Tourism, mountain huts and distribution of corvids in the Bavarian Alps, Germany

Anthropogenic resources related to recreational activities and tourism infrastructure may greatly affect wildlife species in the Alps. In this paper, we explore the effects of mountain tourism in the Bavarian Alps, Germany, on the spatiotemporal distribution of corvids in the post-fledging period in summer and autumn. We contrast corvid point-counts in the surroundings of 28 popular mountain huts (hut areas) with those in 22 similar areas rarely visited by humans (control areas). Carrion crows Corvus corone and magpies Pica pica were exclusively observed at huts, and jays Garrulus glandarius occurred in more hut areas than in controls. Alpine choughs Pyrrhocorax graculus, jays and nutcrackers Nucifraga caryocatactes were more numerous at huts than in control areas. Ravens Corvus corax were equally common,but like Alpine choughs, they spent more time foraging in hut than in control areas. Multivariate analyses confirmed that corvid incidence was significantly related to tourist use. However, corvids visited huts regardless of the actual numbers of humans present. Our results suggest that corvids opportunistically adjust their range use to the availability of resources offered by tourism. Mountain huts and other places frequented by humans may thus contribute to an increased carrying capacity for corvids at higher elevations. This may have major ramifications for other species that corvids prey upon or compete with. Mountain tourism in the Alps may thus conflict with conservation efforts for threatened species such as grouse (Tetraonidae).