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Location Senegal, Cap Vert,Thiès
Central coordinates 16o 55.00' West  15o 8.00' North
IBA criteria A4i
Area 4,000 ha
Year of IBA assessment 2001

Site description This site consists of a string of permanent freshwater lakes and additional temporarily wet depressions (niayes) lying along a line running north-east from the outskirts of Dakar to around 60 km south-west of St Louis. The lakes lie behind the ridge of coastal sandy dunes, in shallow depressions at 1–4 m above sea-level, over a distance of c.150 km. They are replenished both by rainfall and from the underlying water-table, which lies close to the surface. The wetlands cover 40 km² at low water; at high water, all the lakes can increase their surface area five-fold. The largest lakes lie at the southern end and include Nhiarhol Pool and the lakes Mbao, Mbeubeussé, Retba, Tanma, Youyi (or Malika) and Ourouaye. Lake Retba is the largest, with an open water surface of 5 km by 1.7 km wide at low water. Niaye Hann Mariste consists of a depression covering a surface area of about 30 ha (1.3 km by 200 m), but this dried out completely in 1997 due to evaporation, compounded by abstraction of water for agriculture and building construction. The surrounding vegetation is subjected to seasonal inundation and the area is characterized by the oil-palm Elaeis guineensis. There are also elements of vegetation more typical of the Sudan–Guinea Savanna biome and Guinea–Congo Forests biome (e.g. Prosopis africana and Ficus capensis). These are able to flourish here due to the high moisture content of the soils, which results from the water-table lying close to the surface and the moisture-bearing Alizé winds blowing in from the Atlantic. The whole site is very important in terms of human use, for cattle-grazing, fishing, vegetable, fruit and rice-growing and market gardening (estimated at 90% of national production). Many of the individual lakes also have religious and cultural significance.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Little Grebe Tachybaptus ruficollis breeding  1996  250 breeding pairs  medium  A4i  Least Concern 
Little Grebe Tachybaptus ruficollis winter  1996  500 individuals  A4i  Least Concern 
Black Heron Egretta ardesiaca breeding  1996  250 breeding pairs  A4i  Least Concern 
Purple Swamphen Porphyrio porphyrio winter  1996  104 individuals  A4i  Least Concern 
Slender-billed Gull Larus genei winter  1999  145 individuals  A4i  Least Concern 
White-winged Tern Chlidonias leucopterus winter  1988  2,000 individuals  A4i  Least Concern 


IUCN habitat Habitat detail Extent (% of site)
Artificial - terrestrial   59%
Shrubland   3%
Grassland   37%

Land use

Land-use Extent (% of site)
agriculture -
fisheries/aquaculture -
urban/industrial/transport -
water management -

Other biodiversity None known to BirdLife International.

References Diatta et al. (1998), Hughes and Hughes (1992), Reynaud (1999).

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Niayes (from Dakar to St Louis). Downloaded from on 25/10/2014

To provide new information to update this factsheet or to correct any errors, please email BirdLife