Firstly, humans have a moral obligation to protect higher animals.
Higher animals, such as mammals and birds, are born with an advanced nervous system which can enable them to feel. Therefore, like human beings, higher animals also have the right to live and not to suffer abuse.
Secondly, animals are innocent, but humans can be good or evil.
Animals should be forgiven for killing others. Animals have low intelligence, so we cannot require animals to consider other individuals' feelings. However, adult humans are intelligent enough to be able to understand and consider other individuals' feelings. Therefore, if an adult human has killed or abused a 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 higher animal.
Higher animals, such as mammals and birds, are born with an advanced nervous system which can enable them to feel. Therefore, like human beings, higher animals also have the right to live and not to suffer abuse.
Secondly, animals are innocent, but humans can be good or evil.
Animals should be forgiven for killing others. Animals have low intelligence, so we cannot require animals to consider other individuals' feelings. However, adult humans are intelligent enough to be able to understand and consider other individuals' feelings. Therefore, if an adult human has killed or abused a 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 higher animal.