but fossil and subfossil remains suggest it may have been present in Europe in the Upper Pleistocene. The crested porcupine is native to Algeria, Benin, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Côte d'Ivoire, Democratic Republic of the Congo, Eritrea, Ethiopia, Gambia, Ghana, Djibouti, Guinea, Guinea-Bissau, Italy, Kenya, Liberia, Libya, Mali, Mauritania, Morocco, Nigeria, Rwanda, Senegal, Sierra Leone, Somalia, Sudan, South Sudan, Tanzania, Togo, Tunisia and Uganda. It may be locally extinct in Egypt. Behaviour and ecology The crested porcupine is a terrestrial mammal; it very seldom climbs trees, but can swim. It is nocturnal and monogamous. The crested porcupine takes care of the young for an extended period, and small family groups consist of the adult pair and young of various ages. In defense, when disturbed, they raise and fan their quills to make themselves look bigger. If continually bothered, the crested porcupine will stamp its feet, whirr the quills, and charge the disturber back end first trying to stab the enemy with the thicker, shorter quills. These attacks are known to have killed lions, leopards, hyenas, and even humans. Crested porcupines have been known to collect thousands of bones that they find at night. They are mostly nocturnal, and they may come upon the skeletons of animals. They collect these bones and store them in an underground chamber or cave. Diet and digestion The crested porcupine is for the most part herbivorous, eating roots, bulbs, and leaves, but occasionally they do consume insects, small vertebrates, and carrion. To ingest calcium and sharpen incisors, they often gnaw on bones. These animals often travel long distances looking for food. They have high crowned teeth that grind plant tissues which are digested in the stomach, and the undigested fibers are retained in an enlarged appendix and anterior large intestine, where they are broken down by microorganisms. Reproduction Most of what is known about reproduction in the crested porcupine comes from individuals in captivity. Usually, female crested porcupines have one litter every year. One or two well developed young are born in a chamber within the burrow that is usually lined with grass, after on average a 66-day gestation period. The young weigh about at birth, which is about 5% of the mother's weight. They leave the den after one week. At this time, the spines begin to harden. Crested porcupines reach adult weight at one to two years and are