Tree hyraxes Dendrohyrax spp. are nocturnal, morphologically cryptic and consequently highly understudied mammals. Their taxonomy has always been puzzling, thus, their species-level diversity is probably underestimated. Prominent and species-specific loud calls emitted by tree hyraxes are one of the key cues in recognizing their diversity. In 2020, a population of tree hyraxes with a specific vocal repertoire not fully matching vocal repertoire of any known tree hyrax species was discovered in moist montane forests in Taita Hills in Kenya. This population, probably also occurring in Usambara Mountains in Tanzania, most likely represents a taxon unknown to science. In 2015, calls of a captive group of tree hyraxes that have originated from Tanzania and that have been previously identified as the southern tree hyrax Dendrohyrax arboreus were recorded in one Czech zoo. In the present study, we compare calls recorded from this captive population to those recently recorded from the wild population occurring in Taita Hills in Kenya and demonstrate that vocal repertoires of these two populations are essentially identical. Moreover, no loud calls typical for the southern tree hyrax were recorded from the captive population. Therefore, we conclude that these captive ambassadors of extremely rarely kept tree hyraxes are conspecific with those living in Taita Hills, Kenya, and probably represent an apparently undescribed taxon. Our findings highlight the importance of mutual cooperation between zoos, academic institutions and museum collections.