"Flown the Coop!" is a daily quest for the Frenzyheart Tribe in Sholazar Basin.
Me as well as other players got stuck waiting for the chickens to spawn so that we can capture them, we tried restarting the quest, relogging, waiting a day or two and no change at all.
Finally i figured out how to pass it even when buggy, so i hope it helps someone else who was stuck like me.
I am playing as a hunter so i have a pet, I did command "/tar chicken" which showed me some chickens in areas far away., so i right click the target and added it an icon so i can see it easier, the problem is that every time i approached them they disappear before i could trap them.
So all i did was send my pet to kill it and this would cause a new one to spawn in an area i can throw the net over it and then go pick it up.
It kept glitching on me multiple times with those far chickens that you could never catch so i sent my pet to kill it and back in business.
Is not the most efficient way but works, I hope this helps someone.