Information about Wild Pigs

wild pigs boar pleistocene holocene information about

The wild pig, also known as the wild boar, the wild swine, or, scientifically, as Sus scrofa, is a large mammal, belonging to the family Suidae. The term ‘boar’ may also be used to refer to male domesticated pigs, especially those that have not been castrated. A categorization of 16 subspecies was made in 2005, dividing them into 4 regional subgroups, and is based on skull height and lacrimal bone length:

  • Western: S. s. scrofa, S. s. meridionalis, S. s. algira, S. s. attila, S. s. lybicus, S. s. nigripes;
  • Indian: S. s. davidi, S. s. cristatus;
  • Eastern: S. s. sibiricus, S. s. ussuricus, S. s. leucomystax, S. s. riukiuanus, S. s. taivanus, S. s. moupinensis;
  • Indonesian: S. s. vittatus.

wild pigs boar pleistocene holocene information about

One word that can accurately describe wild pigs is massive. They have strong, bulky bodies and short, relatively thin legs, of which the middle hooves are larger than the lateral ones, allowing the pig to move quickly. As a result, they can run at a speed of up to 40km/h and jump at a height of 140-150cm.

Description and distribution

The head is very large (a third of the body’s entire length), with a structure that is well adapted for digging. As such, they can dig between 8-10cm in frozen ground and can upturn rocks as heavy as 40-50kg. The eyes are small and deep-set; the ears are broad and long. The teeth are canine-like, growing throughout life. The upper canines are relatively short, at first growing sideways, then gradually curving upwards. The lower canines are longer and much sharper, the exposed parts measuring between 10-12cm. A wild pig’s jaws are extremely strong, and their bite can easily break bones. The neck is thick and short, with powerful muscles, but nearly immobile.
The colour of the pigs’ coat varies across species, but also across specimens; this variation can therefore arise as a result of genetics, the environment, or age. Some are very light coloured (they can even be white), others are plain black; all piglets have light brown or rusty-brown fur. An adult’s winter coat consists of long, coarse bristles and short, brown fur. The length of the bristles varies along the body; they are shorter around the face and limbs and longer down the back.

Males are typically 5-10% larger and 20-30% heavier than females. Moreover, males sport a mane (which is particularly apparent during the cold months of autumn and winter) down the back. The upper canines are also more prominent in males, protruding from the mouths. During the mating season, males develop a coating of subcutaneous tissue, which can be of up to 2-3cm in thickness. This extends from the shoulder blades to the rump, its purpose being that of protecting vital organs during inevitable fights.
Adult size and weight varies, being largely determined by environmental factors: pigs living in arid areas will be smaller than pigs living in areas where food and water is abundant. In most of Europe, males will weigh between 75-100kg and measure between 75-80cm in shoulder height and 150cm in body length. Females, on the other hand, will weigh between 60-80kg, measure around 70cm in shoulder height and 140cm in body length. In Eastern Europe, large males can reach the size of a brown bear, with a weight of up to 270kg and a shoulder height of up to 110-118cm. Some have even been recorded to weigh between 300-350kg and measure 125cm in shoulder height. In Mediterranean regions, on the other hand, males may weigh as little as 50kg and females as little as 45kg; shoulder heights may vary between 63-65cm.

Wild pigs are originally native to North Africa, Eurasia, as well as the Greater Sunda Islands, but, due to human intervention, they are now spread across the majority of the globe, being one of the widest-ranging mammals and the most widely spread suiform in the world. Habitats range from taigas to deserts; some species even live in alpine zones, at heights of up to 1,900 (in the Carpathians), 2,600 (in the Caucasus), and 3,600-4,000 (in mountains from Central Asia and Kazakhstan). Wild pigs are highly adaptable; all that they require from a habitat is:

  • heavily brushed areas, which provide shelter from predators (they will, however, hunt in the open);
  • water, which can be as far as a day’s walk away;
  • temperatures which do not drop below freezing and an absence of regular snowfall.

Breeding and dietary information

Females live in matriarchal societies, along with younglings (both male and female); these are called “sounders”. Males, on the other hand, are generally solitary, except during the breeding season. They travel long distances in search of females, and, once they find them, they drive off the younglings from the group.
The breeding season generally lasts from November to January, a period during which a single male can mate with 5-10 females. The gestation period depends on the species, but more importantly, on the age of the mother. If the mother is young, gestation can last between 114-130 days; if the mother is old, gestation lasts longer, between 133-140 days. They give birth around March-May, generally to litters of around 4-6 piglets, the maximum being 10-12.
The younglings weigh around 600-1,000g and spend the first weeks of life in a nest built from grass, leaves, and twigs. They start leaving the den at 2 weeks of age, accompanying their mother on journeys; this is also the time when they start to eat solid food, although they are officially weaned only at around 3 months. If the mother happens to die before the piglets are fully grown, the rest of the females in the group will adopt them. Male piglets fully leave the den at around 8-15 months, while female piglets either remain in the same den, or move to a nearby territory. Most females reach sexual maturity at 1 year of age, and males at 2 years.

Wild pigs have a very well-developed sense of smell, to the point that some specimens have even been used to detect drugs in Germany; they are said to be able to detect odours from as far as 12km away and 8m underground. They also have an acute sense of hearing. They rely on both to detect danger and to search for food. By contrast, their eyesight is quite weak; they lack colour vision and are unable to distinguish or to recognize a human being from further than 10-15m away. Interestingly, wild pigs are one of the 4 known mammalian species that possess mutations in the nicotinic acetylchiline receptor, which protects against snake venom by preventing the alpha neurotoxin from binding.
Wild pigs communicate through a number of different sounds. These can be divided into three categories:

  • contact calls: grunting, purring, etc.;
  • alarm calls: cries emitted in response to threats;
  • combat calls: high-pitched, piercing cries.

Adult males are usually quieter than females. Piglets whine very frequently, and they purr when being fed; what is more, they are said to imitate the sounds of their mother, which can lead to different litters having quite different vocalizations.
The wild pigs’ main predators are the grey wolf (Canis lupus), the tiger (Panthera tigris), and the Komodo dragon (Varanus komodoensis). The grey wolf can kill more than 50 — 80 specimens in one year. Other predators include:

  • felines, such as the lynx (Lynx lynx) and the snow leopard (Panthera uncia);
  • the brown bear (Ursus arctos);
  • the yellow-throated marten (Martes flavigula).
  • Wild pigs are also victims of hunting, trapping, or car crashes.

The maximum lifespan of wild pigs is 10-14 years. In reality, though, most specimens only live 4-5 years. In captivity, some species have been known to live up to 20 years.

Wild pigs are known to host at least 20 parasitic worm species, and can carry approximately 15 diseases. Young piglets, in particular, are very vulnerable to parasites such as Metastrongylus, which cause death by parasitizing the lungs. Less harmful parasites include ticks, hog lice, and blood-sucking flies. Some parasites carried by wild pigs can infect humans, as well, including: Gastrodiscoides, Trichinella spiralis, Taenia solium, Balantidium coli, etc. The most important diseases carried by wild pigs are Pseudorabies, Bruscellosis, and Tularemia. Humans can contract the last two, Bruscellosis and Tularemia, as well as foot and mouth disease, Melloidosis, Leptospirosis, and Japanese encephalitis. Despite popular belief, wild pigs do not cause the swine flu, although they may carry it and transmit it (along with other diseases and parasites) to domestic animals, which is a great cause of concern.

When it comes to their dietary needs, wild pigs are omnivores, with a very varied diet. Generally, 85-90% of a wild pig’s diet is composed of vegetation, and only 10% of animal matter.  They eat:

  • roots, bulbs, rhizomes, and tubers, which can be dug up all throughout the year;
  • leaves, twigs, and bark;
  • seeds, nuts, and berries, which are eaten when ripe;
  • earthworms and insects;
  • fish and molluscs;
  • various insectivores, lizards, snakes, and frogs;
  • bird eggs;
  • occasionally, wild pigs may also prey on small vertebrates or new-borns of larger animals, such as new-born deer.

A 50kg specimen generally needs around 4,000-4,500 calories per day, though this increases during winter and during pregnancy. A small pig may therefore eat approximately 5% of its body weight daily; a large pig will eat around 3%. In the case of wild pigs living close to suburban areas, they may also raid through garbage, crops, and any food left unattended outside.

Wild pigs as pests

The relationship between wild pigs and humans is long-standing, considering the fact that the wild pig is the ancestor of most domestic pig breeds. The only exception is the domestic pigs in Timor and Papua New Guinea. Not only that, but it has been a big-game animal for millennia. Cultures throughout Europe and Asia have continuously considered the killing of a wild pig as proof of one’s strength and courage, and some people even eat the meat of wild pigs. Although hunting can come to be a significant mortality factor for wild pigs, it is generally not enough to offset population growth.
Wild pigs can be pests, causing damage to gardens, trees, and, more generally, agriculture. Gardens are an issue if you grow fruits and vegetables in them, which is a tempting source of food. Trees are vulnerable because of the wild pigs’ rooting behaviour, which accelerates leaf litter decomposition; this, in turn, causes nutrients to be lost, and these are important enough to impact on the survival of trees, especially young ones. Furthermore, some wild pigs may actually actively root out seedlings of various tree species and chew the root in order to obtain these nutrients. Agriculture is affected because populations will dig up potatoes and damage melons or watermelons. Another reason why some people consider them to be a pest is that they can do a lot of damage to wire fences. Wanting to gain access to a certain place, wild pigs can tear or lift wire fences off the ground, creating openings through which contained farm animals (chickens, sheep, goats, etc.) or even pets (large dogs) can escape through.

As a result of all these behaviours, in the United States, the damage caused by wild pigs in a year can reach up to $1,5 billion. It is important to note, however, that this is an estimated figure, based on the total population (of around 6 million wild pigs) on American territory and the assumption that approximately $200 worth of damage is caused by each specimen, each year.

However, it is important to realize that wild pigs will generally only venture upon areas populated by humans when food in the wild is scarce; this happens more and more often now, as habitats are destroyed. On the other hand, wild pigs can also be useful in agriculture, helping to keep some pest populations, such as June bugs (also known as European chafers, or Rhizotrogus majalis), under control.
Attacks on humans are rare. However, they are aggressive, and resulting injuries can be serious; these generally consist of penetrating injuries to the lower part of the body, seeing as pigs charge and point their tusks towards the victim. The pig will charge once, then it will step back, assess the situation, and charge again if the victim is still moving; it will only stop once the victim is incapacitated. The most likely time for attacks to happen is the mating period (November through January), when males are already aggressive. Concrete situations include wild pigs being cornered by dogs during the hunting season or humans (accidentally or otherwise) bothering a female pig and her litter. It is important to remember, though, that, when given a choice, wild pigs usually flee and do not fight.

Knowing how to prevent an infestation with wild pigs and also how to eradicate them from your property is very important. Populations of wild pigs can be managed through lethal and nonlethal methods. However, to prevent them from causing damage to your crops, you can use exclusion methods such as installing fences to keep pigs out, using guard animals to protect livestock, and vaccinating animals to prevent disease spread. Getting rid of them can also be done through the use of repellents, fencing, trapping or hunting. For more details on ways in which to ‘Prevent infestation with Wild Pigs’, or on ‘How to get rid of Wild Pigs’, visit our related articles and find out more tips about prevention and eradication.

Got a question?

  1. As pigs have such a sensitive sense of smell can repellents be used successfully and if so which ones??

    Soo Skyrme -
    Answer
    1. In our catalog, we have electronic repellents and gas cannons against wild pigs. Electronic repellents can keep away the wild pigs for a while, but after some time, they get used to them. Gas cannons can also be used, as they are able to deter the pigs away through the loud sound they make.
      Mixing the use of repellents with other methods of prevention or control is the best way to make sure that you will keep your property free of wild pigs.

      Nexles -
      Answer

Leave a Reply

Your email address will not be published. Required fields are marked *

ASK A QUESTION