The site is located in south-eastern Cameroon on the border with Congo. The main access to Nki is via the Dja river, although organizing a boat trip up river from the town of Moloundou to the east is very difficult. The reserve, which has never been logged, is bordered to the south and south-west by the Dja river, which is not navigable beyond the Nki Falls (at 14°30’E). As with Boumba–Bek (CM030), nearby to the north-east, the main forest-type is semi-evergreen with an open canopy dominated by huge (50–60 m) Triplochiton, but which is interspersed with more extensive patches of closed evergreen forest. There are a few small, isolated saline swamps and some seasonally flooded Uapaca forest along the Dja. The topography is more hilly than in Boumba–Bek.
See Box and Tables 2 and 3 for key species. A 20-day survey of the reserve and the buffer zone to the east identified some 265 species. A pair of Bradypterus grandis was discovered holding territory in a 1 ha patch of Rhynchospora marsh; the overall population must be small as suitable swamps are few. As evergreen rainforest is extensively mixed with semi-evergreen forest; Glaucidium sjostedti occurs alongside G. capense. Three species of forest nightjar have been recorded: Caprimulgus batesi and binotatus are widespread (as elsewhere in the south-east), but a rarer, and as yet unidentified, third species has been heard at two places. It has also been found in Lobéké (CM033) and in nearby north Congo; its voice is identical to that of a forest nightjar taped recently (1996) in the Itombwe forest (CD013) of eastern Democratic Republic of Congo whence the only known specimen of C. prigoginei has been collected, thus it will more likely turn out to be C. prigoginei than a new species. The yellow-bellied form of Stiphrornis erythrothorax (which has been described as a new species S. sanghensis, but see under CM030) is common.
Non-bird biodiversity: Nki represents the eastern limit of the rarely-observed Myosciurus pumilio (VU), a Lower Guinea endemic. Among other mammal species of interest are Hylochoerus meinertzhageni; there are good numbers of Loxodonta africana, Gorilla gorilla and Pan troglodytes (all EN).
Pressure/threats to key biodiversity
The site is so inaccessible that it is rarely visited by poachers. A management plan in preparation proposes to designate Nki as a National Park or Faunal Reserve, including the buffer zone between Nki and Boumba–Bek (CM030).