In my opinion, no roleplay is truly "realistic" unless the rp is in a map of it's own based on the real environment in which the creatures lived in. They characters must have the correct colours and corresponding sizes, and they must behave like the real animal. Most importantly, they must NOT talk!!! Communicate via noises or body language. Animals don't talk!
I don't mind it when people say "realistic colours", or when... say for example, prides... when they have mating seasons, only one male, chase young males etc etc.
Again, no rp is realistic. Where in the world do wild cats lose kittens to hyenas?!