Alpine ibex within the Belledonne population migrate from steep south-facing rocky cliffs in low-altitude winter ranges (~1,860 m) to high-altitude alpine pastures for summer ranges (~2,360 m). The ibex use steep south-facing snow-free corridors distributed 50 km along the Belledonne massif and generally avoid crossing roads, even to access other mountain ranges on the opposite side (Oisans and Arvan-Villards mountain ranges). In spring, migratory individuals jump the green wave of vegetation as it progresses up in elevation with snowmelt, arriving just before vegetation reaches peak maturity. In autumn, vegetation senescence and the first snowfalls trigger the return migration to their winter range. This population exhibits a diversity of migration tactics, with some individuals performing relatively short, altitudinal movements while others travel up to several dozen kilometers. Each year, around two-thirds of the population migrate, while the other remain resident. However, nearly half of the ibex switch between migration and residency each year, depending on the timing and speed of spring green-up and the benefits of migration in terms of access to high-quality vegetation.