{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T14:32:17Z","timestamp":1770733937974,"version":"3.49.0"},"reference-count":52,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2026,2,9]],"date-time":"2026-02-09T00:00:00Z","timestamp":1770595200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004230","name":"Korea Polar Research Institute","doi-asserted-by":"publisher","award":["PE25140"],"award-info":[{"award-number":["PE25140"]}],"id":[{"id":"10.13039\/501100004230","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Korean Ministry of Environment","award":["PG25040"],"award-info":[{"award-number":["PG25040"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>\n                    The South Polar Skua (\n                    <jats:italic>Stercorarius maccormicki<\/jats:italic>\n                    ) is an opportunistic feeder, predator, and scavenger widely distributed in the coastal ecosystems of Antarctica. However, although some studies have explored its foraging behavior, many aspects, including regional variations, remain insufficiently understood. Thus, this study aimed to characterize regional variations in the dietary composition of South Polar Skuas breeding at sites along the Northern Victoria Land coast in the Ross Sea, where environmental conditions vary markedly among colonies. The dietary composition and foraging characteristics of the South Polar Skua populations in the Ross Sea region were investigated by analyzing stable carbon (\u03b4\u00b9\u00b3C) and nitrogen (\u03b4\u00b9\u2075N) isotopes in blood samples. The values were then used to quantify isotopic niches and estimate dietary contributions. Results revealed significant regional variations in the dietary composition of skuas. Compared with skuas at other sites, skuas at Cape M\u00f6bius showed higher \u03b4\u00b9\u00b3C values, suggesting a greater reliance on fish and the placenta or carcasses of Weddell seals for food. While \u03b4\u00b9\u2075N values did not significantly differ among skuas at various sites, skuas at Cape M\u00f6bius and Cape Washington had higher values than those at other sites, suggesting access to higher trophic-level prey. Site-specific dietary contributions were revealed, with Ad\u00e9lie Penguin eggs and fish dominating the diet at Cape Hallett and Inexpressible Island, whereas Emperor Penguin eggs and fish were more prominent at Cape Washington. Our findings demonstrate that the species exhibits site-specific foraging patterns shaped by local prey availability. These results provide novel insights into the trophic ecology of this top predator and contribute to a broader understanding of the spatial dietary variation in Antarctic seabirds.\n                  <\/jats:p>","DOI":"10.1371\/journal.pone.0341112","type":"journal-article","created":{"date-parts":[[2026,2,9]],"date-time":"2026-02-09T18:30:12Z","timestamp":1770661812000},"page":"e0341112","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Regional variations in the diet of the South Polar Skua (Stercorarius maccormicki) in the Ross Sea region, Antarctica"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4501-9691","authenticated-orcid":true,"given":"Jihee","family":"Kim","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Youmin","family":"Kim","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jong-U.","family":"Kim","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Younggeun","family":"Oh","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2397-2668","authenticated-orcid":true,"given":"Jeong-Hoon","family":"Kim","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2026,2,9]]},"reference":[{"issue":"2","key":"pone.0341112.ref001","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1007\/s00442-018-4249-5","article-title":"Population response of an apex Antarctic consumer to its prey and climate fluctuations","volume":"189","author":"N Pacoureau","year":"2019","journal-title":"Oecologia"},{"issue":"3","key":"pone.0341112.ref002","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1111\/j.1474-919X.1963.tb02509.x","article-title":"Feeding habits of the south polar skua Catharacta Maccormicki","volume":"105","author":"EC Young","year":"1963","journal-title":"Ibis"},{"issue":"1","key":"pone.0341112.ref003","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1007\/s003000000163","article-title":"Foods of the South Polar skua Catharacta maccormicki at Ardery Island, Windmill Islands, Antarctica","volume":"24","author":"SC Baker","year":"2001","journal-title":"Polar Biology"},{"issue":"2","key":"pone.0341112.ref004","doi-asserted-by":"crossref","first-page":"240","DOI":"10.3390\/birds5020016","article-title":"Diet and feeding behavior of the south polar skuas Stercorarius maccormicki in the Haswell Islands, East Antarctica","volume":"5","author":"S Golubev","year":"2024","journal-title":"Birds"},{"issue":"4","key":"pone.0341112.ref005","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1675\/063.034.0412","article-title":"Diet of South Polar skua chicks in two areas of sympatry with brown skua","volume":"34","author":"M Gra\u00f1a Grilli","year":"2011","journal-title":"Waterbirds"},{"issue":"1","key":"pone.0341112.ref006","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1002\/ece3.5899","article-title":"Prey density affects predator foraging strategy in an Antarctic ecosystem","volume":"10","author":"KM Busdieker","year":"2019","journal-title":"Ecol Evol"},{"issue":"3","key":"pone.0341112.ref007","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1007\/s00300-016-1980-4","article-title":"South Polar Skua breeding populations in the Ross Sea assessed from demonstrated relationship with Ad\u00e9lie Penguin numbers","volume":"40","author":"DJ Wilson","year":"2016","journal-title":"Polar Biol"},{"issue":"4","key":"pone.0341112.ref008","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1093\/auk\/104.4.617","article-title":"Feeding and Nesting Ecology of Sympatric South Polar and Brown Skuas","volume":"104","author":"PJ Pietz","year":"1987","journal-title":"The Auk"},{"issue":"7","key":"pone.0341112.ref009","doi-asserted-by":"crossref","first-page":"827","DOI":"10.1007\/s00300-008-0421-4","article-title":"Diet of the south polar skua Catharacta maccormicki and the brown skua C. antarctica lonnbergi at Cierva Point, Antarctic Peninsula","volume":"31","author":"SL Malzof","year":"2008","journal-title":"Polar Biol"},{"issue":"4","key":"pone.0341112.ref010","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1071\/MU09042","article-title":"The importance of fish in the diet of the South Polar Skua (Stercorarius maccormicki) at the South Shetland Islands, Antarctica","volume":"109","author":"D Montalti","year":"2009","journal-title":"Emu - 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