The Twa (also Cwa, or Batwa plural and Mutwa singular) are a group of indigenous African Pygmy (Central African foragers) tribes. Name It is often supposed that the Pygmies were the aboriginal inhabitants of the forest before the advent of agriculture. Vansina argues that the original meaning of the (Proto-Bantu) word *twa was "hunter-gatherer, bushpeople", alongside yaka used for the western (Mbuti) pygmies (Bayaka). As the Twa developed into full-time hunter-gatherers, the words were conflated, and the ritual role of the absorbed aboriginal peoples was transferred to the Twa. Batwa and Abatwa are Bantu plural forms, translating to "Twa people". Relation to the Bantu populations All Pygmy and Twa populations live near or in agricultural villages. Agricultural Bantu peoples have settled a number of ecotones next to an area that has game but will not support agriculture, such as the edges of the rainforest, open swamp, and desert. The Twa spend part of the year in the otherwise uninhabited region hunting game, trading for agricultural products with the farmers while they do so. Roger Blench has proposed that Twa (Pygmies) originated as a caste like they are today, much like the Numu blacksmith castes of West Africa, economically specialized groups which became endogamous and consequently developed into separate ethnic groups, sometimes, as with the Ligbi, also their own languages. A mismatch in language between patron and client could later occur from population displacements. The short stature of the "forest people" could have developed in the millennia since the Bantu expansion, as happened also with Bantu domestic animals in the rainforest. Perhaps there was additional selective pressure from farmers taking the tallest women back to their villages as wives. However, that is incidental to the social identity of the Pygmy/Twa. Congo Twa live scattered throughout the Congo. In addition to the Great Lakes Twa of the dense forests under the Ruwenzoris, there are notable populations in the swamp forest around Lake Tumba in the west (about 14,000 Twa, more than the Great Lakes Twa in all countries), in the forest–savanna swamps of Kasai in the south-center, and in the savanna swamps scattered throughout Katanga in the south-east, as in the Upemba Depression with its floating islands, and around Kiambi on the Luvua River. The island of Idwji has a native population of approx 7000 BaTwa. And according to UNHRW more than 10000 BaTwa are displaced from Virunga Park in the Northern