The funny thing of all of this is that it's unnatural in human behavior. By this I mean... if you were to let loose a bunch of hyenas, elephants, tigers, lions, gazelles, snakes and alligators in the middle of Central Park; at the end of the day, each animal would be congregating with animals of the same kind. By the same token, if you were to put together a bunch of Indians, Chinese, Latvians, Peruvians and Papua New Guineans in a room; I can almost guarantee that the majority of people would be congregating along racial lines. What I'm trying to say is that this apparently "racist" attitude on the part of animals is really a defense mechanism that comes from many millions of years of evolution: stick to your kind and the probability that you will survive will increase exponentially.