Forget about bomb-sniffing dogs or cats that travel hundreds of miles to get home. If you're looking for signs of intelligent life, no animal (and that includes you, chimpanzees) is as impressive as a bird.
Birds can use scent, landmarks, magnetic fields, the location of the sun, the motion of stars and the plane polarization of light to navigate. Western scrub jays store food and retrieve it later, and if another bird sees them hide the food, they move it again for safekeeping once they're alone. Alex the African Grey parrot (whose obituary ran in the New York Times) learned and combined human words and phrases. New Caledonian crows make and use tools to reach distant food, and, showing an impressive ability to solve complex problems, they can even use tools to get tools to get food. (My all-time favorite typo hints at just how hard it can be for mammals to accept that avians are so clever: the Guardian newspaper attributed the ability to bend a wire into a hook and use it to extract food from a bottle to a New Caledonian "cow" named Betty.)
Anyhow, even though I'm a birder and a bit of a connoisseur of birds-are-smarter-than-your-annoying-pet stories, I was surprised to see these videos of extreme tool use in green herons. Apparently they've learned that the bread people toss to ducks and other waterfowl also attracts fish. So they've started baiting the water themselves.
You can see other bait-fishing green herons here and here.