THE chickens of New York City, for the most part, live fairly sheltered lives, securely tucked into private backyards and padlocked community gardens. Our chickens, by contrast, are public figures — their yard faces 20 feet of busy Bedford-Stuyvesant sidewalk. The chickens themselves chose this bustling thoroughfare, decamping there even when they could have settled in our spacious, semiprivate back garden. They wanted to see and be seen — like so many New York transplants, they seemed to feed on the energy of the street.