Macro-evolutionary trade-offs as the basis for the distribution of European bats

Bats have a high species diversity and show unique ecological traits. The distribution patterns of European bat species differ between species. In this paper we seek to explain which life history traits, or interrelations between traits, can best explain observed differences in the distribution patterns of bats. Traits are interrelated and sometimes involve trade-offs, implying that a change in one trait may have positive or negative consequences for other traits. We describe the main morphological, physiological and ecological adaptations of insectivorous European bat species. We make pair-wise relations between traits, indicating the interrelations between traits, in terms of possible trade-offs. We relate the consequences of these trade-offs to the distribution maps of the species, focusing on the traits relevant for southern and northern distribution limits. We found coarse patterns that might indicate the distribution of related species are a consequence of their physiological, morphological and ecological adaptations and the interrelations between these adaptations. Hence, we think life-history strategies can be used to explain differences in species distribution. The method presented in this paper might also be useful for other mammal groups with a high species diversity, such as Rodentia and Soricidae.