## 1 Introduction  
In mountain regions, global changes linked to climate and human impacts are serious threats to animal species. This issue is particularly relevant for those species with limited dispersal ability during part of or all their life stages [1]. Besides impacts on habitat quality due to climate change, land use and cover changes are usually considered to have important impacts on biodiversity [2]. Upper shifts of the Alpine timberine were reported to be more due to land cover changes than climate change, with a probable interaction between the two [3]. Indeed, sensitive species in mountain environments are more likely to be threatened by land cover changes, which are usually associated with direct human impact. At high altitudes, since physical space is already a limitation [4], the encroachment by shrubs and trees might result in the complete loss of habitat suitable for specialized residents of relatively open forest stands [5], including species of conservation concern [6].  
One important example is the capercaillie (_Tetrao urogallus_ L.), a species of conservation interest according to the Birds Directive (2009/147/EC) of the European Union. This species is found in boreal and temperate forests of Europe (including Russia) and its geographical range stretches from the Alps, Pyrenees, and Balkans to northern Norway. Capercaillie is thought to be an umbrella species for other mountain birds [7], making any change in its habitat distribution a good predictor of changes affecting sympatric bird species. The average home range size of capercaillie in the Alps is around 550 ha [8]. Despite this relatively large home range, the species shows narrow habitat preferences [9; 10]. Habitat suitability models have been developed at the stand and the landscape scale. Using presence-absence data, [PERSON] et al. [11] found that the best single large scale to build habitat suitability models corresponds to a small annual home range, about 250 ha. Ideally, data collected at large scale should be combined with those collected at the stand scale to efficiently develop management guidelines for capercaillie conservation [12].  
At the stand scale, capercaillie prefers mature, structurally diverse forests characterized by canopy gaps and rich undergrowth with the presence of _Vaccinium_ species [13]; branches of trees are used as shelters and roosts [12] and conifer needles form most of the capercaillie winter diet [14]. At the stand mosaic scale, ecotonal zones are important for nesting and brood rearing [13], as well as the proportion of forests, particularly coniferous [11]. At the landscape scale, habitat patches are mostly occupied when their size is 800-1100 ha (minimum: ca. 50 ha) and their distance from the nearest occupied patch is less than 10 km [15]. The uppermost slopes at the tree line are outside capercaillie altitudinal range because they offer little habitat, such as bilberry and trees [16]. Therefore, land cover and climate change together with human pressures, such as tourism, have all been highlighted as impacting on this species [17; 18; 19; 20].  
In the present study, we repeated twice over a decade the investigation of the relationships of capercaillie with habitat structure, at a single stand scale over a 400 ha study area. Our study case is located in a mountainous area on the southern edge of the Alps, which has undergone open land loss and forest expansion in recent decades [21]. At this southern edge of distribution, capercaillie population numbers do not show tendency to cycle [22] and have recently been declining [23]. Two surveys of capercaillie presence-absence, one in 2001 and the other in 2011, were compared to detect any change in the stand-level species-habitat relationships. The results will permit on the one hand to assess the consistency of capercaillie habitat suitability models across time, on the other hand to provide guidelines for managing and conserving habitats for this and other sympatric species living in the studied area.