Editing Western rockhopper penguin

{{Short description|Species of bird}}
{{Use mdy dates|date=September 2021}}
{{speciesbox
| fossil_range = [[Pleistocene]] to recent<ref>{{cite web | url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=173571 | title=Fossilworks: Eudyptes chrysocome }}</ref>
| image = Gorfou sauteur - Rockhopper Penguin.jpg
| image_caption = Adult in the [[New Island]] ([[Falkland Islands]]) rookery
| status = VU
| status_system = IUCN3.1
| status_ref =<ref name=IUCN>{{cite iucn |author=BirdLife International |date=2020 |title=''Eudyptes chrysocome'' |page=e.T22735250A182762377 |doi=10.2305/IUCN.UK.2020-3.RLTS.T22735250A182762377.en |access-date=20 February 2022}}</ref>
| genus = Eudyptes
| species = chrysocome
| authority = ([[Johann Reinhold Forster|Forster, JR]], 1781)
| synonyms =
*''Aptenodytes chrysocome'' <small>J.R.Forster,&nbsp;1781</small>
*''Aptenodytes crestata'' <small>J.F. Miller,&nbsp;1784</small>
*''Eudyptes crestatus'' <small>(J.F. Miller,&nbsp;1784)</small>
| subdivision_ranks = Subspecies
| subdivision = See text:
* ''E. c. chrysocome'' – Western
* ''E. c. filholi'' – Eastern
| range_map = Appearance Eudyptes chrysochome.png
| range_map_caption = Distribution map rockhopper penguins<br />Green: western subspecies, blue: eastern subspecies
}}

The '''western rockhopper penguin''' ('''''Eudyptes chrysocome'''''), traditionally known as the '''southern rockhopper penguin''', is a [[species]] of [[rockhopper penguin]] that is sometimes considered distinct from the [[northern rockhopper penguin]]. It occurs in [[subantarctic]] waters of the western Pacific and Indian Oceans, as well as around the southern coasts of South America. It was formerly considered to be [[conspecific]] with the [[eastern rockhopper penguin]] (''Eudyptes filholi'').

==Taxonomy==
In 1743 the English naturalist [[George Edwards (naturalist)|George Edwards]] included an illustration and a description of the western rockhopper penguin in the first volume of his ''A Natural History of Uncommon Birds''. Edwards based his hand-coloured etching on a preserved specimen owned by [[Peter Collinson (botanist)|Peter Collinson]].<ref>{{ cite book | last=Edwards | first=George | author-link=George Edwards (naturalist) | year=1751 | title=A Natural History of Uncommon Birds | place=London | publisher=Printed for the author at the College of Physicians | volume=Part 1 | page=49, Plate 49 | url=https://www.biodiversitylibrary.org/page/50240695 }}</ref> When in 1758 the Swedish naturalist [[Carl Linnaeus]] updated his ''[[Systema Naturae]]'' for the [[10th edition of Systema Naturae|tenth edition]], he placed the western rockhopper penguin with the [[red-billed tropicbird]] in the [[genus]] ''[[Phaethon]]''. Linnaeus included a brief description, coined the [[binomial name]] ''Phaethon demersus'' and cited Edwards' work.<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1758 | title= Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis | volume=1 | edition=10th | page=135 | publisher=Laurentii Salvii | place=Holmiae (Stockholm) | language=la | url=https://www.biodiversitylibrary.org/page/727040 }}</ref> The use of Linnaeus' binomial name was not adopted by later ornithologists, perhaps because he had already used the specific ''demersa'' for the [[African penguin]] which he placed with the [[wandering albatross]] in the genus ''[[Diomedea]]''.<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1758 | title= Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis | volume=1 | edition=10th | page=132 | publisher=Laurentii Salvii | place=Holmiae (Stockholm) | language=la | url=https://www.biodiversitylibrary.org/page/727037 }}</ref><ref>{{ cite journal | last=Allen | first=J.A. | author-link=Joel Asaph Allen | year=1904 | title=The case of ''Megalestris'' vs. ''Catharacta'' | journal=The Auk | volume=21 | issue=3 | pages=345–348 [346, Footnote 1]| url=https://biodiversitylibrary.org/page/15936080 | doi=10.2307/4070197 | jstor=4070197 | hdl=2027/hvd.32044107327124 }}</ref>

The western rockhopper penguin was [[species description|formally described]] in 1781 by the German naturalist [[Johann Reinhold Forster]] under the binomial name ''Aptenodytes chrysocome''.<ref>{{ cite journal | last=Forster | first=Johann Reinhold | author-link=Johann Reinhold Forster | date=1780 | title=Historia Aptenodytae. Generis Avium orbi Australi proprii | language=Latin | journal=Commentationes Societatis Regiae Scientiarum Gottingensis | volume=3 | pages=121–148 [133, 135] | url=https://archive.org/details/s4id13296820/page/n184/mode/1up }} Although the volume is dated 1780, the article was not published until 1781.</ref> The species is now placed in the genus ''[[Eudyptes]]'' that was introduced by the French ornithologist [[Louis Pierre Vieillot]] in 1816.<ref>{{cite book | last=Vieillot  | first=Louis Pierre | author-link=Louis Pierre Vieillot | year=1816 | title=Analyse d'une Nouvelle Ornithologie Élémentaire| publisher=Deterville/self |  location=Paris | pages=67, 70 | language=French| url=https://gallica.bnf.fr/ark:/12148/bpt6k9745205x/f73.item }}<!--BHL has a scan of an 1883 reprint - same pagination http://biodiversitylibrary.org/page/12830237 --> The genus name is misspelled as ''Endyptes'' on page 67.</ref><ref name=ioc>{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | editor3-last=Rasmussen | editor3-first=Pamela | editor3-link=Pamela C. Rasmussen | date=February 2025 | title=Kagu, Sunbittern, tropicbirds, loons, penguins | work=IOC World Bird List Version 15.1 | url=https://www.worldbirdnames.org/bow/loons/ | publisher=International Ornithologists' Union | access-date=19 March 2025 }}</ref> The genus name combines the [[Ancient Greek]] {{Transliteration|grc|eu}} meaning "fine" with {{Transliteration|grc|dyptes}} meaning "diver". The specific epithet ''chrysocome'' is from the Ancient Greek {{Transliteration|grc|khrusokomos}} meaning "golden-haired" (from {{Transliteration|grc|khrusos}} meaning "gold" and {{Transliteration|grc|komē}} meaning "hair").<ref>{{cite book | last=Jobling | first=James A. | year=2010| title=The Helm Dictionary of Scientific Bird Names | publisher=Christopher Helm | location=London | isbn=978-1-4081-2501-4 | pages=[https://archive.org/stream/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling#page/n152/mode/1up 152], [https://archive.org/stream/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling#page/n105/mode/1up 105] }}</ref> The species is [[monotypic]]: no [[subspecies]] are recognised.<ref name=ioc/>

The rockhopper penguin complex is confusing. Many taxonomists consider all three rockhopper penguin forms [[subspecies]]. Some split the northern subspecies (''moseleyi'') from the southern forms (''chrysocome'' and ''filholi''). Still others consider all three distinct. The subspecies recognized for the western rockhopper penguin complex are:<ref name=IUCN/>
* ''Eudyptes chrysocome chrysocome'', the '''western rockhopper penguin''' or '''American southern rockhopper penguin'''  – breeds around the southern tip of South America.
* ''Eudyptes chrysocome filholi'', the '''[[eastern rockhopper penguin]]''' or '''Indopacific southern rockhopper penguin'''  – breeds on subantarctic islands of the Indian and western Pacific oceans.

The [[northern rockhopper penguin]] lives in a different water mass from the western and eastern rockhopper penguin, separated by the [[Subtropical Front]], and they are genetically different. Therefore, northern birds are sometimes separated as ''E.&nbsp;moseleyi''. The rockhopper penguins are closely related to the [[macaroni penguin]] (''E.&nbsp;chrysolophus'') and the [[royal penguin]] (''E.&nbsp;schlegeli''), which may just be a colour [[morph (zoology)|morph]] of the macaroni penguin.

Interbreeding with the macaroni penguin has been reported at Heard and Marion Islands, with three hybrids recorded there by a 1987–88 Australian National Antarctic Research Expedition.<ref>{{cite journal|doi=10.1071/MU9900198|last1=Woehler |first1=E. J.|year=1990|last2=Gilbert|first2=C. A.|title=Hybrid Rockhopper-Macaroni Penguins, interbreeding and mixed-species pairs at Heard and Marion Islands|journal=[[Emu (journal)|Emu]] |volume=90 |issue=3 |pages=198–210|bibcode=1990EmuAO..90..198W }}</ref>

==Description==
[[Image:Falkland Islands Penguins 88.jpg|thumb|left|Western rockhopper penguin (''Eudyptes chrysocome'') displaying its distinctive crest]]

This is the smallest yellow-crested, black-and-white penguin in the genus ''Eudyptes''. It reaches a length of {{convert|45|-|58|cm|in|abbr=on}} and typically weighs {{convert|2|-|3.4|kg|lb|abbr=on}}, although there are records of exceptionally large rockhoppers weighing {{convert|4.5|kg|lb|abbr=on}}.<ref name="encyclopedia">{{cite book |title=Antarctica: an encyclopedia from Abbot Ice Shelf to Zooplankton |first=Mary |last=Trewby |year=2002 |publisher=Firefly Books |location=Auckland, New Zealand |isbn=978-1-55297-590-9 |page=152}}</ref> It has slate-grey upper parts and has straight, bright yellow eyebrows ending in long yellowish plumes projecting sideways behind a red eye.<ref name="encyclopedia" />

==Ecology==
[[File:Rockhopper-Colony.jpg|thumb|right|''Eudyptes chrysocome chrysocome'' colony on [[Saunders Island, Falkland Islands]]]]
The western rockhopper penguin group has a global population of roughly 1&nbsp;million pairs. About two-thirds of the global population belongs to ''E.&nbsp;c. chrysocome'', which breeds on the [[Falkland Islands]] and on islands off [[Patagonia]].<ref>{{Cite journal |last1=Mays |first1=Herman L |last2=Oehler |first2=David A |last3=Morrison |first3=Kyle W |last4=Morales |first4=Ariadna E |last5=Lycans |first5=Alyssa |last6=Perdue |first6=Justin |last7=Battley |first7=Phil F |last8=Cherel |first8=Yves |last9=Chilvers |first9=B Louise |last10=Crofts |first10=Sarah |last11=Demongin |first11=Laurent |last12=Fry |first12=W Roger |last13=Hiscock |first13=Jo |last14=Kusch |first14=Alejandro |last15=Marin |first15=Manuel |date=2019-12-17 |editor-last=Jackson |editor-first=Jennifer |title=Phylogeography, Population Structure, and Species Delimitation in Rockhopper Penguins ( Eudyptes chrysocome and Eudyptes moseleyi ) |url=https://academic.oup.com/jhered/article/110/7/801/5583958 |journal=Journal of Heredity |language=en |volume=110 |issue=7 |pages=801–817 |doi=10.1093/jhered/esz051 |issn=0022-1503 |pmc=7967833 |pmid=31737899}}</ref> These include most significantly [[Isla de los Estados]], the [[Ildefonso Islands]], the [[Diego Ramírez Islands]] and [[Isla Noir]]. ''E.&nbsp;c. filholi'' breeds on the [[Prince Edward Islands]], the [[Crozet Islands]], the [[Kerguelen Islands]], [[Heard Island]], [[Macquarie Island]], [[Campbell Island, New Zealand|Campbell Island]], the [[Auckland Islands]] and the [[Antipodes Islands]]. Outside the breeding season, the birds can be found roaming the waters offshore their colonies.<ref name=BLIb>[[BirdLife International]] (2008). [http://www.birdlife.org/action/science/species/global_species_programme/whats_new.html [2008 IUCN Redlist status changes&#93;]. Retrieved May 23, 2008.</ref>

These penguins feed on [[krill]], [[squid]], octopus, [[lantern fish]], [[mollusk]]s, [[plankton]], [[cuttlefish]], and mainly [[crustacean]]s.

A rockhopper penguin, named Rocky, in [[Bergen Aquarium]] in Norway lived to 29 years 4 months. It died in October 2003. This stands as the age record for rockhopper penguins, and possibly it was the oldest penguin known.<ref>Glenday, Craig (ed.) (2008). ''Guinness World Records 2008''. Guinness Media, Inc. {{ISBN|1-904994-19-9}}</ref>

==Behaviour==
[[File:Falkland Islands Penguins 91.jpg|thumb|left|''E. c. chrysocome'' on [[Saunders Island, Falkland Islands]] hopping over a crack]]
Their common name refers to the fact that, unlike many other penguins, which get around obstacles by sliding on their bellies or by awkward climbing using their flipper-like wings as aid, rockhoppers will try to jump over boulders and across cracks.<ref name="encyclopedia"/>

This behaviour is by no means unique to this species however – at least the other "crested" penguins of the [[genus]] ''[[Eudyptes]]'' hop around rocks too. But the rockhopper's [[Conspecificity|congener]]s occur on remote islands in the New Zealand region, whereas the rockhopper penguins are found in places that were visited by explorers and [[whaler]]s since the [[Early Modern era]]. Hence, it is this particular species in which this behaviour was first noted.

[[File:Gorfou sauteur MHNT.jpg|thumb|Egg]]
[[File:Rockhopper Penguin Chick (5582542129).jpg|thumb|A chick on the [[Saunders Island, Falkland Islands|Saunders Island]] in the [[Falkland Islands]]]]
Their breeding colonies are located from sea level to cliff-tops and sometimes inland. Their breeding season starts in September and ends in November.<ref name="encyclopedia" /> Two eggs are laid but only one is usually incubated.<ref name="encyclopedia" /> Incubation lasts 35 days and their chicks are brooded for 26 days.

===Variation in foraging behaviour===
Rockhopper penguins are known to have complex foraging behaviors. Influenced by factors such as sea ice abundance, prey availability, breeding stage, and seasonality, rockhopper penguins must be able to adapt their behavior to fit the current conditions.<ref name="Tremblay & Cherel 2003">{{cite journal |last1=Tremblay|last2=Cherel|first1=Yann|first2=Yves|title=Geographic variation in the foraging behaviour, diet and chick growth of rockhopper penguins |journal=Marine Ecology Progress Series|year=2003 |volume=251|pages=279–297|doi=10.3354/meps251279|bibcode=2003MEPS..251..279T|doi-access=free}}</ref> Rockhopper penguins employ different strategies according to their conditions. When making foraging trips, rockhoppers typically leave and return to their colonies in groups. One study showed they are known for going up to {{convert|157|km|||abbr=on}} away from their colonies when foraging.<ref name="Brown 1987">{{cite journal |last1=Brown |first1=Christopher |title=Traveling Speed and Foraging Range of Macaroni and Rockhopper Penguins at Marion Island (Velocidad de Movimiento y Extensión de las Áreas de Forrajeo de los Pingüinos Eudyptes chrysolophus y e. Chrysocome) |journal=Journal of Field Ornithology |year=1987 |volume=58 |issue=2 |pages=118–125 |jstor=4513209 |url=https://www.jstor.org/stable/4513209}}</ref> Females typically forage during the day in 11–12 hour trips consisting of many dives, but they will occasionally forage at night.<ref name="Tremblay & Cherel 2003"/> Night dives are typically much shallower than day dives. Dives typically last around 12h, but can be up to 15hrs, with penguins leaving the colony around dawn (04:00) and returning at dusk (19:00).<ref name="Putz et al 2005">{{cite journal |last1=Putz |first1=Klemens |title=Diving characteristics of southern rockhopper penguins (Eudyptes c. chrysocome) in the southwest Atlantic |journal=Marine Biology |date=November 29, 2005 |volume=149 |issue=2 |pages=125–137 |doi=10.1007/s00227-005-0179-y|s2cid=84393587 }}</ref>

[[File:Rockhopper penguin.jpg|thumb|Rockhopper penguin skeleton in [[Manchester Museum]]]]
Rockhopper penguins employ different strategies and foraging behaviors depending on the climate and environment. A main factor is food location. Subantarctic penguins must dive for longer periods of time and much deeper in search of food than do species in warmer waters where food is more easily accessible.<ref name="Tremblay & Cherel 2003"/>

==== Benthic and pelagic dives ====
Rockhopper penguins are known to employ two different types of dives when foraging, pelagic and benthic dives. Pelagic dives are typically short and relatively shallow and used very frequently. Benthic dives are much deeper dives near the seafloor (up to {{convert|100|m|||abbr=on}} deep)<ref name="Putz et al 2005"/> that typically last longer and have longer bottom time. Penguins performing benthic dives typically only perform a few depth wiggles (changes in depth profile) at their maximum depth.<ref name="Tremblay & Cherel 2000">{{cite journal |last1=Tremblay|last2=Cherel |first1=Yann|first2=Yves |title=Benthic and pelagic dives: a new foraging behaviour in rockhopper penguins |journal=Marine Ecology Progress Series |year=2000|volume=204 |pages=257–267 |doi=10.3354/meps204257|bibcode=2000MEPS..204..257T |doi-access=free }}</ref> at an average speed of range of {{convert|6.9|-|8.1|km/h|m/h}}.<ref name="Brown 1987"/> Although deeper dives tend to be a bit longer than shallow dives, foraging rockhoppers will minimize their travel time when performing benthic dives to gain maximum efficiency. Benthic dives in particular show a stronger correlation to full stomachs than pelagic dives. [[Emperor penguin]]s, [[gentoo penguin]]s, [[yellow-eyed penguin]]s and [[king penguin]]s also use this deep-dive technique to obtain food.<ref name="Tremblay & Cherel 2000"/>

Prey availability is dependent on many factors, such as current climate and conditions of the area. Typically, females will bring back a majority of crustaceans and occasionally some fish for their young. The female's foraging success directly affects chick growth.<ref name="Tremblay & Cherel 2003"/> If food is scarce, females are able to fast for very long periods of time and sometimes will only forage for the chick's benefit.<ref name="Putz et al 2005"/>

==== Dive limitations ====
Because foraging conditions and outcomes are so variable, several factors can limit foraging practices. The timing of breeding, incubation and brooding periods greatly affect foraging time, as females are unable to leave broods for long periods of time.<ref name="Brown 1987"/> Females during the brooding period will follow a much more fixed foraging schedule, leaving and returning to the colony at roughly the same time each day. When not in breeding season, females have much more variability in the length of foraging trips. If females have low energy levels because they are fasting while provisioning chicks, they may make several short foraging trips instead of one longer one.<ref name="Tremblay & Cherel 2003"/>

While benthic dives are efficient and favorable for rockhoppers, they present physiological limitations such as limits in lung capacity, which affects duration of dives. The longest aerobic dive rockhoppers can perform is about 110 seconds long,<ref name="Tremblay & Cherel 2000"/> but dives can last upwards of 180–190 seconds.<ref name="Tremblay & Cherel 2003"/><ref name="Brown 1987"/>

==Status and conservation==
The western rockhopper penguin group is classified as [[Vulnerable species|vulnerable]] by the [[IUCN]].<ref name=IUCN/> Its population has declined by about one-third in the last thirty years [when?].<ref name=BLIb/><ref name=BLI>[[BirdLife International]] (2008) [http://www.birdlife.eu/datazone/species/index.html?action=SpcHTMDetails.asp&sid=32472&m=0 Southern Rockhopper Penguin Species Factsheet] {{Webarchive|url=https://web.archive.org/web/20081211023147/http://www.birdlife.eu/datazone/species/index.html?action=SpcHTMDetails.asp&sid=32472&m=0 |date=December 11, 2008 }}. Retrieved May 27, 2008.</ref>
This decline has earned them the classification of a vulnerable species by the IUCN. Threats to their population include commercial fishing and [[oil spill]]s.<ref name="E.C.1">{{cite web| author=Devon Phelan| title=Eudyptes chrysocome rockhopper penguin | publisher=Animal Diversity Web| access-date=July 9, 2013| url= http://animaldiversity.ummz.umich.edu/accounts/Eudyptes_chrysocome/}}</ref>

With the approval of the [[European Association of Zoos and Aquaria]] (EAZA), Drusillas Park in East Sussex holds the studbook for rockhopper penguins in Europe. Zoo manager Sue Woodgate has specialist knowledge of the species, so the zoo is responsible for co-ordinating the movements of penguins among zoos in Europe to take part in breeding programmes and offer their advice and information about the species.<ref>{{Cite press release 
| title= Wild penguins get a helping hand from Drusillas Park in Sussex
| website= Drusillas Park
| date= 2012
| url=https://www.drusillas.co.uk/news/wild-penguins-get-a-helping-hand-from-drusillas}}</ref>

==Relationship with humans==
[[File:Eudyptes chrysocome.jpg|upright|thumb|Adult ''E.&nbsp;c. chrysocome'' in the [[New Island]] ([[Falkland Islands]]) rookery]]
The indigenous [[Yahgan people]] whose territory in [[Tierra del Fuego]] overlaps with its distribution often hunted them by slingshot or dart as a source of food.<ref>{{cite book |title=Yaghans, Explorers and Settlers: 10,000 years of Southern Tierra del Fuego Archipelago History |publisher=[[Martin Gusinde Anthropological Museum]] |page=19 |location= Puerto Williams |url=https://www.museoyaganusi.gob.cl/sites/www.museoyaganusi.gob.cl/files/images/articles-25319_archivo_01.pdf}}</ref>

Rockhopper penguins are the most familiar of the [[crested penguin]]s to the general public in the present day. Their breeding colonies, namely those around South America, today attract many tourists who enjoy watching the birds' antics. Historically, the same islands had been popular stopover and replenishing sites for [[whaler]]s and other seafarers since at least the early 18th century. Almost all crested penguins depicted in movies, books and other media are ultimately based on ''Eudyptes chrysocome chrysocome''.{{citation needed|date=January 2019}}

==References==
{{Reflist}}

==External links==
{{Commons|Eudyptes chrysocome}}{{Wikispecies|Eudyptes chrysocome}}
* ARKive – [https://web.archive.org/web/20060224085823/http://www.arkive.org/species/GES/birds/Eudyptes_chrysocome/ images and movies of the rockhopper penguin, ''Eudyptes chrysocome'']
* [https://web.archive.org/web/20061018164656/http://www.70south.com/resources/antarctic-animals/antarctic-penguins/rockhopperpenguin 70South: Info on rockhopper penguins]
* [http://www.penguins.cl/rockhopper-penguins.htm Rockhopper penguins from the International Penguin Conservation website]

{{Penguins}}
{{Taxonbar|from=Q688641}}

[[Category:Eudyptes|Western rockhopper penguin]]
[[Category:Penguins|Western rockhopper penguin]]
[[Category:Flightless birds]]
[[Category:Birds of Tierra del Fuego]]
[[Category:Birds of the Falkland Islands]]
[[Category:Birds of islands of the Atlantic Ocean]]
[[Category:Birds of subantarctic islands]]
[[Category:Birds of the Indian Ocean]]
[[Category:Birds of the Southern Ocean]]
[[Category:Vulnerable fauna of Australia]]
[[Category:Birds described in 1781|Western rockhopper penguin]]
[[Category:Taxa named by Johann Reinhold Forster|Western rockhopper penguin]]
[[Category:Fauna of Macquarie Island]]