Are badgers to blame for the decline in hedgehogs?
A position statement by British Hedgeghog Preservation Society (BHPS) and People’s Trust for Endangered Species (PTES)
Several studies have demonstrated that badgers will kill hedgehogs, but they also eat many of the same prey items (especially worms). The same food cannot be eaten twice. Badgers are both a predator and a species competing for food.
The two species have coexisted in Britain for several thousand years and, whilst it is likely that where badger numbers are high the number of hedgehogs will be low, to identify badgers as the single most important factor affecting hedgehogs today is a mistake when there are more pressing issues like habitat loss. We know that when the habitat is rich with nesting and feeding sites, the species are able to coexist.
Hedgehogs are declining severely even in parts of the country with low badger densities (e.g. East Anglia). It is clear that several interacting pressures are at work. Bolstering hedgehog populations would be better achieved by increasing and improving habitat that supports both species – for example: restoring hedgerows to improve shelter and nesting opportunities; managing field margins and grasslands in ways that encourage abundance and diversity of invertebrates.
Badgers: the cull and vaccination
Defra announced early in 2020 that it is planning to gradually replace the badger cull with badger vaccination. It is good news for farmers, the general public and wildlife. Vaccination is more likely to eradicate TB, is cheaper than culling and, importantly, safeguards badgers too. It is estimated that cattle-to-cattle transmission accounts for 94% of new herd infections. “The available evidence suggests that reducing cattle-to-cattle transmission of M. bovis is the most important action required to improve TB control. However, achieving eradication … is likely to require some intervention to reduce transmission from badgers. The available evidence raises significant concerns about the current policy of large-scale nonselective badger culling…which contributes little to this goal because it increases the prevalence of infection in badgers and spreads TB to herds in new areas. Hence, while culling may contribute somewhat to TB control in the short term, its effects are not sustainable in the long term.” (Woodroffe 2018)
PTES has been funding Rosie Woodroffe at Zoological Society of London to research how effective a badger vaccine can be. Woodroffe said bTB had to be controlled in badgers if the disease was to be completely eradicated. But she said: “Vaccination is the most promising option because, unlike culling, it has the potential to eradicate TB from badgers, as well as being cheaper, more humane, and more environmentally friendly.” She said a phased transition from culling to vaccination was sensible as it would take time to train vaccinators.
Research funded by BHPS and PTES investigated factors in the wider countryside associated with low numbers of hedgehogs (https://www.nature.com/articles/s41598-018-30130-4). Hedgehog occupancy was generally low (22% nationally), and also significantly negatively related to badger sett density. However, hedgehogs were also absent from 71% of sites with no badger setts, indicating large areas of our rural landscape are not occupied by hedgehogs. Therefore whilst increasing badger abundance combined with intensive agriculture may have provided a perfect storm for hedgehogs in rural Britain, to place all the blame on badgers is inaccurate.
None of the scientific evidence supported the idea that culling badgers is an effective means of controlling bovine TB in the field. Pilot culls (2013, 2014) failed to kill sufficient animals for the cull to have been effective (despite extending the length of the trial) and raised doubts about the humaneness of the method. Given this, BHPS and PTES joined leading wildlife scientists in arguing against a cull of badgers to control bovine TB. Indeed, scientific evidence suggested that culling badgers may make the TB situation worse, a further reason why PTES/BHPS did not advocate culling badgers to benefit hedgehogs.