A bovine TB research project in Co Down which involved wildlife intervention had no impact on the roaming behaviour of badgers, scientists have concluded.

A study of badger roaming was included in the Test and Vaccinate or Remove (TVR) project which took place in a 100km2 area near Banbridge over a five-year period.

The project involved badgers being caught and tested for TB. All badgers with negative results were microchipped, vaccinated and released, while TB-positive badgers were culled from the second year onwards.

Tracking devices were also fitted on 105 badgers and the findings have been included in a newly published study in the scientific journal Epidemiology and Infection.

The average roaming area for each badger was found to be 1.41km2 during the first year of the project.

However, scientists from DAERA and AFBI found that the roaming behaviour did not change when TB-positive badgers were culled from the second year onwards.

“Home ranges […] were not significantly altered by the TB intervention/badger removal,” the paper reads.

There were some concerns that wildlife intervention could lead to increased roaming in the remaining badger population which in turn could spread TB to other areas.

This effect, which is known as perturbation, has been seen in Britain in the past. However, it has not been observed in the Republic of Ireland where, unlike the TVR approach, badgers were not tested for TB before being culled.

The conclusions from the latest study explain why Agriculture Minister Edwin Poots did not include a vaccination zone in the area surrounding a cull, despite that being among recommendations made by the TB Strategic Partnership Group in 2016.

Low cull rate

The latest study also provides further insight into other aspects of the TVR project, particularly the low cull rate of badgers.

Over the four-year period when TB-positive badgers were removed, only 108 badgers were culled across the 100km2 area.

The new study states that more badgers were killed in road traffic collisions than through the TVR intervention measures.

“It is known for example that during 2016, 29 road traffic fatalities were reported in the TVR area while only 11 badgers were removed through the intervention in the same year,” the paper reads.