Firstly, humans have a moral obligation to protect non-human higher animals.
Higher animals, such as mammals and birds, are born with an advanced nervous system which can enable them to feel. Therefore, like humans, non-human higher animals also have the right to live and not to suffer abuse.
Secondly, non-human animals are innocent, but humans can be good or evil.
Non-human animals should be forgiven for killing others. Non-human animals have low intelligence, so they cannot be required to consider other individuals' feelings. However, adult humans are very intelligent, so they are able to understand and consider other individuals' feelings. Therefore, if an adult human has killed or abused a non-human higher animal, this human is evil.
Thirdly, humans must fight against cruel nature.
Nature has no empathy at all, but human morality is empathic. Therefore, human beings must fight against cruel nature and protect every non-human higher animal.