I use Parasaurus to locate enemies for me in a set location so I can find these guys. But at night is difficult, because they see you before you see them.

This strategy let's you know a rough location.

Have Parasaurus find them.

(Bring carnivores to help in case goes wrong.)

Have the bola actively swinging.

Once you see the red eyes...let her fly and cross your fingers.

(Hopefully there's only one)