Bola it, then use a slingshot to body shot it. Don't head shot it; it'll die within 5 hit of the slingshot. I used a crossbow and two headshots and dead. Use fists, sling, or boomerang to knock it out. Good luck, 2 2.5x Coels should suffice for the taming.
If you see one that you want to tame walking around on land, throw a tent on top of it, and get your bola ready. It can help keep them trapped. However they can escape if you're not quick enough with the bola, also they can destroy the tent if they start to attack it. I've tamed them many times this way, so it can be done.
Very hard to tame. Absolutely worth it though. I managed to tame one, and it's my primary source for meat and fish, especially prime.
But I've wasted 20+ tranq arrows with confirmed hits on a flying one, with the arrows sticking out on a level 24. Eventually I died.
So bola first. Or it must be a new bug.
These things are weak so use darts since it does less damage, easiest way to knock it out is to watch it until it comes down to steal your stuff then bola it head on. Worked every time for me. Also force feeding it a little meat will keep it from dying, that's what happened with me. Hope this was helpful.
One of my personal favorite tames. They're extremely fun to use, and extremely useful for killing fish then using a sickle to harvest raw prime meat from them, and use the meat to tame carnivores much faster. For something really fun, tame at least 12 or so and put them all on aggressive! Also, tranq arrows are much easier than bolas, I suggest using them.
Annoying little b*ggers but can have their uses. If you have them on your shoulder and you enable hunt, they will gather fish, but they fish they gather will turn into lovely gorgeous prime fish. Fabulous ;)