More from the article...

... Whether playing tricks, mimicking speech, or holding "funerals," crows and ravens (collectively known as corvids) have captured the public's attention due to their unexpected intelligence.

Thanks to results from a new Current Biology study, our understanding of their capabilities only continues to grow, as researchers from the University of Tbingen found for the first time that crows can perform statistical reasoning. These results can help scientists better understand the evolution of intelligence (and may give us a better appreciation of what's going on in our backyard).

Bird brains

With a population of over 27 million and counting, crows seem almost ubiquitous across the US. Their loud "caws" are hard to miss, and the tone of these cries varies depending on what the birds are communicating. Like other corvids, crows have a large brain for their size and a particularly pronounced forebrain, which is associated with statistical and analytical reasoning in humans. ...

@#7 ... I've observed first hand how smart Jays are. ...

There was a PBS documentary a few years ago called "Bird Brains." The people in the documentary devised various puzzles to challenge birds. I was quite surprised at the level of difficulty of the puzzles that the birds could figure out.