Ecology and Phylogeography of the Riparian Habitat Specialist Myotis daubentonii

Riparian ecosystems are known as habitats with high biodiversity levels which perform several ecological functions. The importance of riparian habitats for foraging and commuting of many bats species was observed in different geographic areas. Bats are highly vulnerable to habitat changes, in addition specialist taxa are more sensitive to small-scale environmental alterations. Myotis daubentonii constitutes an interesting model species widespread in Europe as riparian specialist. The objectives of this thesis were to study the effects of an altitudinal gradient on ecology and thermal physiology of M. daubentonii males of a population in Central Italy, for which intra-male spatial segregation was known, and investigate the genetic structure and phylogeography of this species in different river basins of Europe. The first study was carried out comparing habitat productivity, body condition, thermoregulation strategies, use of space and habitat selection between males from two altitude zones. Results show that the more selective and diurnally homoeothermic downstream males, show a better body condition in late spring (possibly as a consequence of higher food availability in that period and/or hibernating in milder climate) but then they lose weight. Upstream males prove more flexible as they forage in a broader range of habitats and make a larger use of daily torpor, strategies that in the long run appear rewarding as unlike downstream males at least they showed no body condition drop over summer. I conclude that the main benefit for downstream males is not energetic but probably reproductive as they may increase fitness by extra-mating. However, a better body condition following hibernation might also imply a higher survival likelihood of downstream males at that time of year. The second study was carried out analyzing the cytocrome b gene (Cyt b) and hypervariable non-coding domains I and II (HVI and HVII), from the control region (D-loop) of the mtDNA of respectively 157 and 123 samples of M. daubentonii from sixty three localities of Europe. The data show quite a remarkable differentiation with more than fifty different haplotypes. All phylogenetic reconstructions point to the distinction of three main lineages very differentiated and highly structured: a lineage spread throughout the Iberian Peninsula, in previous research identified as M. d. nathalinae; a lineage found in Italy, France, Switzerland, Germany, Sweden and in the Central and Northern Iberia; another lineage consisted of samples from Serbia, Montenegro, Greece, Netherlands and from the North of Spain and Portugal. My analysis demonstrated that the Mediterranean Peninsulas (Italy, Iberia, Balkan) acted as glacial refugia for M. daubentonii and its European populations have originated from the postglacial Palaearctic expansions of the Italian and Balkan lineages, while the Iberian lineage did not cross the Pyrenees with a possible pattern of refugia-within-refugia as a consequence of the climatic cycles from the Pleistocene. ORGANIZATION OF THESIS This thesis consists of an introductive chapter devoted to riparian habitats and a model specialist bat typical of these ecosystems in temperate regions, Myotis daubentonii. The next two chapters are two papers that have been or will be submitted to international scientific journals. The first is a study of the ecological and physiological intra-sexual differences of M. daubentonii along an altitudinal gradient. The second study investigates the genetic structure and phylogeography of Daubenton’s bat populations of Europe. The last chapter contains the conclusions of the thesis.