Had a tribe in the small tribe servers able to keep 2 of them alive for a little over a week. I think there is a problem with the game because they are temporary tames but the tribes says they can be fed and have had them for quite some time. Please devs do something.
Easily killable with a wyvern. Lightning and poison easiest down to longer range in attack. Just hover above and light it up :) killed my first today and it didn't touch me once. Just remember to watch stamina ;)