Article

Projected continent-wide declines of the emperor penguin under climate change

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Abstract

Climate change has been projected to affect species distribution(1) and future trends of local populations(2,3), but projections of global population trends are rare. We analyse global population trends of the emperor penguin (Aptenodytes forsteri), an iconic Antarctic top predator, under the influence of sea ice conditions projected by coupled climate models assessed in the Intergovernmental Panel on Climate Change (IPCC) effort(4). We project the dynamics of all 45 known emperor penguin colonies(5) by forcing a sea-ice-dependent demographic model(6,7) with local, colony-specific, sea ice conditions projected through to the end of the twenty-first century. Dynamics differ among colonies, but by 2100 all populations are projected to be declining. At least two-thirds are projected to have declined by > 50% from their current size. The global population is projected to have declined by at least 19%. Because criteria to classify species by their extinction risk are based on the global population dynamics(8), global analyses are critical for conservation(9). We discuss uncertainties arising in such global projections and the problems of defining conservation criteria for species endangered by future climate change.

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... All of those classed as endangered have population trends that are decreasing (Table 1). The populations' trend for emperor penguins is unknown (Table 1); however, various studies suggest that they will decline in the coming decades (Jenouvrier et al. 2009(Jenouvrier et al. , 2012(Jenouvrier et al. , 2014Trathan et al. 2011Trathan et al. , 2020. Indeed, it is recommended for the status of emperor penguins to be changed to vulnerable in the IUCN Red List due to the projected scenarios for this species (Trathan et al. 2020). ...
... However, the impact of global factors on penguins, such as climate change and how it may change in the future, is yet to be evaluated in numerous species (Gutt et al. 2015;Rintoul et al. 2018;Trathan et al. 2015;Xavier et al. 2017). Previous research suggests that ice-intolerant penguins (e.g., gentoo penguins) have expanded their range southward, whereas ice-obligate penguin species (e.g., emperor and Adélie penguins) may shift their distribution poleward in the future (Forcada and Trathan 2009;Jenouvrier et al. 2009Jenouvrier et al. , 2012Jenouvrier et al. , 2014McClintock et al. 2008). Such scenarios may vary regionally, as for example, Adélie penguins populations have been declining at the West Antarctic Peninsula, but increasing in the Ross Sea and some parts of the eastern Antarctica (Lynch et al. 2012;Trivelpiece et al. 2011). ...
... Indeed, projected changes for the twenty-first century are expected to have an impact in the feeding and foraging ecology of king penguins as well as their population sizes: foraging distance may increase (Cristofari et al. 2018), but detailed understanding is still not yet complete (Meijers et al. 2019). Also, based on long-term datasets, the projected impact of environmental change in emperor penguins will be negative, particularly following changes in the extent, formation, and persistence of sea ice, especially fast ice (Jenouvrier et al. 2014;Trathan et al. 2020). A climate-dependent demographic model projected that many colonies of emperor penguins would decrease from their current size by 2100 (assuming no emigration (Jenouvrier et al. 2014;Trathan et al. 2020)), and that including emigration may slow the anticipated global population decrease, but ultimately only delay it (Jenouvrier et al. 2017). ...
Chapter
Penguins (Family Spheniscidae) are aquatic flightless seabirds breeding in the South Hemisphere, with high diversity in the sub-Antarctic islands (Williams 1995). Some penguins (e.g., Chinstrap penguins Pygoscelis antarcticus, macaroni penguins Eudyptes chrysolophus) breed in vast colonies where food resources are predictable and profitable (Horswill et al. 2016; Lynch et al. 2016). Their physiology is highly specialized for diving, being efficient and fast swimmers (Cherel et al. 2005; Orgeret et al. 2016), with various adaptations in circulatory and metabolic systems (Green et al. 2001). For example, they possess flipper-like wings for wing-propelled diving, densely packed insulating feathers, eyes sensitivity for underwater predation, dense bones, stiff wing joints, and reduced distal wing musculature to overcome buoyancy in water (Ksepka and Ando 2011; Pan et al. 2019; Sivak and Millodot 1977; Taylor 1986). Their sizes range from over 1 m (emperor penguins Aptenodytes forsteri) to less than 0.5 m (little penguins Eudyptula minor) (Williams 1995). By having such diverse distribution and ecology, penguins provide a very interesting model for understanding evolutionary processes such as speciation, adaptation, and demography (Pan et al. 2019). Penguins are considered bioindicators or sentinels of the marine environment health (Barbraud et al. 2020; Boersma 2008; Trathan et al. 2015; Xavier et al. 2017, 2018a) with >90% of all penguins living in the Southern Ocean (Barbraud et al. 2020). This Chapter the diversity, threats and the role in Antarctic marine ecosystems of penguins
... In this review, we therefore highlight some of the potential outcomes of climate change and suggest possible approaches for the effective management of one species, the emperor penguin, Aptenodytes forsteri. We focus on this iconic species as there is a growing body of evidence highlighting the challenges facing this species, given projected climatic conditions over the coming century (Jenouvrier et al., 2009(Jenouvrier et al., , 2012(Jenouvrier et al., , 2014(Jenouvrier et al., , 2017Ainley et al., 2010;Trathan et al., 2011). The emperor penguin is one of the few species (possibly the only one) for which we have modelled colony population forecasts for the global population over the entire species range (Jenouvrier et al., 2014). ...
... We focus on this iconic species as there is a growing body of evidence highlighting the challenges facing this species, given projected climatic conditions over the coming century (Jenouvrier et al., 2009(Jenouvrier et al., , 2012(Jenouvrier et al., , 2014(Jenouvrier et al., , 2017Ainley et al., 2010;Trathan et al., 2011). The emperor penguin is one of the few species (possibly the only one) for which we have modelled colony population forecasts for the global population over the entire species range (Jenouvrier et al., 2014). Moreover, given this body of work, it is perhaps surprising that conservation actions have been slow to emerge. ...
... The current era of rapid environmental change is projected to negatively impact the emperor penguin, particularly by changing the extent, formation and persistence of sea ice, especially fast ice (e.g. Jenouvrier et al., 2009Jenouvrier et al., , 2012Jenouvrier et al., , 2014Jenouvrier et al., , 2017Ainley et al., 2010;Trathan et al., 2011). Owing to regional differences in climate, different colonies may have dissimilar population trajectories (Barber-Meyer et al., 2008;Kooyman and Ponganis, 2016;Jenouvrier et al., 2014), in some cases related to emigration (LaRue et al., 2015;Jenouvrier et al., 2017). ...
Article
Full-text available
We argue the need to improve climate change forecasting for ecology, and importantly, how to relate long-term projections to conservation. As an example, we discuss the need for effective management of one species, the emperor penguin, Aptenodytes forsteri. This species is unique amongst birds in that its breeding habit is critically dependent upon seasonal fast ice. Here, we review its vulnerability to ongoing and projected climate change, given that sea ice is susceptible to changes in winds and temperatures. We consider published projections of future emperor penguin population status in response to changing environments. Furthermore, we evaluate the current IUCN Red List status for the species, and recommend that its status be changed to Vulnerable, based on different modelling projections of population decrease of ≥50% over the current century, and the specific traits of the species. We conclude that current conservation measures are inadequate to protect the species under future projected scenarios. Only a reduction in anthropogenic greenhouse gas emissions will reduce threats to the emperor penguin from altered wind regimes, rising temperatures and melting sea ice; until such time, other conservation actions are necessary, including increased spatial protection at breeding sites and foraging locations. The designation of large-scale marine spatial protection across its range would benefit the species, particularly in areas that have a high probability of becoming future climate change refugia. We also recommend that the emperor penguin is listed by the Antarctic Treaty as an Antarctic Specially Protected Species, with development of a species Action Plan.
... All of those classed as endangered have population trends that are decreasing (Table 1). The populations' trend for emperor penguins is unknown (Table 1); however, various studies suggest that they will decline in the coming decades (Jenouvrier et al. 2009(Jenouvrier et al. , 2012(Jenouvrier et al. , 2014Trathan et al. 2011Trathan et al. , 2020. Indeed, it is recommended for the status of emperor penguins to be changed to vulnerable in the IUCN Red List due to the projected scenarios for this species (Trathan et al. 2020). ...
... However, the impact of global factors on penguins, such as climate change and how it may change in the future, is yet to be evaluated in numerous species (Gutt et al. 2015;Rintoul et al. 2018;Trathan et al. 2015;Xavier et al. 2017). Previous research suggests that ice-intolerant penguins (e.g., gentoo penguins) have expanded their range southward, whereas ice-obligate penguin species (e.g., emperor and Adélie penguins) may shift their distribution poleward in the future (Forcada and Trathan 2009;Jenouvrier et al. 2009Jenouvrier et al. , 2012Jenouvrier et al. , 2014McClintock et al. 2008). Such scenarios may vary regionally, as for example, Adélie penguins populations have been declining at the West Antarctic Peninsula, but increasing in the Ross Sea and some parts of the eastern Antarctica (Lynch et al. 2012;Trivelpiece et al. 2011). ...
... Indeed, projected changes for the twenty-first century are expected to have an impact in the feeding and foraging ecology of king penguins as well as their population sizes: foraging distance may increase (Cristofari et al. 2018), but detailed understanding is still not yet complete (Meijers et al. 2019). Also, based on long-term datasets, the projected impact of environmental change in emperor penguins will be negative, particularly following changes in the extent, formation, and persistence of sea ice, especially fast ice (Jenouvrier et al. 2014;Trathan et al. 2020). A climate-dependent demographic model projected that many colonies of emperor penguins would decrease from their current size by 2100 (assuming no emigration (Jenouvrier et al. 2014;Trathan et al. 2020)), and that including emigration may slow the anticipated global population decrease, but ultimately only delay it (Jenouvrier et al. 2017). ...
... All of those classed as endangered have population trends that are decreasing (Table 1). The populations' trend for emperor penguins is unknown (Table 1); however, various studies suggest that they will decline in the coming decades (Jenouvrier et al. 2009(Jenouvrier et al. , 2012(Jenouvrier et al. , 2014Trathan et al. 2011Trathan et al. , 2020. Indeed, it is recommended for the status of emperor penguins to be changed to vulnerable in the IUCN Red List due to the projected scenarios for this species (Trathan et al. 2020). ...
... However, the impact of global factors on penguins, such as climate change and how it may change in the future, is yet to be evaluated in numerous species (Gutt et al. 2015;Rintoul et al. 2018;Trathan et al. 2015;Xavier et al. 2017). Previous research suggests that ice-intolerant penguins (e.g., gentoo penguins) have expanded their range southward, whereas ice-obligate penguin species (e.g., emperor and Adélie penguins) may shift their distribution poleward in the future (Forcada and Trathan 2009;Jenouvrier et al. 2009Jenouvrier et al. , 2012Jenouvrier et al. , 2014McClintock et al. 2008). Such scenarios may vary regionally, as for example, Adélie penguins populations have been declining at the West Antarctic Peninsula, but increasing in the Ross Sea and some parts of the eastern Antarctica (Lynch et al. 2012;Trivelpiece et al. 2011). ...
... Indeed, projected changes for the twenty-first century are expected to have an impact in the feeding and foraging ecology of king penguins as well as their population sizes: foraging distance may increase (Cristofari et al. 2018), but detailed understanding is still not yet complete (Meijers et al. 2019). Also, based on long-term datasets, the projected impact of environmental change in emperor penguins will be negative, particularly following changes in the extent, formation, and persistence of sea ice, especially fast ice (Jenouvrier et al. 2014;Trathan et al. 2020). A climate-dependent demographic model projected that many colonies of emperor penguins would decrease from their current size by 2100 (assuming no emigration (Jenouvrier et al. 2014;Trathan et al. 2020)), and that including emigration may slow the anticipated global population decrease, but ultimately only delay it (Jenouvrier et al. 2017). ...
... Emperor penguins (Aptenodytes forsteri) are iconic examples of a species threatened by future climate change (Barbraud & Weimerskirch, 2001;Forcada & Trathan, 2009;Jenouvrier, Garnier, Patout, & Desvillettes, 2017;Jenouvrier et al., 2014;Ropert-Coudert et al., 2019). The emperor penguin is classified as 'near threatened' by the International Union for the Conservation of Nature and is currently under consideration for inclusion under the United States Endangered Species Act. ...
... Projections indicate that most breeding colonies will be endangered by 2100 under 'business as usual' emissions scenarios (Jenouvrier et al., 2014), resulting in dramatic declines in the global population size even under optimistic dispersal scenarios (Jenouvrier et al., 2017). These declines occur through projected loss of Antarctic sea ice, to which the emperor penguin life cycle is closely tied. ...
... Our study integrates these new climate projections with a mechanistic metapopulation model previously developed by Jenouvrier, Caswell, Barbraud, and Weimerskirch (2010) and Jenouvrier et al. (2012Jenouvrier et al. ( , 2014Jenouvrier et al. ( , 2017, providing fundamental insight into the capacity for near-term global action on climate policy to alter the future of an iconic marine predator. ...
Article
The Paris Agreement is a multinational initiative to combat climate change by keeping a global temperature increase in this century to 2°C above preindustrial levels while pursuing efforts to limit the increase to 1.5°C. Until recently, ensembles of coupled climate simulations producing temporal dynamics of climate en route to stable global mean temperature at 1.5 and 2°C above preindustrial levels were not available. Hence, the few studies that have assessed the ecological impact of the Paris Agreement used ad-hoc approaches. The development of new specific mitigation climate simulations now provides an unprecedented opportunity to inform ecological impact assessments. Here we project the dynamics of all known emperor penguin (Aptenodytes forsteri) colonies under new climate change scenarios meeting the Paris Agreement objectives using a climate-dependent-metapopulation model. Our model includes various dispersal behaviors so that penguins could modulate climate effects through movement and habitat selection. Under business-as-usual greenhouse gas emissions, we show that 80% of the colonies are projected to be quasiextinct by 2100, thus the total abundance of emperor penguins is projected to decline by at least 81% relative to its initial size, regardless of dispersal abilities. In contrast, if the Paris Agreement objectives are met, viable emperor penguin refuges will exist in Antarctica, and only 19% and 31% colonies are projected to be quasiextinct by 2100 under the Paris 1.5 and 2 climate scenarios respectively. As a result, the global population is projected to decline by at least by 31% under Paris 1.5 and 44% under Paris 2. However, population growth rates stabilize in 2060 such that the global population will be only declining at 0.07% under Paris 1.5 and 0.34% under Paris 2, thereby halting the global population decline. Hence, global climate policy has a larger capacity to safeguard the future of emperor penguins than their intrinsic dispersal abilities.
... Starting in 2012, the International Union for Conservation of Nature listed the emperor penguin as Near Threatened due to climate change threats (BirdLife International, 2021). In 2008, the US Fish and Wildlife Service (FWS) determined that the emperor penguin did not warrant listing under the ESA, in part because of uncertainty in future predictions of sea ice conditions and a lack of significant population decline at the time (US Fish and Wildlife Service, 2008a) (Table 1) (Jenouvrier et al., 2009(Jenouvrier et al., , 2012(Jenouvrier et al., , 2014 were not designed to provide assessments relevant to any legal framework. The analysis described below is specifically tailored for decision-making under the ESA, and expands upon previous research by assessing the effects of annual extreme climate-related perturbations through exploration of various climate scenarios. ...
... Our new analysis builds upon past work (Jenouvrier et al., , 2012(Jenouvrier et al., , 2014(Jenouvrier et al., , 2017, but integrates recent published knowledge about colony dynamics including models that reflect extreme perturbations, something hitherto not included. Specifically, our model includes the effect of sea ice concentrations on vital rates (survival and reproduction) and accounts for differences in the impact of sea ice concentrations on adult survival for males and females to project the intrinsic population growth rate at each colony ( Figure S2). ...
... Here, we present for the first time the regional population projections and Table S1 shows the details of the colony name included in each of the five regions. This model was built over a decade of research (Jenouvrier et al., , 2012(Jenouvrier et al., , 2014(Jenouvrier et al., , 2017; see Supplementary Methods) based on long-term dataset on breeding emperor penguins at Pointe Géologie (#35, Figure 1). This colony has been monitored every year from 1962 onwards allowing the estimation of breeding success and breeding pair number (Barbraud & Weimerskirch, 2001 Figure S2). ...
Article
Full-text available
Species extinction risk is accelerating due to anthropogenic climate change, making it urgent to protect vulnerable species through legal frameworks in order to facilitate conservation actions that help mitigate risk. Here, we discuss fundamental concepts for assessing climate change risks to species using the example of the emperor penguin (Aptenodytes forsteri), currently being considered for protection under the US Endangered Species Act (ESA). This species forms colonies on Antarctic sea ice, which is projected to significantly decline due to ongoing greenhouse gas (GHG) emissions. We project the dynamics of all known emperor penguin colonies under different GHG emission scenarios using a climate-dependent meta-population model including the effects of extreme climate events based on the observational satellite record of colonies. Assessments for listing species under the ESA require information about how species resiliency, redundancy and representation (3Rs) will be affected by threats within the foreseeable future. Our results show that if sea ice declines at the rate projected by climate models under current energy system trends and policies, the 3Rs would be dramatically reduced and almost all colonies would become quasi-extinct by 2100. We conclude that the species should be listed as threatened under the ESA.
... Emperor penguins (Aptenodytes forsteri, Gray) depend on stable fast ice to breed successfully (with a few exceptions of historically land-based colonies) (Wienecke 2010). As the climate warms, sea ice thickness and extent are expected to decrease, negatively impacting many emperor penguin colonies, particularly those at latitudes north of 70°S (Barbraud & Weimerskirch 2001, Jenouvrier et al. 2009, 2014, Ainley et al. 2010. ...
... Model predictions indicate that more southerly habitats should remain suitable for much longer (Ainley et al. 2010, Jenouvrier et al. 2014. ...
... As the sea ice season and stability decline at lower latitudes, many emperor penguin colonies are predicted to decrease in size or disappear (Jenouvrier et al. 2009, Ainley et al. 2010, Trathan et al. 2011, 2019. The Ross Sea may become a refuge for this and other ice-obligate species as populations shift south (Jenouvrier et al. 2009, 2014, Ainley et al. 2010. Indeed, movement between colonies may be a regular and adaptive occurrence for the species that enables it to cope with variable fast ice over the long term (LaRue et al. 2015, Cristofari et al. 2016. ...
Article
Full-text available
Emperor penguins require stable fast ice, sea ice anchored to land or ice shelves, on which to lay eggs and raise chicks. As the climate warms, changes in sea ice are expected to lead to substantial declines at many emperor penguin colonies. The most southerly colonies have been predicted to remain buffered from the direct impacts of warming for much longer. Here, we report on the unusually early breakup of fast ice at one of the two southernmost emperor penguin colonies, Cape Crozier (77.5°S), in 2018, an event that may have resulted in a substantial loss of chicks from the colony. Fast ice dynamics can be highly variable and dependent on local conditions, but earlier fast ice breakup, influenced by increasing wind speed, as well as higher surface air temperatures, is a likely outcome of climate change. What we observed at Cape Crozier in 2018 highlights the vulnerability of this species to untimely storm events and could be an early sign that even this high-latitude colony is not immune to the effects of warming. Long-term monitoring will be key to understanding this species' response to climate change and altered sea ice dynamics.
... Indeed, their long generation time (e.g. 16 years for the emperor penguin (Jenouvrier et al. 2014) but see review for penguins in Forcada and Trathan (2009)) makes evolutionary adaptability unlikely Trathan 2009, Cristofari 2016). This mismatch between the time they would require to adapt and the velocity of the changes is seriously threatening their future (Trathan et al. 2007, Tulloch et al. 2019, Rogers et al. 2020) even though populations of the same species disseminated around Antarctica may not respond uniformly due to regional differences in changes to the physical environment ). ...
... They are the tallest (ca. 80 cm -120 cm when the neck is fully stretched) and heaviest (up to 45 kg) living penguins (Stonehouse 1953), and their lifespan remains still unknown but estimated to be around 35-40 years (Jenouvrier et al. 2014). ...
... Juveniles will not return to their colony of origin and spend their first years of life at sea. Female emperor penguins will start breeding at 3-6 years of age, while males between 4-8 years (Jenouvrier et al. 2005(Jenouvrier et al. , 2014 (Orians and Pearson 1979), i.e. these predators have to commute between their breeding colony to feed their offspring and their feeding areas. The species is even the only central-place predator breeding in the middle of the austral winter (Ainley et al. 2005). ...
Thesis
Iconic species used to raise public awareness, the Emperor penguin is first and foremost a top predator and umbrella species playing a pivotal role in Antarctic ecosystems. Standing at the forefront of climate upheavals, much remains to be learned about the ecology, distribution, and activities at sea of the species. Biologging allows to refine our understanding of the interactions between a species and the different components (biotic and abiotic) of its environment, in particular with a view of management, conservation, and assessment of the adaptive capacity of populations to face global change.In this study, we develop and share new equipment methods that increase equipment and data collection duration, while reducing the disturbance of the equipped individuals. By carrying out a spatio-temporal analysis of the data collected on individuals of different life-history stages, reproductive status, and from different colonies spanning around Antarctica, we investigate the species’ foraging behaviours and strategies and assess the influence of environmental conditions and habitat on these parameters. Such knowledge acquisition allows us to assess the degree of protection of the species at the scale of the Southern Ocean and to discuss strategic plans for conservation and management, such as the establishment of networks of Marine Protected Areas around the Antarctic continent.
... Further, a biogeographical shift of diatoms and their zooplankton predators away from the SIZ northward towards the ACC, could cause Antarctic predators to travel further to consume prey and return it to their young during the breeding season. This, in combination with declining sea ice, could cause population declines in species such as the Emperor penguin (Jenouvrier et al., 2014). ...
... If phytoplankton blooms occur before zooplankton populations are sufficiently large to graze them down, more production may be exported out of the pelagic ecosystem, reducing flow of biomass to top predators. Mismatch in phenology would be further complicated by changing sea ice cover in the Antarctic SIZ, which is necessary for krill (Meyer et al., 2009) and many sea birds (Jenouvrier et al., 2014;Iles et al., 2020) and marine mammals (Bester et al., 2017). In short, the basic rearrangements of phytoplankton communities shown here for the CESM1-LE under climate change could have a multitude of cascading consequences for Antarctic ecosystems. ...
Article
Full-text available
Southern Ocean phytoplankton production supports rich Antarctic marine ecosystems comprising copepods, krill, fish, seals, penguins, and whales. Anthropogenic climate change, however, is likely to drive rearrangements in phytoplankton community composition with potential ramifications for the whole ecosystem. In general, phytoplankton communities dominated by large phytoplankton, i.e., diatoms, yield shorter, more efficient food chains than ecosystems supported by small phytoplankton. Guided by a large ensemble of Earth system model simulations run under a high emission scenario (RCP8.5), we present hypotheses for how anthropogenic climate change may drive shifts in phytoplankton community structure in two regions of the Southern Ocean: the Antarctic Circumpolar Current (ACC) region and the sea ice zone (SIZ). Though both Southern Ocean regions experience warmer ocean temperatures and increased advective iron flux under 21st century climate warming, the model simulates a proliferation of diatoms at the expense of small phytoplankton in the ACC, while the opposite patterns are evident in the SIZ. The primary drivers of simulated diatom increases in the ACC region include warming, increased iron supply, and reduced light from increased cloudiness. In contrast, simulated reductions in ice cover yield greater light penetration in the SIZ, generating a phenological advance in the bloom accompanied by a shift to more small phytoplankton that effectively consume available iron; the result is an overall increase in net primary production, but a decreasing proportion of diatoms. Changes of this nature may promote more efficient trophic energy transfer via copepods or krill in the ACC region, while ecosystem transfer efficiency in the SIZ may decline as small phytoplankton grow in dominance, possibly impacting marine food webs sustaining Antarctic marine predators. Despite the simplistic ecosystem representation in our model, our results point to a potential shift in the relative success of contrasting phytoplankton ecological strategies in different regions of the Southern Ocean, with ramifications for higher trophic levels.
... Seabirds face multiple imminent threats (overfishing and incidental death, pollution, introduced species, habitat destruction, and human disturbance) that may seem more urgent than gradual climate change and its associated climate phenomena (Croxall et al., 2012;Quillfeldt & Masello, 2013). However, some of these threats are locally restricted, whereas the climate phenomena have the potential to alter an entire region and increase the cumulative pressures that affect many seabirds, especially endemic species (Quillfeldt & Masello, 2013;Jenouvrier et al., 2014). ...
... However, under the severe scenario, the prediction decreased to near −20%. This trend is similar to other studies described for seabirds, whose breeding distribution will be reduced by climate change (Jenouvrier et al., 2014;Krüger et al., 2018). This increase in habitable area is explained by the climatic conditions in southern Chile, and those climatic conditions will likely be similar to the current conditions of the central coast of Chile (Falvey & Garreaud, 2009;Garreaud, 2011). ...
Article
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Background The effects of global climate change on species inhabiting marine ecosystems are of growing concern, especially for endemic species that are sensitive due to restricted distribution. One method employed for determining the effects of climate change on the distribution of these organisms is species distribution modeling. Methods We generated a model to evaluate the potential geographic distribution and breeding distribution of the Peruvian pelican ( Pelecanus thagus ). Based on maximum entropy modeling (MaxEnt), we identified the environmental factors that currently affect its geographic distribution and breeding. Then we predicted its future distribution range under two climate change scenarios: moderate (rcp 2.6) and severe (rcp 8.5). Results The mean daytime temperature range and marine primary productivity explain the current potential distribution and breeding of the pelican. Under the future climate change scenarios, the spatial distribution of the pelican is predicted to slightly change. While the breeding distribution of the pelican can benefit in the moderate scenario, it is predicted to decrease (near −20 %) in the severe scenario. Discussion The current potential geographic distribution of the pelican is influenced to a large extent by thermal conditions and primary productivity. Under the moderate scenario, a slight increase in pelican breeding distribution is predicted. This increase in habitable area is explained by the climatic conditions in southern Chile, and those climatic conditions will likely be similar to the current conditions of the central coast of Chile. We predict that the coasts of southern Chile will constitute an important refuge for the conservation of the Peruvian pelican under future climate change scenarios.
... While most studies exploring population consequences of climate change have been conducted on declining and/or endangered populations (e.g., emperor penguin [Aptenodytes forsteri], Jenouvrier et al. 2009Jenouvrier et al. , 2012Jenouvrier et al. , 2014; polar bear [Ursus maritimus], Hunter et al. 2011), little is known regarding the response of abundant species to global warming (but see Gaillard et al. 2013, Vetter et al. 2015, and Gauthier et al. 2016 for examples on roe deer [Capreolus capreolus], wild boar [Sus scrofa], and Greater Snow Goose [Chen caeruslescens atlantica], respectively). Thus, we focused on wild boar, a widespread and abundant species across Europe that mainly feeds on acorns when available (Massei et al. 1996, Schley and Roper 2003, Servanty et al. 2009). ...
Article
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Mast seeding in temperate oak populations shapes the dynamics of seed consumers and numerous communities. Mast seeding responds positively to warm spring temperatures and is therefore expected to increase under global warming. We investigated the potential effects of changes in oak mast seeding on wild boar population dynamics, a widespread and abundant consumer species. Using long-term monitoring data, we showed that abundant acorn production enhances the proportion of breeding females. With a body mass-structured population model and a fixed hunting rate of 0.424, we showed that high acorn production over time would lead to an average wild boar population growth rate of 1.197 whereas non-acorn production would lead to a stable population. Finally, using climate projections and a mechanistic model linking weather data to oak reproduction, we predicted that mast seeding frequency might increase over the next century, which would lead to increase in both wild boar population size and the magnitude of its temporal variation. Our study provides rare evidence that some species could greatly benefit from global warming thanks to higher food availability and therefore highlights the importance of investigating the cascading effects of changing weather conditions on the dynamics of wild animal populations to reliably assess the effects of climate change.
... Different functional relationships and contrasting population trends reflect regionally specific differences in sea ice change and variability, and in species ecology and life history (Jenouvrier et al., 2005;Massom and Stammerjohn, 2010;Constable et al., 2014;. Sea ice characteristics affect foraging behavior (e.g., Le Guen et al., 2018) and breeding habitat , with consequences on vital rates (reproduction: Jenouvrier et al., 2003;Massom et al., 2009;Stroeve et al., 2016;Ropert-Coudert et al., 2018a;survival: Barbraud and Weimerskirch, 2001b;Jenouvrier et al., 2005;Kooyman et al., 2007;Fretwell and Trathan, 2019), ultimately affecting population dynamics (Jenouvrier et al., 2003Ainley et al., 2010) and species persistence (Jenouvrier et al., 2014). ...
Article
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The massive number of seabirds (penguins and procellariiformes) and marine mammals (cetaceans and pinnipeds) – referred to here as top predators – is one of the most iconic components of the Antarctic and Southern Ocean. They play an important role as highly mobile consumers, structuring and connecting pelagic marine food webs and are widely studied relative to other taxa. Many birds and mammals establish dense breeding colonies or use haul-out sites, making them relatively easy to study. Cetaceans, however, spend their lives at sea and thus aspects of their life cycle are more complicated to monitor and study. Nevertheless, they all feed at sea and their reproductive success depends on the food availability in the marine environment, hence they are considered useful indicators of the state of the marine resources. In general, top predators have large body sizes that allow for instrumentation with miniature data-recording or transmitting devices to monitor their activities at sea. Development of scientific techniques to study reproduction and foraging of top predators has led to substantial scientific literature on their population trends, key biological parameters, migratory patterns, foraging and feeding ecology, and linkages with atmospheric or oceanographic dynamics, for a number of species and regions. We briefly summarize the vast literature on Southern Ocean top predators, focusing on the most recent syntheses. We also provide an overview on the key current and emerging pressures faced by these animals as a result of both natural and human causes. We recognize the overarching impact that environmental changes driven by climate change have on the ecology of these species. We also evaluate direct and indirect interactions between marine predators and other factors such as disease, pollution, land disturbance and the increasing pressure from global fisheries in the Southern Ocean. Where possible we consider the data availability for assessing the status and trends for each of these components, their capacity for resilience or recovery, effectiveness of management responses, risk likelihood of key impacts and future outlook.
... Breeding emperor penguins are colonial, returning to discrete locations each year and huddling for protection from the wind and cold, especially during incubation, which occurs during the coldest part of the year (July-August), when temperatures at breeding sites may drop below À40°C. Their need for stable fast ice renders emperor penguins vulnerable to altered wind regimes, rising temperatures and reduced sea ice extent and persistence, as many recent studies have highlighted (Ainley et al. 2010;Jenouvrier et al. 2014;Jenouvrier et al. 2017;Jenouvrier et al. 2019). All such studies project that a large percentage of the emperor penguin population will be lost by the end of this century. ...
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The distribution of emperor penguins is circumpolar, with 54 colony locations currently reported of which 50 are currently extant as of 2019. Here we report on eight newly discovered colonies and confirm the rediscovery of three breeding sites, only previously reported in the era before Very High Resolution satellite imagery was available, making a total of 61 breeding locations. This represents an increase of ~20% in the number of breeding sites, but, as most of the colonies appear to be small, they may only increase the total population by around 5–10%. The discoveries have been facilitated by the use of Sentinel2 satellite imagery, which has a higher resolution and more efficient search mechanism than the Landsat data previously used to search for colonies. The small size of these new colonies indicates that considerations of reproductive output in relation to metabolic rate during huddling is likely to be of interest. Some of the colonies exist in offshore habitats, something not previously reported for emperor penguins. Comparison with recent modelling results show that the geographic locations of all the newly found colonies are in areas likely to be highly vulnerable under business‐as‐usual greenhouse gas emissions scenarios, suggesting that population decreases for the species will be greater than previously thought. Sentinel2 enables us to track and discover emperor penguin colonies. We use the new technology to discover 11 new colony sites, increasing the number of known colonies by 20%. However, it is not all good news for emperors, as all the newly found colonies are in areas vulnerable to future sea ice loss, and the new discoveries actually make the species more vulnerable to climate change than previously thought.
... In the Earth system, changes to sea ice have the capacity to impact local boundary layer clouds, temperature, and humidity, which can feed back on sea ice evolution (Boisvert & Stroeve, 2015;Huang et al., 2019;Kay & Gettelman, 2009;Morrison et al., 2018) and the large-scale atmospheric circulation (e.g., Alexander, 2004;Barnes & Screen, 2015;Deser et al., 2016). Changing sea ice impacts ecosystems and human infrastructure (Hunter et al., 2010;Jenouvrier et al., 2014;Kovacs et al., 2011;Moon et al., 2019). In order to assess possible future sea ice changes and their impacts with confidence, we must evaluate our historical climate model representations of the sea ice state as well as their representation of variability and trends. ...
Article
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Arctic and Antarctic sea ice has undergone significant and rapid change with the changing climate. Here, we present preindustrial and historical results from the newly released Community Earth System Model Version 2 (CESM2) to assess the Arctic and Antarctic sea ice. Two configurations of the CESM2 are available that differ only in their atmospheric model top and the inclusion of comprehensive atmospheric chemistry, including prognostic aerosols. The CESM2 configuration with comprehensive atmospheric chemistry has significantly thicker Arctic sea ice year-round and better captures decreasing trends in sea ice extent and volume over the satellite period. In the Antarctic, both CESM configurations have similar mean state ice extent and volume, but the ice extent trends are opposite to satellite observations. We find that differences in the Arctic sea ice between CESM2 configurations are the result of differences in liquid clouds. Over the Arctic, the CESM2 configuration without prognostic aerosol formation has fewer aerosols to form cloud condensation nuclei, leading to thinner liquid clouds. As a result, the sea ice receives much more shortwave radiation early in the melt season, driving a stronger ice albedo feedback and leading to additional sea ice loss and significantly thinner ice year-round. The aerosols necessary for the Arctic liquid cloud formation are produced from different precursor emissions and transported to the Arctic. Thus, the main reason sea ice differs in the Arctic is the transport of cloud-impacting aerosols into the region, while the Antarctic remains relatively pristine from extrapolar aerosol transport.
... The rate of anthropogenic heat and carbon uptake in the SO is a key influence on the rate of global warming not just in the future, but in the present day (Frölicher et al., 2015;Hwang et al., 2017;Bushinsky et al., 2019;Gruber et al., 2019). Within the region, sensitive ecosystems are projected to be strongly affected by, for example, changes in sea ice extent, ice-free land area and regional warming (Jenouvrier et al., 2014;Turner et al., 2014;Lee et al., 2017;Rintoul et al., 2018). Therefore, although isolated geographically from the main concentrations of human population, Antarctica is at the centre of one of the major regulators and drivers of climate change globally. ...
Article
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Two decades into the 21st century there is growing evidence for global impacts of Antarctic and Southern Ocean climate change. Reliable estimates of how the Antarctic climate system would behave under a range of scenarios of future external climate forcing are thus a high priority. Output from new model simulations coordinated as part of the Coupled Model Intercomparison Project Phase 6 (CMIP6) provides an opportunity for a comprehensive analysis of the latest generation of state‐of‐the‐art climate models following a wider range of experiment types and scenarios than previous CMIP phases. Here the main broad‐scale 21st century Antarctic projections provided by the CMIP6 models are shown across four forcing scenarios: SSP1‐2.6, SSP2‐4.5, SSP3‐7.0 and SSP5‐8.5. End‐of‐century Antarctic surface‐air temperature change across these scenarios (relative to 1995–2014) is 1.3, 2.5, 3.7 and 4.8°C. The corresponding proportional precipitation rate changes are 8, 16, 24 and 31%. In addition to these end‐of‐century changes, an assessment of scenario dependence of pathways of absolute and global‐relative 21st century projections is conducted. Potential differences in regional response are of particular relevance to coastal Antarctica, where, for example, ecosystems and ice shelves are highly sensitive to the timing of crossing of key thresholds in both atmospheric and oceanic conditions. Overall, it is found that the projected changes over coastal Antarctica do not scale linearly with global forcing. We identify two factors that appear to contribute: (a) a stronger global‐relative Southern Ocean warming in stabilisation (SSP2‐4.5) and aggressive mitigation (SSP1‐2.6) scenarios as the Southern Ocean continues to warm and (b) projected recovery of Southern Hemisphere stratospheric ozone and its effect on the mid‐latitude westerlies. The major implication is that over coastal Antarctica, the surface warming by 2100 is stronger relative to the global mean surface warming for the low forcing compared to high forcing future scenarios. Surface climate changes across Antarctica and the Southern Ocean are assessed from CMIP6 21st century projections based on four radiative forcing scenarios: SSP1‐2.6, SSP2‐4.5, SSP3‐7.0 and SSP5‐8.5. 21st century Antarctic surface‐air temperature changes across these scenarios are 1.3, 2.5, 3.7 and 4.8°C. The corresponding proportional precipitation rate changes are 8, 16, 24 and 31%. However, when considering temperature responses relative the global mean change (GSAT) it is the lower forcing scenarios that exhibit more GSAT‐relative high‐latitude warming.
... An important challenge in the study of population fluctuations is to reveal the link between demographic parameters and climatic variables, mediated by their influence on foraging resources [1][2][3]. It is difficult, however, to single out the effect of a single climatic variable on a given biological system because variables can act directly [4], indirectly through multiple paths [5], alone [6] or in combination with others [7]. ...
Article
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Large-scale climatic indices are extensively used as predictors of ecological processes, but the mechanisms and the spatio-temporal scales at which climatic indices influence these processes are often speculative. Here, we use long-term data to evaluate how a measure of individual breeding investment (the egg volume) of three long-lived and long-distance-migrating seabirds is influenced by i) a large-scale climatic index (the North Atlantic Oscillation) and ii) local-scale variables (food abundance, foraging conditions, and competition). Winter values of the North Atlantic Oscillation did not correlate with local-scale variables measured in spring, but surprisingly, both had a high predictive power of the temporal variability of the egg volume in the three study species, even though they have different life-history strategies. The importance of the winter North Atlantic Oscillation suggests carry-over effects of winter conditions on subsequent breeding investment. Interestingly, the most important local-scale variables measured in spring were associated with food detectability (foraging conditions) and the factors influencing its accessibility (foraging conditions and competition by density-dependence). Large-scale climatic indices may work better as pre-dictors of foraging conditions when organisms perform long distance migrations, while local-scale variables are more appropriate when foraging areas are more restricted (e.g. during the breeding season). Contrary to what is commonly assumed, food abundance does not directly translate into food intake and its detectability and accessibility should be considered in the study of food-related ecological processes.
... Furthermore, mean winter SIC explained over 80% of the variation in population trends across this range of conditions. Thus, efforts to fuse our population model with IPCC-class climate projections will avoid extrapolations into novel climate conditions and thereby provide robust insights into potential changes in Adélie distribution and abundance under scenarios of future change (Ballerini, Tavecchia, Pezzo, Jenouvrier, & Olmastroni, 2015;Iles & Jenouvrier, 2019;Jenouvrier, 2013;Jenouvrier et al., 2014). ...
Article
Understanding the scales at which environmental variability affects populations is critical for projecting population dynamics and species distributions in rapidly changing environments. Here, we used a multi‐level Bayesian analysis of range‐wide survey data for Adélie penguins to characterize multi‐decadal‐ and annual effects of sea ice on population growth. We found that mean sea ice concentration at breeding colonies (i.e., “prevailing” environmental conditions) had robust non‐linear effects on multi‐decadal population trends and explained over 85% of the variance in mean population growth rates among sites. In contrast, despite considerable year‐to‐year fluctuations in abundance at most breeding colonies, annual sea ice fluctuations often explained less than 10% of the temporal variance in population growth rates. Our study provides an understanding of the spatially and temporally dynamic environmental factors that define the range limits of Adélie penguins, further establishing this iconic marine predator as a true sea ice obligate and providing a firm basis for projection under scenarios of future climate change. Yet, given the weak effects of annual sea ice relative to the large unexplained variance in year‐to‐year growth rates, the ability to generate useful short‐term forecasts of Adélie penguin breeding abundance will be extremely limited. Our approach provides a powerful framework for linking short‐ and longer‐term population processes to environmental conditions that can be applied to any species, facilitating a richer understanding of ecological predictability and sensitivity to global change.
... In response to growing concern for how a future changing environment will affect biota worldwide (Walther et al., 2002), there has been a strong focus by ecologists to develop quantitative models to predict the future trajectory and state of species' distributions and populations, with several studies focussing on Antarctic penguins Ballerini, Tavecchia, Pezzo, Jenouvrier, & Olmastroni, 2015;Che-Castaldo et al., 2017;Cimino, Lynch, Saba, & Oliver, 2016;Jenouvrier et al., 2009Jenouvrier et al., , 2012Jenouvrier et al., , 2014 (Elith & Leathwick, 2009). Our finding that Adélie penguins breeding in mountain nunatak habitats occur not only at higher occupancy rates, but also on steeper slopes and greater distances inland that are unoccupied in other regional populations, demonstrates that occupancy and habitat use are density-dependent and can vary under certain conditions for this species. ...
Article
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Abstract Density‐dependent regulation is an important process in spatio‐temporal population dynamics because it can alter the effects of synchronizing processes operating over large spatial scales. Most frequently, populations are regulated by density dependence when higher density leads to reduced individual fitness and population growth, but inverse density dependence can also occur when small populations are subject to higher extinction risks. We investigate whether density‐dependent regulation influences population growth for the Antarctic breeding Adélie penguin Pygoscelis adeliae. Understanding the prevalence and nature of density dependence for this species is important because it is considered a sentinel species reflecting the impacts of fisheries and environmental change over large spatial scales in the Southern Ocean, but the presence of density dependence could introduce uncertainty in this role. Using data on population growth and indices of resource availability for seven regional Adélie penguin populations located along the East Antarctic coastline, we find compelling evidence that population growth is constrained at some locations by the amount of breeding habitat available to individuals. Locations with low breeding habitat availability had reduced population growth rates, higher overall occupancy rates, and higher occupancy of steeper slopes that are sparsely occupied or avoided at other locations. Our results are consistent with evolutionary models of avian breeding habitat selection where individuals search for high‐quality nest sites to maximize fitness returns and subsequently occupy poorer habitat as population density increases. Alternate explanations invoking competition for food were not supported by the available evidence, but strong conclusions on food‐related density dependence were constrained by the paucity of food availability data over the large spatial scales of this region. Our study highlights the importance of incorporating nonconstant conditions of species–environment relationships into predictive models of species distributions and population dynamics, and provides guidance for improved monitoring of fisheries and climate change impacts in the Southern Ocean.
... This 'capital' breeding strategy contrasts with 'income' breeding, in which individuals rely directly on exogenous food sources consumed concomitantly with breeding to build offspring . Understanding such nutrient allocations during reproduction is valuable because it illuminates the evolution of life-history strategies and the relative importance of different habitats and food sources at different points during the annual cycle, a key factor in organismal responses to environmental shifts (Jenouvrier et al., 2014). However, tracing allocation of endogenous and exogenous nutrients to reproduction in wild animals is challenging. ...
Article
Capital breeders accumulate nutrients prior to egg development, then use these stores to support offspring development. In contrast, income breeders rely on local nutrients consumed contemporaneously with offspring development. Understanding such nutrient allocations is critical to assessing life-history strategies and habitat use. Despite the contrast between these strategies, it remains challenging to trace nutrients from endogenous stores or exogenous food intake into offspring. Here, we tested a new solution to this problem. Using tissue samples collected opportunistically from wild emperor penguins Aptenodytes forsteri, which exemplify capital breeding, we hypothesized that the stable carbon (δ13 C) and nitrogen (δ15 N) isotope values of individual amino acids (AAs) in endogenous stores (e.g. muscle) and in egg yolk and albumen reflect the nutrient sourcing that distinguishes capital versus income breeding. Unlike other methods, this approach does not require untested assumptions or diet sampling. We found that over half of essential AAs had δ13 C values that did not differ between muscle and yolk or albumen, suggesting that most of these AAs were directly routed from muscle into eggs. In contrast, almost all non-essential AAs differed in δ13 C values between muscle and yolk or between muscle and albumen, suggesting de novo synthesis. Over half of AAs that have labile nitrogen atoms (i.e. 'trophic' AA) had higher δ15 N values in yolk and albumen than in muscle, suggesting that they were transaminated during their routing into egg tissue. This effect was smaller for AAs with less labile nitrogen atoms (i.e. 'source' AA). Our results indicate that the δ15 N offset between trophic-source AAs (Δ15 Ntrophic-source ) may provide an index of the extent of capital breeding. The value of emperor penguin Δ15 NPro-Phe was higher in yolk and albumen than in muscle, reflecting the mobilization of endogenous stores; in comparison, the value of Δ15 NPro-Phe was similar across muscle and egg tissue in previously published data for income-breeding herring gulls Larus argentatus smithsonianus. Our results provide a quantitative basis for using AA δ13 C and δ15 N, and isotopic offsets among AAs (e.g. Δ15 NPro-Phe ), to explore the allocation of endogenous versus exogenous nutrients across the capital versus income spectrum of avian reproduction.
... For example, industrialization led to warmer climate which in turn rises temperatures in the poles causing the melting of ice sheets. Inhabitants of the polar regions like the polar bear and penguins, now face alarming levels of food scarcity (Hunter et al. 2010;Jenouvrier et al. 2014). Due to lack of arctic ice, polar bears often have to cover exceedingly long distances in search of prey. ...
Technical Report
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A tri-monthly newsletter published by Centre for studies in Ethnobiology, Biodiversity and Sustainability (CEiBa) that focusses on a diverse array of topics, mostly covering ecology and environment, natural and cultural history to oral history and conservation. The purpose is to introduce awe-inspiring facets of natural or semi-natural world to a wider group of readers who tend to distance themselves owing to inherent complexities of dry scientific findings. Moreover, it is also a vehicle of communication of aspiring scholars who wish to share their fascinating 'research stories'.
... This requires data on demographic rate means, variances and covariances, and population sizes divided into age or stage distributions (Johnson et al. 2010). Integrated population models (Kery and Schaub 2012) and transient life table response experiments (Koons et al. 2016(Koons et al. , 2017) that incorporate environmental stochasticity (Tuljapurkar 1982), correlations among demographic rates (Coulson et al. 2005), and non-stationarity (Jenouvrier et al. 2014) are useful tools for analysing demographic mechanisms underlying population fluctuations (Maldonado-Chaparro et al. 2018). ...
Chapter
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In this Chapter, we describe patterns of ungulate population dynamics, intrinsic and extrinsic causal factors underlying population growth, and consequences of variation in these causal factors in the face of anthropogenic change. We group ungulates as grazers and browsers, and review how each main functional feeding group copes with spatial and temporal variability of forage availability. Densities of browsers and grazers are highly variable in space and time, with the highest densities (top 10%) realized within specific body mass ranges. Among browsers, highest densities are usually found in smaller-bodied species (range: 20–233 kg, median: 45 kg), whereas highest densities for grazers are realized in larger species and within a wider body mass range (17–325 kg, median: 137.5 kg). A literature review of demographic processes (births, deaths, and movements) governing population dynamics suggests that direct effects of environmental variation on demographic rates, cohort effects, and indirect effects of perturbations on the age structure, all influence population growth rates. Additionally, the role of direct versus indirect effects can depend on life history strategies. Which specific demographic processes are most important to population growth rate are largely context dependent. Population growth rates of browsing and grazing ungulates are strongly influenced by environmental variation, with primary productivity—which varies strongly in space and time—the fundamental factor influencing the carrying capacity of a given area. Competition, direct and indirect effects of predation, and diseases can lower population densities below their resource-determined potential. Resource availability, predation, diseases, and perturbations of the environment (e.g. drought, fire, and land use change) interact synergistically in their regulation of herbivore populations to create indirect-, additive-, reciprocal-, and interaction-modifying relationships. In particular, human-caused perturbations (land use and climate change, introduction of livestock, and direct exploitation) may directly or indirectly affect both “bottom up” and “top down” regulation. A qualitative threat review indicates that obligate grazers in sub-tropical regions may be particularly threatened given the scale and diversity of anthropogenic perturbations projected to be influential.
... Demographic coalescent models have demonstrated dramatic population declines during the Pleistocene ice ages, followed by rapid population expansions in response to global warming [51][52][53][54]. Future global warming is predicted to cause significant population declines [44,[55][56][57]. Understanding past demographic histories and inferring future demographic trajectories therefore remain important steps for predicting ecosystem-wide changes in this rapidly warming part of the planet. ...
Article
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Background: Penguins (Sphenisciformes) are a remarkable order of flightless wing-propelled diving seabirds distributed widely across the southern hemisphere. They share a volant common ancestor with Procellariiformes close to the Cretaceous-Paleogene boundary (66 million years ago) and subsequently lost the ability to fly but enhanced their diving capabilities. With ∼20 species among 6 genera, penguins range from the tropical Galápagos Islands to the oceanic temperate forests of New Zealand, the rocky coastlines of the sub-Antarctic islands, and the sea ice around Antarctica. To inhabit such diverse and extreme environments, penguins evolved many physiological and morphological adaptations. However, they are also highly sensitive to climate change. Therefore, penguins provide an exciting target system for understanding the evolutionary processes of speciation, adaptation, and demography. Genomic data are an emerging resource for addressing questions about such processes. Results: Here we present a novel dataset of 19 high-coverage genomes that, together with 2 previously published genomes, encompass all extant penguin species. We also present a well-supported phylogeny to clarify the relationships among penguins. In contrast to recent studies, our results demonstrate that the genus Aptenodytes is basal and sister to all other extant penguin genera, providing intriguing new insights into the adaptation of penguins to Antarctica. As such, our dataset provides a novel resource for understanding the evolutionary history of penguins as a clade, as well as the fine-scale relationships of individual penguin lineages. Against this background, we introduce a major consortium of international scientists dedicated to studying these genomes. Moreover, we highlight emerging issues regarding ensuring legal and respectful indigenous consultation, particularly for genomic data originating from New Zealand Taonga species. Conclusions: We believe that our dataset and project will be important for understanding evolution, increasing cultural heritage and guiding the conservation of this iconic southern hemisphere species assemblage.
... However, the sea ice habitat that influences polar species is diverse at a fine scale (Ainley et al., 2010). Sea ice characteristics affect both the foraging routes and the effort of polar species (e.g., Le Guen et al., 2018), with consequences for their vital rates (reproduction: Massom et al., 2009;Ropert-Coudert et al., 2018;survival: Kooyman et al., 2007;Fretwell & Trathan, 2019), ultimately affecting population dynamics (Ainley et al., 2010) and species persistence (Jenouvrier et al., 2014). Yet, we lack an understanding of these proximate mechanisms. ...
Article
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Plain Language Summary Polar ecosystems are threatened by future loss of sea ice. The availability of satellite sea ice products has facilitated a better assessment of the impact of sea ice on polar species. Yet most studies have focused on coarse spatial scale sea ice products hampering an understanding of the mechanisms by which sea ice affects species. The development of fine‐scale sea ice products now provides an unprecedented opportunity to better understand the responses of sea ice obligate species to climate change. The emperor penguin is an iconic species threatened by projected sea ice loss in Antarctica. Here we used fine‐scale satellite sea ice observations to understand the emperor penguin's sea ice habitat during the entire breeding and Antarctic winter season. Sea ice characteristics affect both the foraging routes and effort of polar species, with consequences for their reproduction and survival, ultimately affecting population dynamics and species persistence. Emperor penguins dived at the edge of the landfast sea ice in cracks, flaw leads and open water areas called polynyas, formed by winds on both long and short time scales. By using daily passive microwave observations, we identified that emperor penguins did not venture into the large/persistent polynyas but dived instead in the ephemeral polynyas associated with daily changes in wind direction.
... Diese Prognose wird durch Modellrechnungen einer französischen Arbeitsgruppe gestützt, die bis zum Jahr 2100 einen langfristigen Rückgang um durchschnittlich 19 Prozent prognostizieren. Punktuell werden die Verluste Schätzungen zufolge durchaus auch 40 Prozente und mehr (bis zu 81 Prozent) betragen können [21,24]. ...
Article
Nach vorsichtigen Schätzungen beherbergt das antarktische Ökosystem knapp 200 Millionen Seevögel, davon sind etwa 26 Millionen Pinguine. Kaiserpinguine machen davon nur ca. 600.000 Individuen aus. Sie gehören zu den am wenigsten untersuchten Pinguinarten, weil sie nur auf dem Antarktischen Kontinent vorgelagerten Meereis brüten. Im Winter – während Eiablage und Brutzeit – sind sie durch einen bis zu 1.000 Kilometer breiten Meereisgürtel isoliert, der nur von Polynjas unterbrochen wird, offene Stellen im Eis, die den Vögeln Zugang zum Meer ermöglichen. Erst ab Oktober kommen auch Eisbrecher wieder in die Nähe einzelner Kolonien, so dass das Studium des ganzen Jahreszyklus, ja nicht einmal des ganzen Brutzyklus, nicht ohne weiteres möglich ist. 1902 wurde überhaupt die erste Kolonie in der Ostantarktis entdeckt. Ab den 1950er Jahren kamen gut 40 weitere dazu. Der Kontinent hat sehr lange (17.968 km) und unübersichtliche Küsten. Erst durch neue Techniken der Fernerkundung konnten neue Kolonien aus dem Weltraum entdeckt werden, heute zählt man mehr als 54 und gewinnt auch einen guten Überblick über die Population. Ihre Zukunft wird stark vom Eisregime abhängen. Die Tendenz in der West‐Antarktis ist stark rückläufig. Neue Auswertungen der letzten 40 Jahre der Eisentwicklung auf Satellitenfotos bestätigen auch deutliche Rückgänge für Teile der Ost‐Antarktis [23]. Emperor Pinguin – a bird of superlative The antarctic ecosystem is home of 200 million seabirds. 26 million of them belong to the penguins and only 600.000 are Emperor Penguins. They breed along the remote coasts of Antarctica. Their first colony was discovered in 1902. In the course of the 1950ies more colonies were detected and today with the help of satellite technique we know more than 54 in total. The breeding cycle starts during winter, when a 1.000 kilometer sea ice belt surrounds the continent. Emperor Penguins use Polynjas during this time to get access to the food sources in the sea. During incubation and breeding they are very hard to study due to stormy weather and temperatures of sometimes below minus 30° Celsius. From October onwards the first big icebreakers are capable to reach some of these places and biologists can start to study breeding success by counting chicks and adults. The few best monitored colonies are in the reach of Antarctic winter stations. Remote sensing of faeces stain on the ice give an introspection of the spacing of colonies all over the coasts. Counts in the colonies give figures of population sizes in relation to faeces covered areas. So we got a rough idea about the number of individuals. Satellite imaging over the last 40 years has provided data on the sea and glacier ice loss: Most loss is to be found in western Antarctica, but also in eastern Antarctica we can find more and more melting due to raising temperatures. Der Kaiserpinguin ist der schwerste heute lebende Vogel und besitzt proportional das kleinste Ei. Für die Brut im eisigen antarktischen Winter ist er auf das Meereis rund um den Kontinent angewiesen. Dieses ist jedoch auf dem Rückzug, mit Folgen für den Kaiserpinguin.
... Alternatively, certain species may be considered as "leading" sentinels, whereby population level responses in these species precede observable change in responses of other species or the ecosystem (Hazen et al., 2019). The penguin species that breed in Antarctica and forage in the Southern Ocean, feed extensively on krill or are ice-obligates, and are exemplar species for studying the potential links between system fluctuations and predator populations (e.g., fisheries pressures: Hinke et al., 2017;Trathan et al., 2018;Watters et al., 2020), or Antarctic marine ecosystem responses to environmental perturbations (e.g., climate change: Jenouvrier et al., 2014;Johnson et al., 2019;Emmerson et al., 2015;. Indeed, evidence already shows that penguin populations in particular are at risk from overexploitation of resources and climate change Dias et al., 2019;Ropert-Coudert et al., 2019). ...
Article
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Global targets for area-based conservation and management must move beyond threshold-based targets alone and must account for the quality of such areas. In the Southern Ocean around Antarctica, a region where key biodiversity faces unprecedented risks from climate change and where there is a growing demand to extract resources, a number of marine areas have been afforded enhanced conservation or management measures through two adopted marine protected areas (MPAs). However, evidence suggests that additional high quality areas could benefit from a proposed network of MPAs. Penguins offer a particular opportunity to identify high quality areas because these birds, as highly visible central-place foragers, are considered indicator species whose populations reflect the state of the surrounding marine environment. We compiled a comprehensive dataset of the location of penguin colonies and their associated abundance estimates in Antarctica. We then estimated the at-sea distribution of birds based on information derived from tracking data and through the application of a modified foraging radius approach with a density decay function to identify some of the most important marine areas for chick-rearing adult penguins throughout waters surrounding Antarctica following the Important Bird and Biodiversity Area (IBA) framework. Additionally, we assessed how marine IBAs overlapped with the currently adopted and proposed network of key management areas (primarily MPAs), and how the krill fishery likely overlapped with marine IBAs over the past five decades. We identified 63 marine IBAs throughout Antarctic waters and found that were the proposed MPAs to be adopted, the permanent conservation of high quality areas for penguin species would increase by between 49 and 100% depending on the species. Furthermore, our data show that, despite a generally contracting range of operation by the krill fishery in Antarctica over the past five decades, a consistently disproportionate amount of krill is being harvested within marine IBAs compared to the total area in which the fishery operates. Our results support the designation of the proposed MPA network and offer additional guidance as to where decision-makers should act before further perturbation occurs in the Antarctic marine ecosystem.
... Most observed impacts were assessed with low evidence, but high agreement, and focused on plants and insects. Impacts described included abundance changes and extirpations (Jenouvrier et al., 2014), altitudinal range shifts (Koide et al., 2017), increased invasive alien species' abundance and extent in Madagascar (H76, 77), Balearic (H51) and Pacific islands (Ghulam, 2014;Silva-Rocha et al., 2015;Goulding et al., 2016;Dawson et al., 2017), increased temperature affecting physiology, body size and behaviour of frogs in the Caribbean (H20) (Narins and Meenderink, 2014) and phenological alterations (Fontúrbel et al., 2018). One positive observation was the high resilience to recovery of intact forest ecosystems to tropical cyclones within Caribbean (H20) and Pacific islands (medium confidence) (Keppel et al., 2014;Marler, 2014;Shiels et al., 2014). ...
... To our knowledge, no studies of Antarctic vertebrate eDNA from snow samples have been published to date. This gap in the literature presents a potential for future eDNA studies on Antarctic wildlife (Box 1); importantly, eDNA could aid in monitoring of ice-dependent species that are likely to be negatively impacted by climate change in the near future (Siniff et al. 2008;Ainley et al. 2010;Jenouvrier et al. 2014;Trathan et al. 2020). Box 1. Weddell seals case study. ...
Article
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Antarctica is home to numerous species that are vulnerable to environmental change, and assessing species responses requires long-term monitoring. However, Antarctica’s extreme nature presents limitations to conducting the type of long-term or broad-scale studies necessary for understanding changes in community composition. In this paper, we evaluate the potential for the use of environmental DNA (eDNA) methods in expanding scientific research efforts for biodiversity monitoring and conservation genetics in Antarctica. Through a systematic literature review, we identify that most Antarctic eDNA studies have focused on microbial metabarcoding using samples from soil, sediment, snow, and water. Few eDNA studies in Antarctica have focused on vertebrate biodiversity or population genetics, but we highlight several examples that have effectively and creatively used eDNA to study vertebrates. We highlight the potential for the use of portable sequencing technologies in the future of Antarctic eDNA research. We conclude that eDNA could be a valuable tool for researchers in their efforts to assess, monitor, and conserve biodiversity in the Antarctic.
... The most effective actions to protect the emperor penguin from anthropogenic impacts would be a reduction in greenhouse gas emissions [31,32] as well as the establishment of MPAs throughout its habitat range [31]. Long-lived seabirds, emperor penguins reach sexual maturity between 4 and 8 years [33,34]. However, little is known about the first years at sea of the species, even though the survival of this age class referred as 'juvenile' is crucial for the viability of the global population [33,35]. ...
Article
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To protect the unique and rich biodiversity of the Southern Ocean, conservation measures such as marine protected areas (MPAs) have been implemented. Currently, the establishment of several additional protection zones is being considered based on the known habitat distributions of key species of the ecosystems including emperor penguins and other marine top predators. However, the distribution of such species at sea is often insufficiently sampled. Specifically, current distribution models focus on the habitat range of adult animals and neglect that immatures and juveniles can inhabit different areas. By tracking eight juvenile emperor penguins in the Weddell Sea over 1 year and performing a meta-analysis including previously known data from other colonies, we show that conservation efforts in the Southern Ocean are insufficient for protecting this highly mobile species, and particularly its juveniles. We find that juveniles spend approximately 90% of their time outside the boundaries of proposed and existing MPAs, and that their distribution extends beyond (greater than 1500 km) the species' extent of occurrence as defined by the International Union for Conservation of Nature. Our data exemplify that strategic conservation plans for the emperor penguin and other long-lived ecologically important species should consider the dynamic habitat range of all age classes.
... Except for Antarctic petrels, the current status and trends of most seabird species breeding in DML or using the marine area outside DML remains largely unknown. Data from the longest-studied population of emperor penguins at Terre Adélie coupled with future levels of sea ice variability modelled under various climate change scenarios demonstrated that not only is the demographic trajectory of the species highly dependent upon variability in sea ice, but that the DML coastline is predicted to be the region most likely to experience the greatest levels of sea ice variability into the future (Jenouvrier et al. 2014). Despite this apparent threat, there are no available data on emperor penguin populations in DML and their current trend is unknown. ...
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Despite the exclusion of the Southern Ocean from assessments of progress towards achieving the Convention on Biological Diversity (CBD) Strategic Plan, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) has taken on the mantle of progressing efforts to achieve it. Within the CBD, Aichi Target 11 represents an agreed commitment to protect 10% of the global coastal and marine environment. Adopting an ethos of presenting the best available scientific evidence to support policy makers, CCAMLR has progressed this by designating two Marine Protected Areas in the Southern Ocean, with three others under consideration. The region of Antarctica known as Dronning Maud Land (DML; 20°W to 40°E) and the Atlantic sector of the Southern Ocean that abuts it conveniently spans one region under consideration for spatial protection. To facilitate both an open and transparent process to provide the vest available scientific evidence for policy makers to formulate management options, we review the body of physical, geochemical and biological knowledge of the marine environment of this region. The level of scientific knowledge throughout the seascape abutting DML is polarized, with a clear lack of data in its eastern part which is presumably related to differing levels of research effort dedicated by national Antarctic programmes in the region. The lack of basic data on fundamental aspects of the physical, geological and biological nature of eastern DML make predictions of future trends difficult to impossible, with implications for the provision of management advice including spatial management. Finally, by highlighting key knowledge gaps across the scientific disciplines our review also serves to provide guidance to future research across this important region.
... For example, with continued lengthening thaw season and diminishing sea ice in the Arctic, polar bear distributions may shift away from prey dependent on sea ice such as ringed seal pups, and toward prey on solid ground, such as snow geese eggs (117), a shift that could reduce polar bear body condition and survival and increase competition with land-based brown bears (118). In Antarctica, receding glaciers have enabled more breeding habitat and increased abundances of Adélie penguins in some areas (119), whereas continued sea ice decline is detrimental to emperor penguin breeding habitat and populations (120). Multiple SAI scenarios predict diminished seasonality in high latitudes, with warmer winters and cooler summers, resulting in sea ice decreasing during winter and increasing during summer (32). ...
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Making informed future decisions about solar radiation modification (SRM; also known as solar geoengineering)—approaches such as stratospheric aerosol injection (SAI) that would cool the climate by reflecting sunlight—requires projections of the climate response and associated human and ecosystem impacts. These projections, in turn, will rely on simulations with global climate models. As with climate-change projections, these simulations need to adequately span a range of possible futures, describing different choices, such as start date and temperature target, as well as risks, such as termination or interruptions. SRM modeling simulations to date typically consider only a single scenario, often with some unrealistic or arbitrarily chosen elements (such as starting deployment in 2020), and have often been chosen based on scientific rather than policy-relevant considerations (e.g., choosing quite substantial cooling specifically to achieve a bigger response). This limits the ability to compare risks both between SRM and non-SRM scenarios and between different SRM scenarios. To address this gap, we begin by outlining some general considerations on scenario design for SRM. We then describe a specific set of scenarios to capture a range of possible policy choices and uncertainties and present corresponding SAI simulations intended for broad community use.
... There is also evidence of an increase of breeding attempts of king penguins in Antarctic Peninsula suggesting an expansion in their distribution (Petry et al. 2013, Juarés et al 2017, Borowicz et al. 2020). Finally, based on genomics, population sizes of emperor penguins also expanded in the warming period after the Last Glacial Maximum (Cole et al. 2019), but more recent declines at the Antarctic Peninsula and East Antarctica (see next subsection) are projected to shift their distribution pole ward during the 21st century (Jenouvrier et al. 2014). ...
... Penguins are observed and predicted to drastically abandon or relocate their breeding colonies in response to the climate change. By the end of 21 st century nearly all colonies of the Emperor penguin would experience substantial population decline of more than 90% (Jenouvrier et al., 2009(Jenouvrier et al., , 2014(Jenouvrier et al., , 2021. As a sea-ice dependent species, Ad elie penguins are observed to decrease in number at almost all locations on the Antarctic Peninsula (Lynch et al., 2012) due to reduced sea-ice extent. ...
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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.
... In only one species (northern gannet) was breeding success predicted to increase under the future climate scenario. Our results build upon previous findings that have demonstrated the importance of climate on breeding success and other vital rates in seabirds globally, but which have tended to focus on single breeding colonies or species (Jones et al. 2007, Barbraud et al. 2011, Jenouvrier et al. 2014, Monticelli et al. 2014, Carroll et al. 2015, Christensen-Dalsgaard et al. 2018; but see Sydeman et al. 2021) or on abundance, not vital rates (Johnson et al. 2013). Very few studies have estimated future vital rates for seabirds under projected future climates (but see Carroll et al. 2015) or across broad regions such as the North Sea (but see recent review by Pearce-Higgins 2021). ...
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Europe has set ambitious green energy targets, to which offshore renewable developments (ORDs) will make a significant contribution. Governments are legally required to deliver ORDs sustainably; however, they may have detrimental impacts on wildlife, especially those already experiencing declines due to climate change. Population viability analysis (PVA) is the standard method for forecasting population change in ORD assessments, but PVAs do not currently account for climate effects. We quantified climate effects on seabird breeding success for 8 UK species breeding in the North Sea. We assessed the potential for seabirds to mitigate climate-driven changes in breeding success by accessing wider resources through increased foraging ranges around colonies. We demonstrate strong links between breeding success and climate in 5 species. In 4 of these species, future climate projections indicated large declines in breeding success relative to current rates. Only one species was predicted to increase breeding success under future climate. In all 5 species, there was limited opportunity for species to increase breeding success by expanding foraging ranges to access more suitable future climatic conditions. Climate change will have significant ramifications for future breeding success of seabirds breeding in the North Sea, an area undergoing extensive and rapid offshore renewable energy development. We recommend 3 methods for including climate-driven changes to seabird breeding success within ORD assessments: development of predictive climate-driven habitat use models to estimate ORD-wildlife interactions; delivery of a new ORD assessment framework that includes dynamic predictions of climate-driven habitat use and demography of wildlife populations; and consideration of climate-driven changes in the implementation of compensatory measures.
... Most importantly, we define disturbance as a sudden event impacting the structure of the population (Capdevila, Stott, et al., 2020;Stott et al., 2011); however, perturbations can also alter the vital rates of a population (e.g. Capdevila et al., 2019;Jenouvrier et al., 2014). Changes in the vital rates will alter the stable structure of the population, generating discrepancies between the actual population structure and the stable structure. ...
... Most importantly, we define disturbance as a sudden event impacting the structure of the population (Capdevila, Stott, et al., 2020;Stott et al., 2011); however, perturbations can also alter the vital rates of a population (e.g. Capdevila et al., 2019;Jenouvrier et al., 2014). Changes in the vital rates will alter the stable structure of the population, generating discrepancies between the actual population structure and the stable structure. ...
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Accelerating rates of biodiversity loss underscore the need to understand how species achieve resilience—the ability to resist and recover from a/biotic disturbances. Yet, the factors determining the resilience of species remain poorly understood, due to disagreements on its definition and the lack of large‐scale analyses. Here, we investigate how the life history of 910 natural populations of animals and plants predicts their intrinsic ability to be resilient. We show that demographic resilience can be achieved through different combinations of compensation, resistance and recovery after a disturbance. We demonstrate that these resilience components are highly correlated with life history traits related to the species’ pace of life and reproductive strategy. Species with longer generation times require longer recovery times post‐disturbance, whilst those with greater reproductive capacity have greater resistance and compensation. Our findings highlight the key role of life history traits to understand species resilience, improving our ability to predict how natural populations cope with disturbance regimes.
... Emperor penguin is a relevant empirical example to test our theoretical prediction that long lived species (comparable to species 4) may permit an earlier detection of the time at which the signal of anthropogenic climate change emerges from the noise of natural climate variability (Fig. 3, section 4.2). Penguins are threatened by future climate change as most of their breeding colonies will be endangered by 2100 if greenhouse gases continue their current course [Jenouvrier et al., 2020[Jenouvrier et al., , 2014[Jenouvrier et al., , 2021. These declines occur through projected loss of Antarctic sea ice, which affects survival and reproduction. ...
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Climate impacts are not always easily discerned in wild populations as detecting climate change signals in populations is challenged by stochastic noise associated with natural climate variability, variability in biotic and abiotic processes, and observation error in demographic rates. Detection of the impact of climate change on populations requires making a formal distinction between signals in the population associated with long-term climate trends from those generated by stochastic noise. The time of emergence (ToE) identifies when the signal of anthropogenic climate change can be quantitatively distinguished from natural climate variability. This concept has been applied extensively in the climate sciences, but has not been explored in the context of population dynamics. Here, we outline an approach to detecting climate-driven signals in populations based on an assessment of when climate change drives population dynamics beyond the envelope characteristic of stochastic variations in an unperturbed state. Specifically, we present a theoretical assessment of the time of emergence of climate-driven signals in population dynamics (ToEpop). We identify the dependence of ToEpop on the magnitude of both trends and variability in climate and also explore the effect of intrinsic demographic controls on ToEpop. We demonstrate that different life histories (fast species vs. slow species), demographic processes (survival, reproduction) and the relationships between climate and demographic rates, yield population dynamics that filter climate trends and variability differently. We illustrate empirically how to detect the point in time when anthropogenic signals in populations emerge from stochastic noise for a species threatened by climate change: the emperor penguin. Finally, we propose six testable hypotheses and a road map for future research.
... Drawing on similar studies looking at climate sensitivities for marine mammals in the Arctic (Laidre et al., 2008), we build on the study by Siniff et al. (2008), to explain important habitat variables for each seal species. We discuss implications of a marine protected area (MPA) in one of the important climate refugia in the Southern Ocean (Jenouvrier et al., 2014;Teschke et al., 2020), the Weddell Sea. ...
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The impacts of climate change in Antarctica and the Southern Ocean are not uniform and ice-obligate species with dissimilar life-history characteristics will likely respond differently to their changing ecosystems. We use a unique data set of Weddell Leptonychotes weddellii and crabeater seals' (CESs) Lobodon carcinophaga breeding season distribution in the Weddell Sea, determined from satellite imagery. We contrast the theoretical climate impacts on both ice-obligate predators who differ in life-history characteristics: CESs are highly specialized Antarctic krill Euphausia superba predators and breed in the seasonal pack ice; Weddell seals (WESs) are generalist predators and breed on comparatively stable fast ice. We used presence–absence data and a suite of remotely sensed environmental variables to build habitat models. Each of the environmental predictors is multiplied by a ‘climate change score’ based on known responses to climate change to create a ‘change importance product’. Results show CESs are more sensitive to climate change than WESs. Crabeater seals prefer to breed close to krill, and the compounding effects of changing sea ice concentrations and sea surface temperatures, the proximity to krill and abundance of stable breeding ice, can influence their post-breeding foraging success and ultimately their future breeding success. But in contrast to the Ross Sea, here WESs prefer to breed closer to larger colonies of emperor penguins (Aptenodytes forsteri). This suggests that the Weddell Sea may currently be prey-abundant, allowing the only two air-breathing Antarctic silverfish predators (Pleuragramma antarctica) (WESs and emperor penguins) to breed closer to each other. This is the first basin-scale, region-specific comparison of breeding season habitat in these two key Antarctic predators based on real-world data to compare climate change responses. This work shows that broad-brush, basin-scale approaches to understanding species-specific responses to climate change are not always appropriate, and regional models are needed—especially when designing marine protected areas.
... The habitats of Emperor and King penguin have shrunk significantly as a result of climatic warming and penguin populations have decreased dramatically. By 2100 at least two-thirds of Emperor colonies are projected to have declined by >50% compared to their current size (Jenouvrier et al., 2014), and 70% of the presentday 1.6 million King penguin breeding pairs are expected to have relocated or disappeared (Cristofari et al., 2018;Kintisch, 2020). In addition, a southward contraction in the range of Ad elie penguins in the Antarctic Peninsula is likely over the next century (Lynch et al., 2012), and Ad elie penguins on Litchfield Island near the Palmer Station had already disappeared completely in 2007 (Fraser et al., 2013). ...
Article
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.
... Most emperor penguin colonies are difficult to access due to their location on remote sections of Antarctic fast ice, and very few of the 66 known colonies (Fretwell & Trathan, 2020) are available to survey using ground counts or aerial surveys Barbraud & Weimerskirch, 2001;Kooyman & Ponganis, 2017;Richter, Gerum, Schneider, et al., 2018). However, gaining empirical understanding of population change at multiple spatial scales is critical, as modelling studies suggest that most breeding colonies will be quasi-extinct by 2100 under 'business as usual' emissions scenarios (Jenouvrier et al., 2014, resulting in dramatic declines in the global population size, even under optimistic dispersal scenarios (Jenouvrier et al. 2017). The ability to apply the baseline population provided by Fretwell et al. (2012) to monitor population trends will improve our understanding and predictions of emperor penguin populations at multiple spatial scales, which is critical for conservation . ...
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Very high‐resolution satellite (VHR) imagery is a promising tool for estimating the abundance of wildlife populations, especially in remote regions where traditional surveys are limited by logistical challenges. Emperor penguins Aptenodytes forsteri were the first species to have a circumpolar population estimate derived via VHR imagery. Here we address an untested assumption from Fretwell et al. (2012) that a single image of an emperor penguin colony is a reasonable representation of the colony for the year the image was taken. We evaluated satellite‐related and environmental variables that might influence the calculated area of penguin pixels to reduce uncertainties in satellite‐based estimates of emperor penguin populations in the future. We focused our analysis on multiple VHR images from three representative colonies: Atka Bay, Stancomb‐Wills (Weddell Sea sector) and Coulman Island (Ross Sea sector) between September and December during 2011. We replicated methods in Fretwell et al. (2012), which included using supervised classification tools in ArcGIS 10.7 software to calculate area occupied by penguins (hereafter referred to as ‘population indices’) in each image. We found that population indices varied from 2 to nearly 6‐fold, suggesting that penguin pixel areas calculated from a single image may not provide a complete understanding of colony size for that year. Thus, we further highlight the important roles of: (i) sun azimuth and elevation through image resolution and (ii) penguin patchiness (aggregated vs. distributed) on the calculated areas. We found an effect of wind and temperature on penguin patchiness. Despite intra‐seasonal variability in population indices, simulations indicate that reliable, robust population trends are possible by including satellite‐related and environmental covariates and aggregating indices across time and space. Our work provides additional parameters that should be included in future models of population size for emperor penguins. Most emperor penguin breeding colonies are projected to be quasi‐extinct by 2100 under ‘business as usual’ emissions scenarios and thus it is now critical to gain empirical evidence of population changes. Very high‐resolution satellite images (VHR) provide us unprecedented, remote access to monitor emperor penguin populations. Our study is the first to address the cause of uncertainties in emperor penguin population estimates derived via VHR, and to account for uncertainty to optimize population estimates. We found that (i) the assumption within Fretwell et al. (2012) that a single VHR image of an emperor penguin colony is a reasonable representation of the colony size for that year was violated, and that (ii) environmental and satellite‐related covariates helped determine population indices, in an effort toward realistic population estimates. This work has major implications for the future assessment of emperor penguin responses to climate change.
... Many species are moving toward the poles and mountain tops to escape increasing temperatures (Chen et al., 2011;Lenoir & Svenning, 2015;Pecl et al., 2017) or seeking refugia in the landscape (Keppel et al., 2012;Reside et al., 2014). For species that rely on specific habitats, changes over this century are expected to have dire consequences for populations, such as species dependent on ice environments, such asemperor penguins (Aptenodytes forsteri), Adelie penguins (Pygoscelis adeliae), and polar bears (Ursus maritimus; Kovacs, Lydersen, Overland, & Moore, 2011;Jenouvrier et al., 2014;Cimino, Lynch, Saba, & Oliver, 2016;Jenouvrier et al., 2020). However, species responses to climate change have been varied and complex, with some thriving in new environments (Ling, Barrett, & Edgar, 2018), or demonstrating unexpected redistribution (Archaux, 2004;Fei et al., 2017;Lenoir et al., 2019). ...
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Climate adaptation is an emerging practice in biodiversity conservation, but little is known about the scope, scale, and effectiveness of implemented actions. Here, we review and synthesize published reports of climate adaptation interventions for iconic fauna. We present a systematic map of peer‐reviewed literature databases (Web of Science and Scopus); however, only nine climate adaptation actions targeting iconic fauna were returned. In the grey and informal literature, there were many instances of practical intervention within our scope, that were not uncovered during traditional systematic search methods. The richness of actions reported in commercial news, government and non‐government organization media outlets and other online sources vastly outweighs the limited studies that have been robustly evaluated and reported in the scientific literature. From our investigation of this emerging field of conservation practice, we draw insights and pen a series of recommendations for the field moving forward. Key recommendations for future adaptation interventions include: the sharing and publishing of climate‐related conservation interventions, the use of standardized metrics for reporting outcomes, the implementation of experimental controls for any actions undertaken, and reporting and evaluation of both failures and successes. New Zealand sea lion pups get stuck in muddy wallows/bogs on Campbell Island so the Department of Conservation installed artificial ramps to help them climb out.
... The colonies sampled were divided into at least four metapopulations, with the colonies in the Ross Sea being one of them. The world's largest breeding colonies of both emperor (Fretwell et al., 2012) and Adèlie (Lynch and LaRue, 2014) penguins are located in the Ross Sea, which is also the only region with a predicted stable or increasing population of emperor penguins (Jenouvrier et al., 2014). Genetic tools revealed that the assumption of all colonies being demographically connected was incorrect (Younger et al., 2017). ...
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The current attrition of biodiversity extends beyond loss of species and unique populations to steady loss of a vast genomic diversity that remains largely undescribed. Yet the accelerating development of new techniques allows us to survey entire genomes ever faster and cheaper, to obtain robust samples from a diversity of sources including degraded DNA and residual DNA in the environment, and to address conservation efforts in new and innovative ways. Here we review recent studies that highlight the importance of carefully considering where to prioritize collection of genetic samples (e.g., organisms in rapidly changing landscapes or along edges of geographic ranges) and what samples to collect and archive (e.g., from individuals of little-known subspecies or populations, even of species not currently considered endangered). Those decisions will provide the sample infrastructure to detect the disappearance of certain genotypes or gene complexes, increases in inbreeding levels, and loss of genomic diversity as environmental conditions change. Obtaining samples from currently endangered, protected, and rare species can be particularly difficult, thus we also focus on studies that use new, non-invasive ways of obtaining genomic samples and analyzing them in these cases where other sampling options are highly constrained. Finally, biological collections archiving such samples face an inherent contradiction: their main goal is to preserve biological material in good shape so it can be used for scientific research for centuries to come, yet the technologies that can make use of such materials are advancing faster than collections can change their standardized practices. Thus, we also discuss current and potential new practices in biological collections that might bolster their usefulness for future biodiversity conservation research.
... For example, with continued lengthening thaw season and diminishing sea ice in the Arctic, polar bear distributions may shift away from prey dependent on sea ice such as ringed seal pups, and toward prey on solid ground, such as snow geese eggs (117), a shift that could reduce polar bear body condition and survival and increase competition with land-based brown bears (118). In Antarctica, receding glaciers have enabled more breeding habitat and increased abundances of Adélie penguins in some areas (119), whereas continued sea ice decline is detrimental to emperor penguin breeding habitat and populations (120). Multiple SAI scenarios predict diminished seasonality in high latitudes, with warmer winters and cooler summers, resulting in sea ice decreasing during winter and increasing during summer (32). ...
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As the effects of anthropogenic climate change become more severe, several approaches for deliberate climate intervention to reduce or stabilize Earth’s surface temperature have been proposed. Solar radiation modification (SRM) is one potential approach to partially counteract anthropogenic warming by reflecting a small proportion of the incoming solar radiation to increase Earth’s albedo. While climate science research has focused on the predicted climate effects of SRM, almost no studies have investigated the impacts that SRM would have on ecological systems. The impacts and risks posed by SRM would vary by implementation scenario, anthropogenic climate effects, geographic region, and by ecosystem, community, population, and organism. Complex interactions among Earth’s climate system and living systems would further affect SRM impacts and risks. We focus here on stratospheric aerosol intervention (SAI), a well-studied and relatively feasible SRM scheme that is likely to have a large impact on Earth’s surface temperature. We outline current gaps in knowledge about both helpful and harmful predicted effects of SAI on ecological systems. Desired ecological outcomes might also inform development of future SAI implementation scenarios. In addition to filling these knowledge gaps, increased collaboration between ecologists and climate scientists would identify a common set of SAI research goals and improve the communication about potential SAI impacts and risks with the public. Without this collaboration, forecasts of SAI impacts will overlook potential effects on biodiversity and ecosystem services for humanity.
... Trends over the last 30,000 years in penguin population sizes show responses to climate consistent with those observed in the present (e.g., Clucas et al. 2014), and gentoo patterns in particular are thought to vary as a result of warmer conditions (e.g., Levy et al. 2016, Roberts et al. 2017). Many of the ice-tolerant or pagophilic species may be experiencing an optimal level of ice cover (e.g., Younger et al. 2015), based on modeling ( Jenouvrier et al. 2014, Cimino et al. 2016) and observations of colony decline (e.g., Jenouvrier et al. 2009) or colony loss (e.g., Trathan et al. 2011). ...
Article
In this article, we analyze the impacts of climate change on Antarctic marine ecosystems. Observations demonstrate large-scale changes in the physical variables and circulation of the Southern Ocean driven by warming, stratospheric ozone depletion, and a positive Southern Annular Mode. Alterations in the physical environment are driving change through all levels of Antarctic marine food webs, which differ regionally. The distributions of key species, such as Antarctic krill, are also changing. Differential responses among predators reflect differences in species ecology. The impacts of climate change on Antarctic biodiversity will likely vary for different communities and depend on species range. Coastal communities and those of sub-Antarctic islands, especially range-restricted endemic communities, will likely suffer the greatest negative consequences of climate change. Simultaneously, ecosystem services in the Southern Ocean will likely increase. Such decoupling of ecosystem services and endemic species will require consideration in the management of human activities such as fishing in Antarctic marine ecosystems. Expected final online publication date for the Annual Review of Marine Science Volume 12 is January 3, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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The long-term future of the Antarctic is intrinsically connected to climate change and global environmental change processes driven socially and geopolitically as much as they are biophysically. The impacts and implications of these changes are increasing in global significance, including access to natural resources, biodiversity decline, and potential institutional reforms that will require much more integrated research and support to enable effective decision-making within the Antarctic Treaty System and, potentially, beyond. The 2019 Intergovernmental Panel on Climate Change (IPCC) Special Report on the Ocean and Cryosphere highlighted these issues and the importance of innovative tools and processes to increase capacity to develop appropriate policy including the need for scenario analysis. While research effort relating to Antarctica’s future is increasing, there is currently no coordinated approach to establish a workable set of scenarios in which future possibilities could be actively explored. In response, this paper develops an Antarctic scenarios framework integrated with global environmental change research via an organising structure analogous to the current practice of the IPCC. It draws on Antarctic studies, climate change science and futures studies to identify a concise yet comprehensive set of 17 elements over seven categories that aim to cover all relevant social, economic and environmental factors without any weighting as to overall importance. In particular, it emphasises that biophysical research on its own is not sufficient to engage with the complex policy world which is influenced by geopolitics and, as a result, proposes a more inclusive, reflexive process. The paper then builds on the latest research on scenarios for socio-environmental analysis, modelling and decision-making to examine how this could be implemented through the integration of various components within, potentially, the Antarctic Treaty System.
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This chapter assesses climate information relevant to regional impact and risk assessment. It complements other WG1 chapters which focus on the physical processes determining changes in the climate system and on methods for estimating regional changes. This chapter is new in the IPCC WGI assessment reports, in that it represents a contribution to the “IPCC Risk Framework”. Within this framework, climate-related impacts and risks are determined through an interplay between the occurrence of climate hazards and their consequences depending on the exposure of the affected human or natural system and its vulnerability to the hazardous conditions. In Chapter 12, we are assessing climatic impact-drivers that could lead to hazards or to opportunities, from the literature and model results since AR5. This will particularly support the assessment of key risks related to climate change by WGII (Chapter 16). Despite the fact that impacts may also be induced by climate adaptation and mitigation policies themselves, as well as by socioeconomic trends, changes in vulnerability or exposure, and external geophysical hazards such as volcanoes, the focus here is only on ‘climatic’ impacts and risks induced by shifts in physical climate phenomena that directly influence human and ecological systems.
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1. A changing environment directly influences birth and mortality rates, and thus population growth rates. However, population growth rates in the short‐term are also influenced by population age‐structure. Despite its importance, the contribution of age‐structure to population growth rates has rarely been explored empirically in wildlife populations with long‐term demographic data. 2. Here, we assessed how changes in age‐structure influenced short‐term population dynamics in a semi‐captive population of Asian elephants (Elephas maximus). 3. We addressed this question using a demographic dataset of female Asian elephants from timber camps in Myanmar spanning 45 years (1970‐2014). First, we explored temporal variation in age‐structure. Then, using annual matrix population models, we used a retrospective approach to assess the contributions of age‐structure and vital rates to short‐term population growth rates with respect to the average environment. 4. Age‐structure was highly variable over the study period, with large proportions of juveniles in the years 1970 and 1985, and made a substantial contribution to annual population growth rate deviations. High adult birth rates between 1970‐1980 would have resulted in large positive population growth rates, but these were prevented by a low proportion of reproductive‐aged females. 5. We highlight that an understanding of both age‐specific vital rates and age‐structure is needed to assess short‐term population dynamics. Furthermore, this example from a human‐managed system suggests that the importance of age‐structure may be accentuated in populations experiencing human disturbance where age‐structure is unstable, such as those in captivity or for endangered species. Ultimately, changes to the environment drive population dynamics by influencing birth and mortality rates, but understanding demographic structure is crucial for assessing population growth.
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The effects of climate change on population viability reflect the net influence of potentially diverse responses of individual‐level demographic processes (growth, survival, regeneration) to multiple components of climate. Articulating climate‐demography connections can facilitate forecasts of responses to future climate change as well as back‐casts that may reveal how populations responded to historical climate change. We studied climate‐demography relationships in the cactus Cyclindriopuntia imbricata; previous work indicated that our focal population has high abundance but a negative population growth rate, where deaths exceed births, suggesting that it persists under extinction debt. We parameterized a climate‐dependent integral projection model with data from a 14‐year field study, then back‐casted expected population growth rates since 1900 to test the hypothesis that recent climate change has driven this population into extinction debt. We found clear patterns of climate change in our central New Mexico study region but, contrary to our hypothesis, C. imbricata has most likely benefitted from recent climate change and is on track to reach replacement‐level population growth within 37 years, or sooner if climate change accelerates. Furthermore, the strongest feature of climate change (a trend toward years that are overall warmer and drier, captured by the first principal component of inter‐annual variation) was not the main driver of population responses. Instead, temporal trends in population growth were dominated by more subtle, seasonal climatic factors with relatively weak signals of recent change (wetter and milder cool seasons, captured by the second and third principal components). Synthesis. Our results highlight the challenges of back‐casting or forecasting population dynamics under climate change, since the most apparent features of climate change may not be the most important drivers of ecological responses. Environmentally explicit demographic models can help meet this challenge, but they must consider the magnitudes of different aspects of climate change alongside the magnitudes of demographic responses to those changes.
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Range shift is the primary short-term response of species to rapid climate change but it is hampered by natural or anthropogenic habitat fragmentation. Fragmented habitats expose different critical areas of a species niche to heterogeneous environmental changes resulting in uncoupled effects. Modelling species distribution under complex real-life scenarios and incorporating such uncoupled effects has not been achieved yet. Here we identify the most vulnerable areas and the potential cold refugia of a top-predator with fragmented niche range in the Southern ocean by integrating genomic, ecological and behavioural data with atmospheric and oceanographic models. Our integrative approach constitutes an indispensable example for predicting the effect of global warming on species relying on spatially and ecologically distinct areas to complete their life-cycle (e.g., migratory animals, marine pelagic organisms, central-place foragers) and, in general, on species constrained in fragmented landscapes due to continuously-growing anthropogenic pressure.
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Large ensemble climate modelling experiments demonstrate the large role natural variability plays in local climate on a multi-decadal timescale. Variability in local weather and climate influences individual beliefs about climate change. To the extent that support for climate mitigation policies is determined by citizens' local experiences, natural variability will strongly influence the timescale for implementation of such policies. Under a number of illustrative threshold criteria for both national and international climate action, we show that variability-driven uncertainty about local change, even in the face of a well-constrained estimate of global change, can potentially delay the time to policy implementation by decades. Because several decades of greenhouse gas emissions can have a large impact on long-term climate outcomes, there is substantial risk associated with climate policies driven by consensus among individuals who are strongly influenced by local weather conditions.
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We examined the population dynamics of two Antarctic seabirds and the influence of environmental variability over a 40-year period by coupling the estimation of demographic parameters, based on capture–recapture data, and modeling, using Leslie ma-trix population models. We demonstrated that the demographic parameters showing the greatest contribution to the variance of population growth rate were adult survival for both species. Breeding success showed the same contribution as adult survival for Emperor Penguins, whereas the proportion of breeders had the next stronger contribution for Snow Petrels. The sensitivity of population growth rate to adult survival was very high and the adult survival variability was weak for both species. Snow Petrel males survived better than females, whereas Emperor Penguin males had lower survival than females. These differ-ences may be explained by the different investment in breeding. Emperor Penguin adult survival was negatively affected by air temperature during summer and winter for both sexes; male survival was negatively affected by sea ice concentration during summer, autumn, and winter. On the other hand, there was no effect of environmental covariates on Snow Petrel adult survival. The Emperor Penguin population has declined by 50% because of a decrease in adult survival related to a warming event during a regime shift in the late 1970s, whereas Snow Petrels showed their lowest numbers in 1976, but were able to skip reproduction. Indeed, the retrospective analysis of projection population matrix entries indicated that breeding abstention played a critical role in the population dynamics of Snow Petrels but not Emperor Penguins. Snow Petrels did not breed either when air temperature decreased during spring (probably reducing nest attendance and laying) or when sea ice decreased during autumn (reducing food availability). Emperor Penguin and Snow Petrel breeding population sizes were positively influenced by sea ice through its effect on adult survival for Emperor Penguins and on the proportion of breeders for Snow Petrels. Therefore, we hypothesize that the population sizes of the two species could be negatively affected by reduced sea ice in the context of global warming.
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In 1902, the first breeding colony of emperor penguins was discovered. Over the following decades, the number of known emperor penguin colonies increased steadily and new ones are still being discovered. However, rigorous census work has been carried out at only a few colonies and accurate information on trends in breeding populations is limited to a small number of locations. Thus, the total number of breeding pairs is still unknown as is the size of the global population (breeders, non-breeders, juveniles). The International Union for the Conservation of Nature (IUCN) lists the species’ status as ‘least concern’ and states that although the population trend for emperor penguins has not been quantified, the global population appears to be stable. This review summarises the currently available information on the populations of emperor penguins at known colonies in terms of survey methods, count units used and survey frequency. It examines what is known about the state of various colonies and demonstrates that currently available data are inadequate for a trend assessment of the global population. KeywordsEmperor penguins–Population data–Historical information–Monitoring
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We assess the response of pack ice penguins, Emperor (Aptenodytes forsteri) and Ade´ lie (Pygoscelis adeliae), to habitat variability and, then, by modeling habitat alterations, the qualitative changes to their populations, size and distribution, as Earth's average tropospheric temperature reaches 28C above preindustrial levels (ca. 1860), the benchmark set by the European Union in efforts to reduce greenhouse gases. First, we assessed models used in the Intergovernmental Panel on Climate Change Fourth Assessment Report (AR4) on penguin performance duplicating existing conditions in the Southern Ocean. We chose four models appropriate for gauging changes to penguin habitat: GFDL-CM2.1, GFDL-CM2.0, MIROC3.2(hi-res), and MRI-CGCM2.3.2a. Second, we analyzed the composited model ENSEMBLE to estimate the point of 28C warming (2025–2052) and the projected changes to sea ice coverage (extent, persistence, and concentration), sea ice thickness, wind speeds, precipitation, and air temperatures. Third, we considered studies of ancient colonies and sediment cores and some recent modeling, which indicate the (space/time) large/centennialscale penguin response to habitat limits of all ice or no ice. Then we considered results of statistical modeling at the temporal interannual-decadal scale in regard to penguin response over a continuum of rather complex, meso- to large-scale habitat conditions, some of which have opposing and others interacting effects. The ENSEMBLE meso/decadal-scale output projects a marked narrowing of penguins' zoogeographic range at the 28C point. Colonies north of 708 S are projected to decrease or disappear: ;50% of Emperor colonies (40% of breeding population) and ;75% of Ade´ lie colonies (70% of breeding population), but limited growth might occur south of 738 S. Net change would result largely from positive responses to increase in polynya persistence at high latitudes, overcome by decreases in pack ice cover at lower latitudes and, particularly for Emperors, ice thickness. Ade´ lie Penguins might colonize new breeding habitat where concentrated pack ice diverges and/or disintegrating ice shelves expose coastline. Limiting increase will be decreased persistence of pack ice north of the Antarctic Circle, as this species requires daylight in its wintering areas. Ade´ lies would be affected negatively by increasing snowfall, predicted to increase in certain areas owing to intrusions of warm, moist marine air due to changes in the Polar Jet Stream.
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Climate change has created the need for a new strategic framework for conservation. This framework needs to include new protected areas that account for species range shifts and management that addresses large-scale change across international borders. Actions within the framework must be effective in international waters and across political frontiers and have the ability to accommodate large income and ability-to-pay discrepancies between countries. A global protected-area system responds to these needs. A fully implemented global system of protected areas will help in the transition to a new conservation paradigm robust to climate change and will ensure the integrity of the climate services provided by carbon sequestration from the world's natural habitats. The internationally coordinated response to climate change afforded by such a system could have significant cost savings relative to a system of climate adaptation that unfolds solely at a country level. Implementation of a global system is needed very soon because the effects of climate change on species and ecosystems are already well underway.
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Variations in ocean-atmosphere coupling over time in the Southern Ocean have dominant effects on sea-ice extent and ecosystem structure, but the ultimate consequences of such environmental changes for large marine predators cannot be accurately predicted because of the absence of long-term data series on key demographic parameters. Here, we use the longest time series available on demographic parameters of an Antarctic large predator breeding on fast ice and relying on food resources from the Southern Ocean. We show that over the past 50 years, the population of emperor penguins (Aptenodytes forsteri) in Terre Adélie has declined by 50% because of a decrease in adult survival during the late 1970s. At this time there was a prolonged abnormally warm period with reduced sea-ice extent. Mortality rates increased when warm sea-surface temperatures occurred in the foraging area and when annual sea-ice extent was reduced, and were higher for males than for females. In contrast with survival, emperor penguins hatched fewer eggs when winter sea-ice was extended. These results indicate strong and contrasting effects of large-scale oceanographic processes and sea-ice extent on the demography of emperor penguins, and their potential high susceptibility to climate change.