Editing Rockhopper penguin

{{Short description|Common name for a type of bird}}
[[File:FAL-2016-New Island, Falkland Islands-Rockhopper penguin (Eudyptes chrysocome) 05.jpg|thumb|[[Southern rockhopper penguin]], ''Eudyptes (chrysocome) chrysocome'', [[New Island]], [[Falkland Islands]]]]

The '''rockhopper penguins''' are three closely related [[taxa]] of [[crested penguin]]s 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.

==Appearance==
Rockhopper penguins (Eudyptes chrysocome) are among the smaller species of penguin. After reaching full growth, they are about 20 inches or 50 centimetres in height.<ref name=NatGeo>{{cite web|url=http://animals.nationalgeographic.com/animals/birds/rockhopper-penguin/|archive-url=https://web.archive.org/web/20101005012834/http://animals.nationalgeographic.com/animals/birds/rockhopper-penguin/|url-status=dead|archive-date=October 5, 2010|title=Rockhopper Penguin|work=National Geographic|date=9 November 2010}}</ref> Males and females cannot be distinguished visually, so a DNA test is conducted by taking a feather from the bird to determine its gender.<ref name=Bond>{{cite web|url=http://a-z-animals.com/animals/rockhopper-penguin/|title=Rockhopper Penguin}}</ref> Like many penguins, rockhopper penguins have a white belly and the rest of their body is black.<ref name=Bond/> 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.<ref name=NatGeo/><ref name=AuGov/> Although their yellow and black spiky feathers differentiate them from other penguins, rockhopper penguin chicks do not have them; these feathers develop with age.<ref name=AuGov/> Their orange beak is initially black, but as the penguins get older, their beaks turn orange.<ref name=AuGov/> 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, hence their name.<ref name=Bond/>

The yellow and black ‘hair’ they have on the top of their head is similar to that of the Macaroni penguin (Eudyptes chrysolophus).

==Subspecies==
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.<ref>Jouventin, P. P., Cuthbert, R. J., & Ottvall, R. R. (2006). Genetic isolation and divergence in sexual traits: evidence for the northern rockhopper penguin ''Eudyptes moseleyi'' being a sibling species. Molecular Ecology, 15(11), 3413-3423. doi:10.1111/j.1365-294X.2006.03028.x</ref>

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 and McDonald Islands|Heard Island]], [[Macquarie Island]] and [[Campbell Island, New Zealand|Campbell]], [[Auckland Islands|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.<ref>Baylis, A., Wolfaardt, A., Crofts, S., Pistorius, P., & Ratcliffe, N. (2013). Increasing trend in the number of Southern Rockhopper Penguins (Eudyptes c. chrysocome) breeding at the Falkland Islands. Polar Biology, 1007-1018.
</ref>

The subspecies in the group are:

* [[Southern rockhopper penguin]], ''Eudyptes (chrysocome) chrysocome''
* [[Eastern rockhopper penguin]], ''Eudyptes (chrysocome) filholi''
* [[Northern rockhopper penguin]], ''Eudyptes (chrysocome) moseleyi''

==Habitat and distribution==
[[File:Rockhopper penguin.jpg|thumb|Rockhopper penguin skeleton in [[Manchester Museum]]]]
Northern rockhopper penguins breed in cool temperate climates including on the islands of [[Gough Island|Gough]] and [[Tristan da Cunha]] in the Atlantic Ocean and [[Saint Paul and Amsterdam Islands]] in the Indian Ocean. The southern rockhopper breeds on the [[Falkland Islands]], Argentina and Chile, with breeding colonies around Cape Horn in South America, and [[Gough Island|Gough]], Prince Edward, [[Marion Island|Marion]], [[Crozet Island|Crozet]], [[Kerguelen Island|Kerguelen]], Heard, Macquarie, [[Campbell Island, New Zealand|Campbell]], Auckland and Antipodes Islands in the southern Indian Ocean. Eastern rockhopper penguins are mostly found breeding on Campbell Island in New Zealand, but their numbers have declined immensely. <ref>Rockhopper Penguin: Eudyptes chrysocome. (n.d.). Retrieved October 24, 2014.</ref> Rockhopper penguins usually make their habitat in rocky shorelines. They make nests and burrows in tall grasses called [[Tussock (grass)|tussock]]s.

==Diet==
The rockhopper penguin's diet consists of krill and small crustaceans, which may include shrimp, crabs, lobsters or crayfish.<ref name=Bond/> They also eat squid and  myctophid fish.<ref name=Bond/><ref name=AuGov>{{cite web|url=http://www.antarctica.gov.au/about-antarctica/wildlife/animals/penguins/rockhopper-penguins|title=Rockhopper penguins}}</ref> Rockhopper penguins consume more krill than they do fish; their diet changes during migration and as the seasons change.<ref name=AuGov/> Rockhopper penguins can be at sea for several days while hunting. They can dive up to {{convert|330|ft|m}} for many minutes at a time while searching for prey.<ref name=Bond/>

==Reproduction==
[[File:FAL-2016-New Island, Falkland Islands-Rockhopper penguin (Eudyptes chrysocome) 02.jpg|thumb|Rockhopper penguin with chicks, New Island, Falkland Islands]]
Rockhoppers are the most widespread crested penguins.<ref name=Hull>Hull, C., Hindell, M., Mar, K., Scofield, P., Wilson, J., & Lea, M. (n.d.). The breeding biology and factors affecting reproductive success in rockhopper penguins Eudyptes chrysocome at Macquarie Island. Polar Biology, 711-720.</ref> Their range goes from the Antarctic front to the South Atlantic and Indian Oceans.<ref name=Hull/> Because of how widespread they are, breeding varies among the penguins in different areas. Northern Penguins begin the mating process two months earlier than Southern ones.<ref name=Jouventin>Jouventin, P., Cuthbert, R., & Ottvall, R. (n.d.). Genetic isolation and divergence in sexual traits: Evidence for the northern rockhopper penguin Eudyptes moseleyi being a sibling species. Molecular Ecology, 3413-3423.</ref> Two eggs are usually laid a few days apart during early November in hope that at least one will survive, and the second egg is usually larger than the first. They will use the same nest as they did in previous years as well. Eggs hatch about a month later and the mother will have food for the chick.<ref name=Bingham>Bingham, M. (n.d.). Rockhopper Penguin</ref>

==Taxonomy==
There are currently 19 species and six genera of living penguins. The rockhopper penguin has 3 subspecies: ''Eudyptes filholi'', the Eastern Rockhopper; ''Eudyptes mosleyi'', the Northern Rockhopper; and the ''Eudyptes chrysocome'', the Southern Rockhopper. They are separated by their locations of breeding. There are four other species in the genus ''Eudyptes'': ''E. pachyrhynchus'', ''E. robustus'', ''E. chrysolophus'', and ''E. schlegeli''.<ref>Ksepka, D. (2010, January 30). Family Tree of the Living Penguins. Retrieved October 23, 2014.</ref> The three subspecies of the rockhopper penguin are believed to have split up because of latitude and watermasses rather than because of geographic distances. Research suggests that during the early Pleistocene, the Southern Ocean was cold and rockhopper populations from the Atlantic and Indian Oceans remained undifferentiated and lived in the same watermass. The mid-Pleistocene climatic transition was associated with the southward migration of frontal positions and islands became surrounded by subtropical water masses, resulting in a split between Northern and Southern rockhopper penguins. Many advance and retreat cycles of Patagonian icecaps during the late Pleistocene may have created a barrier to gene flow between Southern Pacific and Southern Atlantic populations, causing a split between Southern and Eastern rockhopper populations.<ref>de Dinechin, M., Ottvall, R., Quillfeldt, P., & Jouventin, P. (2009). Speciation chronology of rockhopper penguins inferred from molecular, geological and palaeoceanographic data. Journal of Biogeography, 36(4), 693-702. doi:10.1111/j.1365-2699.2008.02014.x</ref>

==Predators==
Adult Rockhopper penguins have no land-based predators. They are eaten when at sea by [[leopard seal]]s, [[fur seal]]s, [[killer whale]]s and [[blue shark]]s.<ref>{{Cite web|url=https://penguin-pedia.com/penguin-species/rockhopper-penguins/|title=Rockhopper Penguins|website=Penguin Pedia|language=en-US|access-date=2019-07-03}}</ref> Chicks and eggs are eaten by many birds including [[giant petrel]]s, [[skua]]s, [[sheathbill]]s and various types of [[gull]]s.{{citation needed|date=June 2019}}

==Conservation==
Although the rockhopper penguin is one of the world's most numerous penguin populations, it is estimated that the population declined by some 30 percent over the final 30 years of the 20th century.<ref name="NatGeo"/> The cause of this decline is mainly unknown, but scientists have speculated that humans are involved, mostly by commercial overfishing, oil exploitation, and pollution.<ref name="NatGeo"/> Recent research has shown that rockhopper penguin population declines with changes in ocean surface temperature, indicating a direct impact from climate change.<ref name="Dehnhard, N. 2013">Dehnhard, N., Poisbleau, M., Demongin, L., Ludynia, K., Lecoq, M., Masello, J., & Quillfeldt, P. (2013). Survival of rockhopper penguins in times of global climate change. Aquatic Conservation: Marine and Freshwater Ecosystems, 23(5), 777-789. Retrieved October 23, 2014, from Wiley Online Library.</ref> These activities have depleted much of the rockhopper penguin's food supply and raised the [[sea surface temperature]]s, and because this species is geographically isolated to the tip of South America and the Falkland Islands and is very sensitive to food web changes, there is little foreseeable opportunity for the penguins to recover.<ref name="Dehnhard, N. 2013"/><ref>Hilton, G., Thompson, D., Sagar, P., Cuthbert, R., Cheryl, Y., & Bury, S. (2006). A stable isotopic investigation into the causes of decline in a sub-Antarctic predator, the rockhopper penguin Eudyptes chrysocome. Global Change Biology, 2006(12), 611-625. Retrieved October 23, 2014, from Web of Science.</ref>

=== Oil spills ===
An oil spill followed the grounding of the [[MS Oliva|MS ''Oliva'']] off Nightingale Island in 2011, which resulted in thousands of Rockhopper penguins becoming oiled. Oil spills have [[List of oil spills impacting penguins|impacted many penguin species]] since the conversion of shipping from sail and coal propulsion to liquid-based fuels in the early 20th century.

==Gallery==
<gallery>
File:Gorfou sauteur - Rockhopper Penguin.jpg| [[Southern rockhopper penguin]], ''Eudyptes (chrysocome) chrysocome''
File:Eudyptes moseleyi -Zoologischer Garten Berlin, Germany-8a.jpg| [[Northern rockhopper penguin]], ''Eudyptes (chrysocome) moseleyi''
File:MacquarieIslandRockhoppers.JPG| [[Eastern rockhopper penguin]], ''Eudyptes (chrysocome) filholi''
</gallery>

==In films==
Rockhoppers are seen in the films, ''[[The Pebble and the Penguin]]'', ''[[Happy Feet]]'' and ''[[Happy Feet 2]]'', ''[[Surf's Up (film)|Surf's Up]]'' and ''[[Surf's Up 2: WaveMania]]'', and ''[[The Wild]]''.

==See also==
* [[Rockhopper (disambiguation)|Rockhopper]]
* [[Macaroni penguin]]
* [[Northern rockhopper penguin]]

==References==
{{reflist|30em}}

== External links ==
{{wiktionary|rockhopper penguin}}
{{Commons|Eudyptes chrysocome}}
* [https://www.penguinworld.com/types/rockhopper.html Rockhopper penguin on PenguinWorld]

[[Category:Penguins]]
[[Category:Flightless birds]]