Middle Earth Ecology : The wargs and fell beasts of The Lord of the Rings

The wargs and fell beasts set upon the the fellowship proved a lethal menace to the heroes of middle earth, just as the wargs did 60 years prior to Bilbo. But how does a warg pack operate, how does a fell beast fly, and how much would they both cost in meat for any evil overlord? Let's look to our own natural world to find out! Also includes some minor battlefield analysis for the two species so hopefully Skallagrim or Shadiversity won't stamp me out if they ever see it...