What you CAN do is use their weakness against them: greed. Most of these groups will try to hold 3+ birds at a time to try to beat you out of the camp. Unfortunately, if 3+ birds are held, one of them will go yellow after a very short time, and last I checked, SE has stated very clearly that yellow is fair game......
I will PM you the specifics, but I have found a technique that will drive other parties out 9/10 times. I have had several arrogant HNMLS' camp on my party there, even LOLing at some of my party members gear in an attempt to intimidate my party. Then I apply my tactic. They dont like it, but they cant GM me because there really is no proof of griefing. Now, those repeat offenders dont camp on me anymore, and if they see me in the party, they will camp on the other poor SOBs at the other bird camp.
I've always wondered how people outside of Valefor find threads like this? Anyways you probably mean diaing mobs that have been slept & went unclaimed. LOL Fun stuff.
I'm really stuck in the middle of this argument and I'll leave it at that.
The Greater Colibri camp in general is classified as a different exp spot (More like a NM) since there's only 2. The FF society in general I think is split on this too. Ugh... just a tough situation. ; ;