Lorenz, Konrad Zacharias, LOH rehnts, KOHN raht tsah kah REE ahs (1903-1989), an Austrian naturalist, was one of the founders of ethology, the study of animal behavior. Lorenz and two other ethologists--Karl von Frisch of Austria and Nikolaas Tinbergen, born in the Netherlands--received the 1973 Nobel Prize for physiology or medicine for their work on animal behavior.