26 AMERICAN MUSEUM NOVITATES NO. 3963 
but has been also been observed flying low over streams and a farm pool, suggesting that it 
may also forage by trawling over open water (Ratcliffe, 2002; Moratelli, 2019). Myotis tricolor 
in South Africa feeds primarily on hard-bodied prey with coleopterans making up the greatest 
proportion of the diet, followed by hemipterans (Stoffberg and Jacobs, 2004). There is no evi- 
dence that they feed on lepidopterans, and no insects or other arthropods that are potential 
substrate prey have been found in dietary analyses based on fecal samples (Stoffberg and Jacobs, 
2004). The diet of M. nimbaensis remains unknown. 
PHYLOGENETIC RELATIONSHIPS, BIOGEOGRAPHY, AND EVOLUTION: Molecular phylogenies 
indicate that Chrysopteron split from other Old World Myotis early in the radiation of the genus 
(Stadelmann et al., 2004; Morales et al., 2019). Stadelmann et al. (2004) dated this split to the 
middle Miocene (~10-13 Mya), but a slightly older Miocene date (~16-18 Mya) was recently 
proposed using revised calibration points and a more extensive data set (Morales et al., 2019). 
Not surprisingly given the overlap of our data sets, our phylogenetic results echoed those of 
Csorba et al. (2014) and Patterson et al. (2019) in confirming monophyly of Chrysopteron with 
moderate support. Within this clade, each of the currently recognized species (sensu Csorba 
et al,, 2014) was found to be distinct and, if represented by more than one sequence, mono- 
phyletic (figs. 10, 11). Although support values for some basal relationships with Chrysopteron 
were not high, some biogeographically and morphologically interesting clades were strongly 
supported in our analyses. Two dichromatic species from different continents, Myotis rufoniger 
(Asia) and the M. welwitschii complex (Africa) were found to be sister taxa, suggesting that 
they shared a dichromatic common ancestor. Rather than grouping with this clade, the two 
other dichromatic species, M. nimbaensis and M. formosus, group in different parts of the tree. 
Myotis nimbaensis is strongly supported as the sister taxon of the M. tricolor species complex, 
which does not have dichromatic coloring although both are from mainland Africa; Myotis 
formosus from Asia forms a weakly supported clade with nondichromatic M. emarginatus from 
the Mediterranean region. Another strongly supported clade within Chrysopteron is comprised 
of monochromatic species known only from Africa and nearby Indian Ocean islands (Myotis 
bocagii, M. goudoti, and M. anjouanensis). Although low support values limit the value of fur- 
ther interpretations, it seems clear that dichromatic coloration evolved at least twice and pos- 
sibly three or four times in Chrysopteron, and that intercontinental dispersal events occurred 
at least twice in this subgenus although directionality of these events cannot be determined 
with any certainty given the data at hand. Additional data from genes capable of resolving more 
basal relationships within Chrysopteron will be necessary to fully resolve these questions. 
THE NiMBA MOUNTAINS AS A CENTER OF BaT DIVERSITY AND ENDEMISM: The Nimba 
Mountains are well known as a center of biodiversity and endemism (Brosset, 2003; 
Lamotte and Roy, 2003; Wieringa and Poorter, 2004; Sandberger et al., 2010; Denys and 

FIGURE 11, Bayesian phylogenetic reconstruction of subgenus Chrysopteron using an alignment of 634 base 
pairs of mitochondrial gene cytochrome b. Colored circles at nodes represent support values as posterior 
probability from Bayesian analyses. Support values lower than 50% at shallow nodes are not shown. Tip labels 
indicate GenBank accession number and locality. Myotis tricolor 1, 2, and 3 and M. welwitschii 1 and 2 are 
labeled following Patterson et al. (2019). 
