On the taxonomic status and distribution of African species of Otomops (Chiroptera: Molossidae)

Abstract

Background: Free-tailed bats of the genus Otomops are poorly known, and most species are documented from a handful of widely scattered localities. Recently, two allopatric species of Otomops were recognized in continental Africa: Otomops martiensseni (Matschie, 1897) in southern, central and western Africa, and the new species O. harrisoni Ralph et al., 2015 in the northeast and in Yemen. Methods: We collected additional samples of Otomops in Kenya and Rwanda where the ranges of these taxa approach one another to clarify their geographic ranges and taxonomic status. Mitochondrial and nuclear intron sequences served to identify and delimit species; we also documented their echolocation call variation and ectoparasite complements. Results: Otomops martiensseni, the southern African species, was documented in northern Kenya in Marsabit National Park. O. harrisoni, the northeastern African–Arabian species, was documented in southern Kenya and in a cave in Musanze District, Rwanda. Moreover, individuals of both species were found together at the Musanze cave, establishing them in precise spatial and temporal sympatry. Analyses of mitochondrial and nuclear loci identify no evidence of admixture between these forms, although available samples limit the power of this analysis. Echolocation call differences are also apparent among the three localities we analyzed. Three orders of insects and two families of mites are newly reported as ectoparasites of O. harrisoni. Discussion: Our results corroborate species rank for O. harrisoni and establish a zone of potential geographic overlap with O. martiensseni spanning at least 800 km of latitude. The new records establish the species in sympatry in northern Rwanda and add an additional species to the bat faunas of both Kenya and Rwanda. Future studies are needed to understand Otomops roosting requirements and movements, thereby explaining the paucity of known colonies and yielding better estimates of their conservation status. The discovery of mixed roosting associations in Rwanda invites further investigation.