Differences in trappability of European badgers Meles meles in three populations in England

1. Many ecological studies on the European badger Meles meles, as well as c ertain programmes to control bovine tuberculosis, would benefit from a grea ter understanding of the factors that influence the probability of capturin g this animal in cage-traps. We therefore investigated some of the factors that could explain differences in trappability between three badger populat ions 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 ac tually captured) did not differ between sexes or adult age classes, but sig nificant differences were found between cubs and adults, study areas, seaso ns and years, and various interactions between these variables. 3. Circumstantial evidence suggests that the culling of badgers in North Ni bley may have resulted in a decrease of adult trappability in the following year. 4. Adult badgers at Wytham Woods and Woodchester Park were significantly mo re likely to be trapped zero times ('trap-shy') or all three times ('trap-h appy') in 1996 than predicted by the estimated capture probabilities under the assumption of equal trappability. 5. Wytham Woods differed from the other study areas in that trappability of its badgers was positively related to their body weight and its adult badg ers were more likely to be trapped than cubs. These differences could be a consequence of differences in trapping procedures that were followed at Wyt ham (no prebaiting and fewer traps per badger). 6. Trappability of badgers was not associated with social group size. Altho ugh it is difficult to determine precisely the movement and tuberculosis st atus of badgers based on mark-recapture data, our analyses did not suggest that either variable affected the likelihood of being trapped. 7. Studies that compare demographic, biometric and epidemiological paramete rs based on data collected from badgers captured at different times or plac es ought to account for the observed differences in trappability.