Rockhopper penguin

The rockhopper penguins are three closely related taxa of crested penguins that have been traditionally treated as a single species and are sometimes split into three species.

Not all experts agree on the classification of these penguins. Some consider all three as distinct species, some split the western and eastern forms into the southern rockhopper penguin and keep the northern rockhopper as distinct, while other experts consider all three potential varieties to be one species.