Arnold Cooke worked for the national nature conservation agencies as a researcher and adviser on a range of topics for 30 years. After studying amphibian population declines with the Nature Conservancy, he was herpetological adviser for the Nature Conservancy Council. In the late 1990s, he left English Nature to pursue his interests in amphibians, birds and deer. He has published widely on subjects as diverse as the status of Britain’s amphibians and reptiles, pollutants in birds and the environmental impacts of introduced species of deer. His book Muntjac and Water Deer was published by Pelagic in 2019.