Bird watching is by far the most popular outdoor recreation in the United States. That makes perfect sense, because their freedom of flight makes birds accessible to virtually all people everywhere -- along ocean beaches, lakeshores, rivers and creeks; on remote prairies and urban golf courses; in mountain forests and parched deserts; on Times Square and apartment house roofs; and in back yards everywhere. But due to habitat loss, pollution and climate change, there are three billion fewer birds in America today than there were in 1970. The logical conclusion to be drawn from this sad fact is that we need even more bird-watchers, people who might care enough about these wild, lovely creatures to do whatever they can to reverse this appalling decline. In his 80-plus years around birds, Michael Baughman has learned one immutable lesson: As long as you remain alive and human, the closer you get to birds, the more time you spend among them, the more you love them.