A white tern in the tropical Pacific, photographed by Theodore Cross ’50 for “Waterbirds” (W. W. Norton, 2009). Nature magazine called the book “extraordinary.” The same might be said of its author, who came to bird photography at midlife after a career as a successful publisher and another in which Cross (who was white) became an authority on black economic empowerment. Cross died on Feb. 28, a little more than a year after the publication of “Waterbirds.” The book’s success is a testament to his keen eye, to hours spent in swamps and tundra around the world, but also to his belief in our potential for reinvention.