"This hallmark of human intelligence may also be at work in both the great apes and New Caledonian crows and may explain why, out of all the crow species in the world, only these crows routinely make and use tools," he said.
There is no evidence yet that the American crow is quite that clever, but they are still regarded as among the smartest animals on the planet. They have at least 250 different calls -- although they may all sound the same to humans -- and they will care for their young and defend crows that they don't even know, according to McGowan.
But that still begs the question: If they are so smart, why are they moving into urban chaos? Crows and humans can be a hard mix.
"No one is ambivalent about crows," Binghamton's Clark said. "Either you hate them or you love them."
They can be really, really annoying. In early spring, the second I step out of my home crows will scream as though I were a harbinger of death, and they will follow me -- cawing endlessly -- until I leave.
Sometimes, I really dislike them, like a woman Clark recently encountered.
"She said 'I hate these guys,'" Clark recalled. "I said, 'You hate crows because they are exactly like people.'"
Maybe not exactly, but we share many of the same genes, and we are increasingly sharing the same landscape. Clark thinks cityscapes may actually look attractive to a crow flying overhead. Nicely manicured lawns, beautiful golf courses, parks with small lakes and fountains, can be alluring.
And then they land and discover that those golf courses are "managed lands" that don't provide the bugs the crows like to eat, and the lawns are full of chemicals that are unhealthy both to crows and humans, and so they end up looking for lunch in dumpsters.
That may be why the nestlings she and Mcgowan have studied in cities are smaller than those in rural areas, and the protein and the calcium so essential to growth was lower in birds in cities. All that has to lead to stress, but Clark said the birds seem to be adapting to their new environment.
But can they really tell us anything about our ecosystem, and about ourselves?
Maybe they already have.
City crows, Clark said, never move back to the countryside.