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Breeding season timing and breeding success of Tufted Duck were studied on three lakes in the years 1987-1989. Clutch laying began in mid May, earliest in a Black-headed Gull colony, and continued to the first days of July. Clutch size ranged between 3 and 18 eggs ( x = 9.3, SD = 2.8, n = 331) and did not differ significantly between lakes and years. There was a significant reduction in clutch size as the nesting season advanced (from 13.3 eggs in May to 6.3 in July). Nesting losses (25-90% failed nests or clutches) grew as the breeding season progressed. Ducklings came to the water beetween the end of June and the beginning of August. Duckling losses (20-90%) were inversely correlated with nesting failures and due mainly to predation. The investigated populations were characterized by very limited production of young in most lakes and seasons and, as a consequence, by a decline in the population to half that noted in the 1970s.
We recorded thirty six Odonata species at five natural and semi-natural peat bog water bodies in the environs of Borne Sulinowo (NW Poland) in two seasons: 2005 and 2006. Besides the predominant number of eurytopic dragonflies, two reported species were tyrphobiontic and three tyrphophilic. Species compositions in particular habitats are shortly discussed.
Thirty-seven dragonfly (Odonata) species were recorded at three localities that were studied during three seasons (2005, 2006 and 2007) in the environs of Borne Sulinowo, northwestern Poland. The article confirms that the studied localities have a high natural value and support populations of dragonflies that are sensitive to anthropogenic changes.
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