|The UNESCO Biosphere Reserve Engiadina Val Müstair is situated in the easternmost part of Switzerland at the border to Italy. Since 2010, together with the Swiss National Park, it forms Switzerlands first UNESCO biosphere reserve in the alpine region. The biosphere reserve is well known for its wildlife such as the ibex, chamois and red deer as well as grouse such as the black grouse and capercaillie (Tetrao urogallus). The latter is a large woodland species with very specialized habitat preferences. Its population has declined in recent decades in Central Europe and therefore the species is classified as endangered EN on the Swiss red list of breeding birds. Due to cold conditions with high snow cover and a lack of feed, capercaillies are very sensitive to disturbance in winter.At the same time, Val Müstair biosphere reserve is a renowned backcountry winter recreation area which attracts many visitors who are passionate about winter sports activities like snowshoeing or ski mountaineering. As a consequence, the issue of conflicts between backcountry activities and conservation has emerged. The situation from 2008 to 2010 was analysed by Rupf et al. (2011). It could be demonstrated that winter recreationists travel quite often through capercaillie core habitats.According to Swiss nationwide representative surveysfrom 2008 to 2020, the number of declared active winter backcountry sports recreationists has increased by 275 % from about 165,000 to 455,000 (Lamprecht et al., 2009, 2015, 2020). Additionally, Haegeli et al. (2019) and Rupf et al. (2019) state that some backcountry visitor groups look to avoid crowds and therefore enter new terrain, even though it would increase their risk of being caught by an avalanche. Based on those findings, there is an implication that the wildlife habitats will continue to subjected to the pressure of recreational backcountry winter sports activities. In this article we will address following research questions:1) Could increased numbers of winter backcountry recreationists also be observed in the countryside, specifically in UNESCO Biosphere Reserve Val Engiadina Val Müstair? – How have the numbers of usage changed in the last ten years?2) What effects did a forest clearance on a ski mountaineering route have for its neighbouring wildlife habitats?