Territory or Home Range
Each badger clan has its own area - called a territory or a home range. There is a lot of discussion about whether these terms have the same meaning, but they are different concepts.
Often nowadays, many people talk only about the territory of a badger group; when they in fact mean the home range.
The territory and the home range contains only one main badger sett and (possibly) one or more non-main setts, as well as a variety of places where the badgers can find regular food. The badgers have their own pathways, linking their setts and feeding areas.
It is possible that, if there is a small area of so-called super-food-abundance; this small area will form part of the home range of two different clans. This is probably because in that small area there is so much food; there is no good reason to start fighting over it.
The size of the home range will vary depending on the local habitat, food availability, landscape features and local badger density. A home range may be as small as 30 hectares in a good rural habitat, but as large as 300 hectares in a poor habitat. On average a territory may be around 50 hectares, with main setts normally at least 500 metres apart. The key exception here is in urban areas of cities/town, where territories can be as small as 5 hectares, IF they can obtain enough food from bird tables, food waste or artificial feeding in suburban gardens. In urban areas where territories can be relatively small, with isolated pockets of high food abundance; the territorial boundaries may be unclear; as most of the latrines will be close to the sett; rather than around the boundaries.
Badgers will have a clear understanding of the location of territorial boundaries. They will also be aware of the risk of crossing them, especially if they are perceived to be causing a conflict. By way of example, such conflicts could arise due to the desire to mate with females from another clan or to access scarce food supplies. Some studies have found that territorial boundaries are defended only in cases where there is a serious conflict of interest. In other words, the boundary will be defended only when conditions persist to make defending it worthwhile.
If a badger from one clan wanders into the territory of another clan, there may be trouble. If the incoming badger is discovered, a fight may break out. As badgers have very powerful jaws and sharp teeth, nasty injuries can be inflicted when they fight. A badger which gets into a fight with another badger may well end up with a wound on its rump, just above the tail. Male badgers tend to get into fights at least twice as often as females; and it is rare for cubs or yearlings to show any bite wounds on their rump. Of those badgers which have serious rump wounds; the majority will be males aged thee years old and over.
Boars (males) are more territorial than females, and mark territorial boundaries more often than females. As well as the need to mark the territory, males may also stray into neighbouring territories looking for receptive females. Accordingly, males are less likely to tolerate other males coming into their territory; as other males may be a threat, whereas other females may be an opportunity.
All this being said, several people have observed males from adjoing territories approaching a territorial boundary, becoming aware of one another, carefully assessing the situation and then walking away with no form of agression. We think the more common activity is that badgers are aware of and usually respect each others borders; and will make an aggressive response only if one is genuinely needed.
The desire of male badgers to breed means that there is a greater degree of territorial marking (and other behaviour) in the period from January to May; with a peak in the main mating season from February through to May.
Fights can also take place between members of the same clan. This usually happens when there are too many badgers in the clan, and not enough food to go round; or when badgers are trying to fight their way up the pecking order to become a dominant boar or sow. If proper fights break out, the younger animals may then be forced out the clan and have to find somewhere else to live. This may be in a small sett on the edge of the territory, or in another territory altogether.
In fact, badgers are a little unusual in having such a strong family group or clan which reigns strongly over a territory. The clan will often take pains to try and cover the key parts of the territory each night, walking on most of their regular well-worn pathways. Dominant males especially may well take the opportunity to scent mark and defecate on the boundaries which mark the edge of their territory. It is believed that the clan does this, because it collectively has the time to mark out and protect its territory. A lone badger would not have enough time to scent-mark its territory and gather and eat enough food to enable its long-term survival.
A territory can vary in size and shape, depending on many factors. These will include the availability of food, the ability to gather that food, the pressures on the territory from other badger clans, physical barriers or hardships (like wide rivers, railways, motorways and busy trunk roads). A particular territory will be sized so as to provide a large enough regular food supply for the clan. Accordingly, "good" territories, such as those with large amounts of regularly cut grassland may be relatively smaller. Territories which have a less good food supply (such as those in rough moorland or steep craggy mountainside areas), may be much larger in relative terms.
In an area which provides a very poor habitat, the territory may be as large as 300 hectares.
In areas where there is a high badger density, they will sleep in the main sett for at least 90% of the days. However, in areas where food is relatively scarce, badgers will need a larger territory in which to find enough to eat. In those cases, badgers may have very large territories; and may move from sett to sett from one night to another.
Although badgers can and do climb, they can be deterred by the presence of large barriers. For this reason, it is often the case that badger territorial boundaries follow dominant physical landscape features, such as walls, dense hedgerows, solid fences, busy trunk roads, railways and wide waterways. You will often find well-used badger paths which approach the boundary; and then result in marking; with examples of latrines (dung pits), scent marking/musking, scratch marks and urine. A line of latrines on both sides of a main landscape feature may be a good indicator of a territorial boundary.
In a sense, a territory is an area which "belongs" to a clan; and that area needs to contain enough food resources to supply the clan on a year round basis. However, there is a "cost" associated with travelling a longer distance from the main sett in order to find food. Therefore, a main sett is likely to be situated close to a high-quality food resource which provides food at all or most times of the year. Consequently, badgers will try to eat locally first, before travelling further distances to locate food. In territories where there are food food resources throughout, you might expect to find a so-called "food-gradient", whereby the food is eaten near the sett first and further away from the sett as a last resort.
Small territories with high badger densities, may show the same high level of badger foraging throughout most areas. Larger territories with low badger densities may sometimes show high levels of food availibility near the boundaries; as it might be too "costly" for badgers to commute to a distance part of the territory every night to eat. In those circumstances, badgers may use occasional small setts away from the main sett from time to time.
Of course, you may have instances where the available (i.e. not yet foraged) food increases as you get further away from the main sett; and is at it's highest nearest a territorial boundary. In terms of badgers and foraging, the feeding "cost" is not just the energy needed to walk to a more distant location, it is also the risk of being attacked if you progress into a neighbouring territory. Except in the cases of extreme food scarcity, it will often be both risky and energetically unviable for a badger to wander deep into a neighbouring clan's territory to go looking for food.
Because territorial use can vary from one area to another; it can be difficult to prove or disprove an area is in use by badgers or not. It can also be the case that when making short-term badger observations, you wrongly conclude that badgers are not there; whereas they have missed using that part of a territory for several days.
Bait Marking Studies
One good technique for finding out about which areas of land are used by badgers is to do a bait marking study. This is where you feed tiny harmless coloured plastic pellets to badgers at a main sett; then survey the local area to see where the coloured pellets appear in badger dung some days later. More information about how to perform a bait marking study is give in our Bait Marking PowerPoint Presentation.