Public engagement offers insights on the Eurasian red squirrel distribution

After centuries of absence, the Eurasian red squirrel (Sciurus vulgaris) is recolonizing and expanding throughout Portugal. We implemented an online community-based project, which enabled us to obtain unprecedented records on the Eurasian red squirrel distribution, not only allowing us to map its current extent area but also to reconstruct its southward range expansion during the past years in Portugal. Possible origins of dispersion are forested areas in the northwestern and eastern Spanish borders and sites of reintroductions in Lisbon, Porto, and Coimbra. This well-established public engagement platform sets a successful example of integrated efforts between society and academy in gathering data on species distribution