If you can get the bird on the water near a raft, (it doesn’t matter what kind) the birds swim in circles, and can climb up on your boat. Bola it and knock it out, and then you can drive out to sea to catch prime fish and not loose your tame! (Recommended: put a preserving bin on your boat. You can store the meat in in and use it when the bird is hungry enough.)
You can find these little guys in basically any beach. Tamed one and saddled it and it is quite useful! You can also fish while on it in the water which is really useful if you dont have a raft. However the speed is quite low and you cannot hold creatures with it.
Currently it's untamable in primitive plus due to the raw fish meat being replaced with fresh fish filet my friends and I tried prime meat and prime fish meat but no luck hopefully this will be patched in a upcoming update