Mediterranean species in Switzerland

Climate warming has accelerated since the late 1980s, especially in spring and in the Alps. In parallel with the rising temperatures, the number of visitors from the Mediterranean region has increased considerably. This phenomenon is only partially explained by increased observer effort and the more rapid transmission of records. Around the same time, certain Mediterranean species began to breed in Switzerland: Spectacled Warbler and Greater Short-toed Lark in 1989 and Subalpine Warbler in 1996. There were no further records in the case of Greater Short-toed Lark, but the two warblers have been sighted regularly in the past two decades and have bred several times, mainly in southern Switzerland and most frequently in central Valais. Here, the topography generates a hot and dry climate, supporting vegetation that strongly resembles conditions in the species' original habitats. 

Even before these localised and relatively recent cases, pioneers from the Mediterranean had bred in Switzerland. In the case of Zitting Cisticola, breeding was irregular (first record in 1975), while Pallid Swift (which probably bred here even before it was first detected in 1987), Cetti's Warbler and Blue Rock-thrush have established themselves permanently, at least in Ticino. The population of Cetti's Warbler fluctuates widely, and the presence of the Pallid Swift is still limited to a single site in Locarno TI – with the exception of a mixed pair of Pallid and Common Swift that bred in Tramelan BE from 2009–2012. The Blue Rock-thrush, on the other hand, has formed a small population in Valais.

Expansions are also apparent in species less reliant on the Mediterranean climate but with a preference for warm environments that has caused them to spread to Switzerland and beyond. Among them are Moustached Warbler (first confirmed breeding in 1981), whose presence is irregular in our country, European Bee-eater, firmly established since 1991, Short-toed Snake-eagle (since 2012) and Eurasian Scops-owl, on the verge of disappearance in 2000, but currently occupying at least 30 territories.</p>

<p>In the context of these northward expansions by Mediterranean and other southern species, only the Western Orphean Warbler stands out. It used to breed in the cantons of Geneva, Ticino and Valais before gradually disappearing. Breeding was no longer recorded in its last vestiges in the Valais after 1994.

This last example is an exceptional case, and with the climate growing warmer, the trend that began a few decades ago is likely to continue. We may not only see more frequent breeding by southern species that are currently scarce, but also breeding attempts – and successes – by new species from the Mediterranean that have never been recorded here before.