Emperor penguins may be cute polar mascots, but they have a secret habit of child-snatching. It’s been observed that when emperor penguins’ nests fail, for whatever reason (life is hard in the Antarctic), some parents will seek out a new, replacement chick. Since penguins nest in colonies, this means they will “kidnap”–or “adopt”, depending on one’s point of view–a chick from another nest and begin to care for it, much to the chagrin of the neighboring parents . Researchers suggest that this is likely due to high levels of prolactin in the penguins . Prolactin is a hormone that drives parental care behaviors in birds and other animals. In many species, prolactin decreases when parental effort declines. However, prolactin can stay high in penguins, which may lead them towards others’ chicks after the loss of their own nestling.
- Jouventin P, Barbraud C, Rubin M. (1995). Adoption in the emperor penguin, Aptenodytes fosteri. Animal Behavior, 50(4):1023-1029. doi: 10.1016/0003-3472(95)80102-2
- Angelier F, Barbraud C, Lormée H, Prud’hom F, Chastel O. (2006) Kidnapping of chicks in emperor penguins: a hormonal by-product? Journal of Experimental Biology, 209:1413-1420. doi: 10.1242/jeb.02138