Konrad Lorenz was an Austrian zoologist and ethologist, renowned for his foundational work in the field of animal behavior, particularly imprinting. His studies on the behavior of young animals, including geese and ducks, established the concept of critical periods for learning and demonstrated how certain behaviors are innate and occur in response to specific stimuli. Lorenz's contributions help us understand both the proximate mechanisms of behavior and the ultimate evolutionary functions that such behaviors serve.