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Declines in European bird populations are reported for decades but the direct effect of major anthropogenic pressures on such declines remains unquantified. Causal relationships between pressures and bird population responses are difficult to identify as pressures interact at different spatial scales and responses vary among species. Here, we uncover direct relationships between population time-series of 170 common bird species, monitored at more than 20,000 sites in 28 European countries, over 37 y, and four widespread anthropogenic pressures: agricultural intensification, change in forest cover, urbanisation and temperature change over the last decades. We quantify the influence of each pressure on population time-series and its importance relative to other pressures, and we identify traits of most affected species. We find that agricultural intensification, in particular pesticides and fertiliser use, is the main pressure for most bird population declines, especially for invertebrate feeders. Responses to changes in forest cover, urbanisation and temperature are more species-specific. Specifically, forest cover is associated with a positive effect and growing urbanisation with a negative effect on population dynamics, while temperature change has an effect on the dynamics of a large number of bird populations, the magnitude and direction of which depend on species' thermal preferences. Our results not only confirm the pervasive and strong effects of anthropogenic pressures on common breeding birds, but quantify the relative strength of these effects stressing the urgent need for transformative changes in the way of inhabiting the world in European countries, if bird populations shall have a chance of recovering.

Protecting habitats for charismatic vertebrates can provide an ‘umbrella’ for less conspicuous organisms, especially when these are threatened by the same processes. However, such a conservation scheme is vulnerable to the extirpation of the focal species. We studied wider biodiversity values in long protected black stork (Ciconia nigra) nest sites, which were abandoned by the bird and thus legally subject to de-listing. In 20 abandoned nest sites in Estonia, we (i) mapped breeding birds within 600 m from the stork nest, and (ii) carried out time-limited surveys of lichens, polypore fungi, vascular plants and bryophytes in 2-ha plots. The breeding bird assemblages (64 species recorded) included 19 red-listed species, and showed no clear aggregation to the immediate surroundings of the stork nest. We recorded 740 plant and fungal species, of which 134 (18%) were of conservation concern (nationally protected, red-listed or extremely rare). Across the 2-ha plots, the numbers of the species of conservation concern varied more than three-fold (maximum 42 species), being affected notably by dead wood accumulation over time and presence of nemoral broad-leaved trees. The results demonstrate that many abandoned nest sites of the black stork have broader biodiversity significance, both due to the bird’s habitat requirements and the natural development during the protection. Expanding the umbrella function to sites abandoned by a focal species, but intact from anthropogenic degradation, can thus be a cost-effective conservation approach due to its low additional administrative burden. In most jurisdictions, the assessment procedure for such situations should be formalized, however.

Climate change is a major global threat to biodiversity with widespread impacts on ecological communities. Evidence for beneficial impacts on populations is perceived to be stronger and more plentiful than that for negative impacts, but few studies have investigated this apparent disparity, or how ecological factors affect population responses to climatic change. We examined the strength of the relationship between species-specific regional population changes and climate suitability trends (CST), using 30-year datasets of population change for 525 breeding bird species in Europe and the USA. These data indicate a consistent positive relationship between population trend and CST across the two continents. Importantly, we found no evidence that this positive relationship differs between species expected to be negatively and positively impacted across the entire taxonomic group, suggesting that climate change is causing equally strong, quantifiable population increases and declines. Species’ responses to changing climatic suitability varied with ecological traits, however, particularly breeding habitat preference and body mass. Species associated with inland wetlands responded most strongly and consistently to recent climatic change. In Europe, smaller species also appeared to respond more strongly, whilst the relationship with body mass was less clear-cut for North American birds. Overall, our results identify the role of certain traits in modulating responses to climate change and emphasise the importance of long-term data on abundance for detecting large-scale species’ responses to environmental changes.

The greatest loss of biodiversity in the EU has occurred on agricultural land. The Common Starling (Sturnus vulgaris) is one of the many numerous and widespread European farmland breeding bird species showing major population declines linked to European agricultural intensification. Here we present results based on monitoring data collected since 1975 in 24 countries to examine the influence of changing extent of grassland and cattle abundance (based on results of earlier studies showing the importance of lowland cattle grazed grassland for the species), wintering provenance and temperature on nationalbreeding population trends of Starlings across Europe. Positive Starling population trends in Central-East Europe contrast with negative trends in North and West Europe. Based on this indicative approach, we found some support for the importance of cattle stock and no support for grassland, temperature or wintering provenance to explain Starling population trends in Europe. However, we acknowledge such a European-wide analysis may conceal regional differences in responses and suggest that currently accessible national land use data might be insufficient to describe the detailed current changes in animalhusbandry and grassland management that may be responsible for changes in food availability and hence breeding Starling abundance and their differences across Europe. Reviewing results from local studies relating Starling population trends to local agricultural change offer contradictory results, suggesting complex interacting processes at work. We recommend combining national datasets on demography, land-use/agricultural practices and from autecological research to better explain the reasons for contrasting Starling trends across Europe, to enable us to predict how changing agriculture will affect Starlings and potentially suggest mitigation measures to restore local populations wherepossible.

We assessed ecological sustainability of seminatural forestry by analyzing 80-year dynamics and the current distribution of all woodpecker species in Estonia. We found that, despite the clear-cutting-based forestry system, woodpeckers inhabited commercial seminatural forests in substantial numbers, including the species generally considered vulnerable to timber harvesting. The only negative trend, a drastic decline in the Green Woodpecker, paralleled the loss of seminatural, wooded grasslands and is mostly an issue for landscape planning and agricultural land use. Major silvicultural factors supporting other species in commercial forests include natural regeneration with multiple native tree species and deadwood abundance. In such context, the main role of protected areas is to provide ecological resilience; however, we estimated that the current strict reserves could further double their carrying capacities for woodpeckers through successional recovery and, perhaps, active restoration. The long time series used were instrumental in detecting unexpected dynamics and the impacts of climatically extreme years. We conclude that (1) seminatural forestry can serve as a basis for reconciling timber harvesting and biodiversity protection at the landscape scale, given appropriate attention to key structures and landscape zoning and (2) woodpeckers represent a biological indicator system for the sustainability of forest landscapes in Europe.

The paper presents the set-up and development of a common bird monitoring scheme in Estonia in 1983-2010. The point-count survey of widespread terrestrial bird species was undertaken to measure long-term population changes and to produce indicators of the condition of habitat types and the wider environment. The scheme has been mostly run by skilled volunteers of the Estonian Ornithological Society. The method applied is point counting on free- choice routes and without limiting recording distance. In the Estonian scheme, each count route consists of 20 points, with 5-minute stops at least 200 m apart. In total, 143 point count routes have been in use by 89 active birdwatchers and professional ornithologists in the course of 28 years. Yearly abundance indices for 87 bird species were calculated using TRIM software. The most evident changes in bird numbers were the declines detected in 1992-1996 among farmland species, and in 2007-2010 among farmland and woodland species. The long-term population trends (1975-2010) in four countries around the Baltic Sea depend on the migratory strategy of bird species. Among trans-Saharan migrants the proportion of declining species was much higher in comparison with short-distance migrants and sedentary species. A marked difference between these countries was found among sedentary bird species - with up to 2/3 of species with increasing trends in Finland and less than 1/3 in Denmark, Sweden, and Estonia. There is a growing interest in using the results of the scheme both at the national and the international scale (PECBMS).