Stone martens Martes foina are common occupants of urban environments across continental Europe. We predicted that like other 'urban adapters', urban stone martens should exhibit smaller home ranges, more extensive home-range overlap and higher population densities than their rural counterparts. We radio-tracked 13 stone martens (10 females, three males) in two towns in southern Luxembourg during a 2-year period, in order to investigate nocturnal ranging behaviour. All martens maintained stable, year-round territories almost wholly within the urban perimeter of the respective study towns. Socio-spatial organization was based on intra-sexual territoriality. Territories (100% minimum convex polygon) were small in size (males: 112.6 AE 24.8 ha; females: 37.0 AE 22.2 ha) and population densities moderately high (4.7-5.8 adults km À2 ) by comparison with previous studies of rural populations. We conclude that although stone martens are clearly well adapted to urban conditions, urbanization has surprisingly little impact on their socio-spatial organization by comparison with its effects on other mesocarnivores. This apparent inflexibility in the spacing patterns of stone martens lends support to the view that spacing in martens (Martes spp.) is a predominantly phylogenetic trait that is under limited environmental influence.

Stone martens (Martes foina) occur in urban environments in many parts of continental Europe, where they cause a nuisance by denning in inhabited houses. We radio tracked 13 stone martens (10 females, 3 males) in two towns in southern Luxembourg during a 2-year period, in order to investigate den preferences and patterns of den use. We predicted that urban martens would make more use of buildings and less use of natural den sites than do their rural counterparts. All martens used multiple den sites but use was concentrated on a subset of these, between which individuals shifted frequently. Denning was almost exclusively in buildings (97.1%), with use of inhabited buildings being the highest (41.9%) recorded to date for this species. Inhabited buildings were used more extensively in winter, presumably because they were warmer and better insulated. We conclude that stone martens can successfully adapt their denning behaviour to an urban environment and that they use anthropogenic den sites more often than do most other mesocarnivore urban adapters.

Monogamy in mammals is characterized by reduced sexual dimorphism in morphology and behaviour. Ten pairs of Eurasian beaver Castor fiber were radio-tracked to test how far this concept can be applied to movement behaviour by focusing on sex-related effects on territory sizes and movement patterns. Within monogamous pairs, males and females occupied territories of almost equal size during the whole radio-tracking period and more specifically after parturition. The territories of pair members overlapped on average by 81.6 ± 14.0% SD while the territory overlap between residents and their neighbours was small to non-existent (on average between 0.5% and 2.2%). Males had larger 95% utility distributions than did females during the whole tracking period and after parturition. There was no significant difference between the 50% utility distributions for both sexes. Furthermore, males and females spent equal proportions of their time in territory border zones. There was a non-significant trend for males to move greater distances at night than females. Nightly distance moved correlated positively with territory size in females but not in males. Nightly distance moved correlated with neither body weight nor colony size. These results suggest that beavers show reduced sexual dimorphism in space use and movement patterns within adult monogamous pairs.