Thread by @RosieWoodroffe

What does today's news of the "beginning of the end" of badger culling mean, in terms of badgers still to be killed? I had a go at estimating the likely trajectories. A thread... 1/9

Defra is consulting on an intention to issue no new culling licences after 2022, and to limit new supplementary culling licences to 2 years consult.defra.gov.uk/bovine-tb-2020… 2/9

This doesn't mean no culling after 2022, it means no *new licences* after 2022. To project what this may mean for the next few years, I first calculated the average size of existing cull areas (510 sq km), and numbers killed per sq km in each year of culling 3/9

Then, based on previous years, I assumed that NE would issue 10 new licences for average-sized cull areas in 2021, and 10 more in 2022. This leads to a peak of over 40,000 badgers killed in 2022, dropping to zero in 2026 4/9

The total over the lifetime of the licensed culling policy would be 276,045 dead badgers, of which 126,783 (46%) would be killed after today's signalling of the end of culling. 5/9

But! Defra is also consulting on the possibility of halting new culls after two years. This leads to the same peak but reduces the numbers killed a bit more rapidly 6/9

The total over the lifetime of the licensed cull policy would then be 256,879, of which 42% would die after today's announcement. The effect is small because most badgers are killed in the first two years of a cull. 7/9

These calculations assume that a full complement of 10 cull zones would be recruited for each of the two years that licences are available, which is not guaranteed. Obviously, fewer licences and smaller numbers reduce the overall total. 8/9

To summarise: today's consultation concerns not so much the end of culling, or even really the beginning of the end, but (to quote Churchill) the end of the beginning. 2025 should see the last culls and by then vaccination should be extensive. /end