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Migratory birds often have tightly scheduled annual cycles, in which a delay in one event can have carry-over effects on the timing of later events, which may ultimately impact reproductive output. We utilize a large-scale study system to investigate carry-over effects in timing: the variation in annual schedules of individual Arctic SkuasStercorarius parasiticusat 12 breeding sites between East Greenland and West Siberia in relation to their use of seven widely divergent wintering areas across the Atlantic Ocean, Mediterranean Sea and Indian Ocean. We studied whether migration schedules differ among breeding populations as a function of their choice of wintering areas, and predicted that migrations over larger distances, with tighter schedules, would provide less room for compensating delays. Breeding at higher latitudes led not only to later timing of reproduction and migration, but also to different allocation of time to different phases, with faster spring migration and shorter time between return to the breeding area and clutch initiation. In contrast, breeding latitude had no effect on the duration of autumn migration and wintering period. Wintering area was consistent within individuals among years and had an additive effect on annual schedules, with more distant areas associated with more time spent on migration and less time spent in the wintering areas. Tracked skuas were able to adjust the period spent in the non-breeding area, regardless of the distance from the colony, which generally buffered the variation in timing of autumn migration. Despite individual variation in migration distances of thousands of km, skuas from the same population arrived largely synchronously at their breeding area. The lack of a consistent effect of migration distance on timing of return to the breeding grounds indicates that individuals synchronize their arrival with others in their population despite extensive individual differences in migration strategies.

Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of adults to perform other activities. Hence, incubating adults trade-off incubation and nest protection with foraging to meet their own needs. Parents can either cooperate to sustain this trade-off or incubate alone. The main cause of reproductive failure at this reproductive stage is predation and adults reduce this risk by keeping the nest location secret. Arctic sandpipers are interesting biological models to investigate parental care evolution as they may use several parental care strategies. The three main incubation strategies include both parents sharing incubation duties (?biparental?), one parent incubating alone (?uniparental?), or a flexible strategy with both uniparental and biparental incubation within a population (?mixed?). By monitoring the incubation behaviour in 714 nests of seven sandpiper species across 12 arctic sites, we studied the relationship between incubation strategy and nest predation. First, we described how the frequency of incubation recesses (NR), their mean duration (MDR), and the daily total duration of recesses (TDR) vary among strategies. Then, we examined how the relationship between the daily predation rate and these components of incubation behaviour varies across strategies using two complementary survival analysis. For uniparental and biparental species, the daily predation rate increased with the daily total duration of recesses and with the mean duration of recesses. In contrast, daily predation rate increased with the daily number of recesses for biparental species only. These patterns may be attributed to two independent mechanisms: cryptic incubating adults are more difficult to locate than unattended nests and adults departing the nest or feeding close to the nest can draw predators' attention. Our results demonstrate that incubation behaviour as mediated by incubation strategy has important consequences for sandpipers? reproductive success. This article is protected by copyright. All rights reserved.

Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active. The sites were not evenly distributed with notably Russia and high Arctic Canada underrepresented. Abundance was monitored at all sites, but methods and levels of precision varied greatly. Other important attributes such as health, genetic diversity and potential drivers of population change, were often not monitored. There was no evidence that lemming populations were decreasing in general, although a negative trend was detected for low arctic populations sympatric with voles. To keep the pace of arctic change, we recommend maintaining long-term programmes while harmonizing methods, improving spatial coverage and integrating an ecosystem perspective. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13280-019-01198-7) contains supplementary material, which is available to authorized users.

This is a post-peer-review, pre-copyedit version of an article published in Ambio. The final authenticated version is available online at: http://dx.doi.org/10.1007/s13280-019-01198-7. Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active. The sites were not evenly distributed with notably Russia and high Arctic Canada underrepresented. Abundance was monitored at all sites, but methods and levels of precision varied greatly. Other important attributes such as health, genetic diversity and potential drivers of population change, were often not monitored. There was no evidence that lemming populations were decreasing in general, although a negative trend was detected for low arctic populations sympatric with voles. To keep the pace of arctic change, we recommend maintaining long-term programmes while harmonizing methods, improving spatial coverage and integrating an ecosystem perspective.

The conservation of migratory marine species, including pelagic seabirds, is challenging because their movements span vast distances frequently beyond national jurisdictions. Here, we aim to identify important aggregations of seabirds in the North Atlantic to inform ongoing regional conservation efforts. Using tracking, phenology, and population data, we mapped the abundance and diversity of 21 seabird species. This revealed a major hotspot associated with a discrete area of the subpolar frontal zone, used annually by 2.9–5 million seabirds from ≥56 colonies in the Atlantic: the first time this magnitude of seabird concentrations has been documented in the high seas. The hotspot is temporally stable and amenable to site-based conservation and is under consideration as a marine protected area by the OSPAR Commission. Protection could help mitigate current and future threats facing species in the area. Overall, our approach provides an exemplar data-driven pathway for future conservation efforts on the high seas. info:eu-repo/semantics/publishedVersion

Collapsing lemming cycles have been observed across the Arctic, presumably due to global warming creating less favorable winter conditions. The quality of wintering habitats, such as depth of snow cover, plays a key role in sustaining population dynamics of arctic lemmings. However, few studies so far investigated habitat use during the arctic winter. Here, we used a unique long-term time series to test whether lemmings are associated with topographical and vegetational habitat features for their winter refugi. We examined yearly numbers and distribution of 22,769 winter nests of the collared lemming Dicrostonyx groenlandicus from an ongoing long-term research on Traill Island, Northeast Greenland, collected between 1989 and 2019, and correlated this information with data on dominant vegetation types, elevation and slope. We specifically asked if lemming nests were more frequent at sites with preferred food plants such as Dryas octopetala x integrifolia and at sites with increased snow cover. We found that the number of lemming nests was highest in areas with a high proportion of Dryas heath, but also correlated with other vegetation types which suggest some flexibility in resource use of wintering lemmings. Conversely, they showed a distinct preference for sloped terrain, probably as it enhances the formation of deep snow drifts which increases the insulative characteristics of the snowpack and protection from predators. With global warming, prime lemming winter habitats may become scarce through alteration of snow physical properties, potentially resulting in negative consequence for the whole community of terrestrial vertebrates.

Most birds incubate their eggs, which requires time and energy at the expense of other activities. Birds generally have two incubation strategies: biparental where both mates cooperate in incubating eggs, and uniparental where a single parent incubates. In harsh and unpredictable environments, incubation is challenging due to high energetic demands and variable resource availability. We studied the relationships between the incubation behaviour of sandpipers (genus Calidris) and two environmental variables: temperature and a proxy of primary productivity (i.e. NDVI). We investigated how these relationships vary between incubation strategies and across species among strategies. We also studied how the relationship between current temperature and incubation behaviour varies with previous day's temperature. We monitored the incubation behaviour of nine sandpiper species using thermologgers at 15 arctic sites between 2016 and 2019. We also used thermologgers to record the ground surface temperature at conspecific nest sites and extracted NDVI values from a remote sensing product. We found no relationship between either environmental variables and biparental incubation behaviour. Conversely, as ground-surface temperature increased, uniparental species decreased total duration of recesses (TDR) and mean duration of recesses (MDR), but increased number of recesses (NR). Moreover, small species showed stronger relationships with ground-surface temperature than large species. When all uniparental species were combined, an increase in NDVI was correlated with higher mean duration, total duration and number of recesses, but relationships varied widely across species. Finally, some uniparental species showed a lag effect with a higher nest attentiveness after a warm day while more recesses occurred after a cold day than was predicted based on current temperatures. We demonstrate the complex interplay between shorebird incubation strategies, incubation behaviour, and environmental conditions. Understanding how species respond to changes in their environment during incubation helps predict their future reproductive success.

Warming-induced biological and ecological responses have been reported from high-northern latitude sites, where changes in dwarf shrub communities translate into complex vegetation-climate feedbacks. Most of the available Arctic tree-ring evidence is, however, restricted to a limited number of species and locations. A combination of wood anatomical and ‘dendro’-ecological techniques provides insights into past growth rates, recruitment dynamics and even community assemblages of Arctic vegetation. Here, we use thin sectioning and ring counting of 1432 dwarf shrub samples from eight species and two tundra regions in coastal east Greenland to assess community recruitment history and its relation to climate. Site and species-specific annual stem increments, as well as estimated plant ages, range from 0.013-0.720 mm and from 4 to 204 years, respectively. The mean ring width is 0.086 mm, with a mean age of 50 years. Decadal-scale recruitment dynamics of the studied vegetation cover respond to Greenlandic summer temperature variations back to the late 19th century (r = 0.7; 1881–2000).

Many rodents, including most populations of arctic lemmings (genus Dicrostonyx and Lemmus), have cyclic population dynamics. Among the numerous hypotheses which have been proposed and tested to explain this typical characteristic of some terrestrial vertebrate communities, trophic interactions have often been presented as the most likely drivers of these periodic fluctuations. The possible role of parasites has, however, only seldom been assessed. In this study, we genetically measured the prevalence of two endoparasite taxa, eimerians and cestodes, in 372 faecal samples from collared lemmings, over a five year period and across three distant sites in Northeast Greenland. Prevalence of cestodes was low (2.7% over all sites and years) and this taxon was only found at one site (although in 4 out of 5 years) in adult hosts. By contrast, we found high prevalence for eimerians (77.7% over all sites and years), which occurred at all sites, in every year, for both age classes (at the Hochstetter Forland site where both adult and juvenile faeces were collected) and regardless of reproductive and social status inferred from the characteristics of the lemming nests where the samples had been collected. Prevalence of eimerians significantly varied among years (not among sites) and was higher for juvenile than for adult lemmings at the Hochstetter Forland site. However, higher prevalence of eimerians (Pt) was only associated with lower lemming density (Nt) at one of the three sites and we found no delayed density dependence between Nt and Pt+1 to support the parasite hypothesis. Our results show that there is no clear relation between lemming density and eimerian faecal prevalence in Northeast Greenland and hence no evidence that eimerians could be driving the cyclic population dynamics of collared lemmings in this region., Graphical abstract Image 1, Highlights • Prevalence of eimerians and cestodes was measured in collared lemming in Greenland. • Prevalence of cestodes was low (2.7%; one site only) compared to eimerians (78%). • Prevalence of eimerians was higher for juveniles and varied among years. • Prevalence of eimerians was negatively associated with lemming density at one site. • lack of delayed density dependence does not support the parasite hypothesis for lemming cycles.

Kubelka et al. (Science, 9 November 2018, p. 680-683) claim that climate change has disrupted patterns of nest predation in shorebirds. They report that predation rates have increased since the 1950s, especially in the Arctic. We describe methodological problems with their analyses and argue that there is no solid statistical support for their claims.

Kubelka et al. (Reports, 9 November 2018, p. 680) claim that climate change has disrupted patterns of nest predation in shorebirds. They report that predation rates have increased since the 1950s, especially in the Arctic. We describe methodological problems with their analyses and argue that there is no solid statistical support for their claims. Fil: Bulla, Martin. Nioz Royal Netherlands Institute For Sea Research; Países Bajos. Max Planck Institute For Ornithology; Alemania. Czech University of Life Sciences; República Checa Fil: Reneerkens, Jeroen. Nioz Royal Netherlands Institute For Sea Research; Países Bajos. University of Groningen; Países Bajos Fil: Weiser, Emily L.. Upper Midwest Environmental Sciences Center; Estados Unidos Fil: Sokolov, Aleksandr. Institute Of Plant And Animal Ecology; Rusia Fil: Taylor, Audrey R.. University of Alaska; Estados Unidos Fil: Sittler, Benoît. Albert Ludwigs University of Freiburg; Alemania. Arctic Ecology Research Group; Francia Fil: McCaffery, Brian J.. U.S. Fish and Wildlife Service; Estados Unidos Fil: Ruthrauff, Dan R.. U.S. Geological Survey; Estados Unidos Fil: Catlin, Daniel H.. Virginia Tech University; Estados Unidos Fil: Payer, David C.. National Park Service; Estados Unidos Fil: Ward, David H.. U.S. Geological Survey; Estados Unidos Fil: Solovyeva, Diana V.. Institute of Biological Problems of the North; Rusia Fil: Santos, Eduardo S. A.. Universidade de São Paulo; Brasil Fil: Rakhimberdiev, Eldar. Lomonosov Moscow State University; Rusia. University of Groningen; Países Bajos Fil: Nol, Erica. Trent University; Canadá Fil: Kwon, Eunbi. Virginia Tech; Estados Unidos Fil: Brown, Glen S.. Ministry of Natural Resources and Forestry; Canadá Fil: Hevia, Glenda Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Gates, H. River. National Audubon Society; Estados Unidos Fil: Johnson, James A.. Fish and Wildlife Service; Estados Unidos Fil: van Gils, Jan A.. Department of Coastal Systems and Utrecht University; Países Bajos Fil: Hansen, Jannik. Aarhus University. Aarhus Institute Of Advanced Studies.; Dinamarca Fil: Lamarre, Jean-François. Polar Knowledge Canada; Canadá Fil: Rausch, Jennie. Environment and Climate Change Canada; Canadá Fil: Conklin, Jesse R.. University of Groningen; Países Bajos Fil: Liebezeit, Joe. Audubon Society of Portland; Estados Unidos Fil: Bêty, Joël. University of Quebec; Canadá Fil: Lang, Johannes. Arctic Ecology Research Group ; Francia. Giessen University; Alemania Fil: Alves, José A.. University of Aveiro; Portugal. University of Iceland; Islandia Fil: Fernández-Elipe, Juan. No especifíca; Fil: Exo, Klaus-Michael. Institute of Avian Research “Vogelwarte Helgoland"; Alemania Fil: Bollache, Loïc. Universite de Franche-Comte; Francia Fil: Bertellotti, Néstor Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Giroux, Marie-Andrée. Université de Moncton; Canadá Fil: van de Pol, Martijn. Netherlands Institute of Ecology ; Países Bajos Fil: Johnson, Matthew. USDA Forest Service; Estados Unidos Fil: Boldenow, Megan L.. University of Alaska; Estados Unidos Fil: Valcu, Mihai. Max Planck Institute für Ornithologie; Alemania Fil: Soloviev, Mikhail. Lomonosov Moscow State University; Alemania Fil: Sokolova, Natalya. Arctic Research Station; Rusia Fil: Senner, Nathan R.. University of South Carolina; Estados Unidos Fil: Lecomte, Nicolas. Université de Moncton; Canadá Fil: Meyer, Nicolas. Universite de Franche-Comte; Francia. Arctic Ecology Research Group; Francia Fil: Schmidt, Niels Martin. Aarhus University. Department of Bioscience; Dinamarca Fil: Gilg, Olivier. Arctic Ecology Research Group; Francia. Universite de Franche-Comte; Francia Fil: Smith, Paul A.. Environment and Climate Change Canada; Canadá Fil: Machín, Paula. No especifíca; Fil: McGuire, Rebecca L.. Wildlife Conservation Society; Estados Unidos Fil: Cerboncini, Ricardo A. S.. Universidade Federal do Paraná; Brasil Fil: Ottvall, Richard. No especifíca; Fil: van Bemmelen, Rob S. A.. Wageningen Marine Research; Países Bajos Fil: Swift, Rose J.. Cornell University; Estados Unidos Fil: Saalfeld, Sarah T.. No especifíca; Fil: Jamieson,Sarah E.. Simon Fraser University; Canadá Fil: Brown, Stephen. No especifíca; Fil: Piersma, Theunis. NIOZ Royal Netherlands Institute for Sea Research; Países Bajos. Conservation Ecology Group; Países Bajos Fil: Albrecht, Tomas. Czech Academy of Sciences; República Checa. Charles University; República Checa Fil: D’Amico, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Lanctot, Richard B.. U.S. Fish and Wildlife Service; Estados Unidos Fil: Kempenaers, Bart. Max Planck Institute für Ornithologie; Alemania

Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3–6 years and long 9–12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13280-019-01191-0) contains supplementary material, which is available to authorized users.

Reproductive timing in many taxa plays a key role in determining breeding productivity , and is often sensitive to climatic conditions . Current climate change may alter the timing of breeding at different rates across trophic levels, potentially resulting in temporal mismatch between the resource requirements of predators and their prey . This is of particular concern for highertrophic-level organisms, whose longer generation times confer a lower rate of evolutionary rescue than primary producers or consumers. However, the disconnection between studies of ecological change in marine systems makes it difficult to detect general changes in the timing of reproduction5 . Here, we use a comprehensive meta-analysis of 209 phenological time series from 145 breeding populations to show that, on average, seabird populations worldwide have not adjusted their breeding seasons over time (−0.020 days yr−1 ) or in response to sea surface temperature (SST) (−0.272 days °C−1 ) between 1952 and 2015. However, marked between-year variation in timing observed in resident species and some Pelecaniformes and Suliformes (cormorants, gannets and boobies) may imply that timing, in some cases, is affected by unmeasured environmental conditions. This limited temperature-mediated plasticity of reproductive timing in seabirds potentially makes these top predators highly vulnerable to future mismatch with lower-trophic-level resources Fil: Keogan, Katharine. University of Edinburgh; Reino Unido Fil: Daunt, Francis. Centre for Ecology & Hydrology; Reino Unido Fil: Wanless, Sarah. Centre for Ecology & Hydrology; Reino Unido Fil: Phillips, Richard A.. British Antarctic Survey; Reino Unido Fil: Walling, Craig A.. University of Edinburgh; Reino Unido Fil: Agnew, Philippa. Oamaru Blue Penguin Colony; . Oamaru Blue Penguin Colony; Nueva Zelanda Fil: Ainley, David G.. HT Harvey and Associates; Estados Unidos Fil: Anker-Nilssen, Tycho. Norwegian Institute For Nature Research; Noruega Fil: Ballard, Grant. Point Blue Conservation Science; Estados Unidos Fil: Barrett, Robert T.. Uit The Arctic University Of Norway; Noruega Fil: Barton, Kerry J.. Landcare Research; Nueva Zelanda Fil: Bech, Claus. Norges Teknisk-naturvitenskapelige Universitet; Noruega Fil: Becker, Peter. Institut Fur Vogelforschung "vogelwarte Helgoland"; Alemania Fil: Berglund, Per-Arvid. University of Agricultural Sciences. Institute of Marine Research, Department of Aquatic Resources; Suecia Fil: Bollache, Loïc. Universite de Bourgogne; Francia Fil: Bond, Alexander L.. Memorial University Of Newfoundland; Canadá Fil: Bouwhuis, Sandra. Institut Fur Vogelforschung "vogelwarte Helgoland"; Alemania Fil: Bradley, Russell W.. Point Blue Conservation Science; Estados Unidos Fil: Burr, Zofia M.. The University Centre In Svalbard; Noruega Fil: Camphuysen, Kees. University of Utrecht; Países Bajos Fil: Catry, Paulo. Ispa - Instituto Universitário; Portugal Fil: Chiaradia, Andre. Monash University; Australia. Phillip Island Nature Park; Australia Fil: Christensen-Dalsgaard, Signe. Norwegian Institute for Nature Research; Noruega Fil: Cuthbert, Richard. Royal Society For The Protection Of Birds; Reino Unido Fil: Dehnhard, Nina. Universiteit Antwerp; Bélgica Fil: Descamps, Sébastien. Norwegian Polar Institute; Noruega Fil: Diamond, Tony. University Of New Brunswick; Canadá Fil: Divoky, George. Friends of Cooper Island; Estados Unidos Fil: Drummond, Hugh. Universidad Nacional Autónoma de México; México Fil: Dugger, Katie M.. United States Geological Survey; Estados Unidos Fil: Dunn, Michael J.. British Antarctic Survey; Reino Unido Fil: Emmerson, Louise. Australian Antarctic Division; Australia Fil: Erikstad, Kjell Einar. Norwegian Polar Institute; Noruega Fil: Fort, Jérôme. Université de la Rochelle; Francia Fil: Fraser, William. Polar Oceans Research Group; Estados Unidos Fil: Genovart, Meritxell. Consejo Superior de Investigaciones Cientificas. Instituto Mediterraneo de Estudios Avanzados; España Fil: Gilg, Olivier. Universite de Bourgogne; Francia. Groupe de Recherches En Ecologie Arctique; Fil: González-Solís, Jacob. Universidad de Barcelona; España Fil: Granadeiro, José Pedro. Universidade de Lisboa; Portugal Fil: Grémillet, David. University Of Cape Town; Sudáfrica Fil: Hansen, Jannik. University Aarhus; Dinamarca Fil: Hanssen, Sveinn A.. Norwegian Institute For Nature Research; Noruega Fil: Harris, Mike. Centre for Ecology & Hydrology; Reino Unido Fil: Hedd, April. Environment Canada; Canadá Fil: Hinke, Jefferson. National Oceanic And Atmospheric Administration; Estados Unidos Fil: Igual, José Manuel. Consejo Superior de Investigaciones Cientificas. Instituto Mediterraneo de Estudios Avanzados; España Fil: Jahncke, Jaime. Point Blue Conservation Science; Estados Unidos Fil: Jones, Ian. Memorial University Of Newfoundland; Canadá Fil: Kappes, Peter J.. Oregon Cooperative Fish And Wildlife Research Unit; Estados Unidos Fil: Lang, Johannes. Groupe de Recherche en Ecologie Arctique; Francia Fil: Langset, Magdalene. Norwegian Institute For Nature Research; Noruega Fil: Lescroël, Amélie. Géosciences Montpellier; Francia Fil: Lorentsen, Svein-Håkon. Norwegian Institute For Nature Research; Noruega Fil: Lyver, Phil O'B.. Landcare Research; Nueva Zelanda Fil: Mallory, Mark. Acadia University; Canadá Fil: Moe, Børge. Norwegian Institute For Nature Research; Noruega Fil: Montevecchi, William A.. Memorial University Of Newfoundland; Canadá Fil: Monticelli, David. University Of Coimbra, Marine And Environmental Sciences Center; Portugal Fil: Mostello, Carolyn. Massachusetts Division Of Fisheries And Wildlife; Estados Unidos Fil: Newell, Mark. Centre for Ecology & Hydrology; Reino Unido Fil: Nicholson, Lisa. Halfmoon Biosciences; Australia Fil: Nisbet, Ian. I. C. T. Nisbet & Company; Estados Unidos Fil: Olsson, Olof. Stockholms Universitet; Suecia Fil: Oro, Daniel. Consejo Superior de Investigaciones Cientificas. Instituto Mediterraneo de Estudios Avanzados; España Fil: Pattison, Vivian. Laskeek Bay Conservation Society; Canadá Fil: Poisbleau, Maud. Universiteit Antwerp; Bélgica Fil: Pyk, Tanya. Deakin University; Australia Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ramos, Jaime A.. University Of Coimbra, Marine And Environmental Sciences Center; Portugal Fil: Ramos, Raül. Universidad de Barcelona; España Fil: Reiertsen, Tone Kirstin. Norwegian Polar Institute; Noruega Fil: Rodríguez, Cristina. Universidad Nacional Autónoma de México; México Fil: Ryan, Peter. University Of Cape Town; Sudáfrica Fil: Sanz-Aguilar, Ana. Consejo Superior de Investigaciones Cientificas. Instituto Mediterraneo de Estudios Avanzados; España Fil: Schmidt, Niels M.. University Aarhus; Dinamarca Fil: Shannon, Paula. National Audubon Society Seabird Restoration Program; Estados Unidos Fil: Sittler, Benoit. Groupe de Recherche en Ecologie Arctique; Francia Fil: Southwell, Colin. Australian Antarctic Division; Australia Fil: Surman, Christopher. Halfmoon Biosciences; Australia Fil: Svagelj, Walter Sergio. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Trivelpiece, Wayne. Bolinas; Estados Unidos Fil: Warzybok, Pete. Point Blue Conservation Science; Estados Unidos Fil: Watanuki, Yutaka. Hokkaido University; Japón Fil: Weimerskirch, Henri. Centre National de la Recherche Scientifique; Francia Fil: Wilson, Peter R.. Landcare Research; Nueva Zelanda Fil: Wood, Andrew G.. British Antarctic Survey; Reino Unido Fil: Phillimore, Albert B.. University of Edinburgh; Reino Unido Fil: Lewis, Sue. University of Edinburgh; Reino Unido

Source at http://dx.doi.org/10.1080/17518369.2017.1319602 The biodiversity working group of the Arctic Council has developed pan-Arctic biodiversity monitoring plans to improve our ability to detect, understand and report on long-term change in Arctic biodiversity. The Arctic fox (Vulpes lagopus) was identified as a target of future monitoring because of its circumpolar distribution, ecological importance and reliance on Arctic ecosystems. We provide the first exhaustive survey of contemporary Arctic fox monitoring programmes, describing 34 projects located in eight countries. Monitored populations covered equally the four climate zones of the species’ distribution, and there were large differences between populations in long-term trends, multi-annual fluctuations, diet composition, degree of competition with red fox and human interferences. Den density, number of active dens, number of breeding dens and litter size were assessed in almost all populations, while projects varied greatly with respect to monitoring of other variables indicative of population status, ecosystem state or ecosystem function. We review the benefits, opportunities and challenges to increased integration of monitoring projects. We argue that better harmonizing protocols of data collection and data management would allow new questions to be addressed while adding tremendous value to individual projects. However, despite many opportunities, challenges remain. We offer six recommendations that represent decisive progress toward a better integration of Arctic fox monitoring projects. Further, our work serves as a template that can be used to integrate monitoring efforts of other species, thereby providing a key step for future assessments of global biodiversity.

Quantifying within- and between-individual variation in animal migration strategies is a first step towards our understanding of the ability of migrants to adjust to changes in the en - vironment. We studied consistency (or, conversely, flexibility) in movement patterns at large (>1000 km) to meso-scales (100−1000 km) during the non-breeding season of the long-tailed skua Stercorarius longicaudus, a long-distance migratory Arctic seabird, using light-based geolocation. We obtained 97 annual tracks of 38 individuals and quantified similarity between routes. Overall, tracks of the same individual were generally within about 200 to 300 km of their previous year’s route, and more similar than tracks of different individuals. Some flexibility was observed during migration, but individuals were faithful to their staging areas in the North Atlantic and in the Benguela Current off Namibia and South Africa. Over the course of the winter, an increasing number of individuals started to deviate—up to 5200 km—from the previous year’s route. Intriguingly, individuals could be highly consistent between 2 consecutive years and flexible between other years. Site-shifts in late winter seem to reflect responses to local conditions, but what promotes this larger flexibility remains unclear and requires further study. Our results show that individual long-tailed skuas are generally consistent in their itineraries, but can show considerable flexibility in some years. The flexibility in itineraries suggests that long-tailed skuas are able to adjust to environmental change, but the mechanisms leading to the observed within- and between-individual variation in movement patterns are still poorly understood. Individual consistency · Repeatability · Stercorarius longicaudus · Seabirds · Tracking · Non-breeding movements · Flexibility

Background Geolocators are useful for tracking movements of long-distance migrants, but potential negative effects on birds have not been well studied. We tested for effects of geolocators (0.8–2.0 g total, representing 0.1–3.9 % of mean body mass) on 16 species of migratory shorebirds, including five species with 2–4 subspecies each for a total of 23 study taxa. Study species spanned a range of body sizes (26–1091 g) and eight genera, and were tagged at 23 breeding and eight nonbreeding sites. We compared breeding performance and return rates of birds with geolocators to control groups while controlling for potential confounding variables. Results We detected negative effects of tags for three small-bodied species. Geolocators reduced annual return rates for two of 23 taxa: by 63 % for semipalmated sandpipers and by 43 % for the arcticola subspecies of dunlin. High resighting effort for geolocator birds could have masked additional negative effects. Geolocators were more likely to negatively affect return rates if the total mass of geolocators and color markers was 2.5–5.8 % of body mass than if tags were 0.3–2.3 % of body mass. Carrying a geolocator reduced nest success by 42 % for semipalmated sandpipers and tripled the probability of partial clutch failure in semipalmated and western sandpipers. Geolocators mounted perpendicular to the leg on a flag had stronger negative effects on nest success than geolocators mounted parallel to the leg on a band. However, parallel-band geolocators were more likely to reduce return rates and cause injuries to the leg. No effects of geolocators were found on breeding movements or changes in body mass. Among-site variation in geolocator effect size was high, suggesting that local factors were important. Conclusions Negative effects of geolocators occurred only for three of the smallest species in our dataset, but were substantial when present. Future studies could mitigate impacts of tags by reducing protruding parts and minimizing use of additional markers. Investigators could maximize recovery of tags by strategically deploying geolocators on males, previously marked individuals, and successful breeders, though targeting subsets of a population could bias the resulting migratory movement data in some species. Electronic supplementary material The online version of this article (doi:10.1186/s40462-016-0077-6) contains supplementary material, which is available to authorized users.

The high Arctic has the world’s simplest terrestrial vertebrate predator–prey community, with the collared lemming being the single main prey of four predators, the snowy owl, the Arctic fox, the long-tailed skua, and the stoat. Using a 20-year-long time series of population densities for the five species and a dynamic model that has been previously parameterized for northeast Greenland, we analyzed the population and community level consequences of the ongoing and predicted climate change. Species’ responses to climate change are complex, because in addition to the direct effects of climate change, which vary depending on species’ life histories, species are also affected indirectly due to, e.g., predator–prey interactions. The lemming–predator community exemplifies these complications, yet a robust conclusion emerges from our modeling: in practically all likely scenarios of how climate change may influence the demography of the species, climate change increases the length of the lemming population cycle and decreases the maximum population densities. The latter change in particular is detrimental to the populations of the predators, which are adapted to make use of the years of the greatest prey abundance. Therefore, climate change will indirectly reduce the predators’ reproductive success and population densities, and may ultimately lead to local extinction of some of the predator species. Based on these results, we conclude that the recent anomalous observations about lack of cyclic lemming dynamics in eastern Greenland may well be the first signs of a severe impact of climate change on the lemming–predator communities in Greenland and elsewhere in the high Arctic.

Summary1. Environmental variability, through interannual variation in food availability or climaticvariables, is usually detrimental to population growth. It can even select for constancy in keylife-history traits, though some exceptions are known. Changes in the level of environmentalvariability are therefore important to predict population growth or life-history evolution.Recently, several cyclic vole and lemming populations have shown large dynamical changesthat might affect the demography or life-histories of rodent predators.2. Skuas constitute an important case study among rodent predators, because of theirstrongly saturating breeding productivity (they lay only two eggs) and high degree of sitefidelity, in which they differ from nomadic predators raising large broods in good rodentyears. This suggests that they cannot capitalize on lemming peaks to the same extent asnomadic predators and might be more vulnerable to collapses of rodent cycles.3. We develop a model for the population dynamics of long-tailed skuas feeding on lemmingsto assess the demographic consequences of such variable and non-stationary prey dynamics,based on data collected in NE Greenland. The model shows that populations of long-tailedskua sustain well changes in lemming dynamics, including temporary collapses (e.g. 10 years).A high floater-to-breeder ratio emerges from rigid territorial behaviour and a long-life expec-tancy, which buffers the impact of adult abundance’s decrease on the population reproductiveoutput.4. The size of the floater compartment is affected by changes in both mean and coefficient ofvariation of lemming densities (but not cycle amplitude and periodicity per se). In Greenland,the average lemming density is below the threshold density required for successful breeding(including during normally cyclic periods). Due to Jensen’s inequality, skuas therefore benefitfrom lemming variability; a positive effect of environmental variation.5. Long-tailed skua populations are strongly adapted to fluctuating lemming populations, aninstance of demographic lability in the reproduction rate. They are also little affected by poorlemming periods, if there are enough floaters, or juveniles disperse to neighbouring popula-tions. The status of Greenland skua populations therefore strongly depends upon floaternumbers and juvenile movements, which are not known. This reveals a need to intensifycolour-ringing efforts on the long-tailed skua at a circumpolar scale.Key-words: demographic buffering, environmental variance, floaters, population cycles,territoriality

The Long-tailed Skua, a small (,300 g) Arctic-breeding predator and seabird, is a functionally very important component of the Arctic vertebrate communities in summer, but little is known about its migration and winter distribution. We used lightlevel geolocators to track the annual movements of eight adult birds breeding in north-east Greenland (n = 3) and Svalbard (n = 5). All birds wintered in the Southern Hemisphere (mean arrival-departure dates on wintering grounds: 24 October-21 March): five along the south-west coast of Africa (0–40uS, 0–15uE), in the productive Benguela upwelling, and three further south (30–40uS, 0–50uE), in an area extending into the south-west Indian Ocean. Different migratory routes and rates of travel were documented during post-breeding (345 km d21 in late August-early September) and spring migrations (235 km d21 in late April) when most birds used a more westerly flyway. Among the different staging areas, a large region off the Grand Banks of Newfoundland appears to be the most important. It was used in autumn by all but one of the tracked birds (from a few days to three weeks) and in spring by five out of eight birds (from one to more than six weeks). Two other staging sites, off the Iberian coast and near the Azores, were used by two birds in spring for five to six weeks. Over one year, individuals travelled between 43,900 and 54,200 km (36,600–45,700 when excluding staging periods) and went as far as 10,500–13,700 km (mean 12,800 km) from their breeding sites. This study has revealed important marine areas in both the south and north Atlantic Ocean. Sustainable management of these ocean basins will benefit Long-tailed Skuas as well as other trans-equatorial migrants from the Arctic. © 2013 Gilg et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

6 pages; International audience; Alpine and arctic lemming populations appear to be highly sensitive to climate change, and when faced with warmer and shorter winters, their well-known high-amplitude population cycles may collapse. Being keystone species in tundra ecosystems, changed lemming dynamics may convey significant knock-on effects on trophically linked species. Here, we analyse long-term (1988-2010), community-wide monitoring data from two sites in high-arctic Greenland and document how a collapse in collared lemming cyclicity affects the population dynamics of the predator guild. Dramatic changes were observed in two highly specialized lemming predators: snowy owl and stoat. Following the lemming cycle collapse, snowy owl fledgling production declined by 98 per cent, and there was indication of a severe population decline of stoats at one site. The less specialized long-tailed skua and the generalist arctic fox were more loosely coupled to the lemming dynamics. Still, the lemming collapse had noticeable effects on their reproductive performance. Predator responses differed somewhat between sites in all species and could arise from site-specific differences in lemming dynamics, intra-guild interactions or subsidies from other resources. Nevertheless, population extinctions and community restructuring of this arctic endemic predator guild are likely if the lemming dynamics are maintained at the current non-cyclic, low-density state.

7 pages; International audience; The Long-tailed Skua (Stercorarius longicaudus) is a specialist predator of lemmings during the summer and hence an important component of the tundra ecosystems, but most of its life cycle takes place offshore and remains largely unknown outside of the breeding season. Using 9.5-g solar-powered satellite transmitters, we were able to document for the first time the post-breeding movements of the Long-tailed Skua, from its high-Arctic breeding-grounds in North and Eastern Greenland to the tropical waters of West Africa. The birds traveled the approximately 10,000 km of this migration in only 3-5 weeks, covering 800-900 km/day during active migration, which also occurred during nighttime. Leaving their breeding areas in August (except for one failed breeder), the Long-tailed Skuas first moved south along the coast of East Greenland towards a staging area off the Canadian Great Banks where they stayed for 1-3 weeks. From there, they crossed the Atlantic Ocean eastwards in just 1 week, entering African waters near the Madeira Archipelago in September. Although only four birds were monitored for 1.5-3 months, the data reveal that the migration routes between birds breeding in different locations and in different years were relatively similar.

Gilg, O., Sittler, B., Sabard, B., Hurstel, A., Sane, R., Delattre, P. and Hanski, I. 2006. Functional and numerical responses of four lemming predators in high arctic Greenland. - Oikos 113: 193-216. The high-arctic tundra ecosystem has the world's simplest vertebrate predator-prey community, with only four predators preying upon one rodent species, the collared lemming {Dicrostonyx groenlandicus). We document the functional and numerical responses of all the four predators in NE Greenland. Using these data, we assess the impact of predation on the dynamics of the collared lemming with a 4 yr cycle and > 100-fold difference between maximum and minimum densities. All predator species feed mostly ( >90%) on lemmings when lemming density is > 1 ha~ \ but the shapes of the predators' responses vary greatly. The snowy owl (Nyctea scandiaca) is present and breeds only when lemming densities at snowmelt are >2 ha~ \ giving rise to a step-like numerical response. The long- tailed skua {Stercorarius longicaudus) has a type III functional response and shifts from alternate food (mainly berries and insects) to lemmings with increasing lemming density. The skua surpasses all the other predators in summer by its total response. The type III functional response of the Arctic fox (Alopex lagopus) starts to increase at much lower lemming densities than the responses of the avian predators, but it has only a weak numerical response. Finally, the stoat (Mustela erminea) is the most specialized predator and the only one with a clearly delayed numerical response. According to their specific functional and numerical responses, each predator plays a key role at some point of the lemming cycle, but only the stoat has the potential to drive the lemming cycle. Stoat predation is greatly reduced in the winter preceding the lemming peak, and it reaches a maximum in the winter preceding the lowest lemming summer density. Stoat predation appears to maintain low lemming densities for at least two successive years. Our study provides empirical support for the specialist predator hypothesis about small mammal population cycles

Die gesamte gronlandische Nordost- und Nordkuste zwischen Kong Oscars Fjord und Rypefjord im Sudosten und dem Petermann Gletscher im Nordwesten sowie der dazwischen liegende Teil des Inlandeises und die angrenzenden Kustengewasser bilden den North-east Greenland National Park (71°00'-83°00'N, 11°39'-63°00'W). Mit einer Gesamtflache von 956 700 km2 ist er groser als Frankreich und Grosbritannien zusammen und das groste Schutzgebiet dieser Art weltweit. 18,4 % der Flache sind eisfreies Land, 11,6 % Fjorde und Kustengewasser und die restlichen 70 % sind von Gletschern und Inlandeis bedeckt. Im Suden gehoren zum Nationalpark Teile des Scoresby Sund, dem mit 314 km Lange grosten Fjord der Welt. In etwa 500 km Entfernung, durch die Danemarkstrase getrennt, liegt Island als nachstgelegene Landmasse. Der zur Gronlandsee und dem Nordpolarmeer gerichtete zerkluftete Kustenstreifen hat eine Gesamtlange von etwa 10 000 km. Von der Nordspitze aus sind es nur noch ca. 750 km bis zum Nordpol und im Nordwesten trennt der an dieser Stelle nur etwa 25 km breite Robeson-Kanal Gronland vom kanadischen Ellesmere-Island. Keywords: Eisbar; Fellfield; Florengeschichte; Geologie; Gletscher; Gletscherschliff; Gronland; Hundeschlitten; Klima; Knutt; Landschaftsform; Landtiere; marine Tierwelt; Nationalpark Nordost-Gronland; Polarfuchs; Polygonboden; Schneebodenvegetation; Schneeeule; Schutzgebiet; Tourismus; Vegetation; Vergletscherung; Vogelwelt; Wale; Zwergstrauchheide; sample article

The collared lemming in the high-Arctic tundra in Greenland is preyed upon by four species of predators that show marked differences in the numbers of lemmings each consumes and in the dependence of their dynamics on lemming density. A predatorprey model based on the field-estimated predator responses robustly predicts 4-year periodicity in lemming dynamics, in agreement with long-term empirical data. There is no indication in the field that food or space limits lemming population growth, nor is there need in the model to consider those factors. The cyclic dynamics are driven by a 1-year delay in the numerical response of the stoat and stabilized by strongly density-dependent predation by the arctic fox, the snowy owl, and the long-tailed skua.

Long-term surveys on Traill Island (Northeast Greenland) show that numbers of king eider (Somateria spectabilis) nests are correlated with high densities of collared lemming (Dicrostonyx groenlandicus). These observations match other zoological records from this region and agree with similar observations recorded elsewhere for arctic geese. Processes at work may be related to the fact that mammalian predators focus on lemmings when lemming numbers are high, but exert higher predation pressure on other prey at low lemming densities. Predators seem to increase their search effort during such low lemming years, thus increasing the likelihood that they will discover eider nests. This study highlights the importance of studying patterns at the community level in any attempt to interpret cyclic fluctuations in northern ecosystems.

The western coast of Svalbard is one of the world's most important seabird regions (Belopol'skij 1961; Løvenskiold 1964; Norderhaug et al. 1977), due to the favourable water temperatures, light regime and amounts of mineral salts (Norderhaug et al. 1977). Seabirds have been censused several times in this area (Kristoffersen 1962; Larsen 1965; Dhondt et al.1969; Voisin 1970; Norderhaug 1974; Sendstad 1978; Alendal et al. 1982). Except for Larsen (1965), there is no comprehensive and quantitative survey of any part of northwestern Svalbard. Further east, Jepsen & Mobæk (1983) surveyed the area between Gråhuken and Nordaustìandet. Recent concern about the potentially detrimental effects of planned oil exploration and increased human activities in the high Arctic has emphasized the need for more information on the ecology in these regions. This paper provides more comprehensive data on seabird populations in northwestern Svalbard, between southern Prins Karls Forland and Verlegenhuken. The results supplement the studies carried out in 1978 and 1979 by Jepsen & Mobæk (1983) between Verlegenhuken and Kong Karls Land.