Constraints on fruit tracking by birds at the range edge

Aims Biotic interactions may be disrupted at the range boundary if the involved species are rare in the most distant sectors. This study assesses fruit tracking by seed‐dispersing birds wintering on the border of the Palaearctic, a region where many species become scarcer before reaching the limits of their distribution in the Sahara. As vagrancy improves fruit tracking, this study tests if vagrant birds track fruit resources better than...