Temporal Partitioning between Forest-Dwelling Small Rodents in a Mediterranean Deciduous Woodland

Temporal partitioning is reported as one of the main strategies adopted by coexistingmammal species to limit interspecific competition and behavioural interference. In the last decades,camera-trapping surveys have provided valuable insights in assessing temporal niche and activityrhythms of medium and large-sized mammalian species. Conversely, this method has been poorlyapplied to small rodents. In this work we aimed at assessing temporal niche partitioning betweentwo species of forest-dwelling small rodents--Apodemus flavicollis and Clethrionomys glareolus--bymeans of intensive camera-trapping. Camera traps were placed in areas where previous geneticanalyses have confirmed the only presence of A. flavicollis amongst wood mice species, to preventmisinterpretation of records. We collected 124 independent records of A. flavicollis and 67 recordsof C. glareolus over three years. The former was mostly nocturnal, with activity peaking after midnight,whereas the latter was mostly active at dawn and dusk. Therefore, a limited temporal overlapwas observed, confirming the potential for interspecific competition. Intraguild interference competitionbetween A. flavicollis and C. glareolus may play a pivotal role forcing C. glareolus to be moreactive in daylight hours where, the more strictly nocturnal A. flavicollis is present. Nocturnal activityof C. glareolus was limited and not influenced by moon phases, whereas A. flavicollis was mostlyactive in the darkest nights, avoiding bright moonlight nights.