A solo tame is pretty easy actually. It works best if you have a longneck rifle (for tranq darts) and a crossbow (grappling hook). Grapple to a pteradon or argentavis (I used a pteradon and it worked fine) and set it to attack my target while aiming at the quetzel. Once it gets close enough set it to passive and shoot for the head. Repeat until knocked out and make sure you keep it alive and not in danger of being killed my random carnivores.
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.