Moorland clouded yellow (Colias palaeno)

As the "moorland" in its name indicates (very similar in German, "Hochmoorgelbling"), this butterfly prefers wetlands, scrubby open areas, forest meadows.
Quoting Wikipedia: “ In the southern areas of its range it is a high alpine species reaching an elevation over 1,500 metres”. We spotted this individual in Valais, Switzerland, at a little less than 2000m.