Northern rockhopper penguin colonies in a range of locations from sea level or on cliff sides, to sometimes inland. The Northern form, found in Amsterdam and Gough island, is reproductively isolated from the Crozet and Kerguelen islands. They are monophyletic; meaning they have a split in the mitochondria DNA trees which forms two subspecies: the northern and southern rockhopper penguin. Another interesting difference between the two subspecies is their mating ritual. They both use different songs and head ornaments in their mating signals. The reproductive isolation has led to not only physical difference but also behavioral. The adults feed their chicks lower trophic
The Bird Lover the lai develops somewhat differently: instead of a happy ending, the lai ends in tragedy. A "sophisticated rationalization" of the type is found in Chrétien de Troyes's "Lancelot, the Knight of the Cart", where Lancelot appears at Guinevere's heavily barred window and cuts his fingers bending the bars back. In French scholarship, this type is often referred to as ""loiseau bleu"" or "the blue bird", so named for a story by Madame d'Aulnoy. The Bird Lover The Bird Lover, also known as The Prince as Bird, is a type of narrative structure in folklore, no. 432 in the Aarne–Thompson classification