Memorandum submitted by English Nature,
on behalf of the Natural England confederation
(English Nature and the Rural Development
Service) (BTB 16)
EXECUTIVE SUMMARY
1. English Nature shares the Government's
concerns about bovine TB in cattle, and is firmly of the view
that a new evidence-based strategy is needed. Introducing a badger
culling policy that is unsupported by the results of scientific
research runs the risk of making the situation worse.
2. Our view is that there is no scientific
support for small area reactive or proactive culls covering less
than 100 km2, and this policy option should not proceed.
3. If large area culls (over 300 km2) were
to be considered, issues of badger conservation and cull deliverability
need careful attention before any policy is adopted. It would
need to address the fact that there is no evidence that even a
complete badger cull would reduce the frequency of herd breakdowns
by more than 60% at most.
4. Elimination of local populations at a
scale of several hundred square kilometres would negatively affect
the conservation status of badger in England, and culls on this
scale would be opposed by English Nature. It is likely that the
UK would come into conflict with the Bern Convention over culling
on this scale.
5. We have concerns about the lack of selectivity
of any cull, since all badgers would be killed, not just infected
ones. Estimates indicate that between 77% and 92% of badgers culled
could be healthy. There is urgent need for the development of
a sensitive and specific live test for bovine TB in badgers.
6. The deliverability of a large area cull
is a key issue that needs much more research. The indications
are that this would be very difficult to achieve, and partial
deliverability would potentially make the situation worse. Access
to land for culling purposes is most unlikely to be comprehensive.
We believe that the modelling used for small area culls needs
to be redesigned and extended to address fully the uncertainties
of large area culling. The culling efficiency of large area culls
in the UK is completely unknown, and so could not form the basis
of an evidence-based strategy.
7. We are deeply concerned that the simultaneous
introduction of three new initiatives (table valuations; pre-movement
testing; and badger culling) means that it will be virtually impossible
to determine the extent to which any individual component contributes
to any observed changes.
8. We believe that pre-movement testing
and other measures to reduce cattle to cattle transmission should
be implemented immediately and independently of any badger cull.
Now that small area badger culls can be effectively ruled out,
much more investigation of the conservation impact and deliverability
of a large area cull is needed before such a policy is considered.
ENVIRONMENT, FOOD
AND RURAL
AFFAIRS COMMITTEE:
INQUIRY INTO
BOVINE TB AND
BADGER CULLING
1. English Nature shares the Government's
concerns about the increasing prevalence of bovine TB (bTB) in
cattle in some parts of Britain. Current strategies are demonstrably
failing to halt the deteriorating situation, and we are firmly
of the view that a new evidence-based strategy is needed. Introducing
a badger culling policy that is unsupported by the results of
scientific research runs a significant risk of either failing
to improve the situation or perhaps even making it worse. A policy
that culled thousands of badgers but resulted in no demonstrable
improvement in the situation would be the worst outcome for both
government and the farming community.
2. The interim results of the Randomised
Badger Culling Trial (RBCT), published recently in Nature, demonstrated
very clearly some of the pitfalls of badger culling strategies.
In its analysis of this and other studies, the Science Advisory
Council (SAC) concluded that localised culling is likely to be
counter productive and that any area to be culled needs to be
at least 300 km2, and preferably more, in order to avoid an overall
adverse effect. Our view is that there is no scientific support
for small area reactive or proactive culls, covering less than
about 100 km2, and that this policy option need be considered
no further.
3. If large area culls (greater than 300
km2 ) are to be considered, issues of badger conservation and
cull deliverability need careful attention before any policy is
adopted. The SAC review concluded that spatial coverage within
an area to be culled would need to be effectively complete to
avoid the creation of a mosaic of unculled and perturbed areas
where incidence would be likely to increase. This suggests that
the only scientifically justifiable policy objective would be
the control of badgers over the total cull area, as partial culls
run the risk of making the situation worse. A similar argument
applies to the intensity of culling. The RBCT showed a decrease
of 19% in herd breakdowns within the proactive cull area in response
to a substantial (but not accurately known) reduction in the badger
population, whilst a decrease of nearer 60% was achieved in the
recent Irish trial, which almost completely removed badgers from
the trial area. Although the RBCT shows some benefit may be achieved
with an imperfect cull, there is no clear relationship between
badger density and the incidence of herd breakdowns, so there
is no target badger density that could be recommended as adequate
to deliver an improvement. The only scientifically justifiable
policy objective would therefore be the removal of as many badgers
as possible rather than the maintenance of a low-density population.
This twin objective of complete coverage and complete removal
presents formidable difficulties, particularly as there is no
evidence that even a complete badger cull would reduce the frequency
of herd breakdowns by more that 60% at the most.
4. Although the badger is not a rare or
threatened species, the elimination of local populations at the
scale of several hundred square kilometres could negatively affect
the conservation status of the species in England by reducing
its natural range. Culls on this scale, resulting in the long-term
removal of badger populations, would be opposed by English Nature.
Even a temporary removal at this scale would be a significant
conservation concern, particularly if the objective is complete
removal. We would wish to see a detailed assessment of the response
of the regional badger population to the predicted rate and spatial
pattern of a cull in order to quantify the wider conservation
impact. In addition, a large-scale culling policy would bring
the UK into conflict with the Bern Convention, which prohibits
methods of control that result in the local disappearance of species
5. The lack of selectivity of any cull remains
a significant issue. Because it is not possible to determine with
any certainty whether an individual live badger is infected with
bTB, a badger culling policy would seek to remove all badgers,
regardless of their disease status. Estimates of the county-level
prevalence of infection made by the ISG from a survey of badgers
killed on the roads ranged between 8% (Devon) and 23% (Gloucestershire),
meaning that between 77% and 92% of badgers culled could be healthy.
This problem could only be addressed by the development of a sensitive
and specific live-test that could be applied to trapped badgers
and this remains an important research need.
6. The deliverability of a large area cull
is a key issue that needs much more research. In the Irish "four
areas" trial, the almost complete elimination of badgers
was achieved over areas of about 250 km2, but the starting density
of badgers was much lower, intensity of removal was very high
and landowner co-operation was almost complete. After four years
of badger removal, the level of herd breakdowns was reduced by
about 60%, but the disease was not eliminated from any of the
trial areas. All culling was carried out by full-time staff of
the Department for Agriculture and Food. This state run approach
has already been ruled out in the UK after cost-benefit analysis
demonstrated there were few circumstances under which a government-funded
badger cull would be cost-effective.
7. Badger culling by licensed farmers or
their agents has been proposed, as this could overcome the unfavourable
cost-benefit ratio of a government-funded cull. Possible methods
under consideration include shooting, restraints and gassing,
though all these present difficulties. Any culling would need
to be licensed under the Protection of Badgers Act 1992 and a
licence could only be issued where the licensed action was likely
to achieve the purpose of preventing the spread of disease. The
extent to which the landowning community would take on this role
is unknown.
8. There are several major considerations
when determining whether a large area cull could achieve an overall
reduction in the incidence of bTB in cattle:
(a) Access to land. In the Irish trial, operatives
had access to almost 100% of land, but this is unlikely to be
the case in England. Some pertinent data on the subject are available
from the RBCT, where the percentage of the trial area for which
permission to cull was available ranged between 48% and 76% (mean
66%). If a similar figure is achieved in a large area cull, this
appears to fall well short of the "effectively complete"
coverage advised by the SAC. Further information can be obtained
by considering maps showing the distribution of agricultural holdings
derived from information held on the Rural Land Register. We are
aware that some simple modelling work based on these data has
already been done for small-area culls for Defra Animal Health
Division and has illustrated some significant challenges to a
comprehensive cull, related to patterns of land ownership and
the proportion of land not in agricultural holdings. This work
should now be repeated using areas of about 300 km2 centred on
TB "hotspots".
(b) Culling efficiency. In the Irish trial,
where badger densities were low, culling efficiency was considered
high as all work was carried out by professional operators, badgers
were captured with restraints, no closed season was observed and
removal operations took place two or three times a year. In the
RBCT, where badger densities were higher, all culling was carried
out by professional operatives, but efficiency was constrained
by the permissible method of capture (cage traps), access to land,
security considerations and the need to observe a close season.
The exact trapping efficiency achieved is unknown. Although a
significant reduction in badger activity was recorded, it was
certainly short of complete elimination. The efficiency that might
be achieved by licensing farmers or their agents to carry out
a badger cull using shooting or other agreed methods is completely
unknown and so could not yet form the basis of an evidence-based
strategy.
(c) Persistence. Any area subject to a wide
area cull would need to be maintained more or less free of badgers
for a considerable period to sustain any improvement in herd breakdown
rates. No policy decision has yet been made about how long such
a situation should persist, but the assumption is that this would
be until badger or cattle vaccination could be introduced. In
addition, experience with the removal of invasive non-native species
shows that a high level of effort and surveillance is required
to remove the last individuals and prevent subsequent re-establishment.
The difficulty of maintaining this effort should not be underestimated.
(d) Public acceptability. Whilst recognising
that the badger plays some role in the maintenance of bTB infection
in cattle in some parts of England, it must also be recognised
that it is an immensely popular animal. Any culling policy, and
anyone delivering that policy, will be under intense public scrutiny.
This is likely to place significant practical constraints on delivery.
9. We remain very concerned that the simultaneous,
or near-simultaneous, introduction of three new initiatives, table
valuations, pre-movement testing of cattle and badger culling
would make it very difficult to determine the extent to which
each of these contributes to any observed change in herd breakdown
rates. We recognise the seriousness of the situation, but are
not persuaded that the need to reduce the level of herd breakdowns
outweighs the need to be clear about the contributions of various
initiatives. Unless steps are taken to separate the introduction
of these treatments, particularly pre-movement testing and badger
culling, it will be difficult to work towards a cost-effective
long-term strategy that minimises the number of cattle and badgers
killed.
10. In our view, pre-movement testing and
other measures to reduce the cattle to cattle transmission of
bTB, which the SAC considers probably the dominant infection route
at present, should be implemented immediately and independently
of any badger cull. Now that small area badger culls can be effectively
ruled out, much more preparatory work on the conservation impact
and deliverability of a large area cull is needed before such
a policy is considered. For culls on this scale, the impact on
the conservation status of the badger is a significant issue requiring
further consideration. In addition, we are not aware of any persuasive
evidence that the landowning community would be able to implement
a badger cull of adequate coverage and intensity to achieve an
overall reduction in herd breakdowns.
February 2006
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