New World Porcupines: Erethizontidae

New World porcupines are assumed to be nocturnal, active at night, and arboreal, living in trees, spending their days sleeping in trees or in private ground places. They spend most of their time alone, but during winter months, several animals often share a winter den. Their winter territory averages 12 acres (5 hectares), while the larger summer territory reaches a maximum of 35 acres (14 hectares). Although not territorial, they defend feeding grounds during winters. They can spear their quills into attackers with spines that are detached. When faced with a predator, an animal that hunts and eats other animals, they erect their quills so they stick out in many directions and chatter their teeth. New World porcupines either remain stationary in a defensive position, or may charge the predator by quickly whipping out with their quill-laden tail.

Most of the time New World porcupines do not communicate with each other. Females do touch their young with their nose, giving them gentle grunts and whines. During the mating season, porcupines become noisy with various grunts, moans, screams, and barks. It is believed that females are either pregnant or lactating, producing milk, for most of their lives. The gestation period, the time period the offspring are in the womb, lasts about 200 days. When gestation is over the female mates again. Females nurse, feed on mother's milk, their newborns for eight to twelve weeks. A litter, young animals born together from the same mother, is usually only one young, which is born with fur and soft quills that harden quickly. The young reach adult size in about one year, and become sexually mature (able to mate) in one-and-a-half to two-and-a-half years. Their average lifespan is fifteen years.