Konrad Lorenz was an Austrian zoologist, ethologist, and ornithologist, born in 1903. He is known for his groundbreaking work on animal behavior and imprinting. Lorenz studied instincts in animals and their social behavior, particularly in geese. He won the Nobel Prize in Physiology or Medicine in 1973. His work laid the foundation for the field of ethology, the study of animal behavior in their natural environments. Lorenz's research significantly influenced our understanding of animal behavior and the concept of critical periods in development.