Wallcreeper winter range could expand across Switzerland
Climate models predict an increase in the Wallcreeper's winter range in Switzerland, tho suitable breeding cliffs will increasingly be found at higher elevations.
Ornithomedia are reporting that climate change could greatly enlarge the Wallcreeper's winter range in Switzerland, even as suitable breeding cliffs move uphill and contract at lower elevations.
The underlying study in Ecology and Evolution modelled breeding and winter distributions separately. Its most extreme long-term scenario projected that suitable winter area could expand by as much as 244%, while overlap between seasonal ranges increased by 123%.
Wallcreepers are cliff specialists that breed mainly in high mountains from Spain to China. After breeding they disperse, often moving to lower cliffs for winter. Their dependence on rock faces makes them useful for climate modelling because the physical habitat is more stable than vegetation or snow-covered ground used by many other alpine birds.
Célestin Luisier and colleagues combined checked observations from the Swiss Ornithological Institute database with intensive abundance surveys in Valais and Vaud. They built species-distribution models using climate, topography, geology, land cover, cliff characteristics and the connectivity of rock faces.
Current models identified about 761 square kilometres of suitable winter area and 1,915 square kilometres of breeding area in Switzerland. Abundance models for the south-west estimated hundreds of winter territories and breeding pairs, although confidence intervals were wide because the bird is difficult to detect on inaccessible cliffs.
The researchers concluded that Switzerland contains enough high-elevation habitat for an upslope shift. Their results contrast with the simple expectation that every cold-adapted mountain species must lose most of its range as temperatures rise.
Sufficient high elevation habitat exists in Switzerland to allow the Wallcreeper to shift and expand its range upslope.
Célestin Luisier and colleagues, Ecology and Evolution
The seasonal picture is more complicated. Winter occurrence was strongly related to temperature, probably because warmer cliffs increase arthropod activity and reduce the energy birds spend keeping warm. Future conditions therefore created new winter opportunities higher in the Alps.
Breeding suitability was predicted to rise above roughly 2,300-2,400 metres but fall below that band. Across Switzerland the total breeding area changed little, yet regions dominated by lower mountains lost between 16.1% and 57.8% of suitable area in the most extreme 2080-2100 projection. High alpine regions gained instead.
That redistribution matters beyond Switzerland. Much of the Wallcreeper's present European range lies in medium-height mountain systems that the authors say may fall outside its future breeding thermal niche. The Swiss Alps could consequently hold a larger share of the continental population even if the national total grows.
The projections used two emissions pathways and two future periods, but they cannot represent every ecological change. The models did not include future shifts in cliff vegetation and arthropod prey, nor can they predict disturbance, disease or extreme events at individual sites.
The authors recommend protecting likely high-quality climate refuges and managing climbing on occupied cliffs. Removing vegetated microhabitats can reduce the invertebrates on which Wallcreepers feed, adding a local pressure to climate-driven change.
Ornithomedia's 19 October brief is therefore new coverage of a paper first published on 19 July. The striking percentage describes modelled expansion in Switzerland under specified scenarios, not an observed population boom or evidence that lower mountain populations are secure.
20 Oct 2026
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