Kea

Kea is the native (New Zealand) name for a genus of parrots, of which only three species are known; these are Nestor notabilis, N. meridionalis, and N. productus, which last appears to have just become extinct. N. notabilis is a mountain species, confined to the South Island; it was originally a vegetable and insect feeding bird, but on the introduction of sheep it began to frequent the stations and to feed on offal; later on the parrot acquired the more objectionable habit of destroying live sheep. A number of birds band themselves together and hunt out a weakly member of a flock, generally at night. The sheep is worried to death by the combined efforts of the parrots, which then proceed to devour the kidney fat. This is one of the most remarkable instances known of a rapid change of habit.