Yes they are wolves (well 5/8ths anyways.) And yes they are fighting.
If you're going to wolfaboo baww on me- the door is that way. Don't let it hit you on the way out.
Some tension will exist when Niko grows up and begins to take responsibility for the pack, Yakone never really grows out of his wicked mentality. He reminds me of his grandfather.
Yakone and Niko used to be so close, and Niko would never harm his brother- unless his brother was trying to dismantle the pack. (probably to get Niko's attention on him again)
That must be what happened here. Yakone isn't really evil- just immature in a sense.