Bola it and knock it out, if you tame it with fish, get like 30-33 fish and 10 narcotics, wait like 30 min and keep giving it narcotics when it’s torpor is almost out, soon you will have tamed your own pelagornis. so beginners like me can see.
Best way I have found to tame these is to build a small quetz like trap on a quest. Make all the walls out of window frames and surround it with ceiling tiles as a walkway. Can use rare flowers to bait them in if needed. Little more advanced but this is how I tame them during events.