When limiting factors increase, diversity in populations decreases. In this sense "limiting factors" can be anything from a lack of resources to a lack of food, meaning it's harder for the population to survive.
The answer to this question would me molecular.
Try playing a game with the dolphin and see how quickly the game stimulates the dolphins brain and see if the dolphin gets used to or gets the hang of that game... I mean isnt how all animals are taught? Lol
