Having written all that, I found this fascinating page summarizing "new" findings about how intelligent chickens and roosters are:
Dr. Chris Evans, Professor of Psychology at Macquarie University, Australia
“Chickens exist in stable social groups. They can recognize each other by their facial features. They have 24 distinct cries that communicate a wealth of information to one other, including separate alarm calls depending on whether a predator is traveling by land or sea. They are good at solving problems. ‘As a trick at conferences I sometimes list these attributes, without mentioning chickens, and people think I’m talking about monkeys,’ Mr. Evans said.
Perhaps most persuasive is the chicken’s intriguing ability to understand that an object, when taken away and hidden, nevertheless continues to exist. This is beyond the capacity of small children.”
Grimes W, “If Chickens Are So Smart, Why Aren’t They Eating Us?” New York Times, January 12, 2003.