Mountain areas often hold special species communities, and they are high on the list of conservation concern. Global warming and changes in human land use, such as grazing pressure and afforestation, have been suggested to be major threats for biodiversity in the mountain areas, affecting species abundance and causing distribution shifts towards mountaintops. Population shifts towards poles and mountaintops have been documented in several areas, indicating that climate change is one of the key drivers of species' distribution changes. Despite the high conservation concern, relatively little is known about the population trends of species in mountain areas due to low accessibility and difficult working conditions. Thanks to the recent improvement of bird monitoring schemes around Europe, we can here report a first account of population trends of 44 bird species from four major European mountain regions: Fennoscandia, UK upland, south-western (Iberia) and south-central mountains (Alps), covering 12 countries. Overall, the mountain bird species declined significantly (-7%) during 2002-2014, which is similar to the declining rate in common birds in Europe during the same period. Mountain specialists showed a significant -10% decline in population numbers. The slope for mountain generalists was also negative, but not significantly so. The slopes of specialists and generalists did not differ from each other. Fennoscandian and Iberian populations were on average declining, while in United Kingdom and Alps, trends were nonsignificant. Temperature change or migratory behaviour was not significantly associated with regional population trends of species. Alpine habitats are highly vulnerable to climate change, and this is certainly one of the main drivers of mountain bird population trends. However, observed declines can also be partly linked with local land use practices. More efforts should be undertaken to identify the causes of decline and to increase conservation efforts for these populations.

BirdLife Österreich Wien Austria

British Trust for Ornithology University of Stirling Stirling Scotland

Catalan Ornithological Institute Natural History Museum of Barcelona Barcelona Spain

Centre d'Ecologie et des Sciences de la COnservation (CESCO UMR 7204 Museum National d'Histoire Naturelle Paris France

CREAF Bellaterra Spain

CSIC Bellaterra Spain

Dachverband Deutscher Avifaunisten e 5 Geschäftsstelle Münster Germany

Department of Biology Lund University Lund Sweden

Estudio y seguimiento de aves SEO BirdLife C Melquíades Biencinto Madrid Spain

Finnish Museum of Natural History University of Helsinki Helsinki Finland

InForest Jru Solsona Spain

Italian Common Breeding Bird monitoring programme Parma Italy

Krkonose National Park Vrchlabi Czech Republic

Norwegian Institute for Nature Research Trondheim Norway

Section of Science Nord University Levanger Norway

Snow and Mountain Research Center of Andorra Sant Julià de Lòria Principality of Andorra

Swiss Ornithological Institute Sempach Switzerland

The British Trust for Ornithology The Nunnery Norfolk UK

Université Paris Sud UMR 8079 Ecologie Systématique Evolution Orsay France

References provided by Crossref.org

Long-term changes in chemical components in the meadow pipit (Anthus pratensis) in the formerly heavily polluted Eastern Sudetes Mountains

Long-term population trends of 48 urban bird species correspond between urban and rural areas

Local colonisations and extinctions of European birds are poorly explained by changes in climate suitability