I’ve found that they normally spawn in pairs. On a quest to obtain a breeding pair, I only found a pair of females near the green obelisk, and a pair of males near North Zone 3. Not sure if they always spawn like this, but don’t accidentally tame both thinking they are each a separate gender.
Carea more about big prey than you, so try to run past anything bigger and meatier than you, then keep running. It won't take long to kill whatever it finds. That being said, I did see a Rex take a long while to kill 2 carbonenemy turtles