保护动物的海报英语表达可以包括以下五句话：

Protect animals, treat creatures kindly.

The protection of wild animals is to care for human beings.

Animal protection, everyone's responsibility.

We must work together to preserve the delicate balance of our planet's ecosystems and ensure the survival of these precious animals.

Save animals, save the world.

这些句子涵盖了保护动物的重要性、道德责任、集体行动、生态平衡以及人与动物的和谐共生等方面，适合用于保护动物的海报宣传。