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Life-history theory predicts that animals should develop adaptive trade-offs between survival and reproduction to maximize their fitness. This results in a continuum of life-history strategies among species, ranging from slow to fast paces-of-life. The optimal pace-of-life has been shown to vary within environmental gradients, with a commonly observed pattern of a slow-to-fast continuum from the tropics to the poles. Within species, pace-of-life variability has however received much less attention. In this study, we investigated whether or not the pace-of-life of populations within a species follows the expected slow–fast continuum associated with latitude. We analysed the variability of life-history strategies among populations of the European roller Coracias garrulus, a long-distance migratory species, comparing breeding parameters and adult survival between populations across a latitudinal gradient. The findings showed a negative correlation between survival and clutch size in roller populations, with a slower pace-of-life in the northern populations and a faster pace-of-life in the southern populations: a reverse gradient to what might be expected from inter-specific studies. These results suggest that northern populations would benefit from measures enhancing adult survival probability, such as reduction in harvesting rates, while southern populations would respond better to actions favouring reproductive success, such as nesting site provisioning. This study highlights that life-history traits can vary substantially between populations of a single species with a large latitudinal breeding range, and pinpoint how knowledge about this variability may be key in anticipating different populations’ responses to threats as well as to conservation strategies.

Climate warming is driving changes in species distributions, although many species show a so-called climatic debt, where their range shifts lag behind the fast shift in temperature isoclines. Protected areas (PAs) may impact the rate of distribution changes both positively and negatively. At the cold edges of species distributions, PAs can facilitate species distribution changes by increasing the colonization required for distribution change. At the warm edges, PAs can mitigate the loss of species, by reducing the local extinction of vulnerable species. To assess the importance of PAs to affect species distribution change, we evaluated the changes in a non-breeding waterbird community as a response to temperature increase and PA status, using changes of species occurrence in the Western-Palearctic over 25 years (97 species, 7,071 sites, 39 countries, 1993– 2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate the species turn-over induced by temperature increase. In addition, we measured whether the thermal community adjustment was led by cold-dwelling species extinction and/or warm-dwelling species colonization, by modelling the change in standard deviation of the CTI (CTIsd). Using linear mixed-effects models, we investigated whether communities within PAs had lower climatic debt and different patterns of community change regarding the local PA surface. Thanks to the combined use of the CTI and CTIsd, we found that communities inside PAs had more species, higher colonization, lower extinction and the climatic debt was 16% lower than outside PAs. The results suggest the importance of PAs to facilitate warm-dwelling species colonization and attenuate cold-dwelling species extinction. The community adjustment was however not sufficiently fast to keep pace with the strong temperature increase in central and northeastern Western-Palearctic regions. Our study underlines the potential of the combined CTI and CTIsd metrics to understand the colonization-extinction patterns driven by climate warming.

Protected area networks facilitate community changes in responses to climate warming. However, the contribution of the site environmental and conservation-oriented characteristics to these responses to climate warming are not well understood. Here, we investigate how composition of non-breeding waterbird communities within the European Union Natura 2000 (N2K) network changes in response to increases in temperature. We measured the community reshuffling of 97 waterbird species in 3,018 N2K sites over 25 years in 26 European countries. We find that N2K sites explicitly designated for protection of waterbirds and with a management plan had faster climate-driven community changes. In contrast, the designation period of the N2K sites was not associated with community adjustment, and sites funded under EU-LIFE had lower climate-driven community changes. Our findings imply that efficient conservation policy that may help waterbird community responses to climate warming is to manage sites that are specifically designated for waterbirds. Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993–2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm-dwelling species or extirpation of cold-dwelling species by modeling change in standard deviation of the CTI (CTISD). Using linear mixed-effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTISD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTISD metrics to improve understanding of the colonization-extirpation patterns driven by climate warming.

Clausen, Preben/0000-0001-8986-294X WOS: 000536149100018 Migratory waterbirds require an effectively conserved cohesive network of wetland areas throughout their range and life-cycle. Under rapid climate change, protected area (PA) networks need to be able to accommodate climate-driven range shifts in wildlife if they are to continue to be effective in the future. Thus, we investigated geographical variation in the relationship between local temperature anomaly and the abundance of 61 waterbird species during the wintering season across Europe and North Africa during 1990-2015. We also compared the spatio-temporal effects on abundance of sites designated as PAs, Important Bird and Biodiversity Areas (IBAs), both, or neither designation (Unlisted). Waterbird abundance was positively correlated with temperature anomaly, with this pattern being strongest towards north and east Europe. Waterbird abundance was higher inside IBAs, whether they were legally protected or not. Trends in waterbird abundance were also consistently more positive inside both protected and unprotected IBAs across the whole study region, and were positive in Unlisted wetlands in southwestern Europe and North Africa. These results suggest that IBAs are important sites for wintering waterbirds, but also that populations are shifting to unprotected wetlands (some of which are IBAs). Such IBAs may therefore represent robust candidate sites to expand the network of legally protected wetlands under climate change in north-eastern Europe. These results underscore the need for monitoring to understand how the effectiveness of site networks is changing under climate change. Academy of FinlandAcademy of Finland [312579, 275606]; Tiina and Antti Herlin Foundation, Helsinki (Finland); Research Council of NorwayResearch Council of Norway [280952/E20]; project Future Bird Scenarios through the 2017-2018 Belmont Forum; Research Council of Norway (Forskningsradet)Research Council of Norway [NINA: 295767]; Academy of Finland (AKA, Univ. Helsinki) [326338]; Swedish Research Council (Formas, Lund Univ.) [2018-02441] We thank the thousands of volunteer birdwatchers that carry out the International Waterbird Census (IWC) across Europe and Africa. We also thank Wetlands International (www.wetlands.org) for coordinating such a large-scale monitoring scheme and for compiling all these data. We acknowledge all the funding sources that allow the continuation of the IWC. This work was supported by the Academy of Finland (projects 312579 and 275606), the Tiina and Antti Herlin Foundation, Helsinki (Finland), the Research Council of Norway (project 280952/E20, cofounded by Statnett and the Norwegian Water Resources and Energy Directorate). In addition, this study is framed within the project Future Bird Scenarios funded through the 2017-2018 Belmont Forum and BiodivERsA joint call for research proposals, under the BiodivScen ERANet COFUND programme, with the following funding organisations: the Research Council of Norway (Forskningsradet, NINA: 295767), the Academy of Finland (AKA, Univ. Helsinki: 326338), and the Swedish Research Council (Formas, Lund Univ.: 2018-02441).

Despite recent advances in avian tracking technology, archival devices still present several limitations. Traditional ring recoveries provide a complementary method for studying migratory movements, particularly for cohorts of birds with a low return rate to the breeding site. Here we provide the first international analysis of ring recovery data in the European Roller Coracias garrulus, a long-distance migrant of conservation concern. Our data comprise 58 records of Rollers ringed during the breeding season and recovered during the non-breeding season. Most records come from Eastern Europe, half are of juveniles and over three quarters are of dead birds. Thus, ring recoveries provide migration data for cohorts of Rollers—juveniles and unsuccessful migrants—for which no information currently exists, complementing recent tracking studies. Qualitatively, our results are consistent with direct tracking studies, illustrating a broad-front migration across the Mediterranean Basin in autumn and the use of the Arabian Peninsula by Rollers from eastern populations in spring. Autumn movements were, on average, in a more southerly direction for juveniles than adults, which were more easterly. Juvenile autumn recovery direction also appeared to be more variable than in adults, though this difference was not statistically significant. This is consistent with juveniles following a naïve vector-based orientation program, and perhaps explains the ‘moderate’ migratory connectivity previously described for the Roller. In the first (qualitative) analysis of Roller non-breeding season mortality, we highlight the high prevalence of shooting. The recovery age ratio was juvenile-biased in autumn but adult-biased in spring. Although not statistically significant, this difference points towards a higher non-breeding season mortality of juveniles than adults. Our study demonstrates the complementarity of ring recoveries to direct tracking, providing an insight into the migration of juvenile Rollers and non-breeding season mortality.

Internationally coordinated censuses of Whooper Swans Cygnus cygnus across continental northwest Europe were undertaken in mid-winter 1995, 2000, 2005, 2010 and 2015. The estimate of 138,500 birds in 2015, the highest to date, represented a more than doubling of the population size (at an annual increase of 4.1%) since the first census total of 59,000 swans in 1995. The largest increase was in Denmark, where numbers almost trebled from 21,740 in 1995 to 62,620 in 2015. More than 97% of all swans were counted in just six countries. The percentage of total numbers increased significantly between 1995 and 2015 in Denmark (from 36.5% to 45.2%) and Germany (26.0% to 34.7%), but declined significantly in Sweden (14.2% to 8.4%), Norway (13.1% to 3.6%), Poland (6.2% to 4.0%) and the Netherlands (2.4% to 1.7%). The counts show an increasing discrepancy between national trends in abundance for Whooper Swans in Sweden and especially in Denmark in comparison with results obtained only from mid-winter International Waterbird Count (IWC) site coverage. This demonstrates the increasing tendency for Whooper Swans to winter in areas away from traditionally counted IWC sites and confirms the continued need for a regular cycle of coordinated dedicated swan counts to anchor population trends generated from other data sources.