The National Park is a combination of Lakes Abijatta and Shalla, and the land between and around them, in East Shewa Zone. The park is 56 km south-west of Lake Ziway and to the west of the main Mojo–Moyale road. Both lakes are without outlets, and the water is alkaline. Lake Abijatta is very shallow (up to 14 m), while Lake Shalla, in the crater of an extinct volcano, is very deep (up to 266 m). Three rivers, the Gogessa, Bulbula and Hora Kelo, feed Lake Abijatta. The lake had an area of 19,600 ha, a shoreline of 60 km and was full of fish, but by 1995, it had shrunk dramatically and no fish-eating birds were seen. Water is being removed from the lake to feed a soda-ash extraction plant, and from the Bulbula river for irrigation. Fish and aquatic plants now regularly occur only around the mouth of the Bulbula and Hora Kelo rivers. The shoreline is gently sloping. The nearby Acacia woodland used to have a more or less continuous (25-m-high) canopy, but most of the trees have been felled and turned into charcoal or sold as fuelwood. Lake Shalla is south of Lake Abijatta and divided from it by a narrow strip of higher land, part of the old crater rim. Two rivers feed the lake. It has an area of c.33,000 ha and a shoreline of 118 km. It has several hot, somewhat sulphurous springs around the shore, and nine islands of which at least four are important breeding sites for birds. Bulrushes grow where the hot springs and rivers enter the lake, but most of the shore comprises steep cliffs, thus there is little place for wading birds and there are no fish. The vegetation to the east and south of the lake is Acacia–Euphorbia savanna, the most common trees being the woodland Acacia spp. (A. etbaica and A. tortilis) and Euphorbia abyssinica, and bushes of Maytenus senegalensis. The woodland around the lakes is important in keeping the highly fragile soil structure intact. In undisturbed/ungrazed areas there is a rich grass and herb flora.
See Box and Table 3 for key species. Over 400 species have been recorded from the park. The park is at one of the narrowest parts of the Great Rift Valley, a major flyway for both Palearctic and African migrants, particularly raptors, flamingos and other waterbirds. Among the globally threatened species known from the park are: Aquila heliaca (a rare passage migrant); Falco naumanni (an uncommon passage migrant with a few wintering); Circus macrourus (fairly common passage migrant, with a few wintering); and Acrocephalus griseldis (status unknown). Glareola nordmanni has also been recorded. Fish-eating birds have mostly abandoned the park since the fish in Lake Abijatta died out. However, huge numbers of many wetland species remain, such as Phoenicopterus ruber, P. minor (the numbers of which fluctuate), Anas clypeata and Charadrius pecuarius. The fringes of Lake Abijatta form an important feeding and resting ground for waders and ducks, particularly Anas clypeata, Recurvirostra avosetta, Calidris minuta and Philomachus pugnax. Smaller insectivores, such as Motacilla flava and Hirundo rustica, have also been recorded in massive numbers. The islands of Lake Shalla used to be important breeding sites for cormorants, storks and pelicans, and colonies of Phalacrocorax carbo and small numbers of Pelecanus onocrotalus still occur. One endemic, Poicephalus flavifrons, and five Afrotropical Highlands biome species have also been recorded. Among the unusual visitors to Lake Abijatta are Calidris alpina, C. melanotos, Charadrius mongolus, C. alexandrinus, Pluvialis fulva, P. squatorola, Phalaropus lobatus, Glareola nordmanni, Grus carunculatus (five in 1991–1992), Netta erythropthalma, Larus ichthyaetus and L. cachinnans.
Non-bird biodiversity: None known to BirdLife International.
Pressure/threats to key biodiversity
The National Park was proposed because of the diverse avifauna, in particular waterbirds, and the scenic beauty of the area. During the 1980s, the park developed well. Staff were properly housed, much of the area was well controlled, and well visited (being adjacent to a major recreation resort, Lake Langano). However, this was all without the support of the local people, and during the early 1990s the park went into decline. By the end of 1996, the rehabilitation of the park was under way and there are plans for active integration of local communities in its future planning and development. Despite the unsuitability of the soils for agriculture and grazing, local people use the area for both of these activities. Additionally, much of the Acacia woodland surrounding Abijatta has been cut down for charcoal. People from the urban centres north and south of the area (many probably unemployed) used to come and fish illegally in Lake Abijatta. Currently, small groups come and remove the Acacia trees and are even removing the salty soil from the shoreline to sell. However, the soda-ash extraction plant on the north-eastern side of Lake Abijatta probably has the greatest impact on the area. Since the plant was set up, the lake area has diminished and many fish have died. The effect of climate change is unclear, although geological records from the area show that there have been great historical fluctuations in lake-levels. Abijatta–Shalla used to support one of the largest African colonies of Pelecanus onocrotalus: the birds bred on an island in Lake Shalla and fed their chicks on fish caught in Lake Abijatta. The pelicans along with other fish-eating birds deserted the area due to the declining fish stocks in the lake. This situation appears to be reversible: in December 1996 the lake-level rose (due to heavy rains), and there were reports of fish in the lake as well as a group of pelicans apparently fishing. Key development requirements are: an integrated water-management and monitoring programme; direction of revenue from the growing tourist industry to the wildlife authority; integration of local people in the development of the park; and control of the use of and access to the woodlands.
BirdLife International (2021) Important Bird Areas factsheet: Abijatta - Shalla Lakes National Park. Downloaded from
http://www.birdlife.org on 24/01/2021.