In relation to the vastness of the territory and the variety of its natural environments, the ethnic groups are varied. The main ethnic group is the Bantu one, which in turn includes several subgroups (luba, lunda, kongo, mongo), characterized by different cultures and social structures. A small minority of pygmies live in the heart of the forest. The most represented ethnic groups are therefore Luba (18%), Kongo (16.1%), Mongo (13.5%), Rwanda (10.3%), Azande (6.1%), Bangi and Ngale (5, 8%), and others (30.2%). The Bantu probably arrived in the country from the northern regions in the sec. X-XIV, founding flourishing kingdoms; they are mainly located in the central and southern regions. AN instead the Sudanese people predominate in importance (sandè and mangbetu), which arrived between the century. XVI and XIX while, limited to the extreme north-eastern area, some Nilotic groups settled, including the alur. The number of Europeans, especially Belgians, Portuguese and Italians, who once constituted a large colony, has also been greatly reduced. According to threergroup, the population of the Democratic Republic of Congo has an average density of 28 residents / km². Only in the last decades of the twentieth century the demographic trend of the country marked a remarkable pace (in 1955 the residents were just over 12 million), determined by an increased birth rate, but above all by a sharp drop in the death rate. However, despite the considerable progress made, all those typical imbalances of developing countries continue to be present, in particular high infant mortality and a clear prevalence of the young classes.
The highest densities are recorded in the most economically dynamic areas since the beginning of colonial era, that is the middle and lower course of the Congo, the western region that extends from the Malebo Pool to the coast, the highlands of Kasai, as well as the eastern highlands, favored by a healthier environment. The phenomenon of urbanization, however, became enormously accentuated after the civil war, which saw inflows of often dramatic magnitude and real escapes from rural villages. The most macroscopic example is offered by which has seen often dramatic influxes and real escapes from rural villages. The most macroscopic example is offered by which has seen often dramatic influxes and real escapes from rural villages. The most macroscopic example is offered by Kinshasa, the former Leopoldville, capital of the Democratic Republic of Congo, located on the banks of the Pool Malebo, the summit of the entire territorial organization of the new state, a center of mediation between the vast Congolese basin – of which it is the largest river port – and the Atlantic coast. Kinshasa is by far the most populous city in black Africa. The capital, a primary financial and cultural center, is also the terminus of the railway to Matadi, the country’s main seaport on the Congo estuary. The other major centers have generally developed as a function of mining activities and related industries; this is the case of Kananga, formerly Luluabourg, and of nearby Mbuji-Mayi, capital respectively of the Western and Eastern Kasai, and of Lubumbashi, formerly Elisabethville, where the main industries linked to the exploitation of the Shaba fields are grouped; Kisangani, formerly Stanleyville, in Upper Zaire, is instead above all a large river port that connects the upper and lower Congo basin, a very active commercial hub for communications with East Africa, while Bukavu is located on the shores of Lake Kivu, in an area of rich plantations.
The Congolese lowland is covered by a rich rainforest, which, towards the south, passes into arborated savannahs or sparse forests on the Shaba, Kasai and Central African plateaus, veined by the evergreen strips of the gallery forest along the rivers. And it is here, on the final stretch of the Congo River, that a dense vegetation of mangroves and palms of the Phoenix thorny species is born. The fauna of the country is particularly diverse and abundant, on the territory there are numerous species of mammals such as the giraffe, the leopard, the lion, the gorilla, the chimpanzee, the elephant, the hippopotamus and the zebra, various species of reptiles and birds and many insects, some of which are harmful to humans and animals as they transmit serious infections, such as the tsé-tsé fly and the Anopheles mosquito. Water pollution, caused by waste, untreated sewage, industrial chemicals discharged into rivers, and air pollution due to exhaust gases in cities are the main causes of degradation in the country. Furthermore, the mining of minerals, such as p. ex. coltan (looks like a radioactive black sand and contains columbite and tantalite minerals), and continued deforestation are at the origin of serious environmental damage. In the Democratic Republic of Congo there are seven national parks, of which four parks and one reserve are World Heritage Sites: Virunga National Park (1979), Kahuzi-Biega National Park (1980), Garamba National Park ( 1980), Salonga National Park (1984) and Okapi Nature Reserve (1996). Protected areas make up 12.2% of the entire territory.