Imprint learning refers to learning behaviors that occur in the early stages of animal life and are formed by direct impressions. Although imprint learning behaviors occur early, they also have a certain impact on later behaviors. According to the above definitions, which of the following is not imprinted learning behaviors? ['The sheep approaches and tries to stay with the owner who has fed it.', 'Zebra finches fed by people will court their fingers.', 'Ewe marks her offspring with tongue lamb.', 'A newborn mallard follows a moving object.']