The Badger Cull: Part 3

   Following our quick look at the more generalised for and againsts (that I can see) of the proposed badger cull, I thought I would go through the findings and contradictions in some of the scientific studies that are used to inform on this current debate. As I stated, each 'set' of papers appear to directly contest each other, highly complicating matters!

Badgers are at risk of being widely hunted in Britain
based on some papers which conclude a cull could
reduce incidences of bovine TB. Picture source.

   Following the Krebs Report and Bourne Report from 1997 and 1998 respectively (the latter initiating a trial cull to determine results; in Part 2), a review was published in 2005 by Reading University. 

   This was to address the question 'how responsible are badgers for higher incidences of TB in cattle'? As Krebs (1997) points out, an association between TB infection in badgers and cattle is not evidence of high transmission between the two. This adds increased uncertainty over how much of a change badger culling could produce (ISG, 2007); if there is little transmission then badger culls will be ultimately pointless. This review from Reading (2005) concluded there is strong evidence that badgers provide a reservoir for TB infection, however culling strategies functioning in other countries were found unlikely to help in Britain. There appears to be little quantitative information on transmission from badgers, although Bohm, Hutchings and White (2009) found that badgers and cattle come into contact with each other much more often than previously thought; possibly indicating high badger-cattle infection rates.

   In 2007 the ISG published their follow up Bourne Report from that in 1998, which discussed the results of their trial badger cull. In my opinion the section on recommendations and conclusions is most interesting to the controversy. The study seems to practically damn any feasible badger cull, stating that only a sustained and coordinated proactive (i.e. before badgers/cattle are infected in an area) cull would be effective. This seems like far too great a measure (and too expensive and difficult!) against one species. The paper contains many telling statements that comment on the feasibility and likely futility of a British badger cull, for example:

• "...we conclude that badger culling is unlikely to contribute positively, or cost effectively, to the control of cattle TB in Britain." (Pg 23).
• "...priority should be given to [...] application of control measures to cattle, in the absence of badger culling." (Pg 23).
• "It is highly unlikely that reactive culling (which is what the proposed cull would be) could contribute other than negatively to future TB control strategies." (Pg 23). They concluded that reactive culling (the most likely form) actually increased bovine TB within culled areas!
• "Repeated reactive culling is likely to increase, rather than decrease, the detrimental effect associated with localised culling." (Pg 23).
• "Culling badgers under license not only could fail to achieve a beneficial effect, but could increase the incidence of cattle TB and increase the geographical spread of the disease" (Pg 24).

The study also concluded that cattle-cattle transmission is additionally very important in the spread of TB within infected areas, and between new areas. 

   However the King Report (also 2007) assessing this scientific evidence came to an entirely different conclusion; it stated that the removal of badgers could significantly contribute to control of bovine TB where its incidence is high and persistent (i.e. reactive culling)! This lends support to another side of the debate, however I, and the ISG, are not sure how they came to this. The ISG published a swift reaction to the King Report, also in 2007, asking how they so misinterpreted the findings, given the former state "badger culling can make no meaningful contribution to cattle TB control in Britain."

  A study by Jenkins, Woodroffe and Donnelly (2010) further supports this conclusion that a badger cull would be ultimately futile in reducing bovine TB incidences. This found that culls initially cut TB (a fall of ~38%), however any benefits disappeared within three years of the cull being carried out. Additionally, they found culling caused perturbation; infected badgers were disturbed and moved into new areas, sometimes causing increasing transmission in nearby zones.

  Again there is a comparative study that contests these results; the Farmers' Union of Wales in 2010 used a computer model to show herd incidences of TB could be reduced by about 5-30% in a five year cull, and even more in the few years following. However this could be subject to slight bias, given farmers obviously have much more to gain from a badger cull than most (even if reductions in bovine TB were negligible).

In some countries badgers are trapped and then shot as
a way of culling, to attempt to reduce bovine TB. Picture source.

  Personally, I know I would from the start favour preservation of another species, however I don't believe that there is enough significant evidence out there to prove that a badger cull would have any real effect on bovine TB incidence in Britain. I think with this limited support the passing of any widespread cull would be basically groundless (until further studies are published), and that this is not a sufficient basis for hunting a species.

    After this look at some of the main studies informing on the badger cull, hopefully you will feel better equipped to decide for yourself whether a cull would be worthwhile!