Immediately after hatching, if baby ducklings see a large object move past them, they will follow the object as though it were their mother, regardless of what the object actually is. It could be a duck, a cardboard box pulled by a string, or even, in the most famous case, Austrian zoologist and ethologist Konrad Lorenz (1903–1989). Lorenz discovered that ducklings come into the world with an instinctive drive to follow the ﬁrst thing that passes by. When a large object or creature appears before them, it triggers this instinctive response, known as imprinting. Imprinting more generally occurs when an animal learns something very fast because a certain event occurring at the right time triggers the learning process.
Lorenz was the originator of the science of ethology, or the study of genetic sources of group and individual behavior patterns, for which he won a Nobel Prize in Physiology. Imprinting is a special case of a more general category of instinctive responses that he discovered, called innate release mechanisms. In his studies of ﬁsh and birds, he found that organisms are often genetically predisposed to be especially responsive to certain stimuli. The duck’s tendency to follow any large moving object that happens by at the right moment is just one well-documented example of this. Another is the behavior of the male stickleback, a small ﬁghting ﬁsh. A male stickleback will attack any other male stickleback that approaches his nest in a manner identical to the way every stickleback attacks. Furthermore, it will attack anything that resembles another male stickleback, even a paper model, as long as it displays the distinctive red spot that all male sticklebacks bear. In the case of both the ducks and the sticklebacks, the advantage of this mechanism to the animal is fairly clear. A complex behavior pattern occurs without any learning.
- Lorenz, K. The Foundations of Ethology. New York: Springer-Verlag, 1981.