Easiest taming method: Have someone fly a wyvern, and have a tribe mate stand on the back of your wyvern and shoot tranqs. The wyvern is smooth and doesn't create any sway when you aim making it very easy. Shoot the wyvern with a grappling hook and you have a safety rope incase you fall. Wyvern rider needs to have a good stam wyvern and fly normally (not sprint speed).
The fun way is to jump off and grapple to your argie and whistle it to attack and since argies are slow it won’t catch up in time so tranq till it goes out also bring parachutes and consider liking so more people will know
If you drop a quetzal due to knockout, and it lands next to a giga...just know, the quetzal belong to the giga. Now you get to watch your would be quetzal get eaten by a giga. Now you can go home and cry.
If your on crystal isle and your soloing it here's a good trick I used, first tame yourself a moth get a couple of parachutes and grappling hooks and your preferred amo with weapon, once you found one you like fly next to the quetzel and hop off the moth and grabbling hook it (dont forget parachute incase) and whistle it to attack quetzel the moth doesnt do damage but instead will slow it down for it bit while you shoot at it from below. This helped me tame it without having to whistle passive, attack target repeatedly.
If you manage to knock a quetzal out, try starve taming. If you never tried starve taming it’s just leaving a Dino’s hunger go to half way or lower and then you start feeding. I’ve done this many times and it’s very useful taming trick.