A long time coming

In a report released today, October 22nd, the Chief Scientific Adviser, Sir David King paves the way for a badger cull in areas of endemic cattle Tb. The report was originally submitted to the Secretary of State, Department of Environment, Food and Rural Affairs (Defra) on 30th July. The report unpicks much of the RBCT Badger Dispersal Trial data and many of its conclusions. It emphasises that this is not a badger 'elimination' exercise. It begins;

...I have had regard that the overiding aim is to control Tb in cattle. As badgers are a continuing source of infection in certain areas of high cattle Tb prevalence, a secondary aim is to control Tb in these badger populations. It is not to eliminate badgers; any removal of badgers must be done humanely and within conservation considerations (including the Bern Convention). Thus references to removal in this report are to reducing the number of badgers in an area rather than completely removing them from that area.

Sir David comments on the surge of new herd breakdowns, and recommends "strong action to reverse the upward trend". He sees badger removal coming parallel to current and 'future' cattle controls. Any description of 'future' ones are not expanded upon. But the ISG described them in a fair amount of detail. After stressing that removal of badgers should only take place "in those areas of the country where there is a high and persistent incidence of TB in cattle", the report concludes:

Removal of badgers is the best option available at the moment to reduce the reservoir of infection in wildlife. But in the longer term, alternative or additional means of controlling Tb in badgers such as vaccination, may become available. Research into these should continue.

The report seems to have taken on board the complete shambles achieved by the ISG in their 8 night hit-and-run visits, repeated annually if at all.

Badger removal programmes should be sustained (unless replaced or supplemented by alternative means of control)
Removal which is improperly carried out, or which is fragmented in space and time, could cause detrimental effects on the incidence of cattle TB.

With that, we would not disagree. Badger dispersal the RBCT most certainly was, and yup, it caused havoc in many a closed herd - including those of our contributors.
On badger behaviour and population density the report is rather less clear, but attributes the RBCT Badger Dispersal Trial published results as 'indirect field signs' and 'an informed guess' at badger density.

Over the whole duration of the RBCT, badger density was reduced by about 70 per cent in each of the proactive trial areas (though the data are indirect field signs and this is, therefore, an informed guess) As the ISG note, removal of badgers disrupts their social structure. When a social group is disrupted, the population density is reduced, other badgers move in rapidly (possibly within days). There will be mixing within groups neighbouring the removal areas. Overall there will be net immigration into the removal areas. If removal is not sustained the badger population is likely to recover over time, although this may happen slowly.

So, ten years and over £50 million, and the ISG works on 'indirect field signs' on which they and Sir David's team thus make an 'informed guess' at data flow? Clever stuff this 'science' then? The report continues:

Dispersed infectious badgers are more likely to come into contact with uninfected susceptible badgers through fighting over mates and territory and via close general contact. Therefore they are more likely to spread TB to new areas.

And on the 'dispersal' of badgers by the ISG;

Because of the dispersal effect brought on by removal, [TB] clustering was disrupted over the course of the trial and there is evidence that the prevalence of infection in badgers in those areas increased.If removal is not sustained, there is a risk that the population of badgers could return to pre-removal levels, but with an increased prevalence of infection. It is therefore extremely important that removal is carried out effectively and be sustained.

Don't 'disperse' the problem in other words. Just what we said. But Sir David's team describe badger disruption as transient or 'temporary'. That is, it is not a continuing factor if the whole social group is removed. This gives a more stable population and reduces badger-to-badger transmission. They note that even using Bourne's hit-and-run occasional visitsthe ISG report's data, any detrimental effect on cattle outside the removal area reduced with successive removals.

And on the conclusions drawn by the ISG: they find that the "ISG statement 'That badger culling cannot meaningfully contribute to the control of cattle TB in Britain' is not supported by the RBCT data and as such it was an 'Unqualified conclusion'. They find some data is 'unsound', confidence levels for the detrimental effect on Bourne's 'edges' are 'very large'. (the levels not the diminutive Prof's edges) They criticise the time frame for resulting cattle tests after the conclusion of the trial and urge caution over interpretation of the first year results. (We would urge extreme caution over most of the results - but let that pass) And the report has concerns that the rug was prematurely pulled from the Reactive culls, and say they are unable to comment on the published results 'with confidence.'

We have concerns about the biological plausibility of the ISG's interpretation of the results and do not consider that the evidence in the ISG report should be used either to support or to rule out reactive removal strategy.

It would have helped if they'd 'reacted' at all, Sir David. Arrival would have been good, or at least more than once in three years, as would a stay longer than 8 nights.

Finally, the report concludes:

In our view, a programme for the removal of badgers could make a significant contribution to the control of cattle TB in those areas of England where there is a high and persistent incidence of TB in cattle, provided removal takes place alongside an effective programme of cattle controls.

Good as far as it goes, but if those bolt on cattle measures upon which Bourne was so insistent, are more of a problem than the disease itself ....

So finally, may we caution those VIP stakeholders on T-BAG: any challenge to these measures must bring up short introduction of any new cattle measures - which are totally unecessary anyway. Otherwise Bourne's Trojan Horse will cut a swath through the cattle herds of the west, with absolutely no reduction in cattle TB, just a reduction in cattle and bankruptcy for cattle farmers.

Farmers Weekly has the story and a link to the full report (pdf)