The Corvid MindI'm not really surprised; I recall being impressed by crows as a child, but the link to Aesop is fun.
Four different rooks, called Cook, Fry, Connelly and Monroe, quickly discovered that they could raise the water level in a transparent container by adding stones, just like the mythical crow in the fable, which illustrates the virtue of ingenuity and how necessity is the mother of invention.
The comments at the link are very entertaining further anecdotal evidence of the wit of corvids.
And there is also this fine book by one of the great nature writers of our time.
h/t Andrew Sullivan