Wild Boar (Sus scrofa): Facts, Diet, Habitat and Behavior

Appearance

A wild boar looks like a hairy, front-heavy pig. The head is large and wedge-shaped, taking up as much as a third of the body length, with small, deep-set eyes, upright ears and a long snout that ends in a flat, mobile disc. The neck is short and thick, the shoulders are high and the hindquarters are comparatively narrow, the reverse of a farm pig’s build.

The coat is made of stiff bristles over a soft, woolly underfur in winter. Most adults are dark gray-brown to almost black, but color varies across the range, from pale sandy animals in Central Asia to very dark boar in eastern Europe. Males grow a mane of long bristles along the back that stands up when they are agitated.

Piglets look completely different. They are light brown with cream stripes running along the body, a pattern that camouflages them in dappled forest light. The stripes fade at about three to four months, and young boar are reddish brown until they take on adult colors.

The tusks are enlarged canine teeth. In males the lower canines grow throughout life and curve upward out of the mouth, with an exposed part that can reach about 10–12 cm (4–5 in). Females have much smaller canines that rarely show.

How big do wild boar get?

Size depends heavily on food and climate. In most of Europe adult males average about 75–100 kg (165–220 lb) and females 60–80 kg (130–175 lb). Boar in dry Mediterranean areas are smaller, while those in productive eastern European forests are larger. The heaviest males in western and central Europe reach about 200 kg (440 lb).

The biggest wild boar live in the Russian Far East and northeastern China, where very large males have been recorded at around 270–300 kg (600–660 lb) or more. Such giants are rare today. Males are usually 20–30% heavier than females of the same population.

Habitat and range

The wild boar’s natural range stretches from Britain, Iberia and North Africa across Europe and Asia to Japan, Korea and the islands of Indonesia. It lives in many habitats, from northern taiga to semi-desert and mountains, but does best in broadleaf and mixed forests, especially oak and beech woods mixed with marshes, meadows and farmland. It needs three things: dense cover, water for drinking and wallowing, and winters without long periods of deep snow.

Hunting wiped boar out of large parts of their range by the early 20th century, including Britain, Denmark and much of Germany. Since the mid-1900s numbers in Europe have climbed sharply, helped by milder winters, more maize and other crops, and few large predators. Boar now live in the suburbs of cities such as Berlin, Barcelona and Rome, and they have spread back into Scandinavia. In Britain they returned in the 1990s after escapes from farms; see are there wild boar in the UK?.

People have also taken wild boar far beyond their native range. In North America, the Caribbean, South America, Australia and New Zealand, released wild boar have mixed with escaped domestic pigs. The resulting feral swine are among the most damaging invasive animals in the United States, where the US Department of Agriculture estimates there are millions of them across many states.

Diet and feeding

Wild boar are true omnivores. Most of their food comes from the ground: roots, bulbs, tubers, fungi, earthworms and insect larvae, which they reach by plowing the soil with their snouts. In autumn, acorns, beechnuts and chestnuts are the most important food in European forests because they are rich in the energy needed to build fat for winter.

They also eat grass, leaves, fruit, seeds and crops such as maize, cereals and potatoes, plus eggs, small mammals, frogs, reptiles and carrion. A 50 kg (110 lb) boar needs roughly 4,000–4,500 kilocalories a day, more in winter and during pregnancy. For the full menu and how rooting changes the soil, see what do wild boar eat?.

Their sense of smell is excellent and they can find food buried deep in the soil or under snow. Their eyesight is comparatively poor.

Behavior and social life

The basic unit of wild boar society is the sounder, a group of related females and their young led by an experienced older sow. Sounders usually number from a handful to about 20 animals, though several families may join up in good feeding areas. Young males leave or are driven out at around 8–15 months and may roam in loose bachelor groups. Adult males are mostly solitary outside the breeding season.

Wild boar are naturally active by day and night, but where they are disturbed by people they become largely nocturnal, resting in dense cover during the day. They make nests of grass, twigs and leaves to rest in, and they love to wallow in mud. Wallowing cools them down, since pigs have few working sweat glands, and the mud coating helps protect against biting insects and parasites. Afterward they often rub against “rubbing trees”, leaving mud and scent marks.

Boar communicate with a wide range of grunts, squeals and snorts. Sows grunt to keep piglets close, and a loud huffing snort signals alarm. They are also strong swimmers that readily cross rivers and lakes.

Reproduction and life cycle

In Europe the breeding season, or rut, runs mainly from November to January. Males travel long distances to find sounders and fight rivals with slashing tusk blows. To protect themselves, they develop a thick layer of tough tissue, sometimes called a shield, over the shoulders. A dominant male may mate with several sows and can lose a fifth of his body weight during the rut.

Pregnancy lasts about 114–140 days, a little under four months to just over four and a half. Before giving birth, the sow leaves the group and builds a large nest of grass and branches. Most piglets are born in spring, from March to May in Europe. A typical litter has four to six piglets, but well-fed sows can have up to 10–12.

Piglets weigh about 0.6–1 kg (1.3–2.2 lb) at birth and stay in the nest for their first week or so. They are nursed for about three months but start eating solid food within a few weeks. Females can breed at one to two years old, males usually later, because older boar keep younger ones from mating. In years with big acorn and beechnut crops, more young females breed and litters are larger, which is one reason boar numbers can jump quickly.

Lifespan

Most wild boar live short lives. Few survive beyond four or five years in the wild because of predators, disease, harsh winters, road traffic and hunting by people. The maximum recorded in the wild is about 10–14 years. In captivity wild boar have lived for around 20 years.

Predators and threats

The gray wolf is the main natural predator of wild boar across most of Europe and Asia, and in some regions boar are a wolf’s most important prey. Wolves mostly take piglets and young animals, especially in deep snow. Tigers, leopards and, on a few Indonesian islands, Komodo dragons also kill boar, while lynx, bears and large birds of prey sometimes take piglets. Adult males with tusks are formidable opponents and are often avoided. Read more about the gray wolf.

Wild boar also share some disease risks with farm pigs. African swine fever, a viral disease that is harmless to people but usually fatal to pigs and boar, has spread through wild boar in parts of Europe and Asia since 2007, causing local die-offs and strict control zones.

Conservation status

The IUCN Red List classes the wild boar as Least Concern, last assessed in 2019, because of its enormous range, large numbers and adaptability. In Europe the species has become far more numerous than it was a century ago. A few island subspecies in Asia are much rarer, and several related pig species, such as the pygmy hog and some island warty pigs, are threatened.

Wild boar and people

The wild boar has shaped human history. Pigs were domesticated from wild boar more than 10,000 years ago in the Near East and separately in China, and domestic and wild animals have exchanged genes ever since. Read more about the domestic pig.

Boar appear in myths and art across Europe and Asia, from the Greek tale of the Calydonian boar to the boar in the Chinese zodiac, and the animal has long been a symbol of courage. Today, people living near boar see two sides of the animal. Rooting can damage crops, lawns and grassland, and collisions with vehicles are common in parts of Europe. At the same time, boar turn over soil, spread seeds and create patches where new plants can grow.

Attacks on people are rare and usually involve a cornered animal or a sow defending piglets. For calm advice on walking in boar country, see are wild boar dangerous?.

Myths and facts

Myth: wild boar are just escaped pigs. Wild boar are the original wild species, Sus scrofa; domestic pigs came from them, not the other way round. Feral pigs and boar-pig hybrids do exist, especially outside Europe.

Myth: boar are dirty animals. Mud wallowing is a way to stay cool and protect the skin. Boar keep their resting nests clean and do not defecate in them.

Fact: boar are surprisingly resistant to snake venom. Pigs carry a change in a nerve receptor that stops some snake neurotoxins from binding, a trait that evolved separately in mongooses, honey badgers and hedgehogs too.