it certainly disturbed the peace.  

We always have crows and jackdaws around our gardens, but I normally only see them in groups of three or four at most.  There will have been forty or fifty birds at least involved in this affair, and the commotion went on for at least a quarter of an hour.  During this time the squabble, if that's what it was, gradually moved south through the wood from the major oak until the birds were mostly in or wheeling above the trees (ash, elm and sycamore) that our own garden backs on to.  And then after a while they dispersed, leaving just a few jackdaws to shout at each other now and again.  I’d love to know what was really going on here, what started it, and how typical it is - after all, these are intelligent and quite highly organised birds.  Was it perhaps about carving out winter territories, or were these young birds just rousting about? I'm sure someone will know, or at least have a theory.