Notes on the breeding biology of the clamorous reed warbler Acrocephalus stentoreus in Tajikistan

The clamorous reed warbler Acrocephalus stentoreus brunnescens is a widespread but insufficiently studied species from Central Asia. We recorded first singing territorial birds at Kabodian region of Tajikistan in small reed patches at crop field at 28 April 2011. We observed transient birds feeding and singing in bushes and tree crowns till 14 May in Kabodian region and at 29 June in Ishkashim region (Panj river valley, 2700 m above sea level, N 36°55' E 72°11'). We inspected a settlement of сlamorous reed warblers at a narrow canal with reed stands near Teshik-Tash village (N 37°06' E 68°14') at 21 May. At the reed patch 180 m long and 3 m wide we found 10 warbler pairs with nests and 4 bachelor males. There were one nest with 3 newly-hatched chickens, three nests with 4 eggs (one contained also an egg laid by cuckoo Cuculus canorus), one nest with 3 eggs, one nest with 2 eggs, two nests with 1 egg, two building nests, five abandoned unfinished nests and one 2010-year nest. Birds preferred green reed stems for supporting their nests; one nest was built on a little elm tree above the water. Distances between occupied nests were 2-26 m (in average 11.5 m). Unlike many its congeners A. s. brunnescens has reduced territoriality, as the other species breeding at semidesert lakes - the paddyfield reed warbler A. agricola. We discuss the phenomenon of reduced territoriality as adaptation for birds breeding at unstable but rich of food wetlands in warm climate.