28 AMERICAN MUSEUM NOVITATES NO. 3963 
Aniskine, 2012; Denys et al., 2013; Marshall and Hawthorne, 2013; Monadjem et al., 2013, 
2016, 2019). As summarized by Monadjem et al. (2016), many surveys of the bats of the 
Nimba region have been conducted over the past several decades, with the majority of 
work done on the Liberian side of the mountain range. The discovery of Myotis nimbaensis 
brings the known number of bat species in the Nimba Mountains to 62 species (Monadjem 
et al., 2016, 2019). Five new species of bats have been described from the region in the last 
decade: M. nimbaensis (this study), Neoromicia roseveari (Monadjem et al., 2013), N. isa- 
bella (Decher et al., 2015), Parahypsugo happoldorum (Hutterer et al., 2019), and Miniop- 
teris nimbae (Monadjem et al., 2019). Two species are endemic to the mountain range 
(Myotis nimbaensis and Hipposideros lamottei) and two more are highly restricted regional 
highland endemics (Hipposideros marisae and Rhinolophus ziama; Monadjem et al., 2016). 
Hipposideros marisae is known only from highland regions of Guinea, Liberia, and Cote 
d'Ivoire (Fahr, 2013), and was observed by the authors in 2018 roosting in a small natural 
cave at 491 m in the buffer zone of the World Heritage Site in the Guinean Nimba Moun- 
tains (unpublished data). Similarly, Rhinolophus ziama is restricted to Guinea and Liberia 
and likely a specialist restricted to mountain habitats (Fahr et al., 2002; Simmons and 
Cirranello, 2020). Given this pattern, if Myotis nimbaensis has a range extending beyond 
the Nimba Mountains, we would expect it to similarly occur in highland regions elsewhere 
in Guinea, Liberia, and Céte d'Ivoire. Acoustic surveys of these areas would be a good way 
to determine if M. nimbaensis has a broader ranger or is an endemic restricted in range to 
only to the Nimba Mountains. 
Two species coroosting in mine adits on the Nimba Mountains with M. nimbaensis are 
considered threatened by IUCN: Rhinolophus guineensis (IUCN status: Endangered) and 
Hipposideros lamottei (IUCN status: Critically Endangered) (Shapiro and Cooper-Bohannon, 
2020; Mickleburgh et al., 2008). In addition, two other species occurring in the Nimba range 
that have been assessed by IUCN are considered threatened—Hipposideros marisae (IUCN 
status: Vulnerable) and Rhinolophus ziama (IUCN status: Endangered) (Monadjem et al. 
2016). Including Myotis nimbaensis, 10 taxa—one sixth of the total bat species diversity of 
the Nimba Mountains—have yet to have their conservation status fully assessed by the IUCN. 
Although some of these lineages may be fairly widespread in West Africa, others will likely 
turn out to mirror the endemic Hipposideros and Rhinolophus of the area that are strictly 
endemic to a one or a few mountainous areas. Myotis nimbaensis, which may be limited by 
both underground roosting habits and affinity for habitat and vegetation combinations found 
only in the highlands, may well be one of these taxa. The striking color pattern of M. nim- 
baensis and its lack of black facial spots (spots highly characteristic of M. welwitschii, the 
only bat in West Africa that it superficially resembles) suggests that M. nimbaensis is unlikely 
to have been overlooked or misidentified in previous surveys in the region. It therefore seems 
very likely that it is an uncommon to rare endemic with a very small geographic range. In 
this context, we expect that M. nimbaensis will be classified as a critically endangered species 
when it is assessed by the IUCN based on having a known extent of occurrence less than 100 
km? (IUCN 2012). 
