Geographic Variation and Taxonomy of Daubenton's Bat, Myotis daubentoni in Europe

Abstract

Multivaríate analyses of 12 cranial and 15 dental measurements demonstrated that Myotis daubentoni increases in size from south to north. Geographic coordinates explained 53 and 43% of cranial and dental variation, respectively. The gradual clinal variation appears to be an example of Wright's (1943) isolation-by-distance model. The latitudinal clines in size are correlated negatively with temperature (as predicted by Bergmann's rule) and associated positively with moisture. Cranial variation, however, is more strictly associated with geoclimatic factors than is dental variation, which shows a more complex pattern. These results suggest that both climate (natural selection) and geographic factors (barriers to gene flow) contributed to differentiation in M. daubentoni. There also is a significant positive correlation between skull size of M. daubentoni and number of presumably competing species of Myotis at a given locality. Significant phenetic overlap exists among the three currently recognized subspecies of M. daubentoni in Europe. I, therefore, propose that M. d. nathalinae and M. d. volgensis be considered synonyms of M. d. daubentoni.