HABITUATION AND IMPRINTING
Habituation is a type of learning that enables an animal to ignore irrelevant stimuli. When an animal is repeatedly shown a harmless stimulus, the animal eventually learns to ignore that stimulus. When a nestling bird sees a shadow passing overhead, it first hides in fear of a raptor flying over. In time, the young bird learns that some shadows come from its parent flying back to feed it, and some shadows are simply nonthreatening. Certainly, ignoring unimportant stimuli is of critical importance. Can you think of examples of habituation from your day-to day life or the life of a pet?

Imprinting is a form of social learning that occurs during a critical period, most often occurring soon after birth or hatching. Ethologist Konrad Lorenz showed that newly hatched birds imprint on the first moving object seen after hatching. At one point, Lorenz raised ducks, and they imprinted on him, following him as they would a mother duck. The imprinting period of time is species-specific. In mallard ducks, imprinting must occur less than 24 hours after birth.

Can you imagine what implications imprinting may have on programs in which humans hand-raise endangered species? Would zoo-raised, endangered whooping cranes imprint on humans?