I hate them with a passion like no other. Fast, travel in groups, very aggressive and strong attack means these things won't hesitate to make a meal out of you. All over SE and heavily concentrated in the Red Forest on The Center. If you can outrun them, (higher level = faster bird) best thing to do before you run out of stamina is introduce them to their oversized cousin the paracer. Stand by it's legs and let the bird try to attack you. I will accidentally bite the Paracer and make it angry. Immediately move out of the paracer's legs and run forward then across the path of the paracer again as the bird won't de-agro off you till it takes damage from the Paracer. If the paracer is anymore than 20 levels below the bird, or if the bird has friends, run like hell! If not, wait and the Paracer will kill it for free meat and hide and often some items, as they carry them usually. Same idea works with wolves, cats, etc. You can also run them into other defensive dinos or their fav snacks!
These little birds are the devil. One minute you're walking all peacefully not a thing in sight, then out of nowhere you're being attacked by this thing! They often travel in pairs too. They are easy tames, but when you're not expecting to come across them, they're deadly. I recommend always carrying at least 5 bolas with you, when you get attacked by one of these, bola it and you then got 30 seconds to run away. Run fast! Don't think hiding on a rock will help you either. Also deep water is your friend. Just Like the raptor, quickly jump into water. They won't be able to attack you.