Rockhopper penguin 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
Bird vocalization and prevent an energetically costly fight . In birds with song repertoires, individuals may share the same song type and use these song types for more complex communication. Some birds will respond to a shared song type with a song-type match (i.e. with the same song type). This may be an aggressive signal, however results are mixed. Birds may also interact using repertoire-matches, wherein a bird responds with a song type that is in its rival's repertoire but is not the song that it is currently singing. This may be a less aggressive act than song-type matching. Communication through bird