With 15 figures in the text)Data from the longest running capture-mark-recapture study of Eurasian badgers, in an undisturbed wild population at Woodchester Park in Gloucestershire, were used to investigate population dynamics. Twenty-one social groups of badgers occupying an area of 7.3km2 were studied from 1978-1993. The density increased steadily over the study period, reaching the highest published density known anywhere at 25.3 adults per km' in 1993, and the average social group size increased to 8.8 adults (S.E. ? 0.85) in 1993. By 1993, 97% of the population trapped was of known age and overall the population consisted of 27% cubs and 73% adults. In addition, the results supported previous studies in that the population had an equal sex ratio as cubs, but became increasingly femalebiased with age. There was high juvenile mortality, nearly 50% dying in their first year. Between 58 and 90.2% of adult females did not breed each year.

No abstract

The movement of 1763 badgers trapped between 36 social groups in Woodchester Park, Gloucestershire, over 18 years was analysed to determine the frequency and duration of moves, the factors associated with a predisposition to move and the spatial pattern of movements. Of those badgers whose capture history could be categorized, nearly half had moved. Of these, 73.1% were classi¢ed as`occasional movers', 22.1% as`permanent movers' and 4.8% as`frequent movers'. Most adult badgers that moved made occasional moves (78.8%, n 67). Cubs made all types of move including permanent moves (29%, n 10). Seventy per cent of females were non-movers compared with 37% of males. Badgers were signi¢cantly more likely to move to smaller groups, whereas male badgers were signi¢cantly more likely to move to groups with a greater proportion of females. The spatial pattern of movement di¡ered from the distribution of groups with bovine tuberculosis in the study area. However, temporal changes in movement were signi¢cantly related to the incidence of Mycobacterium bovis infection in the following year, indicating that as the movement of badgers between groups varies so does the incidence of bovine tuberculosis in the population. This ¢nding is of central importance in the formulation of badger control policy.

Bait‐marking is a widely used technique for determining the territorial configuration of social groups of the European Badger (Meles meles). Applications include ecological research and applied wildlife management problems. Bait laced with indigestible plastic pellets is fed to Badger social groups, and the markers are identified in subsequent defecations. Feeding a unique colour and/or shape of pellet to each social group allows the origin of droppings to be assigned. This method is particularly suited to Badgers because they mark their territorial boundaries with communal latrines. In this paper the technique is described in detail for the first time in the scientific literature. Data from sequential visits to latrines during the survey period showed significant short‐term variation in the number of marked droppings counted at individual latrines. This suggests that counting marked droppings may be of limited value in quantifying defecation rates and latrine use. However, counts of droppings at latrines could be useful if repeated over time and/or grouped into broad categories. Bait marking does provide reliable data for the estimation of territorial boundaries between Badger groups, although it is labour intensive and time‐consuming, with the best results obtained by experienced fieldworkers.

Badgers are facultatively social, forming large groups at high density. Group-living appears to have high reproductive costs for females, and may lead to increased levels of inbreeding. The extent of female competition for reproduction has been estimated from field data, but knowledge of male reproductive success and the extent of extra-group paternity remains limited. Combining field data with genetic data (16 microsatellite loci), we studied the mating system of 10 badger social groups across 14 years in a high-density population. From 923 badgers, including 425 cubs, we were able to assign maternity to 307 cubs, with both parents assigned to 199 cubs (47%) with 80% confidence, and 14% with 95% confidence. Age had a significant effect on the probability of reproduction, seemingly as a result of a deficit of individuals aged two years and greater than eight years attaining parentage. We estimate that approximately 30% of the female population successfully reproduced in any given year, with a similar proportion of the male population gaining paternity across the same area. While it was known there was a cost to female reproduction in high density populations, it appears that males suffer similar, but not greater, costs. Roughly half of assigned paternity was attributed to extra-group males, the majority of which were from neighbouring social groups. Few successful matings occurred between individuals born in the same social group (22%). The high rate of extra-group mating, previously unquantified, may help reduce inbreeding, potentially making philopatry a less costly strategy.

Summary1. Many ecological studies on the European badger Meles meles, as well as certain programmes to control bovine tuberculosis, would bene®t from a greater understanding of the factors that in¯uence the probability of capturing this animal in cage-traps. We therefore investigated some of the factors that could explain dierences in trappability between three badger populations in England: the high-density protected populations of Wytham Woods and Woodchester Park, and the low-density culled population of North Nibley. 2. Trappability (the percentage of all individuals known alive that were actually captured) did not dier between sexes or adult age classes, but signi®cant dierences were found between cubs and adults, study areas, seasons and years, and various interactions between these variables. 3. Circumstantial evidence suggests that the culling of badgers in North Nibley may have resulted in a decrease of adult trappability in the following year. 4. Adult badgers at Wytham Woods and Woodchester Park were signi®cantly more likely to be trapped zero times (`trap-shy') or all three times (`trap-happy') in 1996 than predicted by the estimated capture probabilities under the assumption of equal trappability. 5. Wytham Woods diered from the other study areas in that trappability of its badgers was positively related to their body weight and its adult badgers were more likely to be trapped than cubs. These dierences could be a consequence of dierences in trapping procedures that were followed at Wytham (no prebaiting and fewer traps per badger). 6. Trappability of badgers was not associated with social group size. Although it is dicult to determine precisely the movement and tuberculosis status of badgers based on mark±recapture data, our analyses did not suggest that either variable aected the likelihood of being trapped. 7. Studies that compare demographic, biometric and epidemiological parameters based on data collected from badgers captured at dierent times or places ought to account for the observed dierences in trappability.

Summary1. Capture±mark±recapture data were used to describe the process of recovery from a typical badger removal operation (BRO) at North Nibley, Gloucestershire, UK, which was carried out as part of the government's strategy to control bovine tuberculosis. Data on biometrics, demographics and movement from this low-density disturbed population were compared with those of two nearby high-density undisturbed populations (Wytham Woods and Woodchester Park, UK) in order to study fundamental principles of population dynamics and density-dependence. 2. Badgers moved more between social groups at North Nibley than in the other study areas, particularly in the immediate aftermath of the removal operation. 3. Recolonization of the vacated habitat occurred in the ®rst instance by young females. 4. Although in the ®rst year after the BRO no cubs had been reared in any of the culled groups, and although the shortage of sexually mature boars may have limited the reproductive output of sows in the following year, the population took only 3 years to recover to its (already lowered) preremoval density. 5. Losses from the adult (and cub) population due to mortality or emigration were smaller at North Nibley than at the other sites. 6. There was much evidence that during 1995 and 1996 density-dependent eects constrained the reproductive output of the high-density populations, and some support for the hypothesis that badgers exhibit the non-linear`large mammal' type of functional response to density. 7. Badgers at North Nibley were younger, heavier and in better condition than badgers at Wytham Woods and Woodchester Park. 8. We argue that the disease dynamics are likely to be dierent in disturbed compared with undisturbed badger populations, and that this could aect the eectiveness of BROs.

The mortality rates of badgers Meles meles were estimated, using data from a long-term capture±mark± recapture study of an undisturbed badger population in south-west England. Two life table methods were used: fusion and discounting. Badgers were allocated to a particular TB status for all or part of their lives according to their degree of infection with bovine tuberculosis Mycobacterium bovis. Separate life tables were created for animals with each TB status, and for males and females, and the estimated mortality rates were compared statistically. The progression of M. bovis infection, and the positions of M. bovis lesions were also analysed. The main ®ndings are: (a) uninfected male badgers have a signi®cantly higher mortality rate than uninfected females, (b) infected badgers which are not excreting M. bovis do not have a signi®cantly higher mortality rate than uninfected badgers, (c) badgers which are excreting M. bovis have a much higher mortality rate than uninfected badgers, (d) male badgers appear to cope with M. bovis infection less well than females, and (e) there may be sex differences in the mode of spread of M. bovis in badgers.