Policy paper

Annex A1: updating minimum and maximum numbers during 2021 badger control operations

Published 30 March 2022

Applies to England

© Crown copyright 2022

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This publication is available at https://www.gov.uk/government/publications/bovine-tb-summary-of-badger-control-monitoring-during-2021/annex-a1-updating-minimum-and-maximum-numbers-during-2021-badger-control-operations

Background

In 2021, 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 38[footnote 1] control areas following the advice published by Defra in September 2021 (Section D)[footnote 2] .

Updating numbers in Areas 22 to 31, 33 to 53 and 55 to 61

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 30 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 22 to 61 during 2020 badger control operations.[footnote 5]

Area Day Effort Badgers removed by Day 28 Updated minimum number Updated maximum number
Area 22 – Cornwall* 28 75 514 571 775
Area 23 – Devon* 28 68 387 433 588
Area 24 – Devon* 28 72 107 118 160
Area 25 – Devon* 28 79 95 103 140
Area 26 – Devon* 28 69 153 163 221
Area 27 – Devon* 28 66 69 71 96
Area 28 – Devon 28 71 73 75 102
Area 29 – Gloucestershire* 28 87 431 482 655
Area 30 – Somerset* 28 60 423 504 685
Area 31 – Staffordshire* 28 69 725 789 1070
Area 33 – Avon 28 69 374 407 552
Area 34 – Cheshire* 28 78 655 723 981
Area 35 – Cornwall* 28 81 710 777 1055
Area 36 – Staffordshire* 28 75 303 332 450
Area 37 – Devon* 28 70 326 365 495
Area 38 – Devon* 28 70 644 710 963
Area 39 – Dorset* 28 80 154 170 231
Area 40 – Herefordshire* 28 66 581 657 891
Area 41 – Staffordshire 28 83 346 381 518
Area 42 – Wiltshire* 28 63 907 1016 1378
Area 43 – Wiltshire* 28 65 552 609 827
Area 44 – Avon* 28 61 780 879 1193
Area 45 – Derbyshire 28 80 1053 1144 1552
Area 46 – Gloucestershire* 28 137 144 159 216
Area 47 – Herefordshire* 28 78 750 819 1112
Area 48 – Leicestershire 28 79 276 304 413
Area 49 – Oxfordshire 28 70 444 482 654
Area 50 – Shropshire* 28 86 1840 2026 2750
Area 51 – Somerset* 28 79 1006 1111 1507
Area 52 – Warwickshire 28 67 790 869 1180
Area 53 – Wiltshire* 28 80 212 233 316
Area 55 – Shropshire* 28 116 151 161 219
Area 56 – Hampshire* 28 115 449 491 667
Area 57 – Berkshire* 28 114 118 128 174
Area 58 – Staffordshire 28 160 630 686 931
Area 59 – Worcestershire* 28 156 400 421 572
Area 60 – Shropshire* 28 121 1020 1099 1491
Area 61 – Oxfordshire* 28 111 507 558 757

  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 listed with ‘*’ 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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