A biodiversity tally shows that DRC possesses more species of birds and mammals than any other African country and is one of the most flora-rich countries on the continent (Sayer et al. 1992). What was originally the old Belgian Congo, which included Rwanda, Burundi, and the DRC, contains about 9,500 species of seed plants and of those already described, approximately 15 percent were considered new to science when included in the Flore du Congo Belge (Léonard 1994). The DRC stretches from the volcanoes and the Rwenzori Mountains of Virungas National Park (VNP) in the east to the Atlantic Ocean and the Mangrove Nature Reserve in the west (Fig. 1). There are the northern savannas of Garamba National Park (GNP), the central waterways and dense forests of Salonga National Park (SNP), and the southern wooded savannas of Upemba National Park (UNP). Some of Africa's large spectacular mammals can only be found in the DRC, including: the Okapi (Okapia johnstoni), found in the Okapi Faunal Reserve (OFR) and Maiko National Park (MNP); the Northern White Rhino (Ceratotherium simum cottoni), found in Garamba National Park (GNP); the eastern lowland gorilla (Gorilla beringei graueri), found in Kahuzi-Biega National Park (KBNP) and MNP; and the Bonobo chimpanzee (Pan paniscus), found in Salonga National Park (SNP) (Fig.1).
The great biological richness is partly due to the large size of the DRC, which is larger than all the European countries that had African colonies in the early 20th century combined (i.e., Britain, France, Belgium, Spain, Italy, Germany, and Portugal), or about the area of the United States east of the Mississippi River. Even in relatively small areas, however, remarkable diversity can be found. In the OFR, which is smaller than New York State's Adirondack Park (5300 square miles versus 9375 square miles), there are 97 known species of mammals, even though rodents and bats have not been adequately inventoried (Hart and Bengana 1997, unpublished report of the Centre de Recherche et de Formation en Conservation Forestère, or CEFRECOF). An exhaustive survey of the Adirondack Mountains (DiNunzio 1984), on the other hand, documents only 59 species of mammals. There are 376 known species of birds in the OFR (unpublished compilation by Sacchi and Rüegg 1996) and only 296 in the Adirondacks (DiNunzio 1984). This is despite the fact that the OFR does not have the habitat variation of the Adirondacks, from high peaks to low valleys, nor is the OFR inventory complete; most of the area has had no animal census work. The most striking contrast is with woody plants. When the entire Adirondacks, all altitudes, were inventoried, there were fewer than 85 woody species (DiNunzio 1984), whereas when just 40 ha of homogeneous altitude was inventoried in the OFR there were more than 670 species (Makana 1999).