I very much agree with RJD and Deranged Nasat: the problem is how to define intelligence, particularly if it is of a different kind than ours? (my old Zoology Prof used to say: humans build bombs. No mouse ever would be such an idiot to build a mousetrap)
Eh, he's just being cynical. Animals compete with and kill their own kind all the time. When Humans kill each other it's because they're listening to their animal instincts instead of their rational mind.
Like some others, it's occurred to me to use computers to catalog all the sounds a dolphin makes and then create an artificial language based on those sounds. A computer program could then be written that translates back and forth. Young dolphins could be trained in that language by scientists while still being trained in regular dolphin communication by older dolphins. We would then have a group of dolphin ambassadors.