The use of dormouse Muscardinus avellanarius nest boxes by two species of Apodemus in Britain

The occupancy of Muscardinus auellanarius (Linnaeus, 1758) nest boxes by Apo­demus flauicollis (Melchior, 1834) and A. sylvaticus (Linnaeus, 1758) was studied over a six-year period from five sites in southern Britain. A. flauicollis was a regular visitor to nest boxes, occupying them more frequently than A, sylvalicus or any other small mammal. Litters of A. flauicollis were uncommon in nest boxes suggesting these boxes were rarely used for breeding. It seems likely that nest boxes form temporary nesting places for individuals, pairs or small communal groups. A. flauicollis sometimes take over nest hoxes occupied by M. avellanarius, usually constructing their own nests and sometimes removing old nest material. M. avellanarius may avoid nest boxes occupied by A. flauicollis earlier in the same year. Boxes favoured by M. auellanarius in one year tended to be reselected by them in the following year, but no such trend was apparent in box selection by A. flauicollis. Overall, there was little evidence to suggest that the presence of A. flauicollis had a significant impact on M. avellanarius occupancy of nest boxes.