A badger
With the recent government announcement of a pilot cull will occur in England and the subsequent petitions that have been launched against it what is the reality behind the calls for a general cull on badgers and the manner in which it will be implemented? Harry Raffal investigates.
Firstly I should state that I am not opposed on principle to a cull on badgers. If there is evidence there are too many of any species for the local ecosystem to remain balanced a cull of that species should be considered. However, in this case the calls for a cull on badgers are based on the spreading of tuberculosis (TB) to cattle. Again I am not opposed to a cull of badgers on these grounds if the effectiveness of a cull can be established. The question which must be asked about the government’s proposed scheme is whether it is able to significantly reduce TB in cattle.
Bovine Tuberculosis is a serious problem for the farming industry and cost the taxpayer £90 million last year after 25,000 cows were slaughtered in England alone. If the spread of TB continues in cattle stocks the government predicts it will cost the taxpayer £1 billion in compensation over the next decade. There is clear evidence that badgers carry TB and are capable of transferring TB and since they were made a protected species in 1973 there numbers have greatly expanded and there are now well over 250,000 badgers in the UK.
This being the case, one may wonder why the calls for a cull on badgers are so contentious. Importantly badgers are a relatively marginal spreader of TB. Even an effective cull is only estimated at making a fifteen percent difference to the spreading of TB to cattle. This is because animals such as deer, where the disease has been detected in 5 out of the 6 species of deer in Britain, are also able to spread TB and their contribution is both greater and harder to counter than that of the badger.
Bovine TB can remain in a herd of deer for up to 11 years which makes it a significantly more difficulty to eradicate their role in the spread of the disease but considering their numbers, estimated at around 2 million, it is clear that any effective strategy to eliminate bovine TB must include a policy towards the spreading of the disease through the deer population. This is all the more important when you consider that Fallow deer often graze on cattle pastures in large numbers and that roe deer often live alongside cattle herds frequently only separated by a hedgerow. In addition to this bovine TB is generally spread to wild animals through cattle and these animals then contaminate other wild animals and other cow herds. Until this issue is also focused on it is difficult to gauge the actual effect of any cull on badgers.
But leaving aside the other issues affecting the spread of TB to cattle the effectiveness of the culling scheme itself is questionable. This is because the scheme will involve farmers being able to kill badgers travelling across their land. This seems very reasonable, it will save the government the expense of organising a cull targeting whole setts and place the responsibility for action on farmers. However, the result is likely to be that TB from badgers will actually increase in the short-term.
Because the cull won’t destroy an entire sett, the remaining badgers, say twenty percent, will abandon their sett and spread out individually across a wider area contaminating more herds, known as the perturbation effect. During trials the perturbation effect was shown to significantly decrease over time making culling beneficial. However, these trials did not involve shooting but trapping the animals. Cage trapping will not be used in the trial as it is ten times more expensive than shooting, £2,200 per square kilometre per year, and the government would almost certainly have to subsidise farmers if this technique was employed. Because shooting is seen as more disruptive to setts of Badgers the perturbation effect may well be far more sever and drastically decrease the benefits of any cull. No-one knows what the actual effect will be because despite seven years of trials this technique wasn’t considered, therefore there is no evidence from trials upon which to form an informed opinion.
Nor is the plan considered cost effective and due attention should be paid to other factors before a cull is launched, in short culling was not an effective policy to end the spread of bovine TB. This isn’t the opinion of animal rights activists seeking to preserve walking shaving brushes at all cost but the opinion of the preeminent zoologist Lord Krebs. Lord Krebs is the leading government advisor on this problem and was the individual who wrote the initial report on badgers and TB upon which the current policy is being based on. Asked whether he thought the cull was a mistake he stated definitively that he thought it was. Despite this free-shooting, which Defra has recently renamed controlled-shooting, is likely to go ahead but is there an alternative to be explored?
That depends on your opinion on whether a new bovine TB vaccination for badgers is worth pursuing. Currently the vaccine is estimated at over 70 percent effectiveness, although this claim is disputed by some scientists. However, the cost of the vaccine is high as it involves trapping which as I’ve already mentioned is exorbitantly expensive. The government has provided £250,000 to vaccinate badgers but that isn’t enough to allow farmers to pursue this option, by contrast the studies and culling trials on badgers came in at £7 million. For opponents of a vaccination scheme the time scale of the vaccine is objected to, the real effect may take over 4 years to produce real drops in the spread of TB by badgers. Any decision taken by the government is likely to land it in hot water. If the government stalls on a cull the farmers will accuse them of procrastinating in the same vain as the last government. If the government press ahead with a cull animal rights activists, who can count on a great deal of public support on this issue, will object to the destruction of these furry animals. What is clear is that a cull alone isn’t the answer to the problem of TB in cattle.
Politics on Toast 
Given the growing spread of TB isn’t it better to do something now even if it only has a marginal effect? I haven’t seen any major studies by the department for environment which show that wild deer are a significant spreader of TB to cattle.
Posted by ReginaldRaymond@live.co.uk | August 13, 2011, 4:07 pmI don’t think the argument that it is better to do something than nothing holds much water in this debate. A reduction of 15% which is at the most positive end of predictions will still mean the tax payer incurs high expense in TB compensation in the future. But if Badgers are killed in controlled shooting how will their bodies be disposed of? This isn’t an immaterial concern as the carcasses will be classed as grade 1 toxic waste. this will be a substantial cost to those involved in a cull. So I don’t think this cull should be implemented unless it is coupled with other reforms such as how in how cattle are transported between areas (In essence the same cattle-based controls which all but eradicated bovine TB by the 1970s but which have since been relaxed with a coincidental rise in TB in cattle).
On bovine TB in deers Defra has been, in my opinion and others, negligent in its research. A Defra report in 2008 estimated only 1% of deer had bovine TB but they don’t regularly test deer but a recent herd of park deer destroyed were tested privately by their own and revealed figures of over 30% given their close habitat with cattle this has to be addressed if any solution is to be found.
If a range of measures, including a cull, was introduced then I would probably be supportive but this decision seems costly, ineffective and even has the potential to exasperate the problem given perturbation in areas beyond the sett. If this cull was based on poising sets with carbon monoxide I might even support just the badger cull (though I can’t say I am fully aware of the effects of such an approach other than its lower perturbation effects)
Incidentally the cost for a cull per licensed area is likely to be a little less than £1.5 million according to estimates by Defra. Who is going to bear that cost? Ultimately we might see the provisions for culling in place, no body willing to accept the cost, no badgers killed, and the government able to argue that the lack of action is due to farmers not utilising the measures in place. Of course only a cynic would suggest this.
Posted by Harry Raffal | August 13, 2011, 6:50 pmThe latest results suggest that, on average, 46% of TB in cattle in the English culling areas came from badgers (the figure is the reduction in the centre of the culling areas where the culling can be considered to have been most effective). This is based upon an (average) reduction in badger numbers of about 75%. When they reduced numbers by 100% in the Thornbury trials this eliminated TB in cattle completely for 10 years (until badgers started recolonising the area).
Similarly, a (peer-reviewed) study in 2007 published by the Royal Society estimated that cattle movements are likely to be responsible for just 16 per cent of bTB herd outbreaks, and that “High-risk spread is probably the result of cattle–badger–BTB interaction”
There is therefore no evidence that badgers ‘are a relatively marginal spreader of TB’.
The most significant difference between the cattle measures applied now and those which were successful in eradicating TB up until the mid 1980s is the fact that, back then, there were far lower badger numbers, and therefore a far lower disease reservoir. In fact, the only areas where they failed to eliminate TB were areas in which badger densities were very high. It was the fact that they couldn’t understand why the cattle measures were not working in these areas when they had worked everywhere else which led to them to discover the link between TB in badgers and cattle. Nowadays those high badger densities exist in most of England and Wales, so the problems experienced locally in places like Gloucestershire in the 1970s now occur everywhere. But not in Scotland, because badger numbers there are very low (interesting though to note that they do have high numbers of deer), so the cattle controls worked in Scotland, and Scotland has now been recognised by Europe as being ‘officially bovine TB free’.
Posted by Is | August 15, 2011, 2:08 pmHi, you raise some interesting points but in most over correlations can be suggested. For instance Scotland lacking in TB compared to the South-West. As I understand it in the main the South-West is currently the home of intensive dairy farming as opposed to beef herds which are more prevalent in Scotland. The different techniques in herd management could be playing as important a part as the absence of badgers. If we look at the TB situation in Ireland there is a correspond correlation between areas of TB and the number of dairy to beef herds.
Prior to the 1970s TB wasn’t a hotspot in the south-west but their are significantly more cattle in the region now, this is an important factor. Notably Devon did not see TB eradicate in the 70s and in this area dairy farming is intensive. Also TB in England isn’t always at uniformed levels in across a region even where badger populations are.
As for the deer population in Scotland, I believe studies appear to show that they are relatively free of TB. Particularly wild deer. This isn’t surprising if the cows don’t have bovine TB either. In areas where bovine TB is found in substantive number of deer there is also high numbers of cattle infected. Clearly more evidence is required as studies by Defra thus far haven’t been particularly well funded
You mention the 46% figure. I haven’t seen this study (searched but can’t find it, do you have a link so I can?) but the conclusions from the studies I have seen are open to interpretation which is why I phrased that comment in the way I did. I was more arguing that the effect of a badger cull would be marginal but reading it again that’s not at all how it reads.
Interestingly an article publish in the Royal Society Journal June 2011 (Vial and Donnelly, “Localized reactive badger culling increases risk of bovine tuberculosis in nearby cattle herds”) provided evidence against a cull “The presence of any reactive badger culling activity and increased numbers of badgers culled in the vicinity of a herd were associated with significantly increased bTB risk, even after adjusting for other important local risk factors.”
It’s for these reasons that I’m against a cull in the form it will take. I am NOT opposed to a badger cull in any form and think it would make a substantial difference if it came along side other measures. I feel a cull in isolation is unlikely to bring the benefits to the costs it will entail and its for that reason I argue against it in this article.
Posted by Harry Raffal | August 15, 2011, 4:12 pm