Pigs: Suidae

The basic group is the mother-offspring pair, and group sizes vary from one to fifteen pigs. Females live alone or in a group with other females, and offspring remain with their birth group up to two years. Female offspring sometimes remain with the group permanently, but males always leave. With the exception of the African species, males and females interact only during breeding season. African males live with the group year-round and help raise the young. Male warthogs breed, leave, and then return to help care for the offspring.

Pigs vocalize when they are alarmed or in pain as well as when they are comfortable or breeding. Displays are used to ward off intruders or rivals, but if that fails, pigs will fight using tusks. Cannibalism and infanticide, killing of young, have been observed in some species, and wild piglets have been known to be playful and social.

Wild pigs are active at night. Warthogs are active during daylight hours.

Male pigs breed with several females each season, but warthogs have been known to choose one mate for life. Courtship behavior includes chasing and calling. Pregnancy lasts 100 to 175 days, and during this time the female will build a nest from vegetation. Females give birth to one to twelve piglets in this secluded spot. The litters of domesticated pigs increase in number with age and may reach eighteen piglets. Piglets nurse, drink their mother's milk, up to twenty times each day. Some piglets are taken off mother's milk as early as five weeks, while others wait until thirty-two weeks of age. Sexual maturity of young is reached at eight months in some species, and at two to five years in others.

Primary predators of wild pigs are bobcats, coyotes, and black bears.