Previous studies of Eurasian tundra reindeer (<i>Rangifer tarandus tarandus</i>) in Norway indicate that their rumen microbiota play a key role in degrading lichen secondary metabolites. We investigated the presence of usnic acid and atranorin in faecal samples from Svalbard reindeer (<i>R. tarandus platyrhynchus</i>). Samples were collected in Bolterdalen valley together with vegetation samples ...