Arlettaz, Raphaël, Maumary, Lionel, Cloutier, Jacques, Rnjakovic, Aleksandra, Agten, Klaus, Debons, Valentin, and Wagen-Jaussy, Martine
The upper Rhône valley (cantons of Valais and Vaud, W Switzerland) is currently being colonized by the Short-toed Snake-Eagle. This bird of prey, characterized by a slow life history strategy (one egg per clutch, one annual clutch, late sexual maturity and marked longevity) bred successfully for the first time in Switzerland in 2012, while reproduction became regular since 2015. This paper describes the recent demographic growth and spatial expansion of this small population and discusses various aspects of its ecology. In 2022 and 2023, there were already six breeding pairs. Since 2012, a total of 27 breeding events have been recorded that yielded 20 fledglings, with a maximum of 6 in 2023. A better conservation status as well as global warming are likely the main causes of this spatio-demographic expansion, which has also been reported in other areas of Europe. [ABSTRACT FROM AUTHOR]