Almost Human: That's So Raven
grrlscientist has the goss on avian intelligence.
Apparently Ravens have very logical minds, indeed too logical. While being able to work out that they could get a piece of meat dangling on a string by pulling it up, when the situation was changed so that the raven now had to pull down to get the food up it was a little bit harder.
This sort of abstract thinking is a trait, AFAIK, that really gets into what made Hominids human. While being able to logically associate things is pretty basic biology (even microbes are chemoitactic); and memory is something a lot of animals have (even goldfish, against all prejudices). Imagination and innovation is a pretty limited trait, along with self recognition.
Something that was probably included in the original SCIAM article would be what age-equivalent this level of intelligence makes the ravens. At what age to humans have the capacity to work out that you can pull down on a string and make it go up in certain situations. Such a figure would be quite subjective, avians have far superior memory skills (I keep forgetting where I put my mobile and keys, I'd starve if I had to remember 1000s of food cache locations without a map) and are also adept at deception and mistrust.