Berga flood-plain is in Ada Berga District (Wereda) of West Shoa Zone. It lies 75 km west of Addis Ababa and c.24 km north of Holeta town. It is part of the vast plains on the Central plateau of Shoa, in the Ethiopian North-western Highlands. The Berga river, the main tributary of the Awash river, drains the plain. The vegetation of the Berga flood-plain comprises grasses, sedges and other plants peculiar to these areas, e.g. Trifolium spp. (including the endemdic T. schimperi and T. calancephalum), Haplocarpha schimperi, H. hastata,a Cerastium sp., Cyperus spp. (including C. dichroostachyus, C. atronervatus and C. atroviridis), Ranunculus multifidus, R. simensis, Rumex natalensis, R. marginulata, Uebelinia kigesiensis, Schoenopletus corymbosus, Vossia cuspidata and Habenaria filicornis. The most important and palatable grasses in this area are species of Pennisetum and Andropogon. As on the Sululta plain (site ET024), there are places where water lies up to 50 cm deep, and such areas are often covered with floating grasses, particularly Odontelytrum abyssinicum, and pondweeds Potamogeton spp., and often have the purple flower spikes of Aponogeton abyssinicus emerging from the surface.
See Box and Table 3 for key species. This site is important for a number of globally threatened species, but is particularly so for Sarothrura ayresi. Currently, Sululta plain (site ET024) and Berga flood-plain are the only known locations for this species in Ethiopia, and together account for over 65% of the global population. The species was rediscovered at Sululta in 1995 and then at this site in 1997, when 200 adults were estimated to be present. The first ever nest (with six eggs) was found in August 1999, confirming that the species breeds at this site. Other threatened species include Grus carunculatus (uncommon, with a pair recorded in August 1998), Rougetius rougetii (an uncommon resident on the river banks), Macronyx flavicollis (not uncommon) and Gallinago media (autumn passage migrant of unknown abundance). The open plains are a very important feeding and breeding area for Cyanochen cyanopterus, with more than 260 recorded in August 1998. Vanellus melanocephalus also occurs in good numbers as the plains dry out. More than 700 Bostrychia carunculata have been counted in parts of the plains during the 1998 waterfowl census. Over 100 species have been recorded at this site.
Non-bird biodiversity: None known to BirdLife International.
Pressure/threats to key biodiversity
Unlike neighbouring valleys, the valley where Sarothrura ayresi has been found is not cropped for hay. Whether there are factors that make harvesting in this area problematic is unknown, but any changes in land-use could have severe implications for the productivity of Sarothrura ayresi. Chicks hatched at the end of the rainy season are particularly vulnerable.