For forty years, there has been growing uncertainty about whether Hill's horseshoe bat (Rhinolophus hilli) still persists in Nyungwe National Park, Rwanda. Only known from one small area within the National Park, R. hilli is listed as Critically Endangered by the International Union for the Conservation of Nature (IUCN) based on its extremely small geographic range and presumed low number of mature individuals. Here, we present and describe bat species occurrence data contributed to the Global Biodiversity Information Facility (GBIF) that we collected as part of a long-term collaborative project to rediscover this lost species. This data paper describes the conservation relevance, survey methods, and findings resulting from cave roost surveys, capture surveys, and acoustic sampling of bat echolocation activity in Nyungwe National Park and surrounding areas in southwestern Rwanda from 2013-2020.

We report the discovery of an extant population of Hill's horseshoe bat (Rhinolophus hilli) in Nyungwe National Park, Rwanda, 40 years since the last reported observation of the species in 1981. We also report the first record of Lander's horseshoe bat (Rhinolophus landeri) in Nyungwe National Park, and the first record of the Damara woolly bat (Kerivoula argentata) in Rwanda. The dataset contributed to GBIF described in this paper includes 278 occurrence records from 10 bat species of 5 families detected at 71 locations in or near Nyungwe National Park, Rwanda. We include a description of the morphological descriptions of R. hilli and present the first acoustic echolocation signatures and phylogenetic information for this species.