Species Of Pigs, The Domestic Pig
Pigs, hogs, or swine consist of about eight species of mammals in the family Suidae, which is part of the order Artiodactyla, the cloven-hoofed ungulates. Pigs are closely related to the peccaries (family Tayassuidae) and hippopotamuses (family Hippopotamidae). The natural distribution of pigs includes Africa, Europe, and Asia, but one species, the domestic pig (Sus scrofa), is now found almost worldwide as a domestic and feral species.
Pigs have a relatively large head, with a long, cone-shaped snout, small eyes, long ears, a short neck, short legs, and a stout body. The skin of pigs is thick and tough, and it may be sparsely or thickly haired, depending on species. The largest pigs can weigh more than 660 lb (300 kg).
Pigs have a flat-fronted, cartilaginous, malleable, almost hairless nose that is very tactile, and along with the extremely keen sense of smell, helps these animals to find and root out their food, which is often buried underground. Pigs also have an excellent sense of hearing, which is very useful in helping them to detect the activities of potential predators. However, pigs have poor vision, and they can only see effectively over short distances. The canine teeth of pigs grow continuously, and in male animals (or boars) these can be very large, and curl as tusks outside of the mouth. These sharp teeth can be used by mature pigs as slashing weapons, either in defense against a predator, or in combat between male pigs during the breeding season.
Pigs are omnivorous animals, eating a highly varied diet. Most of the foods consumed by pigs are plant tissues, especially underground roots, rhizomes, and tubers, which are excavated using the snout. Pigs also eat the foliage of many plants, as well as nuts, seeds, and fruits that may be found on the ground. Pigs are opportunistic predators, and will eagerly eat birds eggs and nestlings if these are discovered, as well as small rodents, snakes, and other prey. Pigs will also attack larger, disabled animals, and will eat carrion.
Pigs occur in a wide range of habitats, from alpine tundra, through most types of temperate and tropical forests, savannas, swamps, and the vicinity of human settlements. Wet places are a necessary component of all pig habitats, because mud bathing is important to the physical and mental health of these animals.
Most species of pigs are social, with the animals generally living in family groups consisting of at least a mature female (or sow) and her young. Mature boars are generally solitary, except during the mating season. Grunting and squeaking noises are important in the communications among pigs. Baby pigs are precocious, and can move about only a few hours after their birth. Broods of pigs can be quite large, and can exceed a dozen piglets. Young pigs often fall victim to predators, but mature animals can be ferocious in their self-defense, and are not an easy mark as prey. Pigs can live to be as old as 25 years.