|Most recent IBA monitoring assessment|
|Year of assessment||Threat score (pressure)||Condition score (state)||Action score (response)|
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The IBA is a system of sewage reservoirs situated in natural depressions of the Karaoi plateau, in the semi-desert zone, 80 km north of Almaty. It includes Sorbulak lake itself (formed in 1975-1985) and the line of small lakes with semi-running water with dykes and channels in the Zhamankum hollow. The maximum length of Sorbulak lake is 35 km, width up to 15 km, depth 22 m. The total length of the small lakes in the Zhamankum hollow is about 25 km, maximum width up to 3 km, average depth about 2 m. The lakes have indented coastlines, with many capes, spits, coves and a number of islands of different size. The water is fresh, but with a very high concentration of nitrates. In the second half of the summer it becomes brackish due to evaporation and drying out. It is an IBA for breeding, migrating and wintering waterbirds.
About 300 species of 18 orders have been recorded. Most typical are Anseriformes (28 species) and Charadriiformes (more than 50 species). In some years, the site held the largest SE Kazakhstan breeding colonies of the following species: Larus ridibundus - 8,000 pairs, Sterna nilotica - 2,500 pairs, Phalacrocorax carbo -5,000 pairs, Glareola pratincola - 140 pairs and Himantopus himantopus - 70 pairs. On the coast, Tadorna tadorna and T.ferruginea breed - up to 100 pairs or more. At the end of the summer moulting flocks of T.ferruginea number up to 20,000. On passage, large numbers of wildfowl have been recorded including Anas platyrhychos (up to 50,000), Anas acuta (35,000), Netta rufina (15,000) and Fulica atra (40,000). In some winters, Mergellus albellus numbers reach up to 12,000 and Anas platyrhynchos 20,000. During passage, large numbers of passerines - up to 50,000 or more - concentrate in the water fringe vegetation. These include Sturnus vulgaris, Sturnus roseus, Hirundo rustica, Hirundo rupestris, Motacilla sp etc.
Non-bird biodiversity: Around the lakes, there is typical semi-desert vegetation with low bushes (Salsola, Calligonum, Rosa, Spirea etc.) and grass. In the lakes, there are up to 10 species of fish, the most common are Carassius auratus and Cyprinus carpio. There are two species of amphibians Rana ridibunda and Bufo viridis, 8 species of snake, and one tortoise Agrionemis horsfieldi. Of mammals, there are fox (Vulpes vulpes), desert fox (Vulpes corsac), wolf (Canis lupus), and a number of rodents, the most common being Spermophilus fulvus.
BirdLife International (2021) Important Bird Areas factsheet: Sorbulak Lake System. Downloaded from http://www.birdlife.org on 21/01/2021.