BADGERS: EXCAVATORS OF THE WOODLANDS

Badgers spend most of the day out of sight – underneath a sloping hillside covered with plenty of undergrowth. Inside this hidden lair they are either resting or busy digging to improve and enlarge their chambers and passages. At dusk they are up and about, hunting, playing and searching for new bedding.

Badgers have been described as the oldest land-owners in Britain. There is little doubt that long before Britain was an island they were here rooting among the vegetation of ancient deciduous forests. They belong to the family of mammals that have musk-bearing scent glands under their tails: these are chiefly carnivorous and include the otter, polecat, stoat, weasel and pine marten.

Many millions of years ago the earliest forms of this family group were rather simple land-dwellers, but they have gradually become adapted to their different ways of life and habitats. Thus the otter has become an accomplished swimmer and the pine marten a trapeze artist; the polecat, stoat and weasel are streamlined for speed and the badger has become a skilful excavator.

You can tell from its appearance that the badger is a digger. Its body is wedge-shaped and carried rather low on the ground on short but immensely strong legs — excellent for working in confined spaces. The muscles of the forelimbs and neck are particularly well developed and the five claws on each foot are long, especially those on the front ones.

The badger’s digging activity is geared to enlarging and improving its home: a large underground burrow system called a sett, which consists of several sizeable chambers where the badger sleeps and breeds and a few smaller ones which sometimes serve as latrines. These chambers are linked by a complex network of tunnels.

When enlarging one of its tunnels a badger will loosen the earth with rapid strokes of its forelimbs, using its claws as rakes and for winkling out stones. The loose earth collects under its body, but by arching its back it is able to bring its hind limbs forewards to sweep the earth backwards. When enough soil has collected behind it, it moves backwards in a series of jerks, partly using its bottom as a bulldozer and partly hugging the soil between its forelegs and body. If you stand by an exit hole when a badger is digging you may be showered with earth and stones as it emerges backwards and gives a few last vigorous kicks before returning for another load.

As well as a home improver, the badger is also a tidy housekeeper and will spend a lot of time transporting grass, straw, moss or bracken to and from its sleeping chamber. Setts are handed down like family houses, from generation to generation, and the badger uses the same sett year after year. So regular airing of the bedding is vital as a safeguard against parasites (the scourge of all animals living a settled existence) and to prevent damp, cold conditions — especially harmful to young cubs.

Locating the sett

A mild day in early spring is a good time to start looking for a badger community, although it is very unlikely that you will see a badger itself in broad daylight. Woods, copses and hedgerows are the most usual locations for setts, especially if these are on slopes bordering pastures. Here the badger can make its home where there is adequate cover and plenty of food in the vicinity.

Alders are often associated with badger setts, so look for patches of these trees. Elders will also grow near setts because badgers eat the berries and pass the seeds unharmed through their guts before depositing them in the droppings near their sett. Here the seeds will germinate and eventually become bushes or trees.

A well-established sett is unmistakeable. It will normally have anything from three to 10 entrances and a few have been found with more than 50. These entrances and exits are at least 25cm (10in) wide, much larger than rabbit holes. Outside each entrance is a large pile of earth which includes dried plant material such as hay or straw. This is old bedding which has been discarded. You will usually see a latrine close to an entrance, too. Near a main entrance you may see a tree, often an elder, with mud marks and scratches on it up to a height of about one metre. If you watch at dusk you may see a badger approach such a tree, raise itself on its hind legs, reach up with its forepaws and slowly drag these down the bark. Zoologists still don’t know if the badger is merely stretching its limbs or perhaps marking a territory with its own particular scent.

Well-worn paths lead from the sett in various directions, joining one entrance to another and also leading off to different parts of the badgers’ territory. It is interesting to map this system of paths, which alters little from year to year. Although visible to us these paths are really scent trails, since all the badgers using them mark them periodically with their own scent. Unfortunately some of these paths, which have been used by badgers for generations, are now crossed by roads and many badgers are run over by passing traffic.

Signs of foraging

Look out for signs near the sett where the badgers have been foraging. You may see dead leaves disturbed where badgers have been rooting or shallow pits dug when they have been seeking out some beetle or earthworm. The corms (underground stems) of lords-and-ladies are favourites at this time of year; badgers bite off the poisonous yellow shoots and eat the succulent underground corms.

But what goes on in the depths of a sett?

A large, well-established sett in the Cotswolds which was given a thorough survey had 12 exit holes and a maze of tunnels and chambers totalling 310m (1000ft). From the length and diameter of the tunnels it was estimated that over the years the badgers had excavated 25 tonnes of soil.

Birth of the cubs

If you notice a spurt of digging activity in late December or in January and, if the weather is dry, some fresh grass or bracken dropped near an entrance. You can be fairly certain that the birth of cubs is imminent and the breeding chamber is likely to be quite near that hole.

Bedding is also of great importance for the survival of the cubs as a chamber full of hay. Straw and bracken will act as an insulator. Helping the cubs conserve their body heat. For the first few weeks after birth they lie in this cosy nest and are suckled when the sow (female) returns from foraging trips.

The gathering of bedding is an interesting manoeuvre. The badger collects up bundles of dry vegetation, scraping the pieces together with its claws and biting off tough stalks with its teeth. Hugging each bundle in turn to its chest and using its chin and forelegs to keep it in place, it shuffles backwards towards the sett, eventually disappearing down the tunnel tail first. Usually cubs are born during the first fortnight in February in the south and west, rather later as you go north. They are covered in grey silky hairs and already the dark facial stripes are visible. They are about 12cm (5in) long and weigh about l00g (3-1/2oz). Their eyes are closed for about five weeks, but before long they are ready to explore the tunnels.

Mating period

The first three months of the year are a busy and exciting time for the badger community. Soon after the birth of the cubs, most sows become ready to mate again and yearling females may come ‘on heat’ for the first time at this season. So mating can be a conspicuous feature to watch out for at this time of year.

The dominant boar (male) usually copies a part of the sett well away from where the sow has her cubs; and she will drive him off if he attempts to approach her litter. The boar’s behaviour at this time is largely concerned with mating, territorial defence and feeding. On some evenings he will emerge early and visit the various sett entrances, sniffing and making a deep whinnying purr. If a sow emerges and is on heat he will mate with her. Mating can last half an hour and may be repeated over several nights.

At other times the boar may quickly leave the sett and follow one of the main tracks to the limit of territory owned by his social group. Here he will scent-mark the boundary with droppings, using latrines strategically placed to warn off intruders. He may also patrol the perimeter of the territory and if necessary fight with any trespassing badger.

Meanwhile the sow makes short foraging excursions nearer to home to find food for herself and to build herself up for suckling the cubs. On wet nights, earthworms will be the main source of food, but many other creatures will be taken including the occasional dead bird and any early litter of young rabbits she smells and digs out.

The cubs are weaned in summer and start to venture above ground to feed and play— so summer is a good time to watch badgers.

15. November 2011 by admin
Categories: Ecology/Habitat, General Info, Uncategorized | Tags: , , , , , , , , , , , | Comments Off on BADGERS: EXCAVATORS OF THE WOODLANDS

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