Bat Distribution Size or Shape as Determinant of Viral Richness in African Bats

Maganga, Gaël D.; Bourgarel, Mathieu; Vallo, Peter; Dallo, Thierno D.; Ngoagouni, Carine; Drexler, Jan Felix; Drosten, Christian; Nakouné, Emmanuel R.; Leroy, Eric M.; Morand, Serge

Model ranks AIC Table 7 . Best model explaining viral richness in bats using independent contrasts (initial model is given in Table 6 ), using the phylogenetic regression (independent contrasts) and non-phylogenetic regression (raw values' and independent variables are ranked according to their contributions to the models using F values). parasite species, viruses in the present study, could be related to the historical expansion and contraction of bat species' distribution ranges, with potentially strong effects of distribution edges on virus transmission. Indeed, the marginal effect of phylogenetic signal on the distribution shape of the investigated bats (Table 5) suggests that both history and current ecological drivers may have shaped their distribution. For a given distribution area, the most fragmented distributions contain more edges than the less fragmented ones. Positive edge effects could be responsible for the positive effects of distribution shape on either the abundance or distribution of some bat species that may have facilitated virus host switches. However, critical information to explore this issue further is lacking due to the limits of current knowledge on African bats' phylogeography as well as the geographic distribution and phylogeny of their viruses (such as bats and rabies-related viruses [42] ). Furthermore, it should be noted that the use of the distribution area obtained from ICUN Red List might not accurately describe the distribution shape of bat species. More accurate and precise distributions would definitively improve the robustness of the study. An alternative explanation produced by a theoretical study, attributes a direct role of parasitism in limiting the distribution range of hosts through the extinction of local hosts by virulent parasites [43] . However, this hypothesis has not been tested using empirical data.