Danaus erippus, the southern monarch, is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. It is one of the best known butterflies in South America. Its genome is nearly identical to D. plexippus, but the two are incompatible, and therefore considered separate species.
Though, not as well known as the eastern North American monarch migratory phenomenon, it has been observed to move in a consistent spring/autumn manner by flying south in the autumn towards colder latitudes for the winter.Massive overwintering roosts have not yet been found.