Preserving Short-Sward Natural Grasslands May Provide Suitable Foraging Habitat for a Climate-Threatened Alpine Species Along Ski-Pistes

In many mountain regions, tourism represents one of the main sources of income. Winter sports are often prevalent and, in the last decades, infrastructures linked to the ski industry have expanded worldwide in mountain ranges. Mountains are dramatically suffering the effects of climate change, many species are contracting or declining and ski-pistes are predicted to shrink towards higher elevations. For high-elevation ecosystems and species, the construction of ski-pistes is a major issue, impacting on species such as alpine birds already threatened by climate change. Here, by assessing the ultimate drivers of habitat selection during the breeding season, we investigated the impacts of ski-pistes in the Dolomites on the foraging behaviour of the white-winged snowfinch Montifringilla nivalis, an iconic alpine bird highly threatened by climate change. Our results show that snowfinches, during the critical period of nestling rearing, prefer to forage on snow patches and short grass on medium slope, characteristics frequently found on the studied ski-pistes. We also observed a marked effect of the temperature-solar radiation interaction: snowfinches forage in sunlit areas when ambient temperature is low, while under higher temperatures they prefer shady zones, probably due to specific physiological/thermoregulatory requirements. Foraging snowfinches and ski-pistes are associated with some shared environmental characteristics. This implies that the impact of ski-pistes could be mitigated by adequate management targeted at maintaining short-sward alpine grassland (e.g., through avoidance/reduction of machine grading and controlled grazing) and residual snow patches (preventing the complete levelling of the slope and maintaining shallow depressions in areas with lower solar radiation). Such strategies could contribute to reducing the ecological footprint of current and future ski resorts on alpine ecosystems.