Hard to do, but aggro with rare flower and pull into a covered pen. Close pen. Need a giant gate at least. Wood or stone works. Then bola and tranq at leisure within safety of your pen. No baddies to get him.
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.