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Location Kenya, Coast Province
Central coordinates 39o 16.00' East  4o 28.00' South
IBA criteria A1, A3
Area 250 ha
Altitude 100 - 300m
Year of IBA assessment 2001


Site description This IBA consists of wet coastal forest on a small hill rising from the coastal plain some 60 km south-west of Mombasa, just west of the main Mombasa–Lungalunga road. The hill itself is a part of the alkaline igneous complex centred on Dzombo Hill (IBA KE010) and is known to have significant deposits of ores containing manganese and niobium. Mrima has been prospected over several times by geologists and there are many deep test holes, although no large-scale mining has yet taken place. Rainfall is at least 1,100 mm/year, and probably greater, since precipitation is produced as cloud rises over the slopes during the south-east monsoon. The forest is undifferentiated, with exceptional plant species diversity. Large trees include Combretum schumannii, Milicia excelsa, Terminalia sambesiaca, Nesogordonia holtzii, Sterculia appendiculata, Drypetes usambarica var. mrimae, Cordyla africana, Albizia glaberrima var. glabrescens, Newtonia paucijuga, Erythrina sacleuxii, Antiaris toxicaria, Lovoa swynnertonii, Zanha golungensis, Diospyros mespiliformis, Inhambanella henriquesii, Manilkara discolor, Mimusops aedificatoria and Synsepalum brevipes. Mrima Forest Reserve was gazetted in 1961, and the site was made a strict nature reserve under the Forests Act in the early 1980s. Mrima Hill is also a Kaya, recognized by the site’s gazettement as Mrima Hill Sacred Grove National Monument in 1992. The Kayas are relict patches of forest that once sheltered the fortified villages of the Mijikenda people (in Mrima’s case, the Digo) on the Kenyan coast. They have spiritual and ceremonial significance and are customarily protected by a Council of Elders.

Key Biodiversity See Box and Table 3 for key species. Mrima holds non-breeding populations of the globally threatened Zoothera guttata, and supports a rich avifauna characteristic of the East African coastal forests. The globally threatened Tauraco fischeri (also a restricted-range species) and Anthreptes reichenowi are both fairly common here. Forty-seven forest bird species are recorded. Pogonocichla stellata and Zoothera gurneyi are known from Mrima but no other Kenyan coastal forests. Both are probably altitudinal migrants. Regionally threatened species include Erythrocercus holochlorus.

Non-bird biodiversity: Mrima’s vegetation is exceptionally diverse. A 1989 expedition recorded over 270 taxa, including 25 that are globally or nationally rare. Among others, the rare trees Uvariodendron gorgonis and Gigasiphon macrosiphon are known from this site, though the latter was not relocated in 1989. The rare butterfly Eresinopsides bichroma also occurs. Mammals include the threatened Rhynchocyon petersi (EN), Galagoides zanzibaricus (LR/nt) and Colobus angolensis palliatus. Bats occur in the mineshafts, including the rare and localised Myonycteris relicta (VU).

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Fischer's Turaco Tauraco fischeri resident  1999  present  A1, A3  Near Threatened 
Mombasa Woodpecker Campethera mombassica resident  1999  present  A3  Least Concern 
Chestnut-fronted Helmet-shrike Prionops scopifrons resident  1999  present  A3  Least Concern 
Green-headed Oriole Oriolus chlorocephalus resident  1999  present  A3  Least Concern 
Yellow Flycatcher Erythrocercus holochlorus resident  1999  present  A3  Least Concern 
Fischer's Greenbul Phyllastrephus fischeri resident  1999  present  A3  Least Concern 
Tiny Greenbul Phyllastrephus debilis resident  1999  present  A3  Least Concern 
Black-bellied Glossy-starling Lamprotornis corruscus resident  1999  present  A3  Least Concern 
Spotted Ground-thrush Zoothera guttata winter  1999  present  A1  Endangered 
Plain-backed Sunbird Anthreptes reichenowi resident  1999  present  A1, A3  Near Threatened 
Eastern Green Tinkerbird Pogoniulus simplex resident  1999  present  A3  Least Concern 

IBA Monitoring

2008 high near favourable medium
Medium - based upon reliable but incomplete / partially representative data

Climate change and severe weather drought happening now whole area/population (>90%) slow but significant deterioration high
Energy production and mining mining and quarrying likely in short term (within 4 years) some of area/population (10-49%) moderate to rapid deterioration medium
Transportation and service corridors roads and railroads happening now small area/few individuals (<10%) no or imperceptible deterioration low

Forest   0 0 good (> 90%) moderate (70-90%) near favourable

Whole area of site (>90%) covered by appropriate conservation designation  No management plan exists but the management planning process has begun  Substantive conservation measures are being implemented but these are not comprehensive and are limited by resources and capacity  medium 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Mrima Forest Reserve 390 protected area contains site 250  
Mrima Hill Sacred Grove National Monument Other Area 0 protected area contained by site 0  


IUCN habitat Habitat detail Extent (% of site)
Forest Lowland forest - undifferentiated  -

Land use

Land-use Extent (% of site)
forestry -
nature conservation and research -

References Britton et al. (1980), Larson (1991), Mlingwa et al. (2000), Robertson and Luke (1993), Waiyaki and Bennun (2000).

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Mrima Hill Forest. Downloaded from on 27/10/2016

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