Cross River National Park (CRNP) is a large area of lowland and submontane rainforest situated in south-east Nigeria along the border with Cameroon. The park is divided into two sections. The smaller area to the north-east, Okwangwo Division (NG010), is separated by about 50 km of disturbed forest from the larger Oban Division. Oban Division is contiguous with Korup National Park in Cameroon (CM019). The Cross river and its tributaries drain northern parts of Oban Division, while southern parts are drained by the Calabar, Kwa and Korup rivers. The terrain is rough and elevation rises from the river valleys to over 1,000 m in mountainous areas. Soils are ferralitic and sandy, and steadily become shallower with increasing elevation. Leaching and erosion are intense in exposed sites. The vegetation is lowland rainforest and characteristic tree species include Berlinia confusa, Coula edulis, Hannoa klaineana, Klainedoxa gabonensis, Khaya ivorensis and Lophira alata. In the less accessible areas the forest has had little interference, but elsewhere the vegetation has been much influenced by human activity. Exploitation has resulted in secondary regrowth and the establishment of plantations of oil-palm and rubber. The area has a rainy season of at least nine months (March–November) and receives over 3,500 mm annually.
See Box and Tables 2 and 3 for key species. This is one of the most ornithologically diverse sites in Nigeria. Over 350 bird species have been recorded in this still vastly underexplored park. It is one of only two Nigerian localities for Phyllastrephus xavieri. Other nationally uncommon species include Macheiramphus alcinus, Spizaetus africanus, Guttera pucherani, Canirallus oculeus, Cercococcyx olivinus, Apaloderma aequatoriale, Melichneutes robustus, Criniger chloronotus, Myioparus griseigularis and Malimbus racheliae.
Non-bird biodiversity: Floral diversity in Oban Division is extremely rich. A total of 1,303 flowering plants, 141 lichens and 56 moss species have so far been collected, some of which have restricted distributions, e.g. Biophytum zenkeri. Oban Division also has a rich mammalian fauna, including Loxodonta africanacyclotis (EN), Procolobus preussi (EN), Mandrillus leucophaeus (EN) and Cercopithecus sclateri (EN), a Nigerian endemic.
Pressure/threats to key biodiversity
Illegal logging is the most important threat to the park and has become worse since the withdrawal of funding by the European Union. The park contributes to the protection of the catchment of the Cross river. The human population in the park is currently low and most villages are restricted to the buffer zone. However, the population is growing rapidly and demand for farmland is leading to encroachment in parts of the park previously considered inaccessible and marginal for farming. Traditional exploitation of natural resources includes hunting, fishing and shifting cultivation. All are adversely affecting the park as the human population grows. Fish stocks and other aquatic life have declined as a result of the use of chemicals for fishing.
BirdLife International (2020) Important Bird Areas factsheet: Cross River National Park (Oban Division). Downloaded from
http://www.birdlife.org on 14/08/2020.