It literally only took me an hour to tame a level 145 with only 50 mejoberries.
1. Gather berries and put the berries in your last slot
2. Kneel down and walk up to one of them and feed it the berries
3. Now you just follow it around while kneeling down and feeding it berries whenever it's hungry
4. Congratulations you tamed one.
Since they're commonly found in the red wood forest, I recommend only taming one if you're close to water as if you get attacked by something you can jump into the water to get away. Then when you think it's safe just go find your monkey and go back to following/feeding it.
Dating is the best way to tame these. The appropriate dress for the occasion is a full suit of Ghille Armor. Pick your ape date up with a Quetz, drop in a taming pen, and hand-feed Mejo Berries. He/she will love you for it!
If you have a high enough lvl argy pick him up from the redwoods and take to your base, he will attack but when you get to your base build a stone 1by 1 with door frames then plonk him in it, go far enough away so that he loses agro then sneak up behind him crawl and just feed him berries without having to move anywhere
They are often found in places like a mountain or something. Make sure no hostiles are nearby and sneak up to it in a Ghille suit and feed it some kibble! They are like the mesopethicus but instead of running away from you they start attacking you. If they do start attacking you, I suggest it is time to hop on your Ptera or Argy and find another one.
To tame faster feed it once and then dont feed it till the taming % start going down ... it works like KO tames when u strve them. It worked for me... and tamed a lvl 435 with only x10 balm and 22 mejoberries. Upvote so others can see and try this trick . :)
Have tamed him yet but I no how to make a box of stone and a wood with a door get his attention and run to the box and climb up the ramp and out the door and fly on the parodon fly up until he stops his anger and slowly go up the ramp until you see his head and and tap him with berries and done with it