This quest is not available in game.
Check the cages at the two Witherbark villages, then return to Gryphon Master Talonaxe.
The son of our mightiest gryphon is gone! Swiftwing's heir, Sharpbeak, was lost while hunting with his parents a few days ago, and we believe it was the trolls who took him.
You must aid us! Search the cages in the two Witherbark troll villages to see if Sharpbeak is there.