BADGERS and HEDGEHOGS Q & A
- Do badgers predate on hedgehogs?
Yes, but the extent is still being investigated.
- Do hedgehogs make up a significant proportion of badger diet?
No. Mammals of any sort form a very small proportion of the diet of badgers. This has been shown by examining their stomach contents and dung. In season, the main diet of badgers is worms, insects and larvae. When food is scarce, they also eat fruit, corn, seeds, acorns etc. Badgers are not hunters but opportunist feeders, so they do feed on the young of mammals and ground nesting birds and sometimes road kills if they come across them.
- Has badger predation of hedgehogs changed in recent decades?
Maybe, due to an increase in the badger population. Badgers now have greater protection from human persecution, and milder winters have allowed more to survive. Changes in other food supplies, such as the rapid expansion of maize growing have benefitted badgers because it available in the autumn when badgers need to fatten up to survive winter. But it should be noted that reduced persecution has only allowed badger numbers to reach levels that would be expected in a particular habitat. In the past, large numbers of badgers have co-existed with a much larger hedgehog population than we have now.
- Do hedgehogs compete for food with badgers?
Yes, in part. Badgers are specialist feeders on earthworms and forage on short grassland for them when weather conditions are favourable. Hedgehogs also forage for earthworms in similar habitats but they are a less important part of their diet. Hedgehogs tend to forage nearer to cover such as hedgerows.
In a healthy environment there should be sufficient food for both species to thrive. This observation could point to a different possible reason for low hedgehog numbers though – the lack of suitable habitat for both species.
- Is there evidence that the presence of badgers in an area reduces hedgehog populations?
Yes, where there is a high density of setts, such as in Wytham Woods near Oxford, hedgehog density is lower. However, in areas where badgers are more scarce, hedgehog numbers are still down on the reported high levels of the 1950s.
Hedgehogs may avoid areas where there are a lot of badgers. The lack of really reliable baseline data on the population and distribution of both species makes analysis more difficult. Hogwatch will help address this in our area as we also know where badger setts are.
- Does badger predation explain hedgehog population decline?
No – hedgehogs and badgers have coexisted for thousands of years without the latter threatening the existence of the former. It is has not been shown that all badgers prey on hedgehogs as the technique for opening up rolled up hedgehogs may have to be learned. Zoologist Hans Kruuk studied badgers at Wytham Woods in the 1970s and did not report hedgehogs forming a large proportion of their diet (small mammals and carrion were recorded), or predation in the field. However, hedgehog numbers are lower when badgers are present so it may be that badgers do exert some control of hedgehog populations. Our local Hogwatch survey may help cast more light on this.
- Can hedgehogs and badgers coexist?
Yes. The main requirement is an adequate food supply for both. Suitable habitats will provide good cover for hedgehogs to hide and nest, and an environment free of toxins. Suitable habitats need to be of sufficient size and connectivity to allow both species to forage for food over large areas, if required.
- Is there a reduced food supply for badgers and hedgehogs?
Probably. Intensive use of pesticides over many decades by farmers, and to a lesser extent gardeners, may have reduced invertebrate populations (some species are more susceptible than others). However, research on the impact of pesticides on biodiversity on farms dates from the 1990s and practices have changed considerably since it was carried out. For instance, neonicotinoid seed dressings to control insect pests were not in use then and the weedkiller glyphosate had only limited application. Both chemicals may affect earthworm populations in arable soils. In addition, formulation of rat poisons has changed over the years as rats became resistant to older chemicals. At present there is insufficient evidence to say whether invertebrate populations have reduced.
As well as possible reductions in the availability of food, though, is also the reduced amount of land available to both badgers and hedgehogs. Huge areas of natural habitat have been lost to intensive agriculture, housing, roads and other human activity.
- Is a reduced food supply affecting the relationship between hedgehogs and badgers?
This could be a factor but as above, reliable information on the main food species, particularly on invertebrates, is lacking. Shortage of a staple food such as earthworms may cause badgers to shift their diet. However, this happens during periods of drought fairly frequently (earthworms are not active if the soil is too dry and retreat deeper into the soil) and research on badger dung shows that they move to a more vegetarian diet based on wheat and roots.
- What other factors might be involved in hedgehog decline?
There have been changes in pesticide use, in the active ingredients of slug pellets and rat poisons. All of these are used more than they used to be as well, which could be implicated in hedgehog decline. Farming practices and farm management have also evolved. Practices such as the introduction of minimum tillage, resulting in greater reliance on slug pellets could have an effect. Faster machinery for hay and silage making and creating much larger fields could also be implicated in the decline in hedgehogs. This also applies to urban areas where gardens are sealed off with fences and there are fewer “untidy” corners where hedgehogs might feed, nest and hibernate. Hedgehogs are very reliant on a good food supply to enable them to build up fat reserves to see them through their period of hibernation in the winter. Road deaths, drowning in ponds or cattle grids with steep sides and being killed by grass strimmers also reduce hedgehog populations.
- Is climate change altering the balance between badgers and hedgehogs?
Maybe. Winters are more likely to be milder now than they were in the 1950s. Badgers don’t hibernate and therefore benefit from higher average winter temperature.
Hedgehogs are natural hibernators, but warm spells in winter may cause them to become active. However, hedgehogs waking in mid winter are unlikely to find sufficient food to sustain them.
Therefore climate change could be benefitting badgers more than hedgehogs. But Information on the survival of hedgehogs through hibernation is limited and little is known about the health of hedgehogs before they go into hibernation. Insufficient fat deposits, infections and pests may impact on their survival but we simply don’t know.
- Will badger culling help hedgehogs?
Although there has been research showing an increase in hedgehogs in areas where experimental badger culls took place in the early 2000s, there are many areas where badger numbers are low but are still suffering a decline in hedgehogs. So it is unlikely that culling badgers alone will reverse the decline in hedgehogs. All factors involved need to be understood and then put right. Hogwatch is the first step locally to help with this process.
- What about feeding hedgehogs and badgers?
The ideal is that both species can find sufficient wild food during their nightly foraging trips. Feeding either species in your garden changes their natural behaviours. Hedgehogs should not be fed in winter as this may discourage them from going into hibernation.
Badgers attracted to a garden by regular feeding may decide to stay and create setts in places where they are not wanted. Hedgehogs, however, are beneficial (they eat slugs!) and need help.
The difficulty is that both creatures are attracted to the same food. The best way to help both species is to provide plenty of wild unmanaged areas for them to live and forage. Badgers and hedgehogs both travel considerable distances to search for food, so making sure they can easily get in and out of your garden is essential. Managing areas without using pesticides helps maximise the natural food available for both species.