http://www.uesp.net/wiki/Daggerfall:The_Vanguard
"You have been given the honor to clear out this dungeon before this meeting takes place. To accomplish this task, you must kill the leader of the pack of lycanthropes, a wereboar. As an evidence that you have killed it, you shall bring back one of its tusks."
"You have slain (wereboar's name), the lycanthropes' leader. They will now know better than to trespass in a stronghold of (vampire bloodline)."
Alright, so that alone was something that contributed to the fact that werecreatures have "packs". We have never seen any other source that shows them running in packs other than Bloodmoon(They were under the command of Hircine).
So, I am guessing they can have tribes?
Note: I am not starting a vampire vs werewolf thing on the nature of the quest posted above. The concept it's just silly in the ES universe.
Also, do werewolves attack each other in werewolf form or can they create a bond with each other and hunt together?