Spatial ecology of Apodemus flavicollis in Central Italy

Acquiring knowledge on the spatial behaviour of rodents is crucial to understand their key ecological role in forested habitats. This achievement requires investigations through different habitat types and spatial scales, given that the structure and species composition of vegetation are known to influence considerably the small mammal community. Woodlands actively managed for coppice, with their mosaic of stands differing markedly in plant structure and, to a lesser extent, composition, provide an excellent model for studying the impact of such variation on small mammal spatial ecology. In this light, we planned a study aiming at facilitating the comprehension of factors driving the spatial ecology of the yellow-necked mouse Apodemus flavicollis, a ground-dwelling rodent inhabiting a coppiced sub-Mediterranean deciduous oak forest in central Italy. The first part of the thesis (Chapter 1) relied on radio-tracking to investigate some components of A. flavicollis spatial behaviour in two oak stands coppiced in different years and contrasting in terms of both resource availability (i.e. plant food and cover) and intra- and inter-specific population densities. Our study suggests that A. flavicollis home range and core area size was not influenced by sex but rather by season and habitat type, whereas ranges overlap depended on both sex and season. In particular we found mice to have smaller home ranges in recently coppiced area, suggesting that these areas can represent for this species a high-quality habitat. The second part of the thesis (Chapter 2) consists of a multiscale analysis of A. flavicollis captures over three years of live-trapping to reveal the environmental factors driving the occurrence of the species. More specifically, at the macrohabitat level this chapter aimed to individuate which environmental factors drive A. flavicollis site occupancy dynamics (i.e. local extinction and colonization probabilities) in coppiced stands differing in their structural and compositional characteristics. Furthermore, inside each stand, microhabitat features most likely ruling mice captures at the single trap-site were pointed out. Macrohabitat analyses results suggested that in our study area A. flavicollis shows a clear preference for woods at early stages, with a local probability of extinction gradually growing with time since last coppicing and a lower colonization probability in stands with a more complex and thick vertical structure of the vegetation. In addition, microhabitat analyses revealed that A. flavicollis seems to be mostly conditioned by the resources available at ground level, being a mainly terricolous species. Finally, important issues related to the principal objectives of this thesis were addressed in Appendix A and B. The former investigated by cafeteria experiments the potential role of fruits of several shrub species as a trophic resource for A. flavicollis, while the latter explored the existence of intra- and inter-specific social tolerance in these rodents through the analysis of live-trapping secondary data.