Editing Adélie penguin (section)

===Food and feeding===
The Adélie penguin is known to feed mainly on [[Antarctic krill]], [[ice krill]], [[Antarctic silverfish]], [[lanternfish]] (specifically, the [[Electrona antarctica|Antarctic lanternfish]]), [[amphipod]]s (''[[Themisto gaudichaudii]]'', ''Cyllopus lucassi'', ''[[Hyperia (crustacean)|Hyperia]]'' and unidentified [[Gammaridae|gammariid]]s),<ref name="animaldiversity.org">{{cite web | url=https://animaldiversity.org/accounts/Pygoscelis_adeliae/ | title=Pygoscelis adeliae (Adelie penguin) | website=[[Animal Diversity Web]] }}</ref><ref>{{cite journal|title=Adelie Penguin (Pygoscelis adeliae)|journal=Birds of the World|publisher=[[Cornell Lab of Ornithology]] |first=Isabel|last=Martínez|first2=David|last2=Christie|first3=Francesc|last3=Jutglar|first4=Ernest |last4=Garcia|first5=Christopher J.|last5=Sharpe|date=4 March 2020|location=[[Ithaca, New York|Ithaca, NY, USA]]|doi=10.2173/bow.adepen1.01|url=https://birdsoftheworld.org/bow/species/adepen1/cur/introduction#food|access-date=18 August 2024}}{{subscription required}}</ref> sea [[krill]], [[glacial squid]] and other [[cephalopod]]s<ref name="animaldiversity.org"/> (diet varies depending on geographic location) during the chick-rearing season. The [[stable isotope]] record of fossil [[eggshell]] accumulated in colonies over the last 38,000 years reveals a sudden change from a fish-based diet to krill that began around 200 years ago. This is most likely due to the decline of the [[Antarctic fur seal]] since the late 18th century and [[baleen whale]]s during the early 20th century. The reduction of competition from these predators has resulted in a surplus of krill, which the penguins now exploit as an easier source of food.<ref>
{{cite journal
|author1=S.D. Emslie |author2=W.P. Patterson |title=Abrupt recent shift in δ<sup>13</sup>C and δ<sup>15</sup>N values in Adélie penguin eggshell in Antarctica
|journal=[[Proceedings of the National Academy of Sciences]]
|volume=104
|issue=28
|doi=10.1073/pnas.0608477104
|date=July 2007
|pages=11666–69
|pmid=17620620
|pmc= 1913849|bibcode=2007PNAS..10411666E |doi-access=free }}</ref>

Jellyfish including species in the genera ''[[Chrysaora]]'' and ''[[Cyanea (jellyfish)|Cyanea]]'' were found to be actively sought-out food items, while they previously had been thought to be only accidentally ingested. Similar preferences were found in the [[little penguin]], [[yellow-eyed penguin]] and [[Magellanic penguin]].<ref>{{cite news|title=Penguins Caught Feasting on an Unexpected Prey|url=http://news.nationalgeographic.com/2017/09/penguins-eat-jellyfish-unexpected-prey/|newspaper=National Geographic|author=Christie Wilcox|date=15 September 2017|access-date=16 September 2017|archive-date=2 May 2019|archive-url=https://web.archive.org/web/20190502081534/https://news.nationalgeographic.com/2017/09/penguins-eat-jellyfish-unexpected-prey/|url-status=dead}}</ref>