Further reading of the Irish 4 area study referred to below, details a most extraordinary spat between the UK and Irish beneficiaries of taxpayer's money in the battle to determine the role of badgers in bovine Tb.
"In a recent study, Donnelly et al (2003) anticipated the findings of the current (Irish) study."
How odd. Is it normal for one scientific group to pre judge the outcome of another's work? It would appear that the 'migratory' effect of badgers stumbling into vacant territory, (perturbation) which had been cited as the reason for the 'failure' of UK's Krebs' Reactive culling zones was anticipated for the 4 areas Irish study - by UK 'modellers'. We would point out (with the greatest respect of course) that to be effective in executing a badger cull, a Wildlife team first has to appear. And at least one author on this site is still waiting..... and another experienced a 3 year interval between action in Krebs' reactive areas.
The Irish authors point out most forcefully, and suport PQ's archived on this site, that a substantial geographic boundary is a secure barrier to ingress of migratory badgers. The boundaries of the 4 area study included the sea, wide rivers and mountains - mirroring Thornbury, the most successful of the UK trials. But the Irish trial also had a culling strategy in their buffer area to further prevent inward migration.
When we last looked, the UK was surrounded by sea ......