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Studies of senescence in the wild have traditionally focused on traits like survival or fecundity. Although efforts to measure other salient phenotypic traits and markers of relevant physiological processes are rapidly increasing, traits related to self-maintenance remain understudied in the context of aging. Uropygial or preen gland is a holocrine gland, exclusive to birds, directly linked to self-maintenance of the quality of plumage. We measured the size of uropygial glands of common gulls (Larus canus) in a cross sectional manner in order to test whether it shows the similar age-related decline as reproductive traits previously recorded in this species. Gulls with larger glands started breeding earlier in the season, indicating that gland size is a marker of individual phenotypic quality. We found a senescent decline in the onset of breeding and the size of white wing patches, a sexually dimorphic ornamental trait, while in contrast, preen gland increased with advancing age. This finding supports the view of life-history theory that in long-lived species whose lifetime reproductive success depends heavily on lifespan, self-maintenance is prioritized over reproduction. Altogether our results support the concept that senescence in the wild can be asynchronous for traits related to maintenance versus reproduction. ; This study was supported by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreements no. 701747 to Tuul Sepp.

In recent times metapopulation models have contributed important insights to conservation, and they have inspired field studies that focus on collecting key data on demography and movement. Seabirds are suitable models for studying ecological processes in metapopulations because they breed in discrete local populations (i.e. colonies) both in space and time. However, in the Mediterranean, seabird colonies mostly show conservation problems at an ecosystem level, linked to human activities (e.g. fisheries, tourism, industrial pollution) and the resulting loss of habitat and deterioration of habitat quality. From a conservation point of view, it is crucial to study transfer processes in seabird metapopulations (i.e. emigration, immigration and colonisation) in order to propose management measures. Conservation agencies should always take into account these processes and the spatial factor involved in metapopulation dynamics. However, it is difficult to estimate demographic parameters at a metapopulation level because of technical and financial constraints. In addition, there is a need to act at large geographical scales, since seabirds are wide-ranging species, which operate in ranges beyond political boundaries and far greater than those encompassed by traditional management practices. ; La modelización de metapoblaciones ha aportado importantes avances en la ecología de la conservación, y ha inspirado trabajos de campo centrados en la recogida de datos sobre demografía y movimiento entre poblaciones. Las aves marinas son modelos apropiados para estudiar procesos ecológicos en metapoblaciones ya que crían en poblaciones locales discretas (i.e. colonias) tanto en el espacio como en el tiempo. En el Mediterráneo, además, las colonias de aves marinas suelen presentar problemas de conservación al nivel de ecosistema, principalmente relacionados con las actividades humanas (p. ej. pesquerías, turismo, contaminación) que han resultado en una pérdida y/o deterioro de hábitats de calidad. Desde el punto de vista de la conservación, es crucial estudiar los procesos de transferencia en metapoblaciones de aves marinas (i.e. emigración, inmigración y colonización) para proponer medidas de manejo. Las agencias de conservación deberían tener siempre en cuenta estos procesos y el factor espacial involucrado en la dinámica de las metapoblaciones. No obstante, es difícil estimar parámetros demográficos a nivel metapoblacional a causa de las limitaciones técnicas y económicas que normalmente supone. Además, es indispensable actuar a una elevada escala geográfica, pues las aves marinas son muy móviles, y desarrollan sus funciones más allá de las fronteras políticas, a una escala mucho mayor de la que se ha considerado tradicionalmente en los esfuerzos de gestión.

Publicación online disponible en: http://www.icm.csic.es/scimar/index.php ; [EN] In recent times metapopulation models have contributed important insights to conservation, and they have inspired field studies that focus on collecting key data on demography and movement. Seabirds are suitable models for studying ecological processes in metapopulations because they breed in discrete local populations (i.e. colonies) both in space and time. However, in the Mediterranean, seabird colonies mostly show conservation problems at an ecosystem level, linked to human activities (e.g. fisheries, tourism, industrial pollution) and the resulting loss of habitat and deterioration of habitat quality. From a conservation point of view, it is crucial to study transfer processes in seabird metapopulations (i.e. emigration, immigration and colonisation) in order to propose management measures. Conservation agencies should always take into account these processes and the spatial factor involved in metapopulation dynamics. However, it is difficult to estimate demographic parameters at a metapopulation level because of technical and financial constraints. In addition, there is a need to act at large geographical scales, since seabirds are wide-ranging species, which operate in ranges beyond political boundaries and far greater than those encompassed by traditional management practices. ; [ES] La modelización de metapoblaciones ha aportado importantes avances en la ecología de la conservación, y ha inspirado trabajos de campo centrados en la recogida de datos sobre demografía y movimiento entre poblaciones. Las aves marinas son modelos apropiados para estudiar procesos ecológicos en metapoblaciones ya que crían en poblaciones locales discretas (i.e. colonias) tanto en el espacio como en el tiempo. En el Mediterráneo, además, las colonias de aves marinas suelen presentar problemas de conservación al nivel de ecosistema, principalmente relacionados con las actividades humanas (p. ej. pesquerías, turismo, contaminación) que han resultado en una pérdida y/o deterioro de hábitats de calidad. Desde el punto de vista de la conservación, es crucial estudiar los procesos de transferencia en metapoblaciones de aves marinas (i.e. emigración, inmigración y colonización) para proponer medidas de manejo. Las agencias de conservación deberían tener siempre en cuenta estos procesos y el factor espacial involucrado en la dinámica de las metapoblaciones. No obstante, es difícil estimar parámetros demográficos a nivel metapoblacional a causa de las limitaciones técnicas y económicas que normalmente supone. Además, es indispensable actuar a una elevada escala geográfica, pues las aves marinas son muy móviles, y desarrollan sus funciones más allá de las fronteras políticas, a una escala mucho mayor de la que se ha considerado tradicionalmente en los esfuerzos de gestión. ; This is contribution #8 to the LIFENATURE programme BA 3200/98/447 "Conservation of island Special Protection Areas in the Valencian Region" financed by the Generalitat Valenciana and the EU. ; Peer reviewed

Burrowing seabirds are vulnerable to extirpation by introduced predators such as rats, but much evidence of predation is circumstantial. On Taukihepa, an island off southern New Zealand, two possible predators exist with sooty shearwaters (Puffinus griseus): the weka (Gallirallus australis), a large rail, and the ship rat (Rattus rattus), both introduced to the island. It was expected that chick predation would be principally by weka, the much larger of the two predators. To measure losses of sooty shearwater chicks to weka or rats, nests were monitored with burrow-scopes at six sites in the summers of 2003–04 and 2004–05. In three of the sites rats were removed on 4-ha grids by trapping. In the other three sites rats were not trapped. In addition, weka were removed from all six sites in 2005. Concurrent diet analysis of weka and rat stomachs was undertaken as well as stable isotopic analysis (δ13C, δ15N) of samples from rats and weka. These were compared with possible prey items including sooty shearwaters. Additional stable isotope samples were taken from Pacific rats (Rattus exulans), a small rat species present with weka and sooty shearwaters on nearby Moginui Island. Weka diet comprised ~40% of bird remains by volume and calculations using Isosource, an isotopic source portioning model, estimated sooty shearwaters contributed 59% (range: 15–71%) of weka diet during the sooty shearwater chick-raising period. Ship rats, in contrast, had very depleted δ13C isotope signatures compared with sooty shearwaters and bird remains contributed <9% of diet by volume, with Isosource calculations suggesting that ship rats consumed more passerine birds (mean: 30%; range 5–51%) than sooty shearwaters (mean 24%; range: 0–44%). In both summers, more chicks were lost on sites from which rats had been removed than on control sites. When weka were removed in 2005, fewer chicks were lost than in 2004 and significantly fewer weka-killed chicks were found on weka-removal sites than on non-removal sites. Weka were the principal predator of sooty shearwater chicks, depredating an estimated 9.9% of nests. Combining several techniques quantified the loss and identified the principal predator of a seabird in decline.

Gunshots are a worldwide source of anthropogenic disturbance, and knowledge about the potential effect on wildlife is central for conservation and sustainable management of affected species. This study contributes novel insight of the response behaviour and effect of gunshot disturbance on one of the most culturally important seabird species of the Arctic, the thick-billed murre (Brünnich's guillemot, Uria lomvia). We studied effects of gunshot disturbance at breeding colonies to explore the distance where effects started, the difference in the behavioural response between presumed disturbed colonies (e.g. by traffic and hunting) and largely undisturbed colonies, and among plots with varying seabird densities. We carried out two different types of controlled gunshot experiments – one measuring the distance at which murres first reacted to gunshots (Flight Initiation Distance, "FID") and one measuring the proportion of murres remaining in the colony during and after repeated gunshots (20 gunshots within 78 minutes). FID varied from 0.5 to 5 km. The proportion of murres remaining in the plot after the repeated gunshots ranged from 0.44 to 0.8. Mainly murres not attending offspring took off when disturbed by gunshots, but occasionally also birds incubating their egg or brooding their chick took off. We found that density of seabirds (murres and black-legged kittiwakes (Rissa tridactyla)) at the plot area scale was the best explaining factor for FID, and to some extent also for the effect of repeated gunshots, both for disturbed and undisturbed colonies. Murres in denser colonies reacted earlier (had larger FIDs) and somewhat more strongly (higher proportions fleeing) to gunshots than murres in less densely populated colonies. FID clearly showed that the current legislation in Greenland regulating gunshots near breeding colonies is insufficient. We provide some recommendations for improved management of a popular game species under pressure.

AbstractNative and alkylated polycyclic aromatic hydrocarbons (PAHs) were examined in the muscle, liver, kidneys, and lungs of greater scaup (Aythya marila) and great crested grebe (Podiceps cristatus). Both species showed differences in distribution and profiles among the tissues. The highest ƩPAH concentrations were in the scaup lungs and the grebe kidneys (20 and 19 ng g−1wet weight, respectively). Alkylated derivatives were in the range of 61 to 77% of ΣPAHs in both species. Differences in PAH profiles between birds, analyzed by PCA, were probably results of metabolic capability, not various diet. In comparison to available data from other regions of the world, PAH levels in investigated species are relatively low and do not pose a threat to birds themselves.

Acknowledgments We gratefully acknowledge the support of colleagues at Marine Scotland Science, the crew and scientists of the MRV Scotia 2018 cruise (particularly Chief Scientist Adrian Tait) and ERI interns: Gael Gelis and Martin Forestier. We gratefully acknowledge the constructive comments from reviewers. Finally, we also want to thank Ella Benninghaus for providing the auk illustrations used within the paper. Funding This work was funded by the Bryden Centre project, supported by the European Union's INTERREG VA Programme, and managed by the Special EU Programmes Body (SEUPB). The views and opinions expressed in this paper do not necessarily reflect those of the European Commission or the Special EU Programmes Body (SEUPB). Aspects of this research were also funded by a Royal Society Research Grant [RSG\R1\180430], the NERC VertIBase project [NE/N01765X/1], the UK Department for Business, Energy, and Industrial Strategy's offshore energy Strategic Environmental Assessment programme and EPSRC Supergen ORE Hub [EP/S000747/1]. ; Peer reviewed ; Publisher PDF