Maybe this should go in the "state your unpopular opinions" thread (and if anyone feels this way I'll erase it here and put it there), but here goes:
The notion of "rights" would not exist at all if not for humans. Animals (okay, some of them) do have the capacity to care for others- both their own species and different species (although the latter is a lot less common, I believe). One example: there were two old African Buffalo bulls who had left the herd, as old bulls sometimes do. One was nearly blind. The individual who could still see looked after him, guiding him as they wandered, blocking his way if he was about to walk someplace that might have harmed him.
Animals definitely can show altruism, but I doubt they have the capacity to think abstractly about what is "right" or "wrong" or "ethical". Maybe there are a few exceptions.
Having said that... if humans really are the only species that can think about "ethics", but don't bother applying ethical principles outside their own species, it doesn't count for that much. People HAVE to behave ethically toward other humans or they get punished.
Envy and Werewolf Girl make valid points, too: we don't have to abuse animals, even if you accept that we ARE superior to them. And animals are superior to us in a lot of ways. The things I see cats, rabbits, squirrels, and dogs do...
Peasant (1963-1972) and Fluffy (1970s?-1982- I think of you as 'Ambrose' now)- Your spirits outshone some humans I have known. Be happy forever.