I don't think it is racism as a concept we understand. But, rather natural selection. Grizzlies to use your example look for fit and suitable grizzlies to mate with. Insects are the same way. Driver Ants (Siyafu) in Africa are tuned to their own species and eat everything else. They are programed by chemical scent not any concept of racism as they are blind. If it doesn't have their chemical scent they swarm it and eat it. Racism really is a human weakness.

Interesting question! The definition of species is: A group of animals that are capable of reproducing with each other and have normal offspring. The definition of race, in a biological sense, is a group of species that is capable to interbreed with another group, but doesn´t interbreed in natural conditions. In this context, there is something similar to racism going on in animals. Once, for reasons of temporary geographical separation for example, a sub-group of a species changed appearance, the rest of the species stopps mating with them, even though they could still have fertile offspring together. So animals do discriminate against appearance, or other features like singing tone/pitch in birds for example. This leads to an acceleration of speciation, over evolutionary time, different races of animals will become different species. However, in your example of rabbits, whit rabbits and spotted rabbits don´t need to be different ´races´, biologically speaking. In the same way, human ´races´ aren´t races either, genetics has shown that the differents between, say black and whites, are so small that they can be mostly ignored for the human genome project. Therefore, my reasoning was kind of circular, because the definition of race already includes discrimination. I would rephrase it and say that animals do discriminate, but only in cases where there already is significant genetic distance, and not in the sense that ´human racists´would discriminate.