Penguins Strike Back: A Report on the Unusual Case of Adélie Penguin (Pygoscelis adeliae) Attacks on South Polar Skua Nests Distant from the Breeding Colony

In Antarctica, penguins aggressively defend their territory from skuas in order to guard their offspring, since skuas frequently prey on penguins’ eggs or chicks [3,4,5]. [...]it has been reported that the degree of agonistic behavior was high around the nests and decreased when they were far from the colony [4,5]. [...]the egg trampling might be an accidental event, which is supported by the successful fledging of all the skua offspring except for the egg broken by the penguins. Only one skua egg was lost in the three nests, and we confirmed that all of the other eggs and chicks fledged with success. [...]the egg loss by Adélie penguins seems to be unintended, and our observation is an interesting case of showing aggression to the predator regardless of the prey’s reproduction.