Urban badger setts: characteristics, patterns of use and management implications

Damage caused by badger setts is an important source of human–carnivore conflict in urban areas of the UK, yet little is known about the spatial distribution of urban badger setts or their pattern of occupation. We compared the density, spatial distribution and size of setts in four urban and two rural study areas in the UK and assessed the applicability to urban systems of distinguishing between ‘main’ and ‘outlier’ setts. In addition, we used radio-telemetry to investigate diurnal patterns of sett use in one urban area (Brighton). It was possible to distinguish between main and outlier setts in urban environments, and local sett densities were comparable in urban and rural areas. However, urban badgers used substantially fewer setts than did a nearby rural population, and they spent a smaller proportion of days in outlier setts. Social groups with larger ranges had more setts available to them and, within groups, individuals with larger ranges used more setts. Outliers appeared to serve multiple functions, including allowing efficient and safe travel to important parts of the home range. We conclude that sett densities can be high in urban habitats, suggesting significant potential for sett-related problems to arise. The fact that urban main setts can be distinguished from outliers enables management actions to be tailored accordingly. In particular, because main setts seem to represent a particularly valuable resource to urban badgers, alternatives to the closure of problem main setts need to be considere

Spatial organization, group living and ecological correlates in low-density populations of Eurasian badgers, Meles meles

1. Territoriality and group living are described in a low-density population of Eurasian badgers, Meles meles L., by studying the patterns of spatial grouping and territory marking, as well as the differences between individuals in some of their characteristics (body condition and dispersal) and in their space use (seasonally, periods of activity and interaction between pairs of individuals) under strong seasonal fluctuations in the availability of the key resource ( young rabbits, Oryctolagus cuniculus L.). Finally, the role of the spatial distribution of the main prey ( young rabbits) in the development of sociality was also studied in order to test some of the assumptions and predictions of the resource dispersion hypothesis (RDH). 2. Badgers were territorial, showing a flexible system of territory marking, which includes the marking of the most used areas (sett-latrines at the centres of activity) and additionally, at the smaller territories, a system of border-latrines in the areas of contact between territories. The maximum use of border-latrines was associated with the reproductive season, and that of sett-latrines with the season of food scarcity. 3. In the study area where badgers had rabbits as main prey, territories were occupied by small groups of animals, formed by one adult female who reproduced, one adult male who also showed signs of reproductive activity, the cubs of the year (if there was reproduction) and some animals born during previous years, which remained in their natal territory until their dispersal (normally during the mating season of their third or fourth year of life). This system was not strictly fixed as males, given the opportunity, expanded their territories to encompass additional females. Territories in another study site were occupied by one adult female (marked), plus the cubs of the year and another adult individual (unmarked). 4. In winter and spring dominant females and subordinates used only a small fraction of their territories, moved short distances, at a low speed and covering small areas per night. These seasons corresponded with the reproduction of rabbits (highest food availability). Dominant females were the only individuals using all the territory available in the summer (lowest food availability), when badgers had the worst body condition. Food availability increased again in autumn, as did body condition, while range sizes were again reduced. Dominant males used the same proportion of their territories over all seasons. However, in winter (reproductive season) they moved faster, over longer distances, and covered larger areas per period of activity. These results indicate that use of space by dominant males was affected by different factors from that of dominant females and subordinates. 5. RDH does not seem to explain group living in our populations because: (a) territori- ality in each pair of primary animals was driven by different factors (trophic resources for females and females for males); (b) dominant males acted as expansionists; and (c) territory size was related to its richness and not to patch dispersion.6. We propose an integrative hypothesis to explain not only group formation but also interpopulation variability in the social organization of badgers within ecological, demographic and behavioural constraints and in the light of current theory on delayed dispersalPeer reviewe