Cave biodiversity and ecosystems are underexplored. To guide conservation needs for visitor management, we surveyed the 2,158 m long Danial Cave in northern Iran for vertebrate fauna. We identified four mammalian and two amphibian species in the cave: the greater horseshoe bat Rhinolophus ferrumequinum, Blasius's horseshoe bat Rhinolophus blasii, the lesser mouse-eared myotis Myotis blythii, the Hyrcanian field mouse Apodemus hyrcanicus, the Hyrcanian wood frog Rana pseudodalmatina and the Eurasian marsh frog Pelophylax ridibundus. Considering the increasing tourism pressures at Danial Cave, information on cave fauna is imperative for the conservation management of unique and endemic cave species.
