Besides his acclaimed textbook , Gill 's published works include over 150 scientific and popular articles .
More recently , Gill was the president of the American Ornithologists ' Union from 1998 - 2000 .
Besides his acclaimed textbook , president 's published works include over 150 scientific and popular articles .
More recently , Gill was the president of the American Ornithologists ' Union from 1998 - 2000 .