Ontogeny
In two independent studies conducted into the frequency and cause of kidnapping, only adult penguins that had already bred were observed to kidnap chicks. These results suggest that kidnapping develops along with typical parental behaviors, such as locating and caring for the chick. Emperor penguins become independent within a year from birth, and begin mating at the age of 4-8 years. While kidnapping behavior is not uncommon among the Emperor Penguins, juveniles and sub-adults display no parental behavior, but no kidnapping either.
