Current geographical ranges of Malagasy dung beetles are not delimited by large rivers

We investigated whether the largest river (Mangoro) on the east coast of Madagascar acts as a barrier to dispersal in dung beetles by comparing species composition and genetic differentiation of the most common species on the two banks of the river. Moreover, by analysing the current geographical ranges of all wet forest dung beetle species, possible long-term effects of the largest rivers on the distribution of species were assessed.