Ecology

 

Badgers have been present in Britain for about 250,000 years surviving other wild animals such as wild boar, wolves and bears which became extinct. There are nine species of badger throughout the word but only one (Meles Meles) lives in Britain. They have a scent gland beneath the tail which produces ‘musk’ hence their family name Mustelidae. The gland is used for marking their territory and recognition of the other members within a social group.

Habitat  It has been estimated that there are between 250,000 and 310,000 badgers in the UK living in about 80,000 family groups. They are not evenly distributed throughout the UK with higher densities found in the south-west of England and Wales.

Badgers like to dig their setts in sloping deciduous woodland where the soil is well drained, there is protection from the tree roots to prevent their tunnels from collapsing and there is a plentiful supply of food. There are 4 categories of setts in the countryside.

  1. The Main Sett. This will be large with several entrances, some in use and others disused. There will be large spoil heaps and well used paths leading to and from the sett. There is only one main sett per social group
  2. Annex Setts. These are not as large as a main sett but will also have a number of entrances. They will often have well worn paths to the main sett which will be about 100m away. They will not always be in use.
  3. Subsidiary Setts. These have a smaller number of entrances which are not connected to other setts and may not be in use.
  4. Outlier Setts. These will only have one or two holes, no paths and will only be used sporadically.

Badgers use other places to set up home such as hedgerows (outliers) quarries, coastal cliffs and occasionally in railway embankments and under buildings and roads.

Nocturnal Lifestyle  Badgers are nocturnal emerging from their setts just after dusk and returning home before dawn. As a rule, badgers will emerge between sunset and dusk from May to September and after dusk in other months. If a badger is seen during the day it is likely to be sick or injured and needs attention. If young badgers are spotted in the daytime form June/July to September it may be that the adult has been killed and they need help.

Badgers are also extremely shy which is why so few people have seen one. They are also very wary of people and even if they come into gardens they are easily spooked by humans.

Badgers have very poor eyesight but this is compensated by very acute hearing and smell. If you ever go badger watching never use perfume or after shave and make sure that you are down-wind of the sett otherwise you will see nothing. Badger watching is not illegal as long as you do not interfere with the sett (See: Badger Law). It is always advisable to get the permission of the landowner or you run the risk of prosecution for trespass.

Territories  Badgers are very social animals and live in groups. Each group has its own territory, the size of which depends on the suitability of their habitat. If there is a plentiful supply of food it will be smaller than if they need to travel a long way to find sufficient food. Territories have been recorded in size from 15 hectares (30 football pitches) to over 300 hectares in Scotland.

Badgers mark the edges of their territory with their dung pits (toilets) and by scent marking. This warns the neighbouring badgers that this is the boundary line of their territory. Badgers are very territorial and will fight off outsiders.

Small skirmishes also occur within family groups. Each badger knows his/her place in the hierarchy and none of the badgers challenge the dominant boar or sow. Members of the same social group will scent each other by spraying from the musk glands so the whole group carries the same smell.

Injuries sustained in family feuds are usually restricted to minor bites to the rump although bad wounds have been recorded. Facial injuries to badgers are more likely to be caused by other animals especially dogs.

Physical Features  An adult badger can grow up to 70-80cm long (head and body) plus a tail of up to 12 -18 cm long. Adults weigh between 9-12 kilograms with the males about l Kg heavier than the females. They have short powerful legs, strong shoulders and long claws, especially on the front feet for digging its sett and have a low-slung body for negotiating tunnels easily.

The arrangement of skull bones means that a badgers jaw cannot be dislocated and it has an extremely strong bite. Badgers are omnivores and have teeth which allow them to eat both vegetation and flesh.

Reproduction  Badgers have an unusual method of reproduction. They have the ability to delay the implantation of eggs into the wall of the womb. The sow can mate at any time of the year but still keeps the birth of her cubs until the spring by holding the fertilised eggs in a suspended state within her uterus. The eggs will implant into the uterine wall and begin to develop as foetuses around the end of December. The cubs will be born two months later towards the end of February.

A sow will produce between two and five cubs which are born blind and helpless with silver hair and faint black stripes on their faces. The sow will suckle the cubs until they are approximately three to four months old when she will wean them onto regurgitated solid food. By four months (July) they are feeding themselves. Hot dry summers cause the death of many young cubs through starvation. It is estimated that approximately 60% of cubs die in their first year (English Nature and Mammal Society 1990 figures).

Diet  Badgers are carnivores, enjoying a varied diet of both plant material and meat. Since they are not built for speed they do not hunt or chase their prey, but eat whatever they can find. Earthworms form a major part of their diet, estimated at about 50% of their food. In good weather conditions (still, wet summer nights) badgers may consume about 200 earthworms a night. In these circumstances they may not need to drink a great amount as earthworms are full of water.

In adverse weather conditions such as frost, snow and drought badgers will not find enough worms and will need to find alternative sources of food. The range of alternatives varies according to the time of year. In a hot dry summer they may dig up lawns looking for cranefly larvae (leatherjackets) which often brings them into conflict with gardeners. In the autumn they will supplement their diet with fruit and fungi.

In the winter they may feed on plant roots beech nuts, acorns and carrion. In the spring they may find bird’s eggs, injured or dead baby birds, bulbs and larvae. In the summer they are known to dig out wasp nests, rabbits and rat nests and also feed on cereals. The amount of cereals eaten by badger is minimal but they do upset some farmers by trampling through their crops.

Badger Deaths  It has been conservatively estimated that there is about a 40% mortality rate of adult badgers each year. About 20% die on the roads, 17% die of natural causes and 3% die from direct persecution (about 7,500) through badger digging and baiting. Other than man, badgers do not have any natural predators.

Other causes of death besides old age are:

  1. Injuries - although the injury itself may not be fatal, it may become infected, turn septic and result in death due to weakness or starvation caused by an inability to feed.
  2. Broken/bad teeth - causing starvation.
  3. Disease - TB, mange and lungworm infection. These are relatively uncommon.
  4. Infanticide - female badgers sometimes kill another female’s cubs.
  5. Climate Influence - bad weather and drought may cause food shortages resulting in starvation.

Human influence has a devastating effect on badger populations. For a long time people ‘controlled’ badgers by snaring, trapping, digging and baiting. Unfortunately digging and baiting still occur in certain parts of the country.

Road traffic kills account for the death of a very large number of badgers annually (estimated to be in excess of 40,000). This is particularly evident on new main roads and motorway developments which cut across established badger paths. Badger populations are also reduced by loss of suitable habitat and sett destruction as a result of housing and industrial developments and changes in farming practices.