One of our contributers met Professor Krebs some time ago, when he expressed concern at the way 'his' trial was being carried out. Contributers to this site saw first hand what happened on farms within the trial areas, and operatives and managers concerned in its implementation have also voiced concerns. But how does that compare with the recommendation protocols offered in 1997 by Professor, Sir John Krebs?
We have now obtained sight of a copy of the proposals from the trial's originators, and in them, Professor Krebs explains why they were important to his trial's outcome.
P126 In explaining the efficacy of previous policies:
7.8.3 The gassing and clean ring strategies, in effect, eliminated or severely reduced badger populations from an area and appear to have had the effect of reducing or eliminating TB in local cattle populations. The effect lasted for many years after the cessation of culling, but eventually TB returned.
7.8.4 The interim strategy, introduced following the Dunnet report, is not likely to be effective in reducing badger-related incidence of TB in cattle for the following reasons:
(i) The policy involves removing badgers from a limited area (the reactor land or the entire farm suffering the herd breakdown if the former cannot be identified) ; but social groups of badgers may occupy several setts covering more than one farm.
(ii) Partial removal of groups could exacerbate the spread of TB by peturbation of the social scructure and increased movement of badgers.
(iii) There is no attempt to prevent recolonisation by badgers of potentially infected setts; even if infectivety in the setts is not a problem, immigrant badgers may bring new infection.
In addition, the current operation of the interim strategy involves a delay (27 weeks in 1995) to the start of the removal. The average period from the herd breakdown to the completion of the removal was 41 weeks in 1995.
7.8.5 In common with the clean ring strategy and the live test trial, the effectiveness of the interim strategy is further underminedf by the failure to remove lactating sows which may also be infected. We recognise that culling lactating sows has a welfare cost in terms of cubs left in setts, but this needs to be balanced against wider animal health and welfare considerations for both cattle and badgers.
So, the originators of the Krebs trial protocol recognised that gassing and clean ring strategies worked for several years by reducing or eliminating Tb in cattle, and conversely they considered the 'interim' strategy to be ineffective for the following reasons: that it split social groups of badgers, thus exacerbating peturbation and territorial social structure. It also 'failed to prevent recolonisation of potentially infected setts'- (except by placing 3 sticks across the entrance) - and it allowed lactating sows to offer transmission of Tb to their cubs. It was also very slow in delivering follow up action to a herd breakdown.
In another part of the proposals (7.8.9) Professor Krebs reiterates some key features which he said were likely to influence the effectiveness of any reactive strategy:
(i) The size of the area cleared, (including the extent to which this takes into account badger territory)
(ii) The efficiency of the badger removal operation (to ensure all infected badgers are removed and minimise any problem of peturbation associated with partial removal of social groups)
(iii) The prevention of recolonisation for a sufficient period.
One would assume from that critique that all these failures of the interim strategy and recommendations for the efficacy of a new ££multi million trial would be taken note of by the operators of the RBCT. But in that assumption, one would be quite wrong. Wildlife Manager , Paul Caruana's experience of working under ISG instructions gives a vastly different picture of the methodology employed. And this is backed up by comments on the site from others involved in trial operations.
The original Krebs methodology:
7.8.14 We suggest that the most appropriate Reactive strategy would be to target culling at social groups where a badger-attributed breakdown has been identified. This would involve removing all badgers, including lactating sows, from all social groups with territories including the breakdown farm (or reactor land if this can be rigorously identified). There should be sufficient follow up to ensure that every member of every social group which could have caused the initial breakdown has been removed.
7.8.15 Ideally recolonisation of setts should be prevented for a period of time under the reactive strategy. This would be costly. We therefore consider that costs should be balanced against potential benefits in deciding whether this should be included in the detailed experimental design. In any event given the lack of data on recolonisation times, we recommend that further research should be done on this in areas subject to both reactive and proactive control strategies.
7.8.17 The Proactive strategy would involve total removal of complete badger social groups from localised areas at high risk of breakdown, before breakdowns. This strategy would require regular monitoring and also revisiting after two or three years to deal with renewed badger populations.
Other proposals explored in the Krebs document include stop-snaring as as alternative to trapping, taking into account efficacy, cost and welfare considerations. Farmer particiaption and MAFF involvement in the trial is proposed and Krebs predicted a 20 per cent reduction in Tb over five years.
To reiterate what actually happened:
* That the RBCT attempted badger removal operations using cage trapping for 8 nights only, during their infrequent visits. There was significant interference, particularly during the first 4 years of operations, and many removals were attempted during winter months, when little badger activity above ground is expected.
* No follow up occurred at all. No checks on setts and no confirmation of complete clearance of a social group. No culling at all took place in 2001, because of biosecurity imposed by FMD. Thus all areas within the trial, both reactive and proactive went at least 2 years between these incomplete removals. Some, including our contributers, experienced 3 years of such peturbation chaos.
* Badger social groups were split, and during later years boundaries of trial areas were changed to accomodate this.
* No action was taken at all to prevent recolonisation of setts thought to be cleared.
* A closed season operated from February to May to allow lactating sows to rear cubs.
* There was absolutely no involvement with participating farmers, or local MAFF officers.
As well as a rebranding of the 'Krebs' RBCT, the ISG are at pains to point out that their aim was never to 'cull all the badgers' as proposed by Professor Sir John Krebs. This particular protocol is now downgraded to a mere 'population reduction'. And then there is the ISG's unique and notorious 'edge effect'; a phenomenon which if the original methodology proposed by Professor Krebs had been observed, may not have been evident at all.
The original Krebs' prediction of a 20 percent reduction in incidence was correct, but unfortunately by not following Professor Kreb's protocol with regard to implementation of the trial, the trial operators achieved exactly the results that Krebs described as 'unlikely to be effective' during the interim strategy in his report of 1997.