Spatially explicit modeling of conflict zones between wildlife and snow sports: prioritizing areas for winter refuges

Abstract

Outdoor winter recreation exerts an increasing pressure upon mountain ecosystems, with unpredictable, free-ranging activities (e.g., ski mountaineering, snowboarding, and snowshoeing) representing a major source of stress for wildlife. Mitigating anthropogenic disturbance requires the spatially explicit prediction of the interference between the activities of humans and wildlife. We applied spatial modeling to localize conflict zones between wintering Black Grouse (Tetrao tetrix), a declining species of Alpine timberline ecosystems, and two free-ranging winter sports (off-piste skiing [including snow-boarding] and snowshoeing). Track data (snow-sports and birds' traces) obtained from aerial photographs taken over a 585-km transect running along the timberline, implemented within a maximum entropy model, were used to predict the occurrence of snow sports and Black Grouse as a function of landscape characteristics. By modeling Black Grouse presence in the theoretical absence of free-ranging activities and ski infrastructure, we first estimated the amount of habitat reduction caused by these two factors. The models were then extrapolated to the altitudinal range occupied by Black Grouse, while the spatial extent and intensity of potential conflict were assessed by calculating the probability of human-wildlife co-occurrence. The two snow-sports showed different distribution patterns. Skiers' occurrence was mainly determined by ski-lift presence and a smooth terrain, while snowshoers' occurrence was linked to hiking or skiing routes and moderate slopes. Wintering Black Grouse avoided ski lifts and areas frequented by free-ranging snow sports. According to the models, Black Grouse have faced a substantial reduction of suitable wintering habitat along the timberline transect: 12% due to ski infrastructure and another 16% when adding free-ranging activities. Extrapolating the models over the whole study area results in an overall habitat loss due to ski infrastructure of 10%, while there was a > 10% probability of human-wildlife encounters on 67% of the remaining area of suitable wintering habitat. Only 23% of the wintering habitat was thus free of anthropogenic disturbance. By identifying zones of potential conflict, while rating its relative intensity, our model provides a powerful tool to delineate and prioritize areas where wildlife winter refuges and visitor steering measures should be implemented.

Disturbance of wildlife by outdoor winter recreation: allostatic stress response and altered activity–energy budgets

“…By simultaneously measuring glucocorticoid excretion, activity, and energy budgets, the present experiments contribute to bridging this gap. This study confirms that outdoor winter recreation (by back-country skiers, snowboarders, and snowshoers) has an impact on wildlife (for Black Grouse, see Arlettaz et al 2007, Patthey et al 2008, Braunisch et al 2011, provoking subtle allostatic, physiological adjustments and behavioral responses. To our knowledge, and for the first time, it demonstrates the existence of a funneling effect, as predicted by the allostatic theory of stress, with a non-unidirectional individual stress response to disturbance.…”

“…As these species depend on a regular access to food, they have a particularly sensitive energetic balance, which renders them more susceptible to disturbances stemming from outdoor recreation (Thomas 1987). Critically, wildlife inhabiting mountainous areas increasingly are exposed to winter outdoor recreation, even in remote places far from ski resorts (Arlettaz et al 2007, Braunisch et al 2011, Rehnus et al 2014.…”

“…Black Grouse is a declining key indicator species of boreo-alpine ecosystems in Eurasia (Storch 2007). In the European Alps, its semi-open habitat lies within the subalpine timberline belt, mainly between 1700 and 2300 m altitude, where most skiing infrastructure and outdoor recreation is concentrated (Patthey et al 2008, Braunisch et al 2011, thereby exposing them to anthropogenic disturbance (Arlettaz et al 2007). In winter, alpine Black Grouse show a bimodal daily activity rhythm, with periods of foraging in early morning and late afternoon (hereafter evening) (Marjakangas 1986).…”

“…The resulting information is crucial to better understanding the impact of winter outdoor recreation on wildlife and to suggesting appropriate mitigation and conservation measures. Our study sites were potentially exposed to free-ride activities (back-country skiers, snowboarders, and snowshoers) as spatially predicted in the conflict model by Braunisch et al (2011), but no disturbance other than our experimental flushings was recorded during our activities. We only used males so as to minimize the potentially confounding effect of gender, as stress and sex hormones often interact (Husak and Moore 2008).…”

Early Detection of Bark Beetle Green Attack Using TerraSAR-X and RapidEye Data

“…Maximum entropy is a semiparametric approach that is frequently used in ecological studies (e.g., [26,48]). The aim of ME is to find the maximum entropy given the model parameters in a dataset of presence observations in relation to a set of background data representing the entire study site.…”