First photographic evidence of an insular dwarf fox (Urocyon sp.) on the island of Cozumel, Mexico

Carnivores confined to islands often undergo rapid evolutionary divergence, resulting in dwarfism. However, many of these insular species remain poorly understood. Island carnivores are among the most threatened mammals globally, as environmental change disproportionately impacts islands and restricted ranges combined with small populations inherently heighten their vulnerability. Archaeological evidence indicates that a dwarf fox ( Urocyon sp. ) has inhabited the island of Cozumel, Mexico for thousands of years. However, this population has never been formally described and no observations have been reported since 2001. Here, we present the first photographic evidence of a dwarf gray fox on Cozumel and the first sighting of the species in over two decades. On 14 September 2023, a disoriented adult male was reported near the coastal highway on the island’s southeast coast to local park authorities. Following documentation, capture, and a health assessment, the fox was released into suitable habitat within the Laguna Colombia State Reserve. This record confirms the continued persistence of the Cozumel fox despite decades of uncertainty and provides the first documented image of the species. Considering the species’ rarity and the increasing environmental pressures on Cozumel, systematic surveys targeting the fox are urgently needed to assess its population and taxonomic status in order to inform effective conservation strategies.