Disentangling the importance of interspecific competition, food availability, and habitat in species occupancy: Recolonization of the endangered Fennoscandian arctic fox

► Is red fox competition or lemming abundance limiting recovery of the arctic fox? ► We performed an extensive red fox removal intervention to test these hypotheses. ► We used occupancy modeling to evaluate the recolonization probability of arctic foxes. ► The presence of red foxes was twice more important than abundance of lemmings. ► Conservation actions targeting a major reduction in red fox numbers are needed.