Policy paper

Annex A1: Updating minimum and maximum numbers during 2020 badger control operations

Updated 27 May 2021

Applies to England

© Crown copyright 2021

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This publication is available at https://www.gov.uk/government/publications/bovine-tb-summary-of-badger-control-monitoring-during-2020/annex-a1-updating-minimum-and-maximum-numbers-during-2020-badger-control-operations

Background

In 2020, as in previous years, it became apparent from daily data collected through the course of badger control operations and actual circumstances being observed in the field, that there was a wider variation in badger abundance across the control areas than it had been possible to estimate prior to the control operations. Specifically, some badger control companies were encountering and removing more badgers than expected and some were seeing and removing fewer despite equivalent amounts of effort deployed by similarly trained contractors.

This necessitated updating of the minimum and maximum numbers for 42[footnote 1] control areas following the advice published by Defra in September 2020 (Section D)[footnote 2] .

Updating numbers in Areas 11 to 31 and 33 to 53

The method used to update the minimum and maximum numbers has not been changed since 2017 but has been improved to take into account further data from effective first year control areas[footnote 3] and effective second, third and fourth year control areas in previous years.

For all areas the minimum and maximum numbers were recalculated using an historical comparator. Taking data from the previous years’ effective control areas, the proportion of the Day 42 cull total that was achieved on each day in each area is calculated, then averaged across areas to generate the historical comparator. This allows the prediction of the expected Day 42 total for any area, from any given day. The minimum and maximum numbers are then set equidistant around the expected cull total.

The updated minimum and maximum numbers in 26 areas[footnote 4] were further increased by 1.5% per operational day, to account for their desire to continue beyond 42 days in order to maximise disease control on land parcels where factors such as late maize harvest or poor weather conditions hampered coverage.

The data used to calculate the minimum and maximum numbers is taken from Day 28 of operations and this data and the resulting updated numbers are presented in Table 1.

Table 1: Data for updating minimum and maximum numbers in Areas 11 to 53 during 2020 badger control operations[footnote 5].

Area Day Effort Badgers removed by Day 28 Updated minimum number Updated maximum number
Area 11 – Cheshire 28 78 192 219 297
Area 12 – Devon 28 65 227 259 351
Area 13 – Devon 28 59 176 211 287
Area 14 – Devon 28 72 157 179 243
Area 15 – Devon 28 78 131 149 203
Area 16 – Dorset 28 68 606 691 937
Area 17 – Somerset 28 61 217 255 346
Area 18 – Somerset 28 70 107 122 165
Area 19 – Wiltshire 28 66 361 411 558
Area 20 – Wiltshire 28 79 330 376 510
Area 21 – Wiltshire 28 72 317 361 490
Area 22 – Cornwall 28 66 621 679 921
Area 23 – Devon 28 75 586 641 869
Area 24 – Devon 28 62 146 163 221
Area 25 – Devon 28 73 99 108 147
Area 26 – Devon 28 64 218 239 324
Area 27 – Devon 28 65 46 50 68
Area 28 – Devon 28 75 83 91 123
Area 29 – Gloucestershire 28 95 495 541 734
Area 30 – Somerset 28 77 597 653 886
Area 31 – Staffordshire 28 80 963 1053 1429
Area 33 – Avon 28 66 493 542 735
Area 34 – Cheshire 28 115 975 1072 1454
Area 35 – Cornwall 28 95 1161 1276 1732
Area 36 – Staffordshire 28 113 398 437 594
Area 37 – Devon 28 86 507 557 756
Area 38 – Devon 28 108 890 978 1328
Area 39 – Dorset 28 110 294 323 439
Area 40 – Herefordshire 28 74 778 855 1160
Area 41 – Staffordshire 28 110 515 566 768
Area 42 – Wiltshire 28 83 1276 1402 1903
Area 43 – Wiltshire 28 77 594 653 886
Area 44 – Avon 28 117 1328 1450 1968
Area 45 – Derbyshire 28 144 2317 2530 3434
Area 46 – Gloucestershire 28 152 335 366 497
Area 47 – Herefordshire 28 131 1314 1435 1948
Area 48 – Leicestershire 28 126 541 591 802
Area 49 – Oxfordshire 28 112 781 853 1158
Area 50 – Shropshire 28 121 2558 2794 3791
Area 51 – Somerset 28 129 1543 1685 2287
Area 52 – Warwickshire 28 114 1268 1385 1879
Area 53 – Wiltshire 28 117 421 460 624

  1. Two areas, Area 32- Cumbria and Area 54- Lincolnshire did not have minimum and maximum numbers. ↩

  2. https://www.gov.uk/government/publications/advice-to-natural-england-on-setting-minimum-and-maximum-numbers-of-badgers-to-be-controlled-in-2020 ↩

  3. All first, second, third and fourth year area calculations are based on all historical yearly area data. ↩

  4. For Areas 11, 12, 15, 17, 18, 19, 23, 24, 25, 28, 29, 30, 31, 34, 35, 37, 38, 39, 40, 44, 46, 47, 50, 51, 52 and 53, the minimum and maximum numbers presented in Table 1 exclude the further increase by 1.5% per operational day. ↩

  5. For areas in their first year of control, the minimum effort required was 112.7 units per 100km2 per night over 42 days. For areas in their second, third and fourth years of control, required effort was relative to the abundance of badgers reported in the area, with a recommended target of 64 units per 100km2 per night over 42 days. As some areas choose to continue beyond 42 days to maximise disease control benefits, all areas expended an appropriate level of targeted effort across their control area. ↩

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