High-alpine ecosystems are strongly seasonal and adverse environments. In these ecosystems, the brevity of optimal breeding conditions means species must efficiently track spatiotemporal variations in resources in order to synchronise their reproductive effort with peaks in food availability. Understanding the details of prey-habitat associations and their seasonality in such ecosystems is thus key for deciphering species' ecological niches and developing sound conservation action. However, the ecological requirements of high-alpine avifauna remain poorly documented. Furthermore, mountain ranges in the Old World are affected not only by profound alterations of climate, but also by changes in land-use, the interaction of which hampers both proper forecasting of species' resilience to environmental change and delivery of evidence-based conservation guidance. Here, we investigate the prey-habitat associations of a high-alpine passerine, the White-winged Snowfinch (Montifringilla nivalis), by radio-tracking breeding adults in the Swiss Alps. In late spring and early summer, Snowfinches foraged preferentially next to invertebrate-rich, melting snow patches where Tipulidae larvae abound. Later, in mid-summer, they favoured flower-rich alpine meadows. When foraging, they always preferred short ground vegetation while avoiding rock and scree. Their pattern of foraging habitat selection reflects trade-offs between food abundance and accessibility, i.e. prey availability. The reliance of this passerine on a habitat mosaic where snow plays a major role questions its ability to cope with climate change due to future habitat loss and potential phenological mismatches. Targeted grazing could possibly help in habitat management by aiming at maintaining invertebraterich meadows with short vegetation. Yet, it remains an open question whether habitat management would suffice to compensate for the potentially detrimental effects of the progressive retreat of snow fields to higher elevations.

Agricultural lands can provide suitable habitat for birds under some conditions. 25In particular, waterfowl sometimes rely on ricefields as nocturnal foraging habitat during 26 winter if post-harvest practices make food accessible. To assess whether the winter flooding 27 of ricefields could be a major driver of duck regional abundance in Europe, we relied on a 28 combination of spatial and temporal analyses. In the former, five of the most important 29western European rice growing regions in Spain, Italy and France were compared in terms of 30 habitat composition over the 2002-2012 period. The relative importance of natural wetlands 31 and ricefields (either dry or flooded) in determining the abundance of wintering ducks was 32 then established. In the second approach, the trends in duck numbers before and after 33 implementation of winter-flooding Agri-Environment Schemes (AES) were compared in two 34 of the study regions. Both approaches highlighted the role of winter ricefield flooding in 35 explaining wintering duck numbers and complementing the natural wetlands; flooding 36 harvested ricefields improves habitat attractiveness by enhancing food resource accessibility. 37In Europe, the proportion of ricefields flooded during winter varies considerably between 38 countries (0.17 to 62%), owing to differences in policy initiatives such as Agri-Environment 39Schemes. Promoting such schemes more widely across the European rice production area 40 could make a big difference in terms of waterfowl habitat quality at the scale of their 41 wintering range. 42

The response of montane and subalpine hay meadow plant and arthropod communities to the application of liquid manure and aerial irrigation – two novel, rapidly spreading management practices – remains poorly understood, which hampers the formulation of best practice management recommendations for both hay production and biodiversity preservation. In these nutrient-poor mountain grasslands, a moderate management regime could enhance overall conditions for biodiversity. This study experimentally assessed, at the site scale, among low-input montane and subalpine meadows, the short-term effects (1 year) of a moderate intensification (slurry fertilization: 26.7–53.3 kg N·ha−1·year−1; irrigation with sprinklers: 20 mm·week−1; singly or combined together) on plant species richness, vegetation structure, hay production, and arthropod abundance and biomass in the inner European Alps (Valais, SW Switzerland). Results show that (1) montane and subalpine hay meadow ecological communities respond very rapidly to an intensification of management practices; (2) on a short-term basis, a moderate intensification of very low-input hay meadows has positive effects on plant species richness, vegetation structure, hay production, and arthropod abundance and biomass; (3) vegetation structure is likely to be the key factor limiting arthropod abundance and biomass. Our ongoing experiments will in the longer term identify which level of management intensity achieves an optimal balance between biodiversity and hay production.