Hans Kruuk is a behavioural ecologist with a particular interest in carnivore behaviour, life history and conservation. He did his PhD under Niko Tinbergen at the University of Oxford in 1964, on behaviour of gulls and their predators. He then became Deputy Director of the Serengeti Research Institute in Tanzania, before moving back to the University of Oxford in 1971 as Research Fellow, then to the UK’s Natural Environment Research Council, at the Institute of Terrestrial Ecology in Scotland as a Senior Principal Research Officer. He has authored over 120 scientific publications and seven books, including The spotted hyena, predation and social behavior (1972), The social badger (1989), Wild otters (1995), Otters, ecology, behaviour and conservation (2006), Hunter and hunted (2002) and a biography of Niko Tinbergen (Niko’s Nature, 2003). He has received scientific medals from the Zoological Society of London and the British Mammal Society, and is an Honorary Professor at the University of Aberdeen.