SiuS, SiuiS, SiuiS...
Again, you make the assumption that that they WANT to negotiate.
If Thanqol never did anything to set them off, they might have just decided they like bullying him, or are Evil and don't give a frack...
Moreover, on a serious note: birds are not mammals. They do not think like mammals, they do not interact like mammals (critically, they do not socialise or play in a way like mammals do) - and you cannot train them like mammals. "Cats can't be trained" as said by the masses is a bollocks statement anyway; I mean really, how do people think the people that do animals for telly manage if "cats couldn't be trained?" How many zookeepers have been tragically killed because the tiger wanted to play and were just too strong?
But not birds. Ask any falconer, for example, and they'll tell you that if people think Cats Are Bastards, they have never dealt with a bird of prey. They really REALLY don't care about you and barely tolerate you, to the point that every time you release them, there is a chance that they will just fly off and never come back. Every time. Same with any bird, pretty much. (Nevermind the fact the little frackers will cheerfully stick their talons into you hands and lock tight until you relax your muscle long enough to make them think your hand is dead...) That's how much of a dropping birds think you are worth, mammal. You are even considered worthy enough to be a permenant source of food shelter or medical care.