The rise and fall of an ancient Adélie penguin ‘supercolony’ at Cape Adare, Antarctica

We report new discoveries and radiocarbon dates on active and abandoned Adélie penguin ( Pygoscelis adeliae ) colonies at Cape Adare, Antarctica. This colony, first established at approximately 2000 BP (calendar years before present, i.e. 1950), is currently the largest for this species with approximately 338 000 breeding pairs, most located on low-lying Ridley Beach. We hypothesize that this colony first formed after fast ice began blocking open-water access by breeding penguins to the Scott Coast in the southern Ross Sea during a cooling period also at approximately 2000 BP. Our results suggest that the new colony at Cape Adare continued to grow, expanding to a large upper terrace above Ridley Beach, until it exceeded approximately 500 000 breeding pairs (a ‘supercolony’) by approximately 1200 BP. The high marine productivity associated with the Ross Sea polynya and continental shelf break supported this growth, but the colony collapsed to its present size for unknown reasons after approximately 1200 BP. Ridley Beach will probably be abandoned in the near future due to rising sea level in this region. We predict that penguins will retreat to higher elevations at Cape Adare and that the Scott Coast will be reoccupied by breeding penguins as fast ice continues to dissipate earlier each summer, restoring open-water access to beaches there.

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Ancient Adélie penguin colony revealed by snowmelt at Cape Irizar, Ross Sea, Antarctica

Geology ◽

10.1130/g48230.1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Steven D. Emslie

Keyword(s):

Ross Sea ◽

Bone Collagen ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Adelie Penguin ◽

Terra Nova Bay ◽

Penguin Colony ◽

Marine Productivity ◽

First Time ◽

Adélie Penguins

The Ross Sea (Antarctica) is one of the most productive marine ecosystems in the Southern Ocean and supports nearly one million breeding pairs of Adélie penguins (Pygoscelis adeliae) annually. There also is a well-preserved record of abandoned penguin colonies that date from before the Last Glacial Maximum (>45,000 14C yr B.P.) through the Holocene. Cape Irizar is a rocky cape located just south of the Drygalski Ice Tongue on the Scott Coast. In January 2016, several abandoned Adélie penguin sites and abundant surface remains of penguin bones, feathers, and carcasses that appeared to be fresh were being exposed by melting snow and were sampled for radiocarbon analysis. The results indicate the “fresh” remains are actually ancient and that three periods of occupation by Adélie penguins are represented beginning ca. 5000 calibrated calendar (cal.) yr B.P., with the last occupation ending by ca. 800 cal. yr B.P. The presence of fresh-appearing remains on the surface that are actually ancient in age suggests that only recently has snowmelt exposed previously frozen carcasses and other remains for the first time in ~800 yr, allowing them to decay and appear fresh. Recent warming trends and historical satellite imagery (Landsat) showing decreasing snow cover on the cape since 2013 support this hypothesis. Increased δ13C values of penguin bone collagen further indicate a period of enhanced marine productivity during the penguin “optimum”, a warm period at 4000–2000 cal. yr B.P., perhaps related to an expansion of the Terra Nova Bay polynya with calving events of the Drygalski Ice Tongue.

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A 1000-year record of Adélie penguin diets in the southern Ross Sea

Antarctic Science ◽

10.1017/s0954102002000184 ◽

2002 ◽

Vol 14 (4) ◽

pp. 327-332 ◽

Cited By ~ 33

Author(s):

MICHAEL POLITO ◽

STEVEN D. EMSLIE ◽

WILLIAM WALKER

Keyword(s):

Ross Sea ◽

Prey Selection ◽

Ice Age ◽

Adélie Penguin ◽

Pleuragramma Antarcticum ◽

Adelie Penguin ◽

Radiocarbon Dates ◽

Antarctic Silverfish ◽

The Antarctic

Non-krill prey remains were recovered from ornithogenic sediments at three active Adélie penguin colonies on Ross Island, to assess long-term dietary trends in this species. Radiocarbon dates place the age of these deposits from a maximum of 947 years ago to the present. We identified 12 taxa of fish and two of squid with the Antarctic silverfish (Pleuragramma antarcticum) as the most abundant prey species represented at all sites. In addition, silverfish have decreased in importance in Adélie penguin diet over the past 600 years, perhaps in response to climate change since the onset of the Little Ice Age, though it remains much more abundant in current penguin diet in the Ross Sea than in the Antarctic Peninsula. Other prey taxa reflect the diversity of prey selection by Adélie penguins in Antarctica.

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A 9000-year record of Adélie penguin occupation and diet in the Windmill Islands, East Antarctica

Antarctic Science ◽

10.1017/s0954102005002427 ◽

2005 ◽

Vol 17 (1) ◽

pp. 57-66 ◽

Cited By ~ 43

Author(s):

STEVEN D. EMSLIE ◽

ERIC J. WOEHLER

Keyword(s):

Population Cycles ◽

East Antarctica ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Pleuragramma Antarcticum ◽

Fish Prey ◽

Adelie Penguin ◽

Radiocarbon Dates ◽

Nest Site Fidelity ◽

Windmill Islands

We investigated 17 abandoned Adélie penguin (Pygoscelis adeliae) colonies in the Windmill Islands, East Antarctica, in summer 2002/03. Forty radiocarbon dates on penguin bones and eggshells from 13 of these sites indicate a near continuous occupation by breeding penguins in this region for over 9000 years. These dates refine the recent geological record in this region and indicate that deglaciation of the northern islands occurred much earlier than previously suggested. Dietary remains from these sites include at least 23 taxa of cephalopods and teleost fish. Quantification of these remains indicates significant fluctuations in the relative abundance of two of the more common major prey taxa. The Antarctic silverfish (Pleuragramma antarcticum Boulenger) was the most common teleost prey during all time periods represented by the ages of the sites, but preservational factors may explain a gradual decrease in the remains of this species in increasingly older sites. The most common cephalopod in the sediments was the squid, Psychroteuthis glacialis Thiele, which occurred in low numbers in most sites except one (Site 75). An unusually high number of squid beaks preserved in Site 75, dating to approximately 5700–6100 cal. yr BP, does not correlate with a decrease in fish prey at that time. The high number of abandoned penguin colonies (> 200) in the Windmill Islands may be due to population cycles in the past in association with low nest-site fidelity and movement by breeding penguins to new sites within this region.

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Stable isotope analyses of ancient and modern Adélie Penguin (Pygoscelis adeliae) mummies from the Ross Sea Region, Antarctica

Polar Biology ◽

10.1007/s00300-019-02513-4 ◽

2019 ◽

Vol 42 (6) ◽

pp. 1183-1192 ◽

Cited By ~ 1

Author(s):

Allyson K. Kristan ◽

Steven D. Emslie ◽

William P. Patterson

Keyword(s):

Stable Isotope ◽

Ross Sea ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Adelie Penguin ◽

Stable Isotope Analyses ◽

Isotope Analyses

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Breeding habitats of emperor penguins in the western Ross Sea

Antarctic Science ◽

10.1017/s0954102093000203 ◽

1993 ◽

Vol 5 (2) ◽

pp. 143-148 ◽

Cited By ~ 15

Author(s):

Gerald L. Kooyman

Keyword(s):

Sea Ice ◽

Ross Sea ◽

Open Water ◽

Emperor Penguin ◽

Water Access ◽

Emperor Penguins ◽

Breeding Habitats ◽

Fresh Snow ◽

Fast Ice ◽

Western Ross Sea

Within the Western Ross Sea, there are six emperor penguin colonies of widely different size that occur exclusively on sea ice. In 1990 a survey of all six sites, two by close overflights and four from the ground, showed that the breeding habitats were highly variable. The most important physical characteristics of these habitats appear to be stable fast ice, nearby open water, access to fresh snow, and shelter from the wind.

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Spatial relationships of Adélie penguin colonies: implications for assessing population changes from remote imagery

Antarctic Science ◽

10.1017/s0954102098000546 ◽

1998 ◽

Vol 10 (4) ◽

pp. 449-454 ◽

Cited By ~ 14

Author(s):

Eric J. Woehler ◽

Martin J. Riddle

Keyword(s):

Population Density ◽

Ross Sea ◽

Aerial Photographs ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Data Set ◽

Adelie Penguin ◽

Pair Density ◽

The Relationship ◽

Colony Area

The relationship between colony area and population density of Adélie penguins Pygoscelis adeliae was examined to determine whether colony area, measured from aerial or satellite imagery, could be used to estimate population density, and hence detect changes in populations over time. Using maps drawn from vertical aerial photographs of Adélie penguin colonies in the Mawson region, pair density ranged between 0.1 and 3.1 pairs m−2, with a mean of 0.63 ± 0.3 pairs m−2. Colony area explained 96.4% of the variance in colony populations (range 90.4–99.6%) for 979 colonies at Mawson. Mean densities were not significantly different among the 19 islands in the region, but significant differences in mean pair density were observed among colonies in Mawson, Whitney Point (Casey, East Antarctica) and Cape Crozier (Ross Sea) populations. The relationship between colony area and population may be locality-and/or species-specific, and a robust data set is required to validate the relationship.

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Lagged response of Adélie penguin (Pygoscelis adeliae) abundance to environmental variability in the Ross Sea, Antarctica

Polar Biology ◽

10.1007/s00300-020-02743-x ◽

2020 ◽

Vol 43 (11) ◽

pp. 1769-1781

Author(s):

Xintong Chen ◽

Xiao Cheng ◽

Baogang Zhang ◽

Hao Meng ◽

Di Wu ◽

...

Keyword(s):

Environmental Variability ◽

Ross Sea ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Adelie Penguin

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Spatial and temporal diet variability of Adélie (Pygoscelis adeliae) and Emperor (Aptenodytes forsteri) Penguin: a multi tissue stable isotope analysis

Polar Biology ◽

10.1007/s00300-021-02925-1 ◽

2021 ◽

Author(s):

Vahideh Jafari ◽

Deborah Maccapan ◽

Giulio Careddu ◽

Simona Sporta Caputi ◽

Edoardo Calizza ◽

...

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Ross Sea ◽

Isotope Analysis ◽

Trophic Levels ◽

Emperor Penguin ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Adelie Penguin ◽

Aptenodytes Forsteri

AbstractThe Ross Sea, Antarctica, supports large populations of Emperor Penguin (Aptenodytes forsteri) and Adélie Penguin (Pygoscelis adeliae), two key meso-predators that occupy high trophic levels. Despite these species are largely studied, little is known about their diet outside the breeding period. In the present study, we investigated the intra-annual diet of Adélie and Emperor Penguins belonging to five colonies in the Ross Sea through the stable isotope analysis of different tissues (feathers and shell membranes), synthetized in different seasons, and guano that indicates recent diet. Penguin samples and prey (krill and fish) were collected during the Antarctic spring–summer. δ13C and δ15N of tissues and guano indicate spatio-temporal variation in the penguin diet. The krill consumption by Adélie Penguins was lowest in winter except in the northernmost colony, where it was always very high. It peaked in spring and remained prevalent in summer. The greatest krill contribution to Emperor Penguin’s diet occurred in summer. The relative krill and fish consumption by both species changed in relation to the prey availability, which is influenced by seasonal sea ice dynamics, and according to the penguin life cycle phases. The results highlight a strong trophic plasticity in the Adélie Penguin, whose dietary variability has been already recognized, and in the Emperor Penguin, which had not previously reported. Our findings can help understand how these species might react to resource variation due to climate change or anthropogenic overexploitation. Furthermore, data provides useful basis for future comparisons in the Ross Sea MPA and for planning conservation actions.

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