I have actually never thought of this... I see this a lot with the Warrior cat RPs and TLK Rps, for example, I was sitting in bonfire today when someone caps locked into the chat, "Kills all hyena and foxes". O_o Why can't they just get along...? If this really happened in the wild, ( Lions and hyenas are naturally not all that "peaceful"), there would be no hyenas. They would have gone extinct because of all the lions killing them. -_- I was once in a cheetah RP with hyenas AND zebras, and we didn't all kill each other... It was actually quite pleasant. One of the best Rps I was ever in. :/ Very rarely do I find a RP in which two species coexist peacefully together. Like you said, they either are the same species, or a war as different species.
I don't like it when this happens, neither does anyone I think but great thread post!
When I'm on my fursona and my best friend's on her Leopard character, we always role play together. We've even had a few people accepting her in just lion based role plays because they were kind enough to do so but we've also had our bad times as in such, we were just sitting in Temple of Dreams, minding own our business we weren't even role playing. So this person who's a Hyena, comes up and tells me a Lion and Leopard can't be best friends because it simply doesn't happen in real life but what should it matter? We're comfortable and happy with what we've produced with our characters!