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 two or 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.

Rockhopper penguins are one of the smallest species of penguin in the world. They range from 2.3-2.7 kg where males are larger than females. After reaching full growth, they are about 20 inches in height. Males and females cannot be distinguished just by looks, so a DNA test is conducted by taking a feather from the bird to determine its sex. Like many penguins, rockhopper penguins have a white belly and the rest of their body is black. Some characteristics that differentiate them from the other penguins are their red eyes, orange beak, pink webbed feet, and the yellow and black spiky feathers they have on their head. Although their yellow and black spiky feathers differentiate them from other penguins, rockhopper penguin chicks do not have them; these feathers develop with age. Their orange beak is initially black, but as the penguins get older, their beaks turn orange. Due to the harsh rocky environment, they cannot slide on their bellies like most penguins, so they hop to get from one place to another.

What separates rockhopper penguins into subspecies is their location of reproduction and reproductive behaviors. The difference in mating signals found between the subspecies E. chrysocome (southern) and E. moseleyi (northern) seems to have occurred quickly, thus these behavioral changes are enough to isolate these taxa.

Southern Rockhopper penguins are split into two subspecies and they are defined by their location of reproduction. The subspecies E. c. filholi (eastern) is known to reproduce in the sub-Antarctic around the Prince Edward Islands, Crozet Islands, Kerguelen Islands, Heard Island, Macquarie Island and Campbell, Auckland and Antipodes Islands. The subspecies E. c. chrysocome, which may be referred to the true southern subspecies, reproduces at offshore islands in southern Chile, Argentina and at the Falkland Islands. The Falkland Islands are known to have one of the largest populations of Southern Rockhopper penguins.

...
Wikipedia