Wild boar

Wild boar
General information
Universe	Real Life
Aliases	Common names: Boar Hog Wild pig Common wild pig Eurasian wild pig Wild swine Wild hog Hunting terminology: Squeaker (0-10 months old) Juvenile (10-12 months old) Pig of the sounder (2 years old) Boar of the 4th-5th year (4-5 years old) Old boar (6 years) Grand old boar (7+ years) Solitary boar (unknown)
Classification	Sus scrofa
Species type	Pig
Homeworld	Earth
Environment	Plains
Intelligence	Non-sapient
Biochemistry	Carbon-based
Biological information
Lifespan	Wild: 10-14 years Captivity: 20 years
Reproduction	Sexual, viviparous
Average height	♂: 75–80 cm (30–31 in) at shoulder ♀: 70 cm (28 in) at shoulder
Average weight	♂: 75–100 kg (165–220 lb) ♀: 60–80 kg (130–180 lb)
Average length	♂: 150 cm (59 in) ♀: 140 cm (55 in)
Locomotion	Quadrupedal
Feeding behavior	Omnivorous
Prey	See below
Predators	See below
Lineage information
Descendant(s)	Domestic pig
Related species	Palawan bearded pig Bornean bearded pig Visayan warty pig Oliver's warty pig Philippine warty pig Javan warty pig
Cultural information
Sociocultral characteristics
Scientific taxonomy
Planet	Earth
Domain	Eukaryota
Kingdom	Animalia
Subkingdom	Bilateria
Infrakingdom	Deuterostomia
Phylum	Chordata
Subphylum	Vertebrata
Infraphylum	Gnathostomata
Superclass	Tetrapoda
Class	Mammalia
Subclass	Theria
Infraclass	Placentalia
Superorder	Laurasiatheria
Order	Artiodactyla
Suborder	Suina
Family	Suidae
Subfamily	Suinae
Tribe	Suini
Genus	Sus
Species	S. scrofa
Other information
Status	Least Concern
Creator	God (debated)

The wild boar (Sus scrofa), often shortened to just "boar" is the most well-known wild pig alive today.

Description

The wild boar is a bulky, massively built suid with short and relatively thin legs. The trunk is short and robust, while the hindquarters are comparatively underdeveloped. The region behind the shoulder blades rises into a hump and the neck is short and thick to the point of being nearly immobile. The animal's head is very large, taking up to one-third of the body's entire length. The structure of the head is well suited for digging. The head acts as a plough, while the powerful neck muscles allow the animal to upturn considerable amounts of soil: it is capable of digging 8–10 cm (3.1–3.9 in) into frozen ground and can upturn rocks weighing 40–50 kg (88–110 lb). The eyes are small and deep-set and the ears long and broad. The species has well developed canine teeth, which protrude from the mouths of adult males. The medial hooves are larger and more elongated than the lateral ones and are capable of quick movements. The animal can run at a maximum speed of 40 km/h (25 mph) and jump at a height of 140–150 cm (55–59 in).

Sexual dimorphism is very pronounced in the species, with males being typically 5–10% larger and 20–30% heavier than females. Males also sport a mane running down the back, which is particularly apparent during autumn and winter. The canine teeth are also much more prominent in males and grow throughout life. The upper canines are relatively short and grow sideways early in life, though they gradually curve upwards. The lower canines are much sharper and longer, with the exposed parts measuring 10–12 cm (3.9–4.7 in) in length. In the breeding period, males develop a coating of subcutaneous tissue, which may be 2–3 cm (0.79–1.18 in) thick, extending from the shoulder blades to the rump, thus protecting vital organs during fights. Males sport a roughly egg-sized sack near the opening of the penis, which collects urine and emits a sharp odour. The function of this sack is not fully understood.

Adult size and weight is largely determined by environmental factors; boars living in arid areas with little productivity tend to attain smaller sizes than their counterparts inhabiting areas with abundant food and water. In most of Europe, males average 75–100 kg (165–220 lb) in weight, 75–80 cm (30–31 in) in shoulder height and 150 cm (59 in) in body length, whereas females average 60–80 kg (130–180 lb) in weight, 70 cm (28 in) in shoulder height and 140 cm (55 in) in body length. In Europe's Mediterranean regions, males may reach average weights as low as 50 kg (110 lb) and females 45 kg (99 lb), with shoulder heights of 63–65 cm (25–26 in). In the more productive areas of Eastern Europe, males average 110–130 kg (240–290 lb) in weight, 95 cm (37 in) in shoulder height and 160 cm (63 in) in body length, while females weigh 95 kg (209 lb), reach 85–90 cm (33–35 in) in shoulder height, and reach 145 cm (57 in) in body length. In Western and Central Europe, the largest males weigh 200 kg (440 lb) and females 120 kg (260 lb). In Northeastern Asia, large males can reach brown bear-like sizes, weighing 270 kg (600 lb) and measuring 110–118 cm (43–46 in) in shoulder height. Some adult males in Ussuriland and Manchuria have been recorded to weigh 300–350 kg (660–770 lb) and measure 125 cm (49 in) in shoulder height. Adults of this size are generally immune from wolf predation. Such giants are rare in modern times, due to past overhunting preventing animals from attaining their full growth.

The winter coat consists of long, coarse bristles underlaid with short brown downy fur. The length of these bristles varies along the body, with the shortest being around the face and limbs and the longest running along the back. These back bristles form the aforementioned mane prominent in males and stand erect when the animal is agitated. Colour is highly variable; specimens around Lake Balkhash are very lightly coloured, and can even be white, while some boars from Belarus and Ussuriland can be black. Some subspecies sport a light-coloured patch running backward from the corners of the mouth. Coat colour also varies with age, with piglets having light brown or rusty-brown fur with pale bands extending from the flanks and back.

The wild boar produces a number of different sounds which are divided into three categories:

• Contact calls: Grunting noises which differ in intensity according to the situation. Adult males are usually silent, while females frequently grunt and piglets whine. When feeding, boars express their contentment through purring. Studies have shown that piglets imitate the sounds of their mother, thus different litters may have unique vocalisations.
• Alarm calls: Warning cries emitted in response to threats. When frightened, boars make loud huffing ukh! ukh! sounds or emit screeches transcribed as gu-gu-gu.
• Combat calls: High-pitched, piercing cries.

Its sense of smell is very well developed to the point that the animal is used for drug detection in Germany. Its hearing is also acute, though its eyesight is comparatively weak, lacking color vision and being unable to recognise a standing human 10–15 metres (33–49 ft) away.

Pigs are one of four known mammalian taxa which possess mutations in the nicotinic acetylcholine receptor that protect against snake venom. Mongooses, honey badgers, hedgehogs, and pigs all have modifications to the receptor pocket which prevents the snake venom α-neurotoxin from binding. These represent four separate, independent mutations.

Social behavior and life cycle

Boars are typically social animals, living in female-dominated sounders consisting of barren sows and mothers with young led by an old matriarch. Male boars leave their sounder at the age of 8–15 months, while females either remain with their mothers or establish new territories nearby. Subadult males may live in loosely knit groups, while adult and elderly males tend to be solitary outside the breeding season.

The breeding period in most areas lasts from November to January, though most mating only lasts a month and a half. Prior to mating, the males develop their subcutaneous armour in preparation for confronting rivals. The testicles double in size and the glands secrete a foamy yellowish liquid. Once ready to reproduce, males travel long distances in search of a sounder of sows, eating little on the way. Once a sounder has been located, the male drives off all young animals and persistently chases the sows. At this point, the male fiercely fights potential rivals. A single male can mate with 5–10 sows. By the end of the rut, males are often badly mauled and have lost 20% of their body weight, with bite-induced injuries to the penis being common. The gestation period varies according to the age of the expecting mother. For first-time breeders, it lasts 114–130 days, while it lasts 133–140 days in older sows. Farrowing occurs between March and May, with litter sizes depending on the age and nutrition of the mother. The average litter consists of 4–6 piglets, with the maximum being 10–12. The piglets are whelped in a nest constructed from twigs, grasses and leaves. Should the mother die prematurely, the piglets are adopted by the other sows in the sounder.

Newborn piglets weigh around 600–1,000 grams, lacking underfur and bearing a single milk incisor and canine on each half of the jaw. There is intense competition between the piglets over the most milk-rich nipples, as the best-fed young grow faster and have stronger constitutions. The piglets do not leave the lair for their first week of life. Should the mother be absent, the piglets lie closely pressed to each other. By two weeks of age, the piglets begin accompanying their mother on her journeys. Should danger be detected, the piglets take cover or stand immobile, relying on their camouflage to keep them hidden. The neonatal coat fades after three months, with adult colouration being attained at eight months. Although the lactation period lasts 2.5–3.5 months, the piglets begin displaying adult feeding behaviours at the age of 2–3 weeks. The permanent dentition is fully formed by 1–2 years. With the exception of the canines in males, the teeth stop growing during the middle of the fourth year. The canines in old males continue to grow throughout their lives, curving strongly as they age. Sows attain sexual maturity at the age of one year, with males attaining it a year later. However, estrus usually first occurs after two years in sows, while males begin participating in the rut after 4–5 years, as they are not permitted to mate by the older males. The maximum lifespan in the wild is 10–14 years, though few specimens survive past 4–5 years. Boars in captivity have lived for 20 years.

Behavior and ecology

Habitat and sheltering

The wild boar inhabits a diverse array of habitats from boreal taigas to deserts. In mountainous regions, it can even occupy alpine zones, occurring up to 1,900 m (6,200 ft) in the Carpathians, 2,600 m (8,500 ft) in the Caucasus and up to 3,600–4,000 m (11,800–13,100 ft) in the mountains in Central Asia and Kazakhstan. In order to survive in a given area, wild boars require a habitat fulfilling three conditions: heavily brushed areas providing shelter from predators, water for drinking and bathing purposes and an absence of regular snowfall.

The main habitats favored by boars in Europe are deciduous and mixed forests, with the most favorable areas consisting of forest composed of oak and beech enclosing marshes and meadows. In the Białowieża Forest, the animal's primary habitat consists of well-developed broad-leaved and mixed forests, along with marshy mixed forests, with coniferous forests and undergrowths being of secondary importance. Forests made up entirely of oak groves and beeches are used only during the fruit-bearing season. This is in contrast to the Caucasian and Transcaucasian mountain areas, where boars will occupy such fruit-bearing forests year-round. In the mountainous areas of the Russian Far East, the species inhabits nutpine groves, hilly mixed forests where Mongolian oak and Korean pine are present, swampy mixed taiga and coastal oak forests. In Transbaikalia, boars are restricted to river valleys with nut pine and shrubs. Boars are regularly encountered in pistachio groves in winter in some areas of Tajikistan and Turkmenistan, while in spring they migrate to open deserts; boar have also colonized deserts in several areas they have been introduced to.

On the islands of Komodo and Rinca, the boar mostly inhabits savanna or open monsoon forests, avoiding heavily forested areas unless pursued by humans. Wild boar are known to be competent swimmers, capable of covering long distances. In 2013, one boar was reported to have completed the 11-kilometre (7 mi) swim from France to Alderney in the Channel Islands. Due to concerns about disease, it was shot and incinerated.

Wild boar rest in shelters, which contain insulating material like spruce branches and dry hay. These resting places are occupied by whole families (though males lie separately) and are often located in the vicinity of streams, in swamp forests and in tall grass or shrub thickets. Boars never defecate in their shelters and will cover themselves with soil and pine needles when irritated by insects.

Diet

The wild boar is a highly versatile omnivore, whose diversity in choice of food is comparable to that of humans. Their foods can be divided into four categories:

• Rhizomes, roots, tubers and bulbs, all of which are dug up throughout the year in the animal's whole range.
• Nuts, berries and seeds, which are consumed when ripened and are dug up from the snow when necessary.
• Leaves, bark, twigs and shoots, along with garbage.
• Earthworms, insects, mollusks, fish, rodents, insectivores, bird eggs, lizards, snakes, frogs and carrion. Most of these prey items are taken in warm periods.

A 50 kg (110 lb) boar needs around 4,000–4,500 calories of food per day, though this required amount increases during winter and pregnancy, with the majority of its diet consisting of food items dug from the ground, like underground plant material and burrowing animals. Acorns and beechnuts are invariably its most important food items in temperate zones, as they are rich in the carbohydrates necessary for the buildup of fat reserves needed to survive lean periods. In Western Europe, underground plant material favoured by boars includes bracken, willow herb, bulbs, meadow herb roots and bulbs and the bulbs of cultivated crops. Such food is favoured in early spring and summer, but may also be eaten in autumn and winter during beechnut and acorn crop failures. Should regular wild foods become scarce, boars will eat tree bark and fungi, as well as visit cultivated potato and artichoke fields. Boar soil disturbance and foraging have been shown to facilitate invasive plants. Boars of the vittatus subspecies in Ujung Kulon National Park in Java differ from most other populations by their primarily frugivorous diet, which consists of 50 different fruit species, especially figs, thus making them important seed dispersers. The wild boar can consume numerous genera of poisonous plants without ill effect, including Aconitum, Anemone, Calla, Caltha, Ferula and Pteridium.

Boars may occasionally prey on small vertebrates like newborn deer fawns, leporids and galliform chicks. Boars inhabiting the Volga Delta and near some lakes and rivers of Kazakhstan have been recorded to feed extensively on fish like carp and Caspian roach. Boars in the former area will also feed on cormorant and heron chicks, bivalved molluscs, trapped muskrats and mice. There is at least one record of a boar killing and eating a bonnet macaque in southern India's Bandipur National Park, though this may have been a case of intraguild predation, brought on by interspecific competition for human handouts. There is also at least one recorded case of a group of wild boar attacking, killing, and eating an adult, healthy female axis deer (Axis axis) as a pack.

Predators

Piglets are vulnerable to attack from medium-sized felids like Eurasian lynx (Lynx lynx), jungle cats (Felis chaus), and snow leopards (Panthera uncia), as well as other carnivorans like brown bears (Ursus arctos) and yellow-throated martens (Martes flavigula).

The grey wolf (Canis lupus) is the main predator of wild boar throughout most of its range. A single wolf can kill around 50 to 80 boars of differing ages in one year. In Italy and Belarus' Belovezhskaya Pushcha National Park, boars are the wolf's primary prey, despite an abundance of alternative, less powerful ungulates. Wolves are particularly threatening during the winter, when deep snow impedes the boars' movements. In the Baltic regions, heavy snowfall can allow wolves to eliminate boars from an area almost completely. Wolves primarily target piglets and subadults and only rarely attack adult sows. Adult males are usually avoided entirely. Dholes (Cuon alpinus) may also prey on boars, to the point of keeping their numbers down in northwestern Bhutan, despite there being many more cattle in the area.

Leopards (Panthera pardus) are predators of wild boar in the Caucasus (particularly Transcaucasia), the Russian Far East, India, China and Iran. In most areas, boars constitute only a small part of the leopard's diet. However, in Iran's Sarigol National Park, boars are the second most frequently targeted prey species after mouflon (Ovis gmelini), though adult individuals are generally avoided, as they are above the leopard's preferred weight range of 10–40 kg (22–88 lb). This dependence on wild boar is largely due in part to the local leopard subspecies' large size.

Boars of all ages were once the primary prey of the tiger (Panthera tigris) in Transcaucasia, Kazakhstan, Middle Asia and the Far East up until the late 19th century. In modern times, tiger numbers are too low to have a limiting effect on boar populations. A single tiger can systematically destroy an entire sounder by preying on its members one by one, before moving on to another sounder. Tigers have been noted to chase boars for longer distances than with other prey. In two rare cases, boars were reported to gore a small tiger and a tigress to death in self-defense. In the Amur region, wild boars are one of the two most important prey species for Siberian tigers, alongside the Manchurian wapiti (Cervus canadensis xanthopygus), with the two species collectively comprising roughly 80% of the felid's prey. In Sikhote Alin, a tiger can kill 30–34 boars a year. Studies of tigers in India indicate that boars are usually secondary in preference to various cervids and bovids, though when boars are targeted, healthy adults are caught more frequently than young and sick specimens.

On the islands of Komodo, Rinca and Flores, the boar's main predator is the Komodo dragon (Varanus komodoensis).

Distribution and habitat

Reconstructed range

The species originally occurred in North Africa, North and South America, and much of Eurasia; from the British Isles to Korea and the Sunda Islands. The northern limit of its range extended from southern Scandinavia to southern Siberia and Japan. Within this range, it was only absent in extremely dry deserts and alpine zones. It was once found in North Africa along the Nile valley up to Khartoum and north of the Sahara. The species occurs on a few Ionian and Aegean Islands, sometimes swimming between islands. The reconstructed northern boundary of the animal's Asian range ran from Lake Ladoga (at 60°N) through the area of Novgorod and Moscow into the southern Urals, where it reached 52°N. From there, the boundary passed Ishim and farther east the Irtysh at 56°N. In the eastern Baraba steppe (near Novosibirsk) the boundary turned steep south, encircled the Altai Mountains and went again eastward including the Tannu-Ola Mountains and Lake Baikal. From here, the boundary went slightly north of the Amur River eastward to its lower reaches at the Sea of Okhotsk. On Sakhalin, there are only fossil reports of wild boar. The southern boundaries in Europe and Asia were almost invariably identical to the seashores of these continents including the Americas and North Africa. It is absent in the dry regions of Mongolia from 44 to 46°N southward, in China westward of Sichuan and in India north of the Himalayas. It is absent in the higher elevations of the Pamir and the Tien Shan, though they do occur in the Tarim basin and on the lower slopes of the Tien Shan.

Present range

In recent centuries, the range of wild boar has changed dramatically, largely due to hunting by humans and more recently because of captive wild boar escaping into the wild. Prior to the 20th century, boar populations had declined in numerous areas, with British populations probably becoming extinct during the 13th century. In the warm period after the ice age, wild boar lived in the southern parts of Sweden and Norway and north of Lake Ladoga in Karelia. It was previously thought that the species did not live in Finland during prehistory because no prehistoric wild boar bones had been found within the borders of the country. It was not until 2013, when a wild boar bone was found in Askola, that the species was found to have lived in Finland more than 8,000 years ago. It is believed, however, that man prevented its establishment by hunting. In Denmark, the last boar was shot at the beginning of the 19th century, and by 1900 they were absent in Tunisia and Sudan and large areas of Germany, Austria and Italy. In Russia, they were extirpated in wide areas by the 1930s. The last boar in Egypt reportedly died on 20 December 1912 in the Giza Zoo, with wild populations having disappeared by 1894–1902. Prince Kamal el Dine Hussein attempted to repopulate Wadi El Natrun with boars of Hungarian stock, but they were quickly exterminated by poachers.

A revival of boar populations began in the middle of the 20th century. By 1950, wild boar had once again reached their original northern boundary in many parts of their Asiatic range. By 1960, they reached Leningrad and Moscow and by 1975, they were to be found in Archangelsk and Astrakhan. In the 1970s they again occurred in Denmark and Sweden, where captive animals escaped and now survive in the wild. In England, wild boar populations re-established themselves in the 1990s, after escaping from specialist farms that had imported European stock.

Status in Great Britain

Wild boars were apparently already becoming rare by the 11th century since a 1087 forestry law enacted by William the Conqueror punishes through blinding the unlawful killing of a boar. Charles I attempted to reintroduce the species into the New Forest, though this population was exterminated during the Civil War. Between their medieval extinction and the 1980s, when wild boar farming began, only a handful of captive wild boar, imported from the continent, were present in Britain. Occasional escapes of wild boar from wildlife parks have occurred as early as the 1970s, but since the early 1990s significant populations have re-established themselves after escapes from farms, the number of which has increased as the demand for meat from the species has grown. A 1998 MAFF (now DEFRA) study on wild boar living wild in Britain confirmed the presence of two populations of wild boar living in Britain; one in Kent/East Sussex and another in Dorset.

Another DEFRA report, in February 2008, confirmed the existence of these two sites as 'established breeding areas' and identified a third in Gloucestershire/Herefordshire; in the Forest of Dean/Ross on Wye area. A 'new breeding population' was also identified in Devon. There is another significant population in Dumfries and Galloway. Populations estimates were as follows:

• The largest population, in Kent/East Sussex, was then estimated at approximately 200 animals in the core distribution area.
• The smallest, in west Dorset, was estimated to be fewer than 50 animals.
• Since winter 2005–2006 significant escapes/releases have also resulted in animals colonizing areas around the fringes of Dartmoor, in Devon. These are considered as an additional single 'new breeding population' and currently estimated to be up to 100 animals.

Population estimates for the Forest of Dean are disputed as, at the time that the DEFRA population estimate was 100, a photo of a boar sounder in the forest near Staunton with over 33 animals visible was published and at about the same time over 30 boar were seen in a field near the original escape location of Weston under Penyard many kilometres or miles away. In early 2010 the Forestry Commission embarked on a cull, with the aim of reducing the boar population from an estimated 150 animals to 100. By August it was stated that efforts were being made to reduce the population from 200 to 90, but that only 25 had been killed. The failure to meet cull targets was confirmed in February 2011.

Wild boars have crossed the River Wye into Monmouthshire, Wales. Iolo Williams, the BBC Wales wildlife expert, attempted to film Welsh boar in late 2012. Many other sightings, across the UK, have also been reported. The effects of wild boar on the U.K.'s woodlands were discussed with Ralph Harmer of the Forestry Commission on the BBC Radio's Farming Today radio programme in 2011. The programme prompted activist writer George Monbiot to propose a thorough population study, followed by the introduction of permit-controlled culling.

Introduction to North America

Wild boars usually found into the Americas to North Africa and Eurasia, they are an invasive species in the Americas and cause problems including out-competing native species for food, destroying the nests of ground-nesting species, killing fawns and elk calves, and young domestic livestock, destroying agricultural crops, eating tree seeds and seedlings, destroying native vegetation and wetlands through wallowing, damaging water quality, coming into violent conflict with humans and pets and carrying pig and human diseases including brucellosis, trichinosis and pseudorabies. In some jurisdictions, it is illegal to import, breed, release, possess, sell, distribute, trade, transport, hunt, or trap Eurasian boars. Hunting and trapping is done systematically, to increase the chance of eradication and to remove the incentive to illegally release boars, which have mostly been spread deliberately by sport hunters.

History

While domestic pigs, both captive and feral (popularly termed "razorbacks"), have been in North America since the earliest days of European colonization, pure wild boars were not introduced into the New World until the 19th century. The suids were released into the wild by wealthy landowners as big game animals. The initial introductions took place in fenced enclosures, though several escapes occurred, with the escapees sometimes intermixing with already established feral pig populations.

The first of these introductions occurred in New Hampshire in 1890. Thirteen wild boars from Germany were purchased by Austin Corbin from Carl Hagenbeck and released into a 9,500-hectare (23,000-acre) game preserve in Sullivan County. Several of these boars escaped, though they were quickly hunted down by locals. Two further introductions were made from the original stocking, with several escapes taking place due to breaches in the game preserve's fencing. These escapees have ranged widely, with some specimens having been observed crossing into Vermont.

In 1902, 15–20 wild boar from Germany were released into a 3,200-hectare (7,900-acre) estate in Hamilton County, New York. Several specimens escaped six years later, dispersing into the William C. Whitney Wilderness Area, with their descendants surviving for at least 20 years.

The most extensive boar introduction in the US took place in western North Carolina in 1912, when 13 boars of undetermined European origin were released into two fenced enclosures in a game preserve in Hooper Bald, Graham County. Most of the specimens remained in the preserve for the next decade, until a large-scale hunt caused the remaining animals to break through their confines and escape. Some of the boars migrated to Tennessee, where they intermixed with both free-ranging and feral pigs in the area. In 1924, a dozen Hooper Bald wild pigs were shipped to California and released in a property between Carmel Valley and the Los Padres National Forest. These hybrid boar were later used as breeding stock on various private and public lands throughout the state, as well as in other states like Colorado, California, Wyoming, Idaho, Montana, Oklahoma, Nebraska, Kansas, Florida, Georgia, South Carolina, Virginia, Alabama, Kentucky, Oregon, West Virginia and Mississippi, and occasionally small population in Washington.

Several wild boars from Leon Springs and the San Antonio, Saint Louis and San Diego Zoos were released in the Powder Horn Ranch in Calhoun County, Texas, in 1939. These specimens escaped and established themselves in surrounding ranchlands and coastal areas, with some crossing the Espiritu Santo Bay and colonizing Matagorda Island. Descendants of the Powder Horn Ranch boars were later released onto San José Island and the coast of Chalmette, Louisiana.

Wild boar of unknown origin were stocked in a ranch in the Edwards Plateau in the 1940s, only to escape during a storm and hybridize with local feral pig populations, later spreading into neighboring counties.

Starting in the mid-1980s, several boars purchased from the San Diego Zoo and Tierpark Berlin were released into the United States. A decade later, more specimens from farms in Canada and Białowieża Forest were let loose. In recent years, wild pig populations have been reported in 44 states within the US, most of which are likely wild boar–feral hog hybrids. Pure wild boar populations may still be present, but are extremely localized.

Introduction and lack of control in South America

In South America, the European boar is believed to have been introduced for the first time in Argentina, Colombia, Ecuador, Chile, Paraguay, Mexico, Costa Rica, Honduras, Cuba, Puerto Rico, El Salvador, Panama, Peru, and Uruguay around the 20th century for breeding purposes. In Brazil, the creation of wild boar and hybrids started on a large scale in the mid-1990s. With the invasion of wild boar that crossed the border and entered Rio Grande do Sul around 1989, and the escape and intentional release by several Brazilian breeders in the late 1990s - in response to a IBAMA decision against the import and breeding of wild boar in 1998 - numerous feral species formed a growing population, which progressively advances in Brazilian territory. The species has no natural predators in Brazil, as it is an exotic species, in addition to breeding with the domestic pig, generating the so-called "javaporco" (neologism created to define this hybrid), factors that contribute to the exaggerated increase in the population. With its population in continuous and uncontrolled growth, without predators, the wild boar causes environmental damage, contributing to the aggradation of river and stream springs, attacking native species feeding on eggs and puppies, causing damage to fauna, flora and to agriculture and livestock, since it also attacks farm animals and can carry various diseases, including zoonosis.

Pest control in Brazil

As a form of control for the wild boar population (which is considered a pest and harmful species), hunting and killing are allowed for Collectors, Shooters and Hunters (CACs) duly registered by the environmental control agency, IBAMA, which, on the other hand, seeks to encourage the preservation of similar species of native peccaries, such as the "queixada" and the "caititu".

Effect on other habitats

Wild boars negatively impact other habitats through the destruction of the environment, or homes of wildlife. When wild boars invade new areas, they adapt to the new area by trampling and rooting, as well as displacing many saplings/nutrients. This causes a decrease in growing of many plants and trees. Water is also affected negatively by wild boars. When wild boars are active in streams, or small pools of water, it causes increased turbidity (excessive silt and particle suspension).In some cases, the fecal coliform concentration increases to dangerous levels because of wild boars. Aquatic wildlife is affected, more prominently fish, and amphibians. Wild boars have caused a great decrease in over 300 animal or plant species, 250 being endangered or threatened.

The boars cause many habitats to become less diverse because of their feeding behaviors and predation. Wild boars will dig up eggs of species and eat them, as well as killing other wildlife for food. When these boars compete with other species for resources, they usually come out successful. A study published in the Journal of Experimental Marine Biology and Ecology was conducted on the results of Feral Swine control. Only two years after the control started, the amount of turtle nests jumped from 57 to 143, and the turtle nest predation percent dropped from 74 to 15. They kill and eat deers, lizards, birds, snakes, and more. These boars are called "opportunist omnivores," which means they eat almost anything. This means they can survive almost anywhere. A big surplus of food and the ability to adapt to any new place causes lots of breeding. All of these factors make it difficult to get rid of wild boars.Wild boars also tend to carry diseases and numerous pathogens. This also adds to the decrease in diversity among species.