Crows could be the smartest animal other than primates
This article focuses mostly on problem solving, planning, and tool use as the primary hallmarks of intelligence.  But what problem does writing a poem solve?  Do you have to be intelligent to write a great poem?  What about the intelligence need to compose a great whale song[1]?  Or paint a great painting?These are things not measured on intelligence tests and that don't fit well in to scientific experiments because they can't be "objectively" judged or quantified, but my intuition is that they do in fact have to do with intelligence -- just not the sort of intelligence that problem solving, planning, and tool use demonstrate.  Though they may require problem solving, planning, or tool use to accomplish, there seems to be something else going on there.I'm reminded of the Douglas Adams quote:  "... on the planet Earth, man had always assumed that he was more intelligent than dolphins because he had achieved so much--the wheel, New York, wars and so on--whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man--for precisely the same reasons."[1] - ...if such criteria could be applied to them -- we don't know, and that's part of the point.  If we don't know how can we judge one animal who does one thing to be "smarter" than another who does something else?