Badger setts and social groups

In the UK, badgers live in social groups that share a territory, which they defend. A social group territory usually contains one or more main setts and a number of less frequently used smaller setts. Territory boundaries are marked by latrines. Badger setts tend to be found in woodland, hedgerows and field margins.  Badgers usually forage on grazed pasture and open woodland habitats, with earthworms making up the majority of their diet.

The average life expectancy of a non-captive badger is between three and five years. The single largest cause of death in the wild is thought to be as a result of being hit by road traffic.

How many badgers are there in Wales

Badgers are nocturnal and live underground and so estimating their population can be very difficult. Much of the information we have on the abundance and distribution of badgers in Wales was collected as part of three national badger sett surveys carried out between 1985 and 1987, 1994 and 1997, and 2011 and 2013. As these were surveys of badger setts, they produced estimates of the number of badger social groups, not the number of badgers. The results of the latest survey estimated that there were 7,300 badger social groups in Wales.

The average badger social group size in Britain was estimated to be 5.9 adult badgers in the 1980s. By multiplying this value by the estimated number of badger social groups in the 1980s there was estimated to be around 35,000 adult badgers in Wales at that time. The two subsequent sett surveys found that the number of social groups in Wales has changed little since then. However, the size of badger social groups can vary considerably and there are no current reliable estimates of the average number of badgers per social group in Wales. It is not possible to provide an estimate of the number of badgers in Wales at this time.

Badgers are not an endangered species but are protected by UK and European law in order to prevent their persecution.

Bovine tuberculosis in badgers

Bovine TB can affect all mammals, including badgers. There has been evidence of a link between bovine TB in badgers and cattle since the discovery of an infected badger carcass in Gloucestershire in 1971. Other evidence supporting this link includes:

  • a higher level of bovine TB infection in badgers compared to other wild mammals
  • high levels of infection in badgers being associated with areas of high levels of infection in cattle herds,
  • a survey of badgers found dead in Wales in between 2005 and 2006 found that the geographical distribution of molecular types of Mycobacterium bovis (the bacterium that causes bovine TB) found in badgers was similar to those found in cattle
  • it has been proven experimentally that badgers can transmit bovine TB to cattle.

TB is not a major cause of death in badgers. TB infected badgers can live for several years during which time their ability to infect other animals will vary.

Contact between cattle and badgers

Cattle may pick up infection by coming into close contact with other infected animals. These may be badgers or other cattle, or contaminated material like grass, soil and feed. Badgers have been found to regularly visit farm buildings to take food and bedding. They have been recorded defecating and urinating on stored cattle feed and coming into direct contact with housed cattle. Both represent opportunities for the spread of infection.

Badgers may also come into contact with cattle in the field, although this is thought to be rare. It is more likely that cattle come into contact with badger faeces and urine, which may pose a greater risk of spreading the disease. The organism that causes Bovine TB has been recovered in soil around badger setts. Cattle may come into contact with infectious material if they are able to investigate these areas. Cattle have also been observed investigating dead badgers.

Contribution to bovine TB in cattle

It has proved difficult to eliminate the disease from cattle herds in areas of Wales where infection is also present in badgers.  The testing and slaughter of infected cattle alone is unlikely to clear-up infection in a herd when re-infection occurs from badgers. This makes control very difficult and eradication impossible.

Infection from badgers

The spread of bovine TB is complicated by the fact that wildlife, such as badgers, can also be infected. Cattle and wildlife can infect each other.

Research has shown that badgers frequently visit farm buildings and come into close contact with housed cattle. Certain cattle foods such as maize or whole crop silage, molasses licks and mineral blocks are particularly attractive to badgers. Some farming systems can make it easy for badgers to access feed, which can greatly increase the risk of TB being introduced into herds.

There are common sense, precautionary measures you can take to help protect your herd from possible TB infection from badgers.

Feed stores, cattle accommodation and farmyard

  • the use of solid gates / fences or electric fencing can help keep badgers out of buildings
  • any gaps between gates and fences and the ground should be less than 7.5cm; otherwise a badger will be able to get underneath it
  • if the floor surface is soft, a determined badger will scrape away at it, until the gap is big enough to get underneath
  • gates and walls should be at least 1.5 meters high. They should be sheer. If there are any potential footholds, a badger will be able to climb it
  • electric fencing should have 3 strands at 10cm, 15cm, and 20cm (with an optional 4th strand at 30cm)
  • badgers will frequently return to investigate areas even if they have been unable to gain access in the past.

At pasture

  • be aware of high risk areas e.g. badger latrines and active setts. A permanent or temporary fence should be considered to prevent opportunities for contact
  • intensive / extended grazing may encourage cattle to feed at the edge of the field where there is a greater risk of contamination from badger faeces and urine at badger latrines
  • avoid allowing cattle access to woodland
  • it is very difficult to badger-proof feed-troughs at pasture. Feed troughs in the field should be made more difficult for badgers to access them e.g. by raising them off the ground or using troughs which incorporate rollers around their edges
  • feed troughs can become contaminated by wildlife. Keep an eye out for such signs and clean feed troughs out regularly
  • molasses licks & mineral blocks should be made more difficult for badgers to access them e.g. raising them off the ground.

Improving farm biosecurity videos

There is a series of videos demonstrating practical on-farm biosecurity measures to reduce bovine TB risks to cattle from wildlife. The videos have been jointly funded by Welsh Government, Department for Environment, Food and Rural Affairs, the National Farmers Union (NFU) and the National Animal Disease Information System (NADIS). The videos are available below: