Arabuko-Sokoke Forest (6397)
Kenya, Africa

Site overview

KBA status: confirmed

Global KBA criteria: A1e, B2

Year of last assessment: 2018

National site name: Arabuko-Sokoke Forest

Central coordinates: Latitude: -3.3333, Longitude: 39.9167

System: terrestrial

Elevation (m): 0 to 210

Area of KBA (km²): 410.86637

Protected area coverage (%): 99.76

KBA classification: Global

Legacy site: Yes

Site details

Site description: Arabuko-Sokoke lies a few kilometres inland on the Kenyan coast, between the towns of Kilifi and Malindi and some 110 km north of Mombasa. It is the largest extant fragment of the forests that once covered much of the East African coast, and whose remnants constitute the East African coastal forests Endemic Bird Area. Arabuko-Sokoke was proclaimed a Crown Forest in 1932 and gazetted in 1943, covering an area of 39,100 ha. The Kararacha extension (2,700 ha) to the south-east, which includes important tracts of key habitats, was added in 1968. Part of the forest, containing sections of the three main habitat types, was gazetted as a strict nature reserve (covering 4,300 ha) in the late 1960s. Average annual rainfall ranges from 900 mm (in the relatively dry and scrubby north-west) to 1,100 mm (in the east). The relatively flat eastern section lies on Pleistocene lagoonal sands and clays, separated by a wide band of apparently riverine sandy deposits from the ridge of red Magarini sands that forms the western part of the reserve. Three very distinctive forest types, each with its own special flora and fauna, correspond to these soil types: Mixed forest (7,000 ha) in the east, on grey sands. This habitat is relatively dense, tall and undifferentiated, with a diversity of tree species. Characteristic trees include Combretum schumannii, Drypetes reticulata, Afzelia quanzensis, Dialium orientale, Hymenaea verrucosa and Manilkara sansibarensis. Brachystegia woodland (7,700 ha) runs in a strip through the approximate centre of the forest, on white, very infertile soil. This relatively open habitat is dominated by Brachystegia spiciformis. In the west, on red Magarini sands, is Cynometra forest and thicket, dominated by Cynometra webberi with Manilkara sulcata, Oldfieldia somalensis and (formerly) Brachylaena huillensis. The transition between white and red soil is sudden, and marked by a chain of seasonal ponds. There are two areas of relatively tall Cynometra forest, with a canopy height of up to 20 m, in the north (3,300 ha) and the south (6,600 ha) of this zone. Between these is a lower, scrubbier formation of intermediate Cynometra (11,300 ha) with a canopy height of 7–8 m. The dry north-western part of the reserve is covered by a low, dense, and often almost impenetrable Cynometra thicket (2,300 ha), with the canopy no more than 5 m high. Altogether, the area of indigenous forest or thicket at this site totals c.38,200 ha.

Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs. Alliance for Zero Extinction (2018): site confirmed as an AZE site during the AZE project (2015-2018). Taxonomy, nomenclature and Red List category follow the IUCN 2016 Red List.

Additional biodiversity: See Box and Tables 2 and 3 for key species. Arabuko-Sokoke has been ranked by BirdLife International as the second most important forest for bird conservation on mainland Africa. More than 230 bird species are recorded including nine globally threatened species. Ploceus golandi is known only from Arabuko-Sokoke and the little-studied Dakatcha woodland (IBA KE009). It occurs mainly in Brachystegia woodland, although its numbers fluctuate. The species’ nest is unknown. Otus ireneae is known only from this forest and one other site in north-east Tanzania. It is confined to Cynometra forest and (at much lower densities) intermediate Cynometra. Arabuko-Sokoke holds by far the bulk of the world’s population, with an estimated 850–1,200 pairs. Arabuko-Sokoke may also hold the world’s largest population of Sheppardia gunningi, with as many as 9,000 pairs thought to be present, primarily in the Cynometra forest. It is also a world stronghold for Anthus sokokensis, with around 3,000 individuals estimated to occur in the Brachystegia woodland alone; its status in other habitat types is not well-known. Zoothera guttata is a scarce but regular intra-African migrant from March–October, and Anthreptes pallidigaster is very local, occurring principally in the Brachystegia woodland, with an estimated population of 2,800 birds. Regionally threatened species include: Casmerodius albus, Thalassornis leuconotus and Podica senegalensis (all recorded occasionally on forest pools); Hieraaetus ayresii (a scarce resident); Stephanoaetus coronatus; Pitta angolensis (a scarce non-breeding visitor, with few recent records); Turdoides squamulatus (local and rarely recorded); and Erythrocercus holochlorus. Non-bird biodiversity: Arabuko-Sokoke is rich in rare and endemic wildlife, especially among the fauna. Six taxa of butterfly endemic to the EastAfrican coast are present, as well as three rare, near-endemic mammals: Rhynchocyon chrysopygus (EN), Cephalophus adersi (EN; found only in Sokoke and Zanzibar) and the distinctive small carnivore Bdeogale crassicauda omnivora. There is also a small population of Loxodonta africana (EN), and Felis aurata, rare in Kenya, may occur. Unusual reptiles include the lizard Gastropholis prasina, and the forest is exceptionally rich in amphibians, including coastal endemics such as Mertensophryne micrannotis. Arabuko-Sokoke supports at least 50 globally or nationally rare plant taxa.

Habitats

Land use: forestry | nature conservation and research | tourism/recreation

IUCN Habitat	Coverage %	Habitat detail
Savanna	6
Forest	85

Threats

Summary of threats to biodiversity at KBA: Arabuko-Sokoke is rich in biodiversity, but of particular importance is the exceptionally high degree of endemism. This, together with the forest’s large area of continuous woody vegetation (most remaining coastal forests cover only a few hundreds of hectares, sometimes much less) gives it a very high conservation value. The forest is managed jointly by the Forest Department and the Kenya Wildlife Service under a Memorandum of Agreement, through the Arabuko-Sokoke Forest Management Team (ASFMT) that brings together these two institutions with the Kenya Forestry Research Institute and the National Museums of Kenya. Extensive licensed logging has occurred in the past, with noticeable negative effects on bird communities in the degraded areas. Licensed selective logging continues on a smaller scale, along with licensed collection of dead wood for fuel. Both these practices have proven difficult to police, and regular poaching of valuable trees continues to be a major problem. Brachylaena huillensis, which is preferred for the carving industry and construction, has been severely affected, as have timber species such as Pleurostylia africana. Illegal hunting, mainly of duiker and elephant shrews, is prevalent, although its impacts are somewhat unclear. Local people use forest products for many purposes, including fuelwood and medicinal plants, and collect water at the seasonal pools. The forest is surrounded by agriculture on all sides. The Mahaji settlement was excised from the eastern edge of the forest after Independence, and pressure remains high from some quarters for degazettement and settlement of the south-eastern Kararacha-Mpendakula section—despite the fact that the soils there are extremely infertile and quite unsuitable for agriculture. More profitable and sustainable uses are possible, including ecotourism, which is already growing in scale, and butterfly farming. These activities are being promoted by ASFMT through the European Union-funded Arabuko-Sokoke Forest Management and Conservation Project (to end in December 2001), implemented by the Forest Department, Kenya Wildlife Service and BirdLife International, and by the work of the Kipepeo butterfly farming initiative of the National Museums and Nature Kenya. The latter assists people living close to the forest to produce butterfly pupae, using leaves from forest trees, for export to Europe and America. In 2000, more than US$ 100,000 was earned from the forest in recorded revenues for tourism, honey, timber, fuelwood, seeds and butterflies. Almost 40% of this went to forest-adjacent communities, who have organized their own Forest Adjacent Dwellers Association to promote sustainable forest use. A management plan is currently being developed, which will include participatory forest management as a key component. These are promising signs for the future.

Threat level 1	Threat level 2	Threat level 3	Timing
Agriculture & aquaculture	Annual & perennial non-timber crops	Shifting agriculture	Ongoing
Agriculture & aquaculture	Annual & perennial non-timber crops	Small-holder farming	Only in the future
Agriculture & aquaculture	Livestock farming & ranching	Nomadic grazing	Ongoing
Agriculture & aquaculture	Livestock farming & ranching	Small-holder grazing, ranching or farming	Ongoing
Biological resource use	Logging & wood harvesting	Intentional use: subsistence/small scale (species being assessed is the target) [harvest]	Ongoing
Natural system modifications	Fire & fire suppression	Trend Unknown/Unrecorded	Ongoing
Natural system modifications	Dams & water management/use	Dams (size unknown)	Ongoing
Invasive & other problematic species, genes & diseases	Invasive non-native/alien species/diseases	Named species	Ongoing
Residential & commercial development	Housing & urban areas		Only in the future
Residential & commercial development	Tourism & recreation areas		Ongoing
Energy production & mining	Mining & quarrying		Only in the future
Transportation & service corridors	Flight paths		Only in the future
Transportation & service corridors	Roads & railroads		Ongoing
Human intrusions & disturbance	Recreational activities		Only in the future
Human intrusions & disturbance	Work & other activities		Only in the future
Pollution	Garbage & solid waste		Ongoing
Climate change & severe weather	Habitat shifting & alteration		Ongoing
Climate change & severe weather	Droughts		Ongoing

Additional information