The impact of landslide stabilization on birds: Insights from an Alpine valley

Landslides are a common issue in mountains and other areas with slopes, and their frequency is increasing because of climate change. Interventions aiming at stabilizing slopes are thus common worldwide. The environmental monitoring of consequences of such interventions rarely consider the potential impacts on wild species, and especially on animal taxa. Birds are widely adopted as biological indicators thanks to their ecology and high sensitivity to environmental changes, and could represent an ideal subject also for monitoring the impacts of landslide stabilization. By monitoring birds for 8 years in a complex restoration intervention in the Italian Alps, I investigate their potential use for understanding the impacts of landslide rehabilitation at different scales, in a 350 ha-area. A BACI protocol was adopted, with bird data collected by means of point counts. Generalized linear mixed models were used to evaluate the potential impacts of restoration phases and intervention sites; analyses were developed for the breeding period and for the whole year, and for the local vs. large scale. I found evidence for different types of impacts, including the local impact of construction sites (e.g. negative for chaffinch Fringilla coelebs), of in operam phase (negative for mistle thrush Turdus viscivorus, Eurasian treecreeper Certhia familiaris and crested tit Lophophanes cristatus, positive for grey wagtail Motacilla cinerea and rock bunting Emberiza cia), as well as for a disturbance effect on species' detectability and for independent trends. The overall species richness was not (or very scarcely) affected by restoration works. This 8 yr-work provides an example of the potential efficacy of birds as indicators of the environmental impacts caused by landslide rehabilitation, which will likely become increasingly common in the next decades. Avian monitoring could helpfully be integrated within standard monitoring of environmental impacts of landslide stabilization/restoration.