Badger

Eurasian Badger – Give a Flying Brock

Eurasian Badger – Meles meles

The Eurasian or European Badger is one of seven badger species which forms part of the larger Mustelidae family. Badgers are predominantly nocturnal creatures due to the activity of prey items.

Badgers live in underground burrows called setts, which form a network of tunnels and chambers. They dig out soil from the setts using powerful forepaws and often form small, social family groups including boars (males), sows (females) and cubs headed by a dominant pair.

They can be found in all sorts of habitats including woods, copses, scrub, hedgerows, quarries, moorland, open fields, and even urban gardens and cemeteries. They do particularly well in mosaic habitats with woodland, pasture and arable land favoured habitats. Preference is for setts to be in well-drained (sandy) soils found in hilly terrain, or bank sides, but clay soils are also used.

Protected Status

Due to years of persecution of badgers for sport or perceived threats to crops and livestock, badgers have protection through the Protection of Badgers Act (1992). This makes it illegal to:

• intentionally capture, injure or kill a badger;

• block access, damage or destroy their setts;

• disturb badgers in setts;

• treat a badger cruelly;

• deliberately send or intentionally allow a dog into a sett;

• bait or dig for badgers;

• have or sell a badger or badger parts (dead or alive); and

• mark or attach a device to a badger.

Identification

Foraging_badgersBadgers are medium-sized stocky animals with a body of between 68-80cm, a height of up to 30cm and a tail of 12-17cm. They are predominantly grey, with black legs and chest, and a distinct black and white striped face with a long narrow face and nose. The legs are short and powerful, particularly the forepaws, and tipped with un-retractable claws. Males and females can be difficult to distinguish unless suckling young, but males may tend to be slightly larger with a broader head and a longer, thinner, whiter tail than females.

Life History

Depending on the productivity of the surrounding habitat, badgers can form large, family social groups (called clans), but typically are of 4-5 individuals, which inhabit a network of underground tunnels and chambers called setts. These can be hundreds of years old, maintained and expanded by generations of badgers.

Mating occurs during all times of the year, but due to delayed implantation, they only give birth in winter months such as January and February. Life expectancy for badgers is 5-7 years, although individuals of 12-13 years have been recorded.

Setts

There are four types of commonly recognised setts used by a clan:

Badger Survey CarmarthenshireThe main sett is generally quite extensive with multiple entrances, identified through large spoil heaps which accumulate outside, well-used paths spreading out from the sett and connecting to other setts. This sett is always in use, and there is only one per social group.

An annexe sett is located close to the main sett, may have multiple entrances, spoil heaps and worn paths leading to the main sett, but is not always in use. They may be used by young and sub-dominant sows to rear their own young in safety.

Subsidiary setts are further from the main sett, again they may have multiple entrances, but are not connected by paths to other sets, and not always in use.

Outlier setts are usually simple tunnels with one, occasionally two entrances, no paths, and has sporadic use as a bolt hole, temporary resting place, or a place to forage for worms and insects.

When not foraging, badgers spend considerable amounts of time collecting bedding material – dry, insulating material such as straw (a favourite), or hay and grasses to help keep them warm in the den. These can also have fresh leaves mixed in which will release heat over time as they degrade. Bedding can be re-used, being rolled to the surface to air and dry, before being rolled back down.

During the winter months when most food sources are scarce, they dramatically reduce their activity to conserve energy and may enter torpor, but they do not undergo true hibernation.

Territory

Territories (formed by a clan) can range from 40-180 ha, although non-gregarious individuals will have smaller territories. These are thought to be marked by latrines along territory boundaries, which are often also natural boundaries such as hedgerows and fences. Latrines are used by all members of the clan, particularly the dominant male, who defecate into pits and scented from the subcaudal gland. Boundaries are also regularly patrolled by the dominant male during the breeding season and may play a part in communicating breeding status between individuals of different territories. Boundaries can be aggressively defended against other individuals or groups.

Breeding

Badgers will mate in every month of the year, but particularly from February (peak month) onwards, after the cubs have been born. However, cubs are always born during the winter months, with February being the peak birthing period. This occurs due to delayed implantation, whereby the embryo is not implanted in the uterus wall until December. This allows maximum chances of females becoming pregnant due to multiple mating events, but also to give birth to cubs at the optimal times of the year. Young are suckled underground for approximately eight months, during the low productivity period, and then start to emerge from the sett in April and May when food is more plentiful. This also gives them as long as possible to feed and put on weight before the next winter, increasing survival rates, and allowing reproduction to occur during their first year. Litter sizes can range from 1-5 cubs, but most are just 2 or 3 cubs.

Badgers have been observed to display alloparental behaviour, this is where related individuals assist in the upbringing of a sows cubs. This allows the mother sow increased foraging opportunities during the suckling period when her reserves are lowest. This increases the chances of cub survival and allows female “sitters” to gain experience before they rear their own young.

Feeding

Badgers are foragers and opportunistic omnivores, exploiting a range of resources, especially in times of low productivity. Generally, they will feed alone, although they may be in close proximity to others, or may visit the same areas, but at different times during the night.

The most important component of a badgers diet in the UK is earthworms (Lumbricus terrestris), of which they can consume voraciously (+200 on a good night), and this is what drives their predominantly nocturnal behaviour. This diet allows them to obtain most of their water from the worms. Worming is easiest in short grass, hence the attraction to well kept, mown lawns (too proud gardeners or golfers dismay). Ploughed soil can make worms more accessible, but pasture has a higher density of worms. Woodland can provide sheltered foraging during poorer weather conditions.

Aside from earthworms, badgers feed on other insects, fruits and cereals, but when the opportunity arises, they will also consume small mammals, reptiles and birds. Overall, earthworms make up the largest portion of a badgers diet, but consumption of different food items changes seasonally based on availability.

  • In spring, earthworms makeup between 40-50% of a badger’s diet, followed by insects (~25%) and then cereals, mammals and birds (~10% each).
  • In summer, cereals, earthworms and insects each makeup ~25% of badgers diet, followed by small mammals and birds (~10% each), topped up by a few early fruits.
  • In autumn, the diet changes to fruits, earthworms and cereals each making up ~25%, and the remainder comprising insects, small mammals and birds.
  • During winter, earthworms makeup just under half of the diet, followed by other insects (~25%), while fruits, birds, cereals and small mammals make up between 5-10% each.

Some items known to be consumed by badgers includes bank vole, field vole, mice, rats, moles, shrews, hedgehogs, rabbits, cockchafer beetles (larvae and adults), dung beetles, daddy-long-legs, crane flies, wasp nest grubs, birds and bird eggs, frogs, toads, slugs, snails, oats, wheat, blackberries, yew berries, strawberries, apples, pears, plumbs, acorns, pig-nuts and fungi.

Field Signs

Sett entrances are not always easy to positively identify, as rabbits can excavate large burrows if the soil is soft enough. However, they are likely to quickly constrict to a size too small for a badger to fit through. Badger holes are typically wider than they are high, with a smoothly arched top mimicking the shape of their backs. The entrance often dips down and then up (for drainage purposes) and can have a sharp right or left turn within an arm’s length of the entrance.

Spoil heaps are piles of excavated soil, bedding, faeces accumulated through the winter, and other debris outside of a sett entrance. These are one of the best-identifying features with fresh heaps indicating current occupation. However, there can be some confusion in soft soils where badger and rabbits excavations create similar mounds of ejected soil. However, badgers are able to excavate large rocks beyond the ability of rabbits, and in firmer soils, clumps of the earth may bare claw marks.

Elder trees can also be used to help locate setts and they may often be found in the disturbed soils around a sett where the berries eaten by badgers and passed out in latrines near the sett or ejected from the site during excavations.

Stinkhorn fungus has been noted to regularly be present in the areas around setts (usually within 40m) and may help indicate and locate the presence of setts in the nearby area.

Badger Survey MonmouthDay nests do not seem commonly used as they are particularly prone to disturbance and poor weather. These are above ground resting places made up of grasses, hay, straw and other vegetation. They are most frequently found in remote areas of low disturbance used temporarily by one or a few individuals.

Latrines can be used to identify the presence of badger in the area and their territorial boundaries. These are shallow dug pits into which the badgers defecate. They can be found near setts, along with territory boundaries, and around feeding areas. Faeces not deposited in latrines may indicate the presence of young badgers.

Droppings can be variable due to badgers varied diet, but are often loose, smooth and watery because of their earthworm-based diet.

Footprints are another relatively easy identification method when found clearly imprinted in mud – the wedge-shaped pad with five toes and claws in front as opposed to spreading around the pad.

Footpaths are creBadger Snuffle Holeated along regular routes. Badgers are creatures of habit, foraging in the same patches of woodland and pasture, and following the same routes. This can result in a noticeable pathway being visible through vegetation, or smoothness to the ground. If the footpath leads to a likely sett entrance, or footprints are present, this can help confirm the trail was formed by badgers as opposed to walkers or other animals.

Scratching trees are usually found close to sett entrances. Whether for sharpening their claws or simply to stretch after periods sent underground, they leave vertical claw marks in the bark of trees which may reach to the ground.

Snuffle holes are left by badgers hunting out insects under the surface, having clawed out a lump of the earth to get to them and stuck their nose into them to use their sensitive noses. These leave shallow circular holes and may be the bane of owners with otherwise well-manicured lawns.

Threats

As previously mentioned, badgers were historically persecuted for a number of barbaric activities, usually resulting in the death of the badger as well as dogs, resulting in the creation of their own protection act. While these activities and any form of harm or disturbance to badgers and their setts are illegal, they are still known to occur.

Careless development has also resulted in the destruction of setts and even burying badgers alive, but again, measures have been put in place to minimise negative impacts through these activities.

These days the main factor affecting badger is road fatalities which are highest in February and March when they start to become more active and are moving about at the same time as cars are on the roads. Railway lines are also a cause of a number of badger deaths annually.

It is unclear as to the number of badgers that die from bovine tuberculosis (BT), and even though the transmission of BT to cattle has not been conclusively proven, badger culling programs have been implemented in an attempt to reduce BT levels in cattle.

Badgers are sensitive creatures and can be easily disturbed through damaging or destroying their setts, excessive noise, lighting and vibrations caused by pile driving and quarry blasting, the lighting of fires, use of chemicals, excavation and tree felling. This may result in them abandoning a sett.

A summary of the badger year is shown in the diagram below:

Badger Year


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