The effects of bovine tuberculosis (Mycobacterium bovis) on mortality in a badger (Meles meles) population in England

Abstract

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 findings are: (a) uninfected male badgers have a significantly higher mortality rate than uninfected females, (b) infected badgers which are not excreting M. bovis do not have a significantly 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.