Editing Adélie penguin (section)

===Breeding===
[[File:Manchot Adélie MHNT.jpg|thumb|An egg in the [[Muséum de Toulouse]]]]
[[Image:Mating adele.JPG|left|thumb|Mating in [[Antarctica]]]]
[[File:Specimen of Adélie penguin chick (Pygoscelis adeliae) held at Auckland Museum.jpg|thumb|Stuffed chick at [[:en:Auckland War Memorial Museum|Auckland Museum]]]]

Adélie penguins breed from October to February on shores around the Antarctic continent. Adélies build rough nests of stones. Two [[bird egg|egg]]s are laid; these are [[Egg incubation|incubated]] for 32 to 34 days by the parents taking turns (shifts typically last for 12 days). The chicks remain in the nest for 22 days before joining [[Crèche (zoology)|crèche]]s. The chicks [[moult]] into their juvenile [[plumage]] and go out to sea after 50 to 60 days.<ref>{{cite journal |last1=Taylor |first1=Rowland H. |title=THE ADELIE PENGUIN ''PYGOSCELIS ADELIAE'' AT CAPE ROYDS |journal=Ibis |date=April 1962 |volume=104 |issue=2 |pages=176–204 |doi=10.1111/j.1474-919X.1962.tb08644.x |url=https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1474-919X.1962.tb08644.x |access-date=17 November 2023}}</ref>

Adélie penguins arrive at their breeding grounds in late October or November, after completing a migration that takes them away from the Antarctic continent for the dark, cold winter months. Their nests consist of stones piled together. In December, the warmest month in Antarctica (about {{convert|-2|°C|disp=or}}/-19&nbsp;°C or -2.2&nbsp;°F), the parents take turns incubating the egg; one goes to feed and the other stays to warm the egg. The parent that is incubating does not eat and does not even leave to defecate but instead projects faeces away from the nest.<ref>{{cite news |last1=Ouellette |first1=Jennifer |title=The explosive physics of pooping penguins: they can shoot poo over four feet |url=https://arstechnica.com/science/2020/07/poopy-projectiles-penguins-can-fling-their-feces-over-four-feet-study-finds/ |access-date=8 July 2020 |work=[[Ars Technica]] |date=4 July 2020 |archive-date=7 July 2020 |archive-url=https://web.archive.org/web/20200707234313/https://arstechnica.com/science/2020/07/poopy-projectiles-penguins-can-fling-their-feces-over-four-feet-study-finds/ |url-status=live }}</ref> In March, the adults and their young return to the sea. The Adélie penguin lives on sea ice but needs ice-free land to breed. With a reduction in sea ice, populations of the Adélie penguin have dropped by 65% over the past 25 years in the Antarctic Peninsula.<ref name="Telegraph"/>

Young Adélie penguins that have no experience in social interaction may react to false cues when the penguins gather to breed. They may, for instance, attempt to mate with other males, with young chicks or with dead females. Levick was the first to record such behaviour (1911–12), but his notes were deemed too indecent for publication at the time; they were rediscovered and published in 2012.<ref name="Guardian">{{cite news|url=https://www.theguardian.com/world/2012/jun/09/sex-depravity-penguins-scott-antarctic|title='Sexual depravity' of penguins that Antarctic scientist dared not reveal|newspaper=[[The Guardian]]|date=9 June 2012|first=Robin|last=McKie|access-date=13 December 2016|archive-date=25 December 2018|archive-url=https://web.archive.org/web/20181225080445/https://www.theguardian.com/world/2012/jun/09/sex-depravity-penguins-scott-antarctic|url-status=live}}</ref>{{Refn|group=n|About 100 [[pamphlet]]s of the notes he took had been circulated to a selected few bearing the bold header '''''Not for Publication'''''. "Levick himself was equally cautious. References to these observations in the notebooks have often been coded by his rewriting certain entries on these behaviours using the [[Greek alphabet]] and then pasting this new text over the original entry (Fig. 1), whilst some entries were written directly in the Greek alphabet".<ref name=Levickunpublished/> The following is an example of such a note; a transcription into the [[English alphabet]] is given on the right:
{{Columns-start|num=2}}
{{blockquote|text=Θις ἀφτερνooν ἰ σαυ ἀ μoστ εχτραoρδιναρι σιtε. ἀ πενγυιν ὐας ἀκτυαλλι ενyαyεδ ἰν σoδoμι ᾿uπoν θε βoδι ὀφ ἀ δεαδ ὑιτε θρoατεδ βιρδ ὀφ ἰτς ὀνε σπεσιες. Θε ἀκτ ὀccυπιεδ ἀ φυλλ μινυτε, θε πoσιτιoν τακεν ὐπ βι θε κoχ διφφερινy ἰν νo ρεσπεκτ φρoμ θατ ὀφ ὀρδιναρι κoπυλατιoν, ἀνδ θε ὑoλε ακτ ὐας yoνε θρoυ, δoυν τo θε φιναλ δεπρεςςιoν ὀφ θε χλoακα.<ref name=Levickunpublished/>}}
{{Column}}
{{blockquote|text=This afternoon I saw a most extraordinary site {{sic}}. A penguin was actually engaged in sodomy upon the body of a dead white-throated bird of its own species. The act occurred a full minute, the position taken up by the cock differing in no respect from that of ordinary copulation, and the whole act was gone through down to the final depression of the [[cloaca]].<ref name=Levickunpublished/>}}
{{Columns-end}}}} "The pamphlet, declined for publication with the official Scott expedition reports, commented on the frequency of sexual activity, auto-erotic behaviour and seemingly aberrant behaviour of young unpaired males and females, including [[Non-reproductive sexual behavior in animals#Necrophilia|necrophilia]], sexual coercion, sexual and physical abuse of chicks and homosexual behaviour," states the analysis written by Douglas Russell and colleagues William Sladen and David Ainley. "His observations were, however, accurate, valid and, with the benefit of hindsight, deserving of publication."<ref name=Levickunpublished>{{Cite journal | last1 = Russell | first1 = D. G. D. | last2 = Sladen | first2 = W. J. L. | last3 = Ainley | first3 = D. G. | s2cid = 146584734 | title = Dr. George Murray Levick (1876–1956): Unpublished notes on the sexual habits of the Adélie penguin | doi = 10.1017/S0032247412000216 | journal = Polar Record | volume = 48 | issue = 4 | pages = 1 | year = 2012 }}</ref><ref name="mckie"/> Levick observed the Adélie penguins at [[Cape Adare]], the site of the largest Adélie penguin [[rookery]] in the world.<ref name="TW2012">{{cite news |url=http://www.theweek.co.uk/health-science/47334/shock-sexually-%E2%80%98depraved%E2%80%99-penguins-led-100-year-censorship |title=Shock at sexually 'depraved' penguins led to 100-year censorship |newspaper=The Week |date=10 June 2012 |access-date=10 June 2012 |archive-date=23 December 2017 |archive-url=https://web.archive.org/web/20171223104832/http://www.theweek.co.uk/health-science/47334/shock-sexually-%E2%80%98depraved%E2%80%99-penguins-led-100-year-censorship |url-status=live }}</ref> {{As of|June 2012}}, he has been the only one to study this particular colony and he observed it for an entire [[breeding cycle]].<ref name="mckie"/> The discovery significantly illuminates the behaviour of the species whose population some researchers<ref>{{cite book|last=Ainley|first=David G.|title=The Adélie Penguin: Bellwether of Climate Change|url=https://archive.org/details/adeliepenguin00ainl|url-access=limited|year=2002|publisher=Columbia University Press|isbn=978-0-231-12306-8|pages=[https://archive.org/details/adeliepenguin00ainl/page/n326 310] pp. with 23 illustrations, 51 figures, 48 tables, 16 plates}}</ref> believe to be a bellwether of [[climate change]].<ref name="mckie"/>

Some Adélie penguins also actively and deliberately engage in homosexual activity. In one instance recorded in 1996, two wild male individuals courted each other and took turns mounting and copulating with each other.<ref>{{cite journal | last1 = Davis | first1 = Lloyd S. | last2 = Hunter | first2 = Fiona M. | last3 = Harcourt | first3 = Robert G. | last4 = Heath | first4 = Sue Michelsen | title = Reciprocal Homosexual Mounting in Adélie Penguins ''Pygoscelis adeliae'' | doi = 10.1071/MU98015 | journal = Emu - Austral Ornithology | volume = 98 | issue = 2 | pages = 136–137 | year = 1998 | url = https://www.academia.edu/22467566/Short_Communication_Reciprocal_Homosexual_Mounting_in_Ad_lie_Penguins_Pygoscelis_adeliae | access-date = 23 March 2024}}</ref> The reciprocal nature of the event indicates that both individuals were aware that they were courting and copulating with another male. The observing researchers suggested that this was practice for heterosexual encounters or a "response to high sexual motivation but a lack of females."