Northern rockhopper penguin Island in the south Atlantic Ocean. The rockhopper penguin was split into three distinct subspecies in 1992; the southern, ("E. c. chrysocome"), eastern ("E. c. filholi") and northern rockhopper penguin ("E. c. moseleyi"). The three subspecies are distinguished by differences in the length of the tassels of the crests, the size and colour of the fleshy margin of the gape, colour pattern on the underside of the flipper and differences in the size of the supercilliary stripe in front of the eye. Additionally, the northern rockhopper penguin is larger than the other two subspecies. Proof that the three subspecies were
Northern rockhopper penguin drop in the population at Gough Island has been described as equivalent to the loss of 100 birds every day since the 1950s. A study published in 2009 showed that the world population of the northern rockhopper had declined by 90% since the 1950s, possibly because of climate change, changes in marine ecosystems and overfishing for squid and octopus by humans. Other possible factors in the decline include disturbance and pollution from ecotourism and fishing, egg-harvesting, and predation and competition from subantarctic fur seals ("Arctocephalus tropicalis"). Surveys show that the birds are at risk of infection by goose barnacles. House