You can use tranq darts and shoot them out of the trees instead of having to sneak up on them to try to hit them before they run, it's just hard to hit them due to having such a small hit box so take the time to aim carefully
something no one else seems to have mentioned here though... DO NOT TAKE THEIR EGGS... You will suffer for it
they seem like they're slow animals, but you take those eggs and they are the fastest damn thing you have ever seen. Faster than even raptors.
if you think you're only seeing two or three in one tree... I guarantee you more will show up and attack if you touch those eggs.
I was in the process of trying to find a decent level one to tame, I found a single Archie that just has a dropped egg, and it went up the tree so I grabbed the egg...
I got mobbed by about 10 of them and the only reason I didn't die is because I had five tamed argentavis to fight them off before they could kill me.
Flak armor is useless against flocks of angry archaeopteryx