A field biologist with working experience on four continents, he was also an active conservationist. He served on the Board of Directors of the National Audubon Society, the National Scientific Council of the Nature Conservancy, and the World Resources Institute Council. He was a past president of the American Society of Naturalists, and chairman of the Biology Section of the American Association for the Advancement of Science. He played a key role in initiating the Congressional Fellow Program in Washington DC, and in efforts to preserve wilderness areas in Florida and Texas.