Many breeding birds move to higher ground


Song Thrush © Marcel Burkhardt

Between 1993–1996 and 2013–2016, the average altitudinal distribution of Swiss breeding birds increased by 24 m. This upward shift along the altitudinal gradient is a response to recent environmental changes, in particular to climate change.

Currently, the effects of global warming in Europe are mainly seen in the Mediterranean and the Alps. The environmental changes that ensue are already having a direct or indirect effect on birds and will continue to do so in the future. Initial projections show that many birds will shift their ranges to the north or to higher altitude. Other taxonomic groups are also affected (e.g. plants, butterflies).

Two thirds of common bird species move to higher altitude

Swiss breeding birds are distributed along an altitudinal gradient of more than 3000 m. Using atlas data from 1993–1996 and 2013–2016, we examined whether a shift in altitudinal distribution had taken place. The sample included 71 common species for which we have density change maps; of these, 40 are woodland birds.

The centre of distribution of the studied species (their average altitudinal distribution) has shifted upwards by 24 m in the past 20 years. However, there are significant differences between the species: the range of the Hooded Crow, for example, has shifted downwards by 166 m, while the Willow Warbler has gained 205 m. Overall, altitudinal distribution increased for almost two thirds of all species between the two atlas periods. The difference between upward and downward shifts is particularly apparent in larger movements: only four species have shifted downward by at least 50 m, while 22 species have moved upward along the altitudinal gradient by 50 m or more.

Change in average altitudinal distribution of 71 breeding bird species between 1993–1996 and 2013–2016. The red column shows 16 species with no change (± 10 m); above the red column are 40 species whose distribution shifted upwards, below 15 species that showed a downward shift.

A common pattern: losses in the lowlands and gains at higher altitudes

Among the 47 species that shifted their range upwards, 20 show a similar pattern: their populations have decreased at lower altitudes while increasing in the upper ranges of their distribution, independent of their ecological requirements and their average altitudinal distribution. The remaining 27 species either show only increases at higher altitudes or only losses in lower areas. Only four species show losses at high altitudes and gains in the lowlands.

Patterns in the altitudinal range shifts of 71 breeding birds between 1993–1996 and 2013–2016

The upward shift between the two atlas periods is particularly pronounced in species whose populations are concentrated at high altitude. The ten species with the highest altitudinal distribution in 1993–1996 experienced an average upward shift of 51 m; the ten species with the lowest distribution decreased in altitude by 8 m. In addition to the species included in this analysis, Black Grouse and Rock Ptarmigan also show an upward range shift.

Average altitudinal distribution per species between 1993–1996 and 2013–2016. Mountain birds have experienced a more pronounced upward shift than lowland species.

Finally, the ten species that are either included on the Red List of threatened breeding birds or classified as Near Threatened (NT) experienced a marked upward range shift of 84 m. In this group, the change presumably does not reflect a spread to higher altitudes but, rather, losses at lower elevations (e.g. Common Redstart, Garden Warbler). In contrast, the altitudinal distribution of species with increasing populations (e.g. Eurasian Blackbird, Common Woodpigeon) remained largely unchanged or even shifted downwards somewhat.

Trends with various causes

There is little doubt that climate change is influencing the upward shift in the distribution of Swiss breeding birds. Climate warming is twice as great in the Alps as it is in the valleys, which could explain the above-average upward range shift of mountain birds compared to lowland species.

Other factors also need to be considered and their effects analysed in more detail. First and foremost are human activities, especially agricultural intensification and the spread of settlements. Both these trends are much more pronounced on the Central Plateau than in the mountains. Most bird species in decline in Switzerland occur at low altitudes and are therefore particularly exposed to human activities. That birds like the Eurasian Skylark and others appear to be moving to higher altitude is actually a result of population collapses in the lower reaches of the range. Changes in mountain farming also influence the distribution of breeding birds. These include intensification and the abandonment of marginal land as well as the spread of forests. However, every species needs to be considered separately, as the interplay of various factors affects each one in a different way.

What does the future hold for mountain birds?

The upward shift of several species and the stable or even increasing populations of other mountain species suggest that the Alps may serve as a refuge in the future, when even more pronounced environmental changes are expected to occur. This is an important aspect to consider when planning large-scale conservation programmes or development projects (tourism, agriculture) in Alpine areas.

Scientists have only recently begun to study altitudinal range shifts. More research is needed in this area. Current trends do not bode well for birdlife. On the one hand, human activities such as intensive agriculture, leisure activities and the construction of roads and tourism infrastructure are expected to continue at much the same pace. On the other hand, the area of suitable habitat for species like the Rock Ptarmigan inevitably shrinks with increasing altitude. Finally, habitats respond to climate warming with a certain time lag, especially forests. But how the resulting ecological imbalances will affect the species occupying these habitats is impossible to predict. The Alps therefore play a central role in conservation, because of their rich and fragile biodiversity, but also because of their future role as a refuge.

keine Übersetzung benötigt: Sylvain Antoniazza

Recommended citation of the Atlas online:
Knaus, P., S. Antoniazza, S. Wechsler, J. Guélat, M. Kéry, N. Strebel & T. Sattler (2018): Swiss Breeding Bird Atlas 2013–2016. Distribution and population trends of birds in Switzerland and Liechtenstein. Swiss Ornithological Institute, Sempach.


Académies suisses des sciences (2016): Coup de projecteur sur le climat suisse. Etat des lieux et perspectives. 3e tirage. Swiss Academies Reports Vol. 11, N° 5. Académies suisses des sciences, Berne.

Akademien der Wissenschaften Schweiz (2016): Brennpunkt Klima Schweiz. Grundlagen, Folgen und Perspektiven. 3. Aufl. Swiss Academies Reports Vol. 11, Nr. 5. Akademien der Wissenschaften Schweiz, Bern.

Chamberlain, D., R. Arlettaz, E. Caprio, R. Maggini, P. Pedrini, A. Rolando & N. Zbinden (2012): The altitudinal frontier in avian climate impact research. Ibis 154: 205–209.

Chamberlain, D. E., M. Negro, E. Caprio & A. Rolando (2013): Assessing the sensitivity of alpine birds to potential future changes in habitat and climate to inform management strategies. Biol. Conserv. 167: 127–135.

Chamberlain, D. E., P. Pedrini, M. Brambilla, A. Rolando & M. Girardello (2016): Identifying key conservation threats to Alpine birds through expert knowledge. PeerJ 4: e1723.

Chen, I.-C., J. K. Hill, R. Ohlemüller, D. B. Roy & C. D. Thomas (2011): Rapid range shifts of species associated with high levels of climate warming. Science 333: 1024–1026.

Eigenbrod, F., P. Gonzalez, J. Dash & I. Steyl (2015): Vulnerability of ecosystems to climate change moderated by habitat intactness. Glob. Chang. Biol. 21: 275–286.

Furrer, R., M. Schaub, A. Bossert, R. Isler, H. Jenny, T. Jonas, C. Marti & L. Jenni (2016): Variable decline of Alpine Rock Ptarmigan (Lagopus muta helvetica) in Switzerland between regions and sites. J. Ornithol. 157: 787–796.

Gentili, R., H. K. Badola & H. J. B. Birks (2015): Alpine biodiversity and refugia in a changing climate. Biodiversity 16: 193–195.

Hickling, R., D. B. Roy, J. K. Hill, R. Fox & C. D. Thomas (2006): The distributions of a wide range of taxonomic groups are expanding polewards. Glob. Chang. Biol. 12: 450–455.

Huntley, B., Y. C. Collingham, S. G. Willis & R. E. Green (2008): Potential impacts of climatic change on European breeding birds. PLoS One 3: e1439.

Imperio, S., R. Bionda, R. Viterbi & A. Provenzale (2013): Climate change and human disturbance can lead to local extinction of alpine rock ptarmigan: new insight from the Western Italian Alps. PLoS One 8: e881598.

Keller, V., A. Gerber, H. Schmid, B. Volet & N. Zbinden (2010): Rote Liste Brutvögel. Gefährdete Arten der Schweiz, Stand 2010. Umwelt-Vollzug Nr. 1019. Bundesamt für Umwelt, Bern, und Schweizerische Vogelwarte, Sempach.

Keller, V., A. Gerber, H. Schmid, B. Volet & N. Zbinden (2010): Liste rouge oiseaux nicheurs. Espèces menacées en Suisse, état 2010. L’environnement pratique n° 1019. Office fédéral de l’environnement, Berne, et Station ornithologique suisse, Sempach.

Keller, V., A. Gerber, H. Schmid, B. Volet & N. Zbinden (2010): Lista Rossa Uccelli nidificanti. Specie minacciate in Svizzera, stato 2010. Pratica ambientale n. 1019. Ufficio federale dell’ambiente, Berna, e Stazione ornitologica svizzera, Sempach.

Maggini, R., A. Lehmann, M. Kéry, H. Schmid, M. Beniston, L. Jenni & N. Zbinden (2011): Are Swiss birds tracking climate change? Detecting elevational shifts using response curve shapes. Ecol. Model. 222: 21–32.

Maggini, R., A. Lehmann, N. Zbinden, N. E. Zimmermann, J. Bolliger, B. Schröder, R. Foppen, H. Schmid, M. Beniston & L. Jenni (2014): Assessing species vulnerability to climate and land use change: the case of the Swiss breeding birds. Divers. Distrib. 20: 708–719.

Marti, C., A. Bossert & H. R. Pauli (2016): Bestand und Verbreitung von Birkhuhn Tetrao tetrix und Alpenschneehuhn Lagopus muta im Aletschgebiet von 1970 bis 2015. Ornithol. Beob. 113: 1–30.

Møller, A. P., W. Fiedler & P. Berthold (2010): Effects of climate change on birds. Oxford University Press, Oxford.

Pepin, N., R. S. Bradley, H. F. Diaz, M. Baraer, E. B. Caceres, N. Forsythe, H. Fowler, G. Greenwood, M. Z. Hashmi, X. D. Liu, J. R. Miller, L. Ning, A. Ohmura, E. Palazzi, I. Rangwala, W. Schöner, I. Severskiy, M. Shahgedanova, M. B. Wang, S. N. Williamson & D. Q. Yang (2015): Elevation-dependent warming in mountain regions of the world. Nat. Clim. Chang. 5: 424–430.

Pernollet, C. A., F. Korner-Nievergelt & L. Jenni (2015): Regional changes in the elevational distribution of the Alpine Rock Ptarmigan Lagopus muta helvetica in Switzerland. Ibis 157: 823–836.

Revermann, R., H. Schmid, N. Zbinden, R. Spaar & B. Schröder (2012): Habitat at the mountain tops: how long can Rock Ptarmigan (Lagopus muta helvetica) survive rapid climate change in the Swiss Alps? A multi-scale approach. J. Ornithol. 153: 891–905.

Roth, T., M. Plattner & V. Amrhein (2014): Plants, birds and butterflies: short-term responses of species communities to climate warming vary by taxon and with altutude. PLoS One 9: e82490.

Thomas, C. D. & J. J. Lennon (1999): Birds extend their ranges northwards. Nature 399: 213.

von dem Bussche, J., R. Spaar, H. Schmid & B. Schröder (2008): Modelling the recent and potential future spatial distribution of the Ring Ouzel (Turdus torquatus) and Blackbird (T. merula) in Switzerland. J. Ornithol. 149: 529–544.


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