Love them or hate them, pigeons are an iconic animal of New York City. But there is much about these birds that remains a mystery to most. "Sunday Morning" contributor Christian Cooper talks with bird enthusiasts about a pigeon's intelligence, ability to thrive in a concrete jungle, and suitability as a pet; and with artist Iván Argote, whose T. Rex-sized sculpture of a pigeon is now on display at New York City's High Line.