You may have missed the story about the pod of dolphins who saved a group of New Zealand swimmers from shark attack. Apparently this behavior is not unique.
To the extent that these reports are true, they are remarkable examples of cross-species altruism by animals without previously existing alliances with humans.
Sometimes it's easy to get depressed and believe that humans are genetically destined to kill each other. As often as not the killing instinct is reinforced by religion or politics.
But in fact altruism is deeply ingrained in our biology, and apparently not only in our own species. Of course, nature and nurture play off each other both ways, but when it comes to ethics, I trust the genes more than I trust the self-appointed guardians of public morality, who include, I suppose, my blogging self.