Behavioural responses to human disturbance in an alpine bird

Mountain habitats are threatened by several factors, including human activities at high elevation, although the negative impacts can sometimes be balanced by positive effects related to human presence. However, knowledge of such interactions is limited in alpine ecosystems. In the study reported here, we assessed the extent of behavioural responses of the Alpine Chough Pyrrhocorax graculus, a bird species found in high-elevation habitats, to differing levels of human disturance in two alpine areas, a ski resort popular with tourists year-round (‘disturbed site’), and a protected area with low tourist activity (‘undisturbed area’). As the accessibility and distribution of food is a potential factor affecting bird behaviour, we focused on the availability of food types to better discriminate between the effect of food and direct disturbance. We found that human presence was negatively associated with intake rates and amount of time spent in a foraging patch (‘stay time’). Moreover, vigilance and flushing distances were shorter in the disturbed site than in the undisturbed area. However, intake rates were highest and stay times were shortest in the site where anthropogenic food (mostly discarded food items) was available. The abundance of a key prey type, grasshopper, changed significantly over space and time and was lower in the more developed ski area, probably due to the presence of ski pistes. In conclusion, the study highlighted that human disturbance potentially affects foraging behaviour in Alpine Choughs and that the effects could be both positive and negative. Further investigations are needed to better disentangle the effects induced by direct and indirect disturbance and, more generally, to evaluate the potential benefits and negative effects of anthropization on mountain biodiversity.