Via Sue Schmitz comes the sad word that Alex, the amazing Gray Parrot whose cognitive abilities were literally incredible, has died. Supposedly (there I go with the doubt), he had a vocabulary of 150 words, could count recognize quantities up to 6, could identify 50 objects, understood concepts such as "bigger" and "smaller," and knew better than to call virtual methods within constructors.

I'm not surprised that Wikipedia has criticisms, but even there it only actually quotes one direct criticism, which in context (in the referenced NY Times article) is pretty clearly simply skepticism, not a repudiation.