TY - JOUR T1 - The occupation history of the longest-dwelling Adélie penguin colony reflects Holocene climatic and environmental changes in the Ross Sea, Antarctica JF - Quaternary Science Reviews Y1 - 2022 A1 - Gao, Yuesong A1 - Salvatore, Maria Cristina A1 - Xu, Qibin A1 - Yang, Lianjiao A1 - Sun, Liguang A1 - Xie, Zhouqing A1 - Baroni, Carlo AB - As a result of climate changes, penguins are predicted to be at risk of losing their breeding habitats. Changes in penguin colony distribution suggest that some colonies have withstood environmental changes better than others, serving as initial post-glacial settlements or refuges in adverse climatic conditions. Here we have synthesized over 200 dates (including 91 new dates) of penguin remains and of guano in 107 ornithogenic profiles from abandoned nests on Inexpressible Island, one of the longest persisting Adélie penguin colonies in Antarctica, to investigate the dynamics of population size and the role of this island in the ecological history of this species. The results indicate that, following the retreat of Ross Ice Shelf, the Adélies first colonized this island at ∼8.6 kyr BP, documenting the earliest known breeding site in the Ross Sea since deglaciation. During ∼7-3 kyr BP the reconstructed population on Inexpressible Island was generally consistent with the change in pack ice, reaching relative peaks at 5.5–5.0 and 4.0–3.5 kyr BP. After brief decline at 3.5–3.0 kyr, substantial enlargement of the penguin colony occurred between 3.0 and 1.5 kyr BP, attributed to the immigration from the abandoned colonies along the Scott Coast. During this time, the persistent efficiency of Terra Nova Bay polynya offered conditions favourable to the expansion of the penguin population on Inexpressible Island, which probably represented a refuge area under increased coastal sea-ice. This longest-dwelling penguin colony may provide a valuable refuge for the Adélie penguin if the recurrent Terra Nova Bay polynya persists under future climatic and environmental changes, as occurred in the past. VL - 284 UR - https://linkinghub.elsevier.com/retrieve/pii/S0277379122001251 ER - TY - JOUR T1 - Adélie penguin dietary remains reveal Holocene environmental changes in the western Ross Sea (Antarctica) JF - Palaeogeography, Palaeoclimatology, Palaeoecology Y1 - 2014 A1 - Lorenzini, Sandra A1 - Baroni, Carlo A1 - Baneschi, Ilaria A1 - Salvatore, Maria Cristina A1 - Fallick, Anthony E. A1 - Hall, Brenda L. AB - Carbon and nitrogen stable isotope analyses were performed on modern and Holocene Adélie penguin guano samples collected from ornithogenic soils along the Scott Coast (Southern Victoria Land, Antarctica), from Cape Irizar to Dunlop Island, and at Cape Bird (Ross Island). Guano samples also were sieved and sorted under stereomicroscope in order to select penguin dietary remains, such as fish bones and otoliths. Carbon and nitrogen stable isotope composition, coupled with the taxonomic identification of fish otoliths from Scott Coast Holocene samples, indicated a mainly fish-based diet for this area, with Pleuragramma antarcticum as the most eaten prey throughout the investigated period (from 390 cal BP to ca 7300 cal BP). The isotopic values of Ross Island samples (from modern to 3850 cal BP) showed a krill consumption increase in the samples younger than 2000 cal BP, with the maximum in modern samples. Scott Coast and Ross Island Holocene samples showed δ13C and δ15N trends similar to those previously published from Terra Nova Bay (northern Victoria Land), whereas modern samples from Ross Island have similar δ15N composition but different δ13C values. This δ13C divergence started at ca 2000 BP and follows the abandonment of the Scott Coast colonies. The δ13C trend observed in Ross Island and Terra Nova Bay samples and the abandonment of the Scott Coast colonies could suggest the stability and the persistence of the previous oceanographic conditions (i.e. polynya) for the Terra Nova Bay area and the establishment of new conditions for water circulation in the Southern Ross Sea since ~ 2000 BP when persistent sea-ice sealed the Scott Coast. VL - 395 UR - http://www.sciencedirect.com/science/article/pii/S0031018213005440 N1 - id: 2347 JO - Adélie penguin dietary remains reveal Holocene environmental changes in the western Ross Sea (Antarctica) ER - TY - JOUR T1 - Insights into the Holocene environmental setting of Terra Nova Bay region (Ross Sea, Antarctica) from oxygen isotope geochemistry of Adélie penguin eggshells JF - The Holocene Y1 - 2012 A1 - Lorenzini, Sandra A1 - Baneschi, Ilaria A1 - Fallick, Anthony E. A1 - Salvatore, Maria Cristina A1 - Zanchetta, Giovanni A1 - Dallai, Luigi A1 - Baroni, Carlo AB - An oxygen isotope record of Adélie penguin (Pygoscelis adeliae) eggshells from Terra Nova Bay (Victoria Land, Antarctica) has been reconstructed in order to provide insights into the palaeoenviroment of this region during the last ~8000 years. The d18O values measured in eggshell carbonate show a great variability over the course of the studied period, with maximum values consistently around +27.5‰. Adopting a metabolic enrichment relative to water source of ~+28.5‰, eggshell d18O values can be interpreted in terms of marine water uptake by the penguins. The spread in d18O of eggshell carbonate at any given time toward more negative values reflects the existence of a low d18O water end member, most plausibly snow or snowmelt. Samples younger than 2000 years are characterized by a general lack of very negative d18O values. As also attested by other proxies, this shift toward more positive isotopic values is likely to be related both to a decreasing contribution of snow or meltwater in the seawaters and consequently to an absence or paucity on the boundary of the nesting sites of snow or snowfall and freshwater that could be directly eaten or drunk by penguins. VL - 22 UR - http://hol.sagepub.com/content/22/1/63.abstract IS - 1 N1 - id: 2348 JO - Insights into the Holocene environmental setting of Terra Nova Bay region (Ross Sea, Antarctica) from oxygen isotope geochemistry of Adélie penguin eggshells ER - TY - JOUR T1 - Stable isotopes reveal Holocene changes in the diet of Ad,lie penguins in Northern Victoria Land (Ross Sea, Antarctica) JF - Oecologia Y1 - 2010 A1 - Lorenzini, Sandra A1 - Baroni, Carlo A1 - Fallick, Anthony E. A1 - Baneschi, Ilaria A1 - Salvatore, Maria Cristina A1 - Zanchetta, Giovanni A1 - Dallai, Luigi AB - Ad,lie penguin (Pygoscelis adeliae) modern and fossil eggshells and guano samples collected from ornithogenic soils in Terra Nova Bay (Victoria Land, Ross Sea) were processed for carbon and nitrogen isotopic ratios with the aim of detecting past penguin dietary changes. A detailed and greatly expanded Ad,lie penguin dietary record dated back to 7,200 years BP has been reconstructed for the investigated area. Our data indicate a significant dietary shift between fish and krill, with a gradual decrease from past to present time in the proportion of fish compared to krill in Ad,lie penguin diet. From 7,200 to 2,000 years BP, delta(13)C and delta(15)N values indicate fish as the most eaten prey. The dietary contribution of lower-trophic prey in penguin diet started becoming evident not earlier than 2,000 years BP, when the delta(13)C values reveal a change in the penguin feeding behavior. Modern eggshell and guano samples reveal a major dietary contribution of krill but not a krill-dominated diet, since delta(13)C values remain much too high if krill prevail in the diet. According to the Holocene environmental background attested for Victoria Land, Ad,lie penguin dietary shifts between fish and krill seem to reflect penguin paleoecological responses to different paleoenvironmental settings with different conditions of sea-ice extension and persistence. Furthermore, Ad,lie penguin diet appears to be particularly affected by environmental changes in a very specific period within the breeding season, namely the egg-laying period when penguin dietary and feeding habit shifts are clearly documented by the delta(13)C of eggshell carbonate. VL - 164 IS - 4 N1 - id: 2350; PT: J; TC: 6; UT: WOS:000284271900007 JO - Stable isotopes reveal Holocene changes in the diet of Ad,lie penguins in Northern Victoria Land (Ross Sea, Antarctica) ER - TY - JOUR T1 - Holocene Adelie penguin diet in Victoria Land, Antarctica JF - Polar Biology Y1 - 2009 A1 - Lorenzini, Sandra A1 - Olmastroni, Silvia A1 - Pezzo, Francesco A1 - Salvatore, Maria Cristina A1 - Baroni, Carlo AB - Ornithogenic soils (N = 97) dated up to 7000 Before Present (Ebp) were sampled in 16 relict and modern breeding colonies of Ad,lie penguin along the Victoria Land coast (Ross Sea, Antarctica). Taxonomic identification of fish otoliths (N = 677) recovered in these soils allowed to identify the Antarctic silverfish as the most eaten prey (90.1%) throughout the investigated period. A morphometric analysis of the otoliths revealed that the Ad,lie penguin primarily selected prey averaging 67.23 +/- A 23 mm of standard length. Temporal distribution of Pleuragramma antarcticum showed a peak between 2,000 and 4,000 years bp, a period corresponding to the maximum spread of Ad,lie penguin in the Victoria Land. Possible explanations of the variations of the abundance of the fish prey in the diet are discussed in the context of the paleoclimatic events and as possible consequences of dietary shifts due to the temporal variation of prey availability in the Ross Sea ecosystem. VL - 32 IS - 7 N1 - id: 1916; PT: J; NR: 60; TC: 2; J9: POLAR BIOL; PG: 10; GA: 457FQ; UT: WOS:000266914300013 JO - Holocene Adelie penguin diet in Victoria Land, Antarctica ER -