If in the redwood biome run to one of the small streams they glitch and don't register as water for you but it does for the terror bird so you can go prone in those streams and the terror bird will lose agro works for carno to.
Everyone seems to limit this to just being a "scout". If you get a high level (170+) the terror bird can easily be one of the most deadly mounts out there. It's speed is unmatched and its ability to glide from any height, if it has the stamina that is, makes it amazing. If you pump HP, speed, stamina, and later on movement speed, you will have an absolute killer. (WARNING: Even high level terror birds will have low weight, only bring your essentials to maximize on speed!)