Lutra 55(1)_Chanin & Gubert_2012

Common dormouse (Muscardinus avellanarius) movements in a landscape fragmented by roads

The common dormouse (Muscardinus avellanarius) is widespread in Europe but populations have declined in some countries as a result of habitat loss and fragmentation. A population of common dormice living beside a dual carriageway road in southwest England was studied in 2007-2010 in order to investigate the impacts of roads on habitat fragmention at the local scale (tens of metres), i.e. the possible isolating effects of roads for a population. Each carriageway was eight metres wide with verges of two metres. Nest boxes and nest tubes were installed on each side of the road, and on the central reservation where areas of woodland or scrub existed. Animals were individually marked using implanted microchips (PIT tags). Common dormice were found in fragments of woodland or scrub as small as 0.2 ha and breeding was regularly recorded in fragments of 0.5 ha or larger. Common dormice were not present in all fragments in all years. Two individuals moved between the central reservation and the side of the road and there was indirect evidence of additional road crossings. This has implications for the conservation of dormice at the landscape scale where it is important to understand the extent to which roads are barriers to movement and the extent to which dormice will use fragmented habitats. It is also important to understand the extent to which dormice use habitats which are fragmented by roads when carrying out surveys for common dormice in connection with development and in mitigating the impacts of this development.