Habitat use by small mammals in agricultural landscapes in NW of Spain

Resumen del trabajo presentado al 14th Rodens et Spatium: International Conference on Rodent Biology, celebrada en Lisboa del 28 de julio al 2 de agosto de 2014.The intensification of agricultural landscapes is usually associated with increases in field size and reduction of natural and semi-natural habitats, particularly field margins and fallows. These habitats are crucial for small mammals, as permanent, less-altered habitats, or as corridors for dispersion. In this study, we assessed seasonal abundance patterns of the small mammal community (Microtus arvalis, Apodemus sylvaticus, Mus spretus, and Crocidura russula) in three main habitats (alfalfa, cereal and fallows), with special emphasis on abundance at various distances from field margins. We also investigated abundance according to the field margin characteristics (topography, height, width, cover, greenness). We show that small mammal abundance typically decrease from field margins towards the core of crop fields, depending on crop type (with a more pronounced margin effect in cereals independently of season). Abundance of M. arvalis, however, was slightly constant in alfalfa at all seasons, representing an optimum habitat for its distribution. For all species, the seasonal abundances were higher in the more vegetated field margins (greater vegetation height and cover). Field margin characteristics also affected the abundance of most species, depending on season. Common vole abundance was positively associated with vegetation cover in July, and with greenness in March and November. Our results highlight the importance of field margins in agricultural landscapes, not only for biodiversity conservation but also for the management of outbreaking species such as M. arvalis.Peer Reviewe