Nikolaas Tinbergen, 1907–88, Anglo-Dutch zoologist, b. Netherlands. He received his Ph.D. in 1932 from the Univ. of Leiden, where he became professor of zoology in 1947. In 1949 he joined the faculty of Oxford. For his work in reviving and developing the biological science of animal behavior, Tinbergen was awarded the 1973 Nobel Prize in Physiology or Medicine. His first independent work concerned the landmark orientation of homing wasps. After collaborating with the Austrian ethologist Konrad Lorenz, he was invited to found a school of animal behavior at the Univ. of Leiden. Studies of the display behavior of certain species revealed that such displays result from a state of conflict between opposite motivations ( "fight or flee" ). Further work clarified the evolutionary origins of many social signals and their subsequent ritualization. Tinbergen emphasized the mutual interaction between predator and prey and, as scientific adviser to the Serengeti Research Institute in Tanzania, applied this approach to African plains game. His best-known books are The Study of Instinct (1951); The Herring Gull's World (1953, rev. ed. 1961). He was named a fellow of the Royal Society in 1962 and a foreign fellow of the Netherlands Academy of Sciences in 1964.