User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-21378804-20131003110715/@comment-4212769-20131003141908

Well, Pink and Azure Raths are better seen as Green (in the Jungle) and Red (in the Volcano) ones. So they need to think more to hunt and fight what makes them more intelligent. And they're fighting more what gives them more fighting experience.

Mystery solved.