The Enhanced Vegetation Index (EVI) as a proxy for diet quality and composition in a mountain ungulate

•Enhanced Vegetation Index (EVI) was used to assess diet composition and quality in Pyrenean chamois.•In spring and winter the EVI was negatively related to diets low in fibre and Calluna but positively to diets high in nitrogen, Festuca, Forbs and Trifolium.•During the summer season, the EVI was not related to diet components of chamois.•Remote sensing can be used as a tool for monitoring nutritional quality of large herbivore populations in management programmes.