WEST ORANGE, N.J. — Along the long road from American icon to endangered species and back again, the bald eagle — the national bird of the Uni…

Under cover of darkness a year ago, someone slipped into the Central Park Zoo, cut a hole in a cage and freed a majestic Eurasian eagle-owl named Flaco. The owl has become one of New York City's most beloved characters since then. By day he lounges in Manhattan's courtyards and parks and perches on fire escapes. He spends his nights hooting atop water towers and preying on the city's abundant rats. Some experts feared he wouldn't be able to hunt after a lifetime in captivity To their surprise, Flaco is thriving. But as his second year in the spotlight begins, the crime that led to his freedom remains unsolved.

On Dec. 28, 1973, President Richard Nixon signed the Endangered Species Act. The powerful law charged the federal government with saving every endangered plant and animal in America. It enjoyed nearly unanimous bipartisan support but soon became controversial. The United States' own national animals, the bison and the bald eagle, had been driven to near extinction. When they started to recover, Americans saw the Endangered Species Act as a success. But when animals that people had never heard of began interfering with development, it was a different story. Whether the government should try to save all species from extinction, or if not, where to draw the line, became a point of conflict that has never been fully resolved.