All you need to know about badger setts

Badger Setts

During a trip to the forest, we came across a badger sett. Finding this interesting, we wanted to find out more. This is what I found out:

Badgers in Britain

Badgers have lived in Britain for over 25,000 years. There are around a quarter of a million badgers in the UK, distributed unevenly across the country. Persecution and changing land use has meant that they are fading out in some areas. (1)

How do badgers live? – Setts

                                                                    (3)

Badgers tend to live in groups of 14 adults or less. (1) Badgers live underground in a home called a sett. These are typically found towards the centre of their territory. Setts are usually found in or near small clearings in woodlands or copses. Around 80% are found in woodlands or hedgerows, where the trees and roots can provide the badgers with some form of protection. Setts can usually be spotted if you are looking for them as the ground around the entrance to the sett usually does not have vegetation, it may also be muddy and show evidence of badger prints. Sometimes, latrines (holes in the ground) can be seen nearby, into which badgers poo. A simple sett is made up of one tunnel with a sleeping chamber at the end. Most setts have lots of different entrances that link up with each other. The tunnels link up with sleeping chambers and nursery chambers. Setts have several interlinking passages underground. Most setts are arranged so that they have a constant supply of fresh air in most weathers. Entrances are sometimes on different levels in order to help stale air rise through the set and be released into the surrounding area. The entrances to setts are larger than those of rabbit holes and have large piles of earth outside. A very large sett can have 50 to 100 entrance holes. These setts will have been dug out by many badgers over many years. (2)

Badgers have powerful front claws, being around 25mm long, which they use to dig their setts. Badgers tend to dig setts where there is soft ground to dig, for example, sandy soil, chalk and broken limestone. Badgers do not like digging setts in clay as clay is wet and sticky. This does not mean to say that you will not find badger setts in clay areas, as badgers will dig their setts here if they cannot find anywhere else. Badgers also like to dig on slopes, such as a hill or a bank. This is because water drains away better on a slope, so the sett stays dry. (2)

Badgers do not only dig setts in woodlands and hedgerows but also in open fields, moorlands, sand dunes, old quarries, abandoned mine workings and sea cliffs. (2)

Nesting chambers

                                                                    (4)

Nesting chambers provide a cool place to sleep during the summer. They also provide constant temperatures in the winter. Badgers fill nesting chambers with bedding materials to keep them insulated and off the wet soil, and also to stop draught getting in. Nesting chambers are often found at the end of tunnels, well away from the entrances, but also at a widening in the tunnel. It is thought that nesting chambers used by nursing sows only have a single entrance to the chamber so the sow can defend the cubs from predators by guarding the entrance. (2)

Nesting chambers can be as small as 600mm in diameter. Compact nesting chambers like this will help badgers to stay warm. This is important in the winter, where there is little food and the badgers are living off reserves of fat. (2)

There is usually a rotation of chambers used in setts. Badgers rotate chambers to ensure that chambers have time to recover and freshen up and so that parasites that drop off badgers into the bedding have time to die before the badgers return to the bedding. (2)

Sett types

The UK has the following sett types:

·         Main setts

·         Annex setts

·         Subsidiary setts

·         Outlying setts (2)

Main setts

Usually have a large number of entrances with spoil heaps. They usually have well used paths to and from the sett and between the entrances. The breeding sett is usually in continuous use, although it has sometimes become disused due to excessive digging or other reasons, in which case the sett becomes a disused main sett. (2)

Annex setts

Annex setts are usually found close to main setts. They are around 150m away and are usually connected to the main sett by one or more worn paths. They entail several holes, but are not always in use all of the time, even whilst the main sett is active. (2)

Subsidiary setts

Often only contain a few holes. They are usually at least 50m away from the main sett. They do not have an obvious path connecting them to another sett and they are not continuously active. (2)

Outlying setts

Usually only have one or two holes, with a little spoil outside the hole. They do not have any obvious paths connecting them to another sett. They are only used intermittently. When they are not in use by badgers, they are often taken over by foxes or rabbits. However, they can still be recognised as badger setts due to the tunnel being 250-300mm wide at the base with a rounder/flattened oval roof. (2)

Note on classifying setts

Classification might be difficult in the field. In areas containing few badgers, main setts may be small, with only a few entrance holes. Many badger social groups do not have annex setts. In a poor badger habitat, there may not be a main sett. These factors must be taken into account when classifying setts. (2)

By Lauren Watmough

     (1)    http://www.wildlifetrust.org.uk/facts/badgers.htm

     (2)    http://badgerland.co.uk/animals/sett.html  

     (3)    http://bedfordshirewild.blogspot.co.uk/2010/04/beauty-parade.html

     (4)    http://news.bbc.co.uk/1/hi/sci/tech/7242930.stm