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International legislation forms a cornerstone of conservation, yet its efficacy is rarely quantified. We assess whether species listed on Annex I of the European Union (EU) Birds Directive, for which EU Member States are obliged to implement special conservation measures, differ systematically in their short-term (2001-2012) or long-term (1980-2012) population trends from those of non-Annex I species. In both periods, Annex I species had more positive trends than non-Annex I species, particularly in countries that joined the EU earlier. There were additional signatures of climate change and life history strategy in the trends of species in one or both periods. Within Annex I species, long-distance migrants fared significantly worse than other species, suggesting that enhanced protection on the breeding grounds alone may be insufficient for these species. We conclude that the EU's conservation legislation has had a demonstrably positive impact on target species, even during a period in which climate change has significantly affected populations.

Aim: Climate and land use can have important effects on the local abundances of species, but few studies have investigated the relative impacts of these factors. Here, we quantify the relative importance of climate, land use and surrounding population size in determining the abundances of birds across a continent. Location: Europe. Methods: We used species abundance models to identify the relative importance of different environmental predictors for estimating the local abundances of 342 species of European breeding birds. Models controlling for phylogeny were used to relate species life history and ecological traits to the climate:land use importance ratio. The mean of this ratio, across all species occurring in a given area, was mapped to explore spatial variation in the major drivers of abundance. Results: At the scale examined, climate is generally more important than land use in determining species abundances. However, the abundance of species in neighbouring areas is also a major correlate. Among climate variables, temperature is of greater importance than moisture availability in determining abundances. The relative importance of these variables varies with latitude, with temperature being most important in the north, and moisture availability in the south. Differences in the importance of specific drivers are related to species ecological traits: climate is more important for determining the abundance of species that have larger global ranges or a smaller body mass. Main conclusions: Abundances of species occurring in northern Europe, an area predicted to experience climatic changes of high magnitude, are most sensitive to climate, particularly temperature. Given the greater confidence in future projections of temperature than precipitation, this increases confidence in projections of the impacts of climate change on species in the north, whilst attempts to predict future populations in central and southern Europe may be dependent on less predictable changes in land use and precipitation.

The altitudinal shifts of many montane populations are lagging behind climate change. Understanding habitual, daily behavioural rhythms, and their climatic and environmental influences, could shed light on the constraints on long-term upslope range-shifts. In addition, behavioural rhythms can be affected by interspecific interactions, which can ameliorate or exacerbate climate-driven effects on ecology. Here, we investigate the relative influences of ambient temperature and an interaction with domestic sheep (Ovis aries) on the altitude use and activity budgets of a mountain ungulate, the Alpine chamois (Rupicapra rupicapra). Chamois moved upslope when it was hotter but this effect was modest compared to that of the presence of sheep, to which they reacted by moving 89–103 m upslope, into an entirely novel altitudinal range. Across the European Alps, a range-shift of this magnitude corresponds to a 46% decrease in the availability of suitable foraging habitat. This highlights the importance of understanding how factors such as competition and disturbance shape a given species’ realised niche when predicting potential future responses to change. Furthermore, it exposes the potential for manipulations of species interactions to ameliorate the impacts of climate change, in this case by the careful management of livestock. Such manipulations could be particularly appropriate for species where competition or disturbance already strongly restricts their available niche. Our results also reveal the potential role of behavioural flexibility in responses to climate change. Chamois reduced their activity when it was warmer, which could explain their modest altitudinal migrations. Considering this behavioural flexibility, our model predicts a small 15–30 m upslope shift by 2100 in response to climate change, less than 4% of the altitudinal shift that would be predicted using a traditional species distribution model-type approach (SDM), which assumes that species’ behaviour remains unchanged as climate changes. Behavioural modifications could strongly affect how species respond to a changing climate.

IntroductionClimate and environmental change have driven widespread changes in body size, particularly declines, across a range of taxonomic groups in recent decades. Size declines could substantially impact on the functioning of ecosystems. To date, most studies suggest that temporal trends in size have resulted indirectly from climate change modifying resource availability and quality, affecting the ability of individuals to acquire resources and grow.ResultsHere, we investigate striking long-term body mass declines in juvenile Alpine chamois (Rupicapra rupicapra), within three neighbouring populations in the Italian Alps. We find strong evidence that increasing population density and warming temperatures during spring and summer are linked to the mass declines. We find no evidence that the timing or productivity of resources have been altered during this period.ConclusionsWe conclude that it is unlikely that environmental change has driven body size change indirectly via effects on resource productivity or phenology. Instead, we propose that environmental change has limited the ability of individuals to acquire resources. This could be due to increases in the intensity of competition and decreases in time spent foraging, owing to high temperatures. Our findings add weight to a growing body of evidence for long-term body size reductions and provide considerable insight into the potential drivers of such trends. Furthermore, we highlight the potential for appropriate management, for instance increases in harvest size, to counteract the impacts of climate change on body mass.