Waterbird populations during dry and wet years in the Hamoun Wetlands Complex, Iran/Afghanistan border

The total extent of the Hamoun wetlands (Pouzak, Hirmand and Sabari) insucculent years (fully wet years) fluctuates from 200,000 to 570,000 ha, but in dry years it reduces to almost zero. The Hirmand River is the only important water resource of theHamoun wetlands. The wintering population of waterbirds varies from 600,000 individualsto zero. The population of wintering waterbirds in a January waterbird count (Scott 1972)comprised 537,482 individuals (wet year), but in January 2007, it was zero because thewetlands were completely dried out. During wet years, 77 species of waterbirds have been recorded in Hamoun. Under succulent conditions in 1972, 1975, 1981, 1983 and 1994, 43 Iranian protected bird species (both terrestrial and aquatic) and three globally threatened species (Pelecanus crispus, Oxyura leucocephala and Aythya nyroca) were observed at the Hamoun wetlands (Mid-winter Waterbird Census, Scott 1972, 1975, DOE 1981–2004).