Mating system and male reproductive strategy of Taiwan greater horseshoe bat (Rhinolophus formosae)

Contrary to most studies on gregarious bats describing their mating system to be polygynous, limited studies on solitary bats suggested food/roosting site resource-defense monogamy or facultative monogamy/polygyny as their most common mating systems and reproductive strategies. However, these studies only base on small sample sizes, and limited observation in temporal and spatial scales. Additional research is needed to examine the mating system and reproductive strategy of solitary bats. In this study, the roosting patterns of Rhinolophus formosae, a solitary cave-dwelling bat, were monitored in Taitung from 2012 to 2013 and in Taipei during 2013, the temporal and spatial distribution of males and females were investigated, and tissue samples from captured individuals were collected for parentage analysis to examine the number of offspring belonging to each male bat in each year. We also added data of roosting bats in Taitung collected from 2010 to 2011 in previous study to compare annual variation of roosting patterns of these bats. The results revealed that males did not significantly use more caves and changed caves more frequency than females. Males also did not significantly stay in caves for shorter periods than females. Single males typically overlapped its roosting caves with 1 female, but on occasion with 2-3 females. Parentage analysis revealed that males usually sired one offspring each year, but one male sired two offspring. Hence, I suggest that the mating system of R. formosae is facultative monogamy/polygyny. In addition, because roosting patterns of male and female bats in the same bonded pair did not significantly synchronize with each other, I suggest that R. formosae adopt roosting site resource-defense reproductive strategy.