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1. The spatial organization of a badger population (North Nibley) is described before and after it was subjected to a UK Ministry of Agriculture, Fisheries and Food badger removal operation (BRO) intended to control bovine tuberculosis. Comparison is made with an undisturbed badger population (Woodchester Park). 2. The Woodchester Park population was organized in group territories with clearly defined boundaries that remained stable during the 3 years of study (1995-97). In North Nibley, however, the badgers' spatial organization was severely perturbed in the first year and, to a lesser extent, also in the second year after the BRO, with badgers using latrines further away from their setts. This resulted in enlarged social group ranges that were difficult to define and overlapped considerably. 3. The disturbance was observed in the removal groups, those immediately adjacent, as well as those at a distance of one or two social groups from the removal area, with an unexpected indication that the latter groups may have been the most affected. 4. The apparent increase in the size of the group ranges in North Nibley was likely to have been caused by an increased proportion of badgers making extra-group excursions in the aftermath of the BRO. 5. Initial recolonization was almost exclusively by females. 6. Although such perturbation might be expected to facilitate disease transmission between badger social groups, there was no evidence that any infectious animals had survived the BRO. However, there were further cattle breakdowns in the area. 7. The behaviour of badgers after the BRO also provided an opportunity to test predictions made by competing hypotheses about the main determinants of the badger's socio-spatial behaviour. [ABSTRACT FROM AUTHOR]

1. 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 first instance by young females. 4. Although in the first 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 effects 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 different in disturbed compared with undisturbed badger populations, and that this could affect the effectiveness of BROs. [ABSTRACT FROM AUTHOR]