when was animal behavior first discovered

The scientific study of animal behavior, known as ethology, has roots going back to ancient times, but it was formally initiated as a scientific discipline in the 19th century. Early influential work began with Charles Darwin in the mid-1800s, who published "On the Origin of Species" in 1859 and later studied animal instincts and expression of emotions in animals in 1872. Darwin's work laid the foundation for understanding behavior through the lens of natural selection and evolution. Throughout the late 19th and early 20th centuries, various scientists studied animal behavior, often focusing on learning and instincts. In the 1930s and beyond, ethologists like Konrad Lorenz, Nikolaas Tinbergen, and Karl von Frisch emerged, developing ethology more fully as a biological science of animal behavior, emphasizing observations of animals in natural environments. This field gained enormous strength when Lorenz, Tinbergen, and von Frisch were awarded the Nobel Prize in Physiology or Medicine in 1973 for their pioneering work in ethology. Thus, while fascination and informal study of animal behavior have existed since antiquity, the formal scientific discovery and study of animal behavior began in earnest during the 19th century with Darwin and culminated as a distinct scientific field by the mid-20th century through the efforts of key ethologists.