The term crested penguin is the common name given collectively to species of

penguin Penguins (order (biology), order List of Sphenisciformes by population, Sphenisciformes , family (biology), family Spheniscidae ) are a group of Water bird, aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: on ...

s of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Eudyptes''. The exact number of species in the genus varies between four and seven depending on the authority, and a

Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about te ...

species became

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

in recent centuries. All are black and white penguins with yellow crests, red bills and eyes, and are found on Subantarctic islands in the world's southern oceans. All lay two eggs, but raise only one young per breeding season; the first egg laid is substantially smaller than the second.

Taxonomy

The genus ''Eudyptes'' was introduced by the French ornithologist Louis Jean Pierre Vieillot in 1816; the name is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

words ''eu'' meaning "fine", and ''dyptes'' meaning "diver". The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

was designated as the southern rockhopper penguin by George Robert Gray in 1840. Six extant species have been classically recognised, with the recent splitting of the rockhopper penguin increasing it to seven. Conversely, the close relationship of the macaroni and royal penguins, and the erect-crested and Snares penguins have led some to propose that the two pairs should be regarded as species. Order Sphenisciformes * Family Spheniscidae ** Fiordland penguin, ''Eudyptes pachyrhynchus'' ** Snares penguin, ''Eudyptes robustus'' – has been considered a subspecies of the Fiordland penguin **

Erect-crested penguin The erect-crested penguin (''Eudyptes sclateri'') is a penguin endemic to the New Zealand region and only breeds on the Bounty Islands, Bounty and Antipodes Islands. It has black upper parts, white underparts and a yellow eye stripe and crest. I ...

, ''Eudyptes sclateri'' ** Southern rockhopper penguin, ''Eudyptes chrysocome'' ***

Eastern rockhopper penguin The eastern rockhopper penguin (''Eudyptes chrysocome filholi'') is a crested penguin with yellow crest feathers. It is a subspecies of the southern rockhopper penguin (''Eudyptes chrysocome'') found in subantarctic regions and the Indian Ocean. ...

, ''Eudyptes (chrysocome) filholi'' ***

Western rockhopper penguin The southern rockhopper penguin group (''Eudyptes chrysocome''), 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 O ...

, ''Eudyptes (chrysocome) chrysocome'' ** Northern rockhopper penguin, ''Eudyptes moseleyi'' – traditionally considered a subspecies of ''Eudyptes chrysocome'' as the rockhopper penguin. **

Royal penguin The royal penguin (''Eudyptes schlegeli'') is a species of penguin, which can be found on the sub-Antarctic Macquarie Island and adjacent islands. The International Union for Conservation of Nature (IUCN) classifies the royal penguin as near th ...

, ''Eudyptes schlegeli'' – sometimes considered a

morph Morph may refer to: Biology * Morph (zoology), a visual or behavioral difference between organisms of distinct populations in a species * Muller's morphs, a classification scheme for genetic mutations * "-morph", a suffix commonly used in tax ...

of ''E. chrysolophus'' ** Macaroni penguin, ''Eudyptes chrysolophus'' **

Chatham penguin The Chatham penguin (''Eudyptes warhami''), also known as the Chatham crested penguin, Chatham Islands penguin, or Warham's penguin, is an extinct species of crested penguin previously endemic to the Chatham Islands of New Zealand. It is known o ...

, ''Eudyptes warhami'' (

) The

Eudyptes warhami is known only from

subfossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

bones, and became extinct shortly following human colonisation of the Chatham Islands. This genetically-distinct species was relatively large, with a thin, slim and low bill. (T.L. Cole et al. (2019) Mol. Biol. Evol.)

Evolution

Mitochondrial and nuclear DNA evidence suggests that the crested penguins split from the ancestors of their closest living relative, the yellow-eyed penguin, in the mid-

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

around 15 million years ago, before splitting into separate species around 8 million years ago in the late Miocene. A

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

penguin genus, '' Madrynornis'', has been identified as the closest known relative of the crested penguins. Found in late Miocene deposits dated to about 10 million years ago, it must have separated from the crested penguins around 12 million years ago. Given that the head ornamentation by yellow

filoplume Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier e ...

s seems

plesiomorphic In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and ...

for the ''Eudyptes''-''Megadyptes'' lineage, ''Madrynornis'' probably had them too.

Description

The crested penguins are all similar in appearance, having sharply delineated black and white plumage with red beaks and prominent yellow crests. Their calls are more complex than those of other species, with several phrases of differing lengths.Williams ''(The Penguins)'' p. 69 The royal penguin (mostly) has a white face, while other species have black faces.

Breeding

Crested penguins breed on Subantarctic islands in the southern reaches of the world's oceans; the greatest diversity occurring around New Zealand and surrounding islands. Their breeding displays and behaviours are generally more complex than other penguin species.Williams ''(The Penguins)'' p. 52 Both male and female parents take shifts incubating eggs and young.Williams ''(The Penguins)'' p. 76 Crested penguins lay two eggs, but almost always raise only one young successfully. All species exhibit the odd phenomenon of ''egg-size dimorphism'' in breeding; the first egg (or A-egg) laid is substantially smaller than the second egg (B-egg). This is most extreme in the macaroni penguin, where the first egg averages only 60% the size of the second.Williams ''(The Penguins)'' p. 38 The reason for this is a mystery remains unknown, although several theories have been proposed. British ornithologist David Lack theorized that the genus was evolving toward the laying of a one-egg clutch. Experiments with egg substitution have shown that A-eggs can produce viable chicks that were only 7% lighter at time of fledging. Physiologically, the first egg is smaller because it develops while the mother is still at sea swimming and thus has less energy to invest in the egg. Recently, brooding royal and erect-crested penguins have been reported to tip the smaller eggs out as the second is laid.

Species photographs

Photographs of adults of the extant (living) species are shown: File:Fiordland penguin (Mattern).jpg, Fiordland penguin
''Eudyptes pachyrhynchus'' File:SnaresPenguin (Mattern).jpg, Snares penguin
''Eudyptes robustus'' File:FMIB_50785_Big-Crested_Penguin_(Catarrhactes_sclateri)_enjoying_the_sunshine,_Antipodes_Island.jpg,

''Eudyptes sclateri'' File:Eudyptes chrysocome.jpg, Southern rockhopper penguin
''Eudyptes chrysocome'' File:Eudyptes moseleyi -Zoologischer Garten Berlin, Germany-8a.jpg, Northern rockhopper penguin
''Eudyptes moseleyi'' File:RoyalPenguins2.JPG,

''Eudyptes schlegeli'' File:Macaroni Penguin (Eudyptes chrysolophus)6.jpg, Macaroni penguin
''Eudyptes chrysolophus''

References

Cited text

* * Cole, Theresa L.; Ksepka, Daniel T.; Mitchell, Kieren J.; Tennyson, Alan J. D.; Thomas, Daniel B.; Pan, Hailin; Zhang, Guojie; Rawlence, Nicolas J.; Wood, Jamie R.; Bover, Pere; Bouzat, Juan L.; Cooper, Alan; Fiddamanl, Steven; Hart, Tom; Miller, Gary; Ryan, Peter G.; Shepherd, Lara D.; Wilmshurst, Janet M.; Waters, Jonathan M. (2019). "Mitogenomes uncover extinct penguin taxa and reveal island formation as a key driver of speciation". Molecular Biology and Evolution. doi:10.1093/molbev/msz017.

External links

*
TerraNature.org: "Three ''Eudyptes'' species endemic to New Zealand"
{{Taxonbar, from=Q591480 . Penguins Spheniscidae Taxa named by Louis Jean Pierre Vieillot