My point here is that if intelligence developed more than once, it didn't come from some one-time random event or divine intervention. It looks like once there are connected neurons, it evolves via continuous improvement.

In some environments, that evolution hits limits. Flying birds are limited in brain mass or they can't get airborne. Which may be why corvids don't rule the world.

Oh yes absolutely. Intelligence certainly developed more than once. Bird brain is no slur.

Before your comment I would have said it emerged twice, but then I had not considered octopuses, they are wicked smart and so unlike other intelligent animals we know.