If the above mentioned male lion should get caught trying to kill a female lions cubs I'm guessing he would find himself in some serious trouble. There would be no investigation nor reports to the lion police, she would simply chew his balls off and spit them in his face.
Actually, she eventually mates with him. Go figure.
Anyway, I disagree with you on self-ownership and on the lack of inherent Rights (if by that you mean natural Rights), however that is neither here nor there because I am more interested in your suggestion that ethics may play a major part in how animals are eventually treated -- not based on the whimsical emotionalism and mysticism displayed by many and subject to fickle change, but a more reliable and grounded base of protection for the lesser critters.
The natural Rights of Man is the center of a political philosophy concerning the relationship between the Individual and the state, and extends to how individuals relate to each other. It is based on negative Rights. Since there seems no logical way of recognizing such negative Rights in animals, perhaps what we need to do is develop a political philosophy concerning the relationship between Man and animal. Such a relationship would probably have to be based on what is referred to as positive rights -- something more one way and directed toward a lesser living being. Determining what those positive rights may be will probably be heavilly dependent on ethical considerations, no? But that can wait for another day. Time for me to hit the sack.
Yours,
Issodhos
p.s. Thanks for the suggestion.