There are several spawns of Tabar Beaks in Sauromugue, most of them on the path and there are three spawns right near town. (If people aren't killing them for meat.) These con IT to me at 33, bring a friend (I had a lvl 62 war helping me, it meant REALLY long rests since I was healing with /whm.) and camp in one of the small 'alcove' bits in the hill wall to the left of the path, they repop (if you're killing them slow as you should) in less than the time it takes you to kill them. There are on goblin, raptor aggros if you push yourself up to the ledge and have your PL bring the Beak right up to you for foot kick.
My friend and I have also observed the following:
Tabar beaks are either smart, have an odd sense of humour, or just downright sadistic. They use Sound Blast and Sound Vaccum with some kind of swapping frequency around 55-60% HP, they seem to spam Hammer Beak, Poison Pick and such when its HP is below this... This could just be our luck, but Sound Blast does seem much rarer after 55% HP (Though it reliably spams its TP when HP is low... so I guess it depends how much you want to stand there versus playing Russian Roulette.)
Hope this helps for anyone trying to get this spell.