Further evidence has emerged to support the thesis that culling badgers to control bovine tuberculosis is likely to increase the prevalence of disease. However, NFU deputy president Meurig Raymond said the study was “an incomplete appraisal of the contribution culling could make to the current situation”.
The report: Social organization and movement influence the incidence of bovine tuberculosis in an undisturbed high-density badger (Meles meles) population, to be published in the March edition of the Journal of Animal Ecology, concludes that a stable, and therefore undisturbed, [badger] social structure may help control the spread of bovine tuberculosis among badgers.
“The evidence suggests that movement of individuals between groups may be instrumental in driving disease dynamics at the population level, and adds further support to the contention that the social disruption of badger populations, for example by culling, is likely to promote disease spread,” according to the authors from the Central Science Laboratory and the Instituto de Investigación en Recursos Cinegético in Spain.
The results also have major implications for future policy to control bovine TB in the UK. “Past badger culling policies have been accompanied by an inexorable rise in the incidence of TB in cattle. Indeed, it has become apparent that the various strategies may actually have been a contributory factor to the increase in disease through perturbation. The results presented in this paper lend weight to this argument.
“The development of successful strategies for the control of TB in badgers and transmission to cattle will require serious consideration of the likely impact of any interventions on badger social organisation,” report the authors.
However, the report does not imply that the incidence of disease will decline if the moratorium on culling continues, but instead supports the belief that disturbing the social balance of a population by culling would exacerbate the problem by increasing the extent of badger movement between local populations. A scenario known as perturbation.
The study was performed at the CSL Badger Research Unit at Woodchester Park, Gloucestershire. It is home to several high-density groups and has been the subject of a long-term intensive study going back almost 20 years. Consequently, quality data is held on the badgers and their activities. It reveals that the incidence of TB within the badger social groups increased by almost 150% per year between 1994 and 2004.
“Although the number of badger social groups in the study area remained relatively constant, the number of incident and prevelant (TB was detected in at least one individual) groups per year generally increased over the course of the study.
“Both mean group incidence and prevelance steadily increased over time,” report the authors.
Mr Raymond added: “The report adds nothing to what we already know about how the disease spreads.”
“It merely reiterates the already understood dangers of a piece-meal culling strategy. Successive studies over the past 20 years have clearly demonstrated that only a coordinated and extensive cull of badgers in those areas suffering heavy infection, such as the south west, parts of central England and south west Wales, will result in a positive impact on the disease.”
Badger Trust public affairs advisor Trevor Lawson said: “The scientific evidence against badger culling is so strong and so consistent that there is no longer any justification for debating it.
“The Government should summon up the courage to rule out badger culling as a policy option. Yet the relentless demands for the slaughter of badgers from some farming and veterinary lobby organisations shows no sign of abating and Ministers are weak and indecisive. This wilful ignorance has to end.”