Over 70% of badgers in an area must be killed to be sure that the disturbed remaining populations do not range more widely and spread the disease further. But the minimum targets set for badger kills in each area were changed during the culls depending on how many were being shot, being reduced by up to 50% in some places.

“This means that there is really no way to tell what reduction in badger numbers was achieved by these culls,” said Woodroffe. “Culling that was consistently ineffective would look like a low badger density and prompt a reduced target. I would therefore consider [Nigel Gibbons’] conclusion to be based on extremely shaky evidence.