Investigations were carried out in three fish-pond complexes in 1993-1999. Clutches were initiated 21 April-9 July (mean 11 May). The average clutch size was 3.83 ± 0.44. In total 66.3% breeding pairs reared fledglings (n = 163). The population studied had a higher hatching success (83.4%) compared to data reported in literature but fledging success (1.29 young per breeding, and 1.94 per successful pair) was lower than those documented in Sweden and Russia. 22.3% of dives observed during foraging bouts were successful. Ponds, which seemed suitable for breeding, were less frequently occupied by breeding pairs when stocked after mid-May than ponds stocked earlier. The proportion of nests which produced fledglings was lower in ponds used for recreation than in ponds without such activities. Removal of littoral vegetation using heavy machinery was responsible for destroying of nearly one third of clutches initiated after 15 June.
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