Habitat suitability modulates the response of wildlife to human recreation

Outdoor recreation activities are growing in popularity, causing increasing pressure on wildlife. There arevarious ways in which wildlife reacts to recreation activities, ranging from behavioural to physiological re-sponses, with regional variation in response-intensity within the same species. We tested whether the effects ofhuman recreation are modulated by overall structural habitat suitability, using a model that included vegetationand topography, at both the regional and local habitat use scale. By undertaking a systematic, plot-based surveyover 13 years in 13 study regions across central Europe, we studied how recreation infrastructure and habitatsuitability interact and affect the variation in regional densities and local habitat use of an endangered modelspecies: the western capercaillie (Tetrao urogallus). Both regional densities and local habitat use varied greatlybetween study years and regions. Capercaillie densities were positively correlated with average habitat suit-ability, but significantly reduced when over 50% of the area was influenced by recreation activities. Habitatsuitability was the main predictor determining local habitat use. Recreation infrastructures were avoided: theeffect being stronger in poor habitat conditions, while slightly mediated by high habitat suitability. Our resultsindicate that effects of recreation activities might be mitigated by improving habitat suitability; however this haslimits because it only affects local scale habitat use but not regional densities. We stress the importance ofrecreation-free areas which must cover extensive (i.e. > 50%) parts of the species range.