At the occasion of the 40th anniversary of Tinbergen's famous paper in the Zeitschrift fur Tierpsychologie an international forum of behavioural biologists revisit Tinbergen's four questions on the roles of Evolution, Function, Development and Causation in shaping animal behaviour and confront his hypotheses with contemporary findings.
Johan J. Bolhuis is Professor of Behavioural Biology at Utrecht University, The Netherlands. Simon Verhulst is Assistant Professor of Behavioural Biology at the University of Groningen, The Netherlands.