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A complete breeding failure in an Adélie penguin clony correlates with unusual and extreme environmental events


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Among the outcomes of the drastic changes affecting the Earth's ecosystems, nothing is more telling than a complete failure in the reproductive success of a sentinel species: a 'zero' year. Here, we found that unusual environmental conditions in the Terre Adelie sector of Antarctica disrupted the breeding activity of Adelie penguins Pygoscelis adeliae on land - but also their foraging activity at sea - to such a degree that no chicks survived in the 2013/2014 breeding season. Uncommonly heavy precipitation for this normally dry desert killed chicks en masse, while weak katabatic winds maintained a persistent sea ice around the colony, thereby impacting chick provisioning by adults. Extreme events such as this have direct repercussions for the species in question, and may also affect the wider sea-ice dependent food web. Understanding the nature, frequency, and consequences of such events are central to the management and conservation of this remote yet crucial ecosystem.
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2003 on Pétrels Island before the 2013/2014 season was ca
30% in 2001 (Jenouvrier et al. 2006). Zero – or near zero –
breeding success years have been reported on other high
latitude species, like in black-browed albatrosses alassarche
melanophris in the Sub Antarctic (Xavier et al. 2003, and
papers cited therein) but they remain rare events. Similarly,
such events for Adélie penguins have been recorded occa-
sionally in other regions of the Antarctic continent (e.g. at
Béchervaise Island, Irvine et al. 2000) but the causes for
these events appear to be diverse according to the study site
and season considered.
e year 2013 saw the greatest sea-ice extent around
the Antarctic continent since 1979 (ca 19.5 million km2
in 2013 for an 18.0–19.4 million km2 range between
1979–2012, NOAA:
IOTD/view.php?id=82160 ), which was also observed
in the Adélie Land region (IFREMER: wwz.ifremer.
fr/institut ). Monthly data from the Dumont d’Urville
meteorolo gical station (
/READER/ ) showed that autumn and winter 2013
were among the coldest since recording started in 1956
(Supplementary material, Appendix 1). However, the
trend reversed completely in August 2013 so that air
temperatures in spring and summer became warmer
than usual. Perhaps more importantly, the wind direc-
tion was predominantly and unusually blowing from the
east throughout the year and wind strength was low at
the start of the breeding season. Normally, strong kata-
batic winds blow from the continent towards the north
in this region, helping to push the sea ice away from the
coast (Adolphs and Wendler 1995) and create access to
open water, usually polynyas, which is critical to penguin
breeding success (Massom et al. 1998).
us, in the 2013/2014 season penguins suffered
from two contrasting plagues: an extensive sea-ice cover
that forced them to walk more often on compact ice,
hampering their efforts to forage for themselves and their
Ecography 37: 001–003, 2014
doi: 10.1111/ecog.01182
© 2014 e Authors. Ecography © 2014 Nordic Society Oikos
Subject Editor: Eric Post. Editor-in-Chief: Miguel Araújo. Accepted 21 August 2014
Among the outcomes of the drastic changes affecting
the Earth’s ecosystems, nothing is more telling than a
complete failure in the reproductive success of a senti-
nel species: a ‘zero’ year. Here, we found that unusual
environmental conditions in the Terre Adélie sector of
Antarctica disrupted the breeding activity of Adélie pen-
guins Pygoscelis adeliae on land – but also their foraging
activity at sea – to such a degree that no chicks survived
in the 2013/2014 breeding season. Uncommonly heavy
precipitation for this normally dry desert killed chicks
en masse, while weak katabatic winds maintained a
persistent sea ice around the colony, thereby impacting
chick provisioning by adults. Extreme events such as this
have direct repercussions for the species in question, and
may also affect the wider sea-ice dependent food web.
Understanding the nature, frequency, and consequences
of such events are central to the management and conser-
vation of this remote yet crucial ecosystem.
Adélie penguins are one of the most important predators
in Antarctic sea-ice ecosystems, totalling up to 3.79 million
pairs (Lynch and LaRue 2014). eir foraging and breeding
ecology is highly related to the status of the sea ice (Ainley
2002), and increasing (Ross Sea, Smith et al. 1999) or
decreasing (Antarctic Peninsula, Wilson et al. 2001) popula-
tion trends have been related to winter sea-ice conditions or
occurrence of polynia in the vicinity of colonies. While the
populations in the Terre Adélie sector of east Antarctica are
generally increasing, the colony of ca 34 000 Adélie penguins
from Pétrels Island (66°40S, 140°01E) has experienced a
complete breeding failure for the first time since the early
monitoring began in the 1950s. Not a single chick on this
island survived the summer, despite a 55% hatching success
(relative to e.g. a 77% hatching success and a total of 0.65
chicks per breeding pair in 2012/2013, Centre d’Etudes
Biologiques de Chizé unpubl.). To put this into perspec-
tive, the lowest breeding success recorded between 1992 and
A complete breeding failure in an Adélie penguin colony correlates
with unusual and extreme environmental events
Yan Ropert-Coudert, Akiko Kato, Xavier Meyer, Marie Pellé, Andrew J. J. MacIntosh,
Frédéric Angelier, Olivier Chastel, Michel Widmann, Ben Arthur, Ben Raymond and Thierry Raclot
Y. Ropert-Coudert (, A. Kato, X. Meyer, M. Pellé, M. Widmann and T. Raclot, CNRS and Univ. de Strasbourg,
UMR7178, IPHC, 23 rue Becquerel, FR-67087 Strasbourg, France. – A. J. J. MacIntosh, Center for International Collaboration and Advanced
Studies in Primatology, Kyoto Univ. Primate Research Inst., Kanrin 41-2, Inuyama, Aichi, 484–8506, Japan. – F. Angelier and O. Chastel,
Centre d’Etudes Biologiques de Chizé, FR-79360 Villiers-en-Bois, France. – B. Arthur and B. Raymond, Inst. for Marine and Antarctic Studies,
Univ. of Tasmania, Hobart 7001, Australia. BR also at: Australian Antarctic Division, Dept of the Environment, Australian Government,
Channel Highway, Kingston 7050, Australia.
Figure 1. Daily temperature (average, maximum and minimum in red and pink lines, respectively) and snow/rainy episodes (open and
filled red circles, respectively) at Dumont d’Urville during the 2013/2014 breeding season show a progressive deterioration of the weather
around the turn of the year that culminated into intensive rainfall on 31 December and 1 January. Average temperature evolution over
1981–2010 is shown in grey for comparison. Finally, cumulative Adélie penguin hatching success (dotted black line) and chick mortality
(solid black line) are also indicated.
chicks, and a warm and wet summer with alternating periods
of snowfall and especially rain – an extremely rare feature
in east Antarctica (Fig. 1). GPS devices (Cottin et al. 2012)
attached to chick-rearing birds revealed that the extreme
sea-ice extent affected foraging behaviour and success in a
variety of ways. Penguins were forced to travel twice the dis-
tance they covered in the previous season (217.5 56.1 km,
n 35 birds in 2013/2014; 117.7 73.0 km, n 38 birds
in 2012/2013, student t-test t –6.91, p 0.001). Adults
started their foraging trips with a lower body mass (4.0 0.4
kg, n 40 birds in 2013/2014; 4.3 0.5 kg, n 42 birds in
2012/2013, t 3.0, p 0.004) and they also spent longer
at sea (5.3 3.3 d, n 41 birds in 2013/2014; 3.3 3.7
d, n 43 birds in 2012/2013, t –2.60, p 0.011). As a
result, the chicks were not adequately provisioned and ema-
ciated chicks were a common sight throughout the summer.
Yet, extensive sea-ice cover was perhaps the lesser of two
evils: relatively warm temperatures in the summer provoked
unprecedented rainy episodes and snowmelt. Small chicks
are covered with a downy plumage that has little – if any –
waterproofing ability (Duchamp et al. 2002). With unusual
rain in this normally dry and cold desert, the chicks’ thermo-
regulation capacities weakened rapidly and the rainy episode
that took place just around the turn of the year led to the
death of 49% of the chicks in the colony we monitored (Fig.
1). e rest of the chicks were taken by starvation, additional
precipitation and predators/scavengers.
is complete breeding failure was a result of multiple
factors: several temporal and spatial scales need to be consid-
ered to understand its ramifications. is clearly highlights
the need to monitor the breeding and foraging activity of
polar species both on land and at sea simultaneously. What
ecophysiological mechanisms are triggered in response to
such a catastrophic year, especially at the hormonal level
where the endocrine responses to stressors are known to
affect foraging performances and/or parental care? Although
a zero year has relatively little immediate impact on the
survival of long-lived species, we can wonder how population
dynamics may be affected by the absence of an entire cohort
over the long term? What will be the long-term effects on
other species and trophic levels of the regional ecosystem?
Extreme events like those reported here are indeed likely to
have direct repercussions on other levels of the sea-ice depen-
dent food web. ese fundamental questions echo those
voiced at the 1st Horizon Scan (Kennicutt et al. 2014) of the
Scientific Committee on Antarctic Research (SCAR). ese
are research priorities for SCAR, as well as for the Antarctic
Treaty Consultative Meetings and the Commission for the
Conservation of Antarctic Marine Living Resources, espe-
cially since predictions from the Intergovernmental Panel
on Climate Change announce the coming of an era with
more frequent extreme events (IPCC 2007). In this context,
the recent breakdown of a giant iceberg in Antarctica and
the resultant havoc it created for the ecosystem (Lescroël
et al. 2014), the increasing frequency of storms and rain-
fall (Dee Boersma and Rebstock 2014), or the extreme event
reported here bode ominously for the future of these remote
and fragile ecosystems.
Acknowledgements – is project was supported by the French
Polar Inst. (IPEV, prog. 1091, YR-C, and partly prog. 109, H.
Weimerskirch), the WWF and the zone atelier Antarctique at
CNRS. e meteorological team of TA64 at Dumont d’Urville,
especially D. Lacoste, gave us access to a wealth of data. M. Bruecker,
N. Chatelain and F. Crenner at the IPHC customized the GPS
devices used in this study. e study was authorized by IPEV and
the Terres Australes et Antarctiques Françaises through the Arrêté
no. 2013-79 from the 29 October 2013.
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Supplementary material (Appendix ECOG-01182 at ). Appendix 1.
... available data suggest that Adélie penguins preferably forage in areas of moderate sea ice cover, such as the marginal ice zone at the sea ice edge (Le Guen et al., 2018). In contrast to the East Antarctic and Ross Sea sectors of the Southern Ocean, where unusually extensive sea ice can cause dramatic breeding failures (Ropert-Coudert et al., 2015), our results show that Adélie penguins breeding at the South Shetland Islands forage mostly in ice-free areas during the austral summer (Stammerjohn et al., 2008). While both breeders and nonbreeders are capable of targeting sea ice habitat early in the breeding season (during incubation), only the nonbreeders can continue this exploitation in the latter parts of the breeding season, when chick-rearing heighten breeders' spatial central-place foraging constraints. ...
Full-text available
Information on marine predator at-sea distributions is key to understanding ecosystem and community dynamics and an important component of spatial management frameworks that aim to identify regions important for conservation. Tracking data from seabirds are widely used to define priority areas for conservation, but such data are often restricted to the breeding population.This also applies to penguins in Antarctica, where identification of important habitat for nonbreeders has received limited attention. Nonbreeding penguins are expected to have larger foraging distributions than breeding conspecifics,which may alter their interactions with physical environmental factors, con-specifics, other marine predators, and threats. We studied the movement behavior of nonbreeding Adélie penguins tracked during the 2016/2017 breeding season at King George Island in the South Shetland Islands, Antarctica.We quantify how nonbreeding penguins horizontal moment behavior varies in relation to environmental conditions and assess the extent of spatial overlapin the foraging ranges of nonbreeders and breeders, which were tracked over several years. Nonbreeders increased their prey search and area-restricted foraging behavior as sea surface temperature and bottom depths decreased, and in response to increasing sea ice concentration. Nonbreeders tended to transit (high directional movement) over the relatively deep Central Basin of theBransfield Strait. The majority of foraging behavior occurred within the colder,Weddell Sea–sourced water of the Antarctic Coastal Current (incubation) andin the Weddell Sea (crèche). The utilization distributions of breeders and non-breeders overlapped in the central Bransfield Strait. Spatial segregation wasgreater during the crèche stage of breeding compared to incubation and brood,because chick provisioning still constrained the foraging range of breeders to ascale of a few tens of kilometers, while nonbreeders commenced with premolt for-aging trips into the Weddell Sea. Our results show that breeding and nonbreedingpenguins may not be impacted similarly by local environmental variability, given that their spatial and temporal scales of foraging differ during some part of the austral summer. Our study highlights the need to account for different life history stages when characterizing foraging behavior of marine predator populations.This is particularly important for“sentinel”species monitored as part of marine conservation and ecosystem-based management programs.
... Moreover, the Antarctic rainfall events will heavily impact Antarctic ecology. According to Ropert-Coudert et al. (2015), the rainfall events can cause serious damage to penguin colonies. Given the importance of rainfall to the climate variability and ecosystems over Antarctica, it is important to understand the variability of Antarctic rainfall and unravel the mechanisms behind it. ...
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Using the ERA-interim reanalysis and output of regional climate model MAR forced by ERA-Interim, this study investigates the mechanisms governing the persistent extreme rainfall events (PEREs) in the Antarctic Peninsula (AP) during austral summer (December, January, and February) for the period 1980–2017. Due to the topography’s blocking effect on the warm and humid airflow, increase in the rainfall concentrates on the western AP during the periods of the PEREs. Contributed mainly by the low-frequency variations, the positive rainfall anomalies on the western AP can persist for multiple days, leading to the persistence of the extreme rainfall events. The additional rainfall anomalies can be attributed to the increase in the total precipitation. Through regulating the total precipitation, the low-frequency atmospheric circulation anomalies are vital to the formation of the PEREs.Specifically, a persistent circulation pattern with an anomalous cyclone (anticyclone) to the east (west) of the AP is conductive to the enhancement of poleward moisture fluxes. As a result, the total precipitation around the AP is strengthened, as well as the rainfall. Further investigation reveals that the barotropic feedback of the high-frequency eddies plays an important role in maintaining the low-frequency circulation anomalies.
... During the first weeks of life, chicks are more vulnerable to weather-induced Fig. 1 Analytical process used to implement the Measure-Understand-Project (MUP) approach to model population changes of wild turkeys at the northernmost limit of their range mortality before additional thermo-protective plumage is developed (Roberts and Porter 1998) and endothermy is acquired (Dégletagne et al. 2013). For example, during an extreme warm and wet summer, > 50% of the chicks of Adélie penguin (Pygoscelis adeliae) from a colony in Antarctica died from hypothermia (Ropert-Coudert et al. 2015). ...
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For species inhabiting areas at the limit of their environmental tolerance, extreme events often drive population persistence. However, because extreme events are uncommon, their effects on population dynamics of expanding species are poorly known. We examined how extreme climate events in winter and summer affected three populations of wild turkeys occupying a natural climate gradient at the northern edge of their range. First, we examined the mechanism by which vital rates affect the population growth rate. Second, we developed a climate-dependent structured population model. Finally, by linking this population model to IPCC-class climate projections, we projected wild turkey population abundance in response to the frequency of extreme snow events by 2100 for the northernmost population. We showed that the population dynamics of the three populations is driven through different pathways expected from the theory of invading population dynamics; that those populations were mainly limited by heavy snow that decreases winter survival by restraining food access; and that a population of immigrant is projected to decline at the northern species range. This study exemplifies how extreme events affect population dynamics and range expansion of temperate species at the northern edge of the distribution.
... Archipel de Pointe Géologie en Terre Adélie, Antarctique. l'archipel(Ropert-Coudert et al. 2015. ...
L’impact du changement climatique sur la glace de mer et les écosystèmes polaires qui en dépendent est reconnu depuis plusieurs décennies. Cependant, ces milieux sont généralement difficiles à étudier en raison de leur climat extrême, de leur isolement et des difficultés logistiques associées. Le manque de connaissances concernant les mécanismes reliant les traits d’histoire de vie des organismes polaires et la variation de la glace de mer est particulièrement préjudiciable à notre compréhension des conséquences du changement climatique sur les espèces longévives comme les oiseaux marins polaires. Ces derniers, généralement situés au sommet des réseaux trophiques, pourraient cependant constituer des espèces sentinelles des écosystèmes liés à la glace de mer. L’objectif de cette thèse est d’améliorer les connaissances sur les processus impliqués dans les réponses des populations de prédateurs marins polaires aux variations environnementales, et principalement les mécanismes liés à la glace de mer. Pour répondre à cet objectif nous nous sommes basés sur le suivi individuel à long terme de deux espèces d’oiseaux marins polaires, le pétrel des neiges (Pagodroma nivea) et le damier du Cap (Daption capense). Les deux espèces se reproduisent en milieu polaire. L’une est particulièrement dépendante de la glace de mer pour s’alimenter (le pétrel des neiges) tandis que l’autre préfère un habitat libre de glace (le damier du Cap). Au cours de ce travail, nous avons estimé l’influence de facteurs extrinsèques (forçages ascendants, descendants, météorologie locale) et intrinsèques (âge, expérience de reproduction, sexe, colonie) sur les réponses démographiques des espèces à l’aide de modèles multi-états de capture-marquage-recapture. Nous avons également testé l’influence des facteurs environnementaux sur les traits phénotypiques (condition corporelle et phénologie de reproduction) du pétrel des neiges. Chez les damiers du Cap nous montrons une diminution du succès reproducteur ainsi que l’influence de plusieurs paramètres extrinsèques (température de surface de l’eau de mer, prédation, météorologie locale) sur celui-ci. En parallèle nous montrons une augmentation de la survie des adultes et une corrélation de celle-ci avec l’oscillation Antarctique. Chez le pétrel des neiges, nous avons mis en évidence l’influence de la glace de mer et d’autres facteurs extrinsèques (prédation, oscillation Antarctique, météorologie locale) et intrinsèques (sexe, colonie, expérience de reproduction) sur de multiples traits démographiques. Nous avons également montré un décalage (retard) dans la phénologie de reproduction des pétrels des neiges en réponse à des changements environnementaux (concentration de glace de mer, vents) et nous avons constaté que la reproduction retardée avait un impact négatif sur la probabilité d'envol des poussins. Enfin nous avons aussi montré que la concentration de glace de mer et l’oscillation Antarctique ont une influence négative sur la survie et la condition corporelle des juvéniles de pétrel des neiges. Cette thèse permet d’apporter de nouvelles connaissances sur les liens entre glace de mer et les traits d’histoire de vie d’une espèce pagophilique, le pétrel des neiges et d’une espèce moins associée à la glace, le damier du Cap. Ces connaissances permettent de mieux appréhender les conséquences du changement climatique sur les oiseaux marins polaires et les écosystèmes polaires en général, et apporte une contribution à la compréhension de la dynamique des populations concernant les variations démographiques intra spécifiques à fine échelle spatiale.
... With an exceptionally low prey availability, adults might not have been able to both selfmaintain and feed their chick [68], leading to the extremely low breeding success [69]. As well as low food availability, low breeding success can be triggered by extreme environmental events such as intense rain [70], or infectious diseases [71]. However, the sequence of delayed phenology, low hatching success, low chick growth and low fledging success support a scenario of reduced availability of important prey [72]. ...
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... The decrease in pack ice under regional warming is projected to cause population decline and widespread disappearance of Ad elie colonies north of 70 S . Anomalous atmospheric circulation has also been observed to cause extremely low breeding success and decline in breeding population, due to decreased food abundance, prolonged foraging trips, drowned eggs, or hypothermia of chicks (Massom et al., 2006;Olmastroni et al., 2004;Ropert-Coudert et al., 2015). Land-based drivers such as snow/ice cover are also important to the penguins, which may exert diverse effects on different penguin colonies depending on the local topography. ...
Drastic climate change is widely believed to threaten the ecological security of penguins. Previous studies have concluded that penguins on the Scott Coast, southern Ross Sea, disappeared from ∼2000 yr BP; two opposite hypotheses of “cooling” and “warming” have been proposed for the disappearance. Here, by identifying penguin guano and remains such as eggshell fragments, bones and feathers in a sediment profile from Dunlop Island, we found that this island was not abandoned at ∼2000 yr BP. In addition, sedimentological evidence from Cape Ross deduced the permanent snow/ice cover at ∼1700 yr BP, which is consistent with a Neoglacial cooling period on the Scott Coast. We suggest that Neoglacial cooling caused the widespread abandonment of penguin colonies on the Scott Coast, by the increased coastal sea ice and/or snow/ice accumulation. However, penguins persisted at particular localities due to specific topographical or oceanic conditions shielding them from the impacts of snow and ice.
Extreme weather events are becoming more frequent and severe, leading to an increase in direct, adverse thermoregulatory impacts on wildlife. Here, we document an unprecedented, single-day, heat-related mortality event of Magellanic Penguins (Spheniscus magellanicus) at Punta Tombo, Chubut Province, Argentina, one of the largest breeding colonies for this species. We found 264 dead adults and 90 dead chicks in the breeding colony and along the beaches after recording the highest temperature in the shade (44°C on January 19, 2019) since the study started in December 1982. We found dead adults and chicks in postures used to release heat (i.e. lying prone with flippers and feet extended away from the body and/or bills open). We found no evidence for other causes of mortality other than heat (e.g., disease, toxic algae, starvation). Adults potentially died of dehydration, because dead adults were in significantly worse body condition than adults that survived. Dead adults had either empty stomachs or <50 g of food, and 27% of the dead adults died traveling between the nesting area and the water. More males died than females (83% male and 17% female; n = 94). In one section of the colony, ~5% of 1,153 adults died in the heat. Mortality rates of adults were unevenly distributed across the colony, suggesting that the presence of microclimates or easier beach access was an important factor to penguin survival. The body condition indices of dead and live chicks were similar and chicks that died from heat had food in their stomachs (mean = 405 ± 128 g; n = 14), suggesting that food likely inhibited their ability to thermoregulate. Documenting the effects of extreme weather events on populations is crucial to predicting how they will respond to climate change because these events, although rare, are expected to become more frequent and could have severe impacts on populations.
Changes in sea ice extent and polynya size and productivity associated with climate conditions in the Ross Sea region have an important role on the ecological responses of Adélie penguins (Pygoscelis adeliae). Nevertheless, there have been few studies that elaborate on the effects of atmospheric and oceanic circulation on their populations. Here, we reconstructed the population dynamics of Adélie penguins on Beaufort Island during the past 350 years using various alternative geochemical indices and Generalized Additive Models (GAMs). We explored the effects of atmospheric-ocean circulation patterns, including the El Niño-Southern Oscillation (ENSO), the Southern Annular Mode (SAM), and the Amundsen Sea Low (ASL), on the population ecology of penguins. The results indicated that their population on the island has been growing with fluctuations since ~1650 AD, and there were three significant increases, corresponding to 1650–1750, 1825–1900 and after 1950 AD. It was revealed that climate warming in this region was not a necessary factor for penguin population growth, since their populations maintained an increasing trend during the Little Ice Age (LIA) when relatively colder climate conditions prevailed. The present results indicated that atmospheric-ocean circulation patterns likely impose prominent influences on the historical change of penguin populations on Beaufort Island.
Foraging behaviour is crucial to breeding success for marine predators, including seabirds. Yellow-eyed penguins Megadyptes antipodes are central-place, predominantly benthic foragers around mainland New Zealand. The northern (mainland) population of this Endangered species is declining, with changes in the marine environment a suspected cause, particularly warming water and poorer foraging success. We undertook a detailed foraging study of the data-deficient subantarctic population, which is distinct from the northern population. Over 2 breeding seasons, we collected 91 GPS foraging logs from 69 breeding yellow-eyed penguins from Enderby Island, Auckland Islands, New Zealand. The mean foraging distance was 24 km from shore (max 47 km). Foraging area size was greater for females and for pelagic foragers, although benthic foragers travelled further from shore on average. Diving plasticity was evident both in diving behaviour and foraging area use. Foraging area and distance from shore were greater for all birds in a year of greater breeding effort and fledging success (2016). Foraging occurred over continental shelf waters, similar to the mainland, and in areas up to 150 m deep, so any differences in foraging behaviour compared to those reported for the northern population are likely influenced by local bathymetry, environmental conditions, and individual preference. Despite comparable bathymetry in some areas, the southern population showed greater foraging plasticity, with 62% of foraging trips categorised as pelagic, implying that subantarctic foraging conditions may differ from the predominantly benthic mainland foraging. Variable foraging conditions may therefore have implications for future breeding success in the subantarctic.
Rapid environmental changes can dramatically and durably affect the animal's foraging behavior. In the Ross Sea (Antarctica), calving of the Nansen Ice Shelf in 2016 opened a newly accessible marine area of 214 km2. In this study, we examined the foraging behavior of Adélie penguins from the nearby Inexpressible Island in December 2018, by tracking 27 penguins during their at-sea trips using GPS, depth and video loggers. The penguins mainly foraged within 88.2 ± 42.9 km of their colony, for 23.4 ± 6.8 h. Five penguins headed south to the newly exposed habitat along the Nansen Ice Shelf, whereas 22 penguins exploited previously available foraging areas. There was no significant difference in any of the foraging trip or diving parameters between the two penguin groups; however, in the calved region the penguins were diving into shallow areas more often than did the other penguins. These results show that Adélie penguins on Inexpressible Island had explored the newly exposed area after calving. We conclude that the penguins respond to newly available habitat following stochastic environmental events, either through information sharing at the colony, and/or by balancing prey availability per capita across the foraging sites. Considering that this penguin breeding area is under investigation for the establishment of an Antarctic Specially Protected Area (ASPA), the results of this study may provide insights for evaluating the ecological importance of this area and formulating an ASPA management plan for conservation.
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This paper describes the diet and foraging behaviour of Adelie penguins (Pygoscelis adeliae) at Bechervaise Island during 1998/99, a season of low breeding success. Fifty-six percent of nests with eggs failed during the three weeks following first hatch. A breeding success of 0.43 chicks cr6ched per nest was achieved, compared to previous seasons with higher annual breeding success rates ranging from 0.69 to 1.06 chicks crPched per nest. Evidence from analyses of foraging location, foraging trip duration and diet suggests that the death of chicks during the guard stage was due to an inadequate rate of food supply. In most previous seasons adults have foraged both at the continental shelf edge (particularly females) and locally (particularly males). This season male penguins carried out fewer local trips and both sexes spent longer at sea than in years of higher breeding success. Meal masses brought back to the chicks were within the normal range but extended foraging trip durations reduced feeding frequency. These findings contrast with observations made in 1994/95 (a season in which all chicks died of starvation), when smaller meals were delivered and birds foraged further offshore than in this or any other season studied. The significance to CCAMLR of these variations in foraging behaviour is discussed. Resume
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We report on the first global census of the Adelie Penguin (Pygoscelis adeliae), achieved using a combination of ground counts and satellite imagery, and find a breeding population 53% larger (3.79 million breeding pairs) than the last estimate in 1993. We provide the first abundance estimates for 41 previously unsurveyed colonies, which collectively contain 420,000 breeding pairs, and report on 17 previously unknown colonies, 11 of which may be recent colonizations. These recent colonizations represent similar to 5% of the increase in known breeding population and provide insight into the ability of these highly philopatric seabirds to colonize new breeding territories. Additionally, we report on 13 colonies not found in the survey, including 8 that we conclude have gone extinct. We find that Adelie Penguin declines on the Antarctic Peninsula are more than offset by increases in East Antarctica. Our global population assessment provides a robust baseline for understanding future changes in abundance and distribution. These results are a critically needed contribution to ongoing negotiations regarding the design and implementation of Marine Protected Areas for the Southern Ocean.
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Climate change is causing more frequent and intense storms, and climate models predict this trend will continue, potentially affecting wildlife populations. Since 1960 the number of days with >20 mm of rain increased near Punta Tombo, Argentina. Between 1983 and 2010 we followed 3496 known-age Magellanic penguin (Spheniscus magellanicus) chicks at Punta Tombo to determine how weather impacted their survival. In two years, rain was the most common cause of death killing 50% and 43% of chicks. In 26 years starvation killed the most chicks. Starvation and predation were present in all years. Chicks died in storms in 13 of 28 years and in 16 of 233 storms. Storm mortality was additive; there was no relationship between the number of chicks killed in storms and the numbers that starved (P = 0.75) or that were eaten (P = 0.39). However, when more chicks died in storms, fewer chicks fledged (P = 0.05, R (2) = 0.14). More chicks died when rainfall was higher and air temperature lower. Most chicks died from storms when they were 9-23 days old; the oldest chick killed in a storm was 41 days old. Storms with heavier rainfall killed older chicks as well as more chicks. Chicks up to 70 days old were killed by heat. Burrow nests mitigated storm mortality (N = 1063). The age span of chicks in the colony at any given time increased because the synchrony of egg laying decreased since 1983, lengthening the time when chicks are vulnerable to storms. Climate change that increases the frequency and intensity of storms results in more reproductive failure of Magellanic penguins, a pattern likely to apply to many species breeding in the region. Climate variability has already lowered reproductive success of Magellanic penguins and is likely undermining the resilience of many other species.
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IN THE CONTEXT OF PREDICTED ALTERATION OF SEA ICE COVER AND INCREASED FREQUENCY OF EXTREME EVENTS, IT IS ESPECIALLY TIMELY TO INVESTIGATE PLASTICITY WITHIN ANTARCTIC SPECIES RESPONDING TO A KEY ENVIRONMENTAL ASPECT OF THEIR ECOLOGY: sea ice variability. Using 13 years of longitudinal data, we investigated the effect of sea ice concentration (SIC) on the foraging efficiency of Adélie penguins (Pygoscelis adeliae) breeding in the Ross Sea. A 'natural experiment' brought by the exceptional presence of giant icebergs during 5 consecutive years provided unprecedented habitat variation for testing the effects of extreme events on the relationship between SIC and foraging efficiency in this sea-ice dependent species. Significant levels of phenotypic plasticity were evident in response to changes in SIC in normal environmental conditions. Maximum foraging efficiency occurred at relatively low SIC, peaking at 6.1% and decreasing with higher SIC. The 'natural experiment' uncoupled efficiency levels from SIC variations. Our study suggests that lower summer SIC than currently observed would benefit the foraging performance of Adélie penguins in their southernmost breeding area. Importantly, it also provides evidence that extreme climatic events can disrupt response plasticity in a wild seabird population. This questions the predictive power of relationships built on past observations, when not only the average climatic conditions are changing but the frequency of extreme climatic anomalies is also on the rise.
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Infrared satellite images of the coastal area off Adélie Land were examined together with two wind data sets, one from the manned French station, Dumont d'Urville, the other one from an Automatic Weather Station (AWS) during the 1986 austral winter. A correlation between the development of open water areas (polynyas) and the appearance of extremely strong offshore winds can be drawn. The wind direction tended to be more perpendicular to the coastline during these extreme , suggesting a katabatic origin of the increase in wind strength. In the study area the influence of the katabatic wind on the sea ice extends 20–100 km offshore. Sea ice motion further off the coast seems to be more dominated by synoptic scale weather systems. Broader scale atmospheric influences may create large polynya structures which influence the development of coastal winds, as the temperature contrast between open water and the cold continent generates its own circulation. Strong wind events can have a weakening effect on the coastal sea ice which can lead to a much more sensitive reaction of the sea ice in response to following anomalous wind events.
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A study of polynya characteristics in East Antarctica was undertaken using ice concentrations derived from special sensor microwave/imager data for the period July 1987-August 1994. The areas of polynyas were defined as having an ice concentration ≤75%. The analysis revealed a total of 28 coastal polynyas within the study region. The spatial and temporal variability in areal extent was quantified. The timing of mean maximum areal extent varied from June to October. The bathymetry and wind regime at each polynya site was examined to gauge the relative importance of these parameters in polynya formation and maintenance. In 20 locations, shallow banks and shoals form grounding zones for icebergs and anchoring sites for fast ice, which form barriers to the predominantly westward drift of the pack ice; elsewhere north-south coastal protrusions or alignments form similar barriers. The subsequent removal of newly formed sea ice from the lee of such barriers by katabatic and synoptic winds maintains areas of reduced ice concentration and open water. Very few coastal polynyas are attributed solely to katabatic outflow. The combined influence of bathymetry, topography and winds is responsible for the characteristics of the majority of polynyas. Many were considered to be marginal, characterised by occasional periods when the ice concentration falls below 75%. An analysis of annual winter totals of areas with ice concentrations <75% shows no trends in total polynya areal extent over the period 1987-94. Known locations of emperor penguin (Aplenodytes forsteri) rookeries were also found to be associated with the locations of coastal polynyas.
Mahlon C. Kennicutt II, Steven L. Chown and colleagues outline the most pressing questions in southern polar research, and call for greater collaboration and environmental protection in the region.