email a friend
printable version
Location Tanzania, Arusha
Central coordinates 35o 10.00' East  3o 40.00' South
IBA criteria A1, A4i, A4iii
Area 116,000 ha
Altitude 1,030 m
Year of IBA assessment 2001

Site description Lake Eyasi is the most significant water-body in the Eyasi and Yaida internal catchment basin, which also includes Wembere steppe (site TZ043) and Lake Kitangire (TZ026). The lake lies in a trough between the Mbulu Highlands to the east and south-east and the Ngorongoro Highlands to the north and north-west. It is 80 km long with an average width of 14.5 km and is fed mainly from the south-west, where the Sibiti river flows in from Lake Kitangire. However, only during wet years is this a significant inflow of water. The shallowness of the lake, the low amounts of direct precipitation (around 600 mm per annum) and high rates of evaporation ensure the water is highly alkaline. During years of low rainfall the lake is reduced to a dry soda crust. The escarpment wall to the north-west rises some 800 m, virtually from the shore of the lake, and assists in protecting the western shoreline. To the north-east numerous farms have expanded in recent years exploiting the seasonal streams to grow vegetables.

Key Biodiversity See Box for key species. The lake holds large numbers of waterbirds particularly Phoenicopterus ruber and Phoenicopterus minor. There is a regular, virtually constant, movement of these species and of Mycteria ibis between the lake and Lake Manyara. There is usually sufficient fresh/brackish water to provide habitat for a few Gallinago gallinago and the occasional Calidris temminckii. There are few trees suitable as nest-sites for large waterbirds, but ground-nesting Platalea alba breed on offshore islands. At least two Tanzanian endemics are known from lake-shore habitats. Cosmopsarus unicolor reaches its altitudinal limits to the north of the lake near Mang’ola and Agapornis fischeri was formerly common, at least along the eastern shore. Apalis karamojae frequents Acacia drepanolobium woodland throughout the Eyasi drainage basin, but is extremely local. As yet there are no records from lake-shore habitat. At least one species of the Serengeti plains EBA and 29 species of the Somali–Masai biome have been recorded from the surrounding area (see Tables 2 and 3).

Non-bird biodiversity: None known to BirdLife International.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Greater Flamingo Phoenicopterus roseus winter  1995  50,000 individuals  A4i  Least Concern 
Lesser Flamingo Phoeniconaias minor winter  1995  700,000 individuals  A1, A4i  Near Threatened 
Yellow-billed Stork Mycteria ibis winter  1995  11,072 individuals  A4i  Least Concern 
African Spoonbill Platalea alba winter  1995  2,850 individuals  A4i  Least Concern 
Great White Pelican Pelecanus onocrotalus winter  1995  15,831 individuals  A4i  Least Concern 
Pied Avocet Recurvirostra avosetta winter  1995  2,002 individuals  A4i  Least Concern 
Grey-headed Gull Larus cirrocephalus winter  1995  3,954 individuals  A4i  Least Concern 
Fischer's Lovebird Agapornis fischeri resident  2000  present  A1  Near Threatened 
A4iii Species group - waterbirds winter  1995  500,000-999,999 individuals  unknown  A4iii   

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Ngorongoro Conservation Area World Heritage Site 809,440 protected area overlaps with site 16,886  


IUCN habitat Habitat detail Extent (% of site)
Artificial - terrestrial   11%
Wetlands (inland)   75%
Grassland   13%

Land use

Land-use Extent (% of site)
agriculture -
forestry -

References Baker (1993, 1997), Elliot (1983), Rose and Scott (1997).

Contribute  Please click here to help BirdLife conserve the world's birds - your data for this IBA and others are vital for helping protect the environment.

Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Lake Eyasi. Downloaded from on 23/10/2016

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