Alfred Viola is Professor Emeritus of Chemistry at Northeastern University, Boston, where he taught for 41 years. His interests in nature photography began in the 1950's during vacations in the American West. He has now photographed birds and mammals on all seven continents. His photos, together with those of his wife, Joy, have been willed to the Center for Invasive Species and Ecosystem Health. Now an octogenarian, his most recent images have been the birds of Costa Rica, Florida and Arizona as well as the polar bears of Cape Churchill, Canada.