Knocking it out is pretty hard, as it has high torpor and low health. I recommend using tranq darts, as it will most likely die otherwise. You can however use a bola on it, which makes your job already a lot easier. Taming it doesn't take too long either.
ARRRRRRRGH I just had THE WORST taming experience! Pro tip: DON'T try taming a high level one by dangling from an argy by a grappling hook... You'll end up dying TWICE and losing your argy, guns, and 80 narcotics... >:( :(
Extremely difficult to tame. Best options are to bola it, and then use a longneck rifle with tranq darts. Otherwise trying to get it to fly into the side of a cliff and get stuff is the other option for a solo tame.