Seeing in the dark: molecular approaches to the study of bat populations

Whilst the use of molecular genetic techniques is widespread in the fields of population and evolutionary biology, their application within the mammal ian order Chiroptera neither reflects the species richness nor the ecologic al and behavioural diversity of the order. This is despite the fact that th e Chiroptera are problematic to study using more direct observational techn iques. Here, we standardize and synthesise the current data, assess the con tribution of molecular research to the study of bat species and highlight t he importance of its continued and expanded use. At an inter-population lev el, molecular studies have demonstrated a great diversity of population gen etic structure within the order. Among populations of migratory species, ge netic structure appears universally low, and hence seasonal movement is lik ely to be the prevailing influence. However, for sedentary species an array of factors including dispersal ability, extrinsic barriers to gene flow an d historical events may determine the extent of genetic partitioning among populations. Intrinsic factors such as wing morphology or roost requirement s may also influence population genetic structure in sedentary bat species, a proposal which requires further research. Molecular studies have also ma de important contributions towards an understanding of social organisation in bats. Evidence indicates that in many polygynous species male mating suc cess does not translate directly into reproductive success, perhaps as a re sult of multiple mating by females. Estimates of relatedness within and gen etic structure among colonies are, in general, very low; a finding which ha s important implications regarding theories concerning the formation and pe rsistence of bat social groups. Molecular studies have provided new and imp ortant insights into the ecology of bats, and have opened up exciting and p reviously unexplored avenues of research. The data from these studies sugge st not only a predictive framework for future studies, but also the use of genetic data in the management and conservation of bat species.