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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.
Intestinal nematodes of the Aythyini ducks in Western Pomerania. Biology, including ecology, of the Aythyini renders them particularly attractive subjects of parasitological studies. The tribe is represented in Poland by 4 nesting species; two of them, Aythya fuligula and A. ferina, are very abundant game birds. However, their helminth fauna, including nematodes, is stili very poorly known. This study was aimed at quantifying the structure of parasitic intestinal nematodes of the Westem Pomeranian Aythyini. The study, performed in 1999-2004, involved a total of 71 ducks representing 3 species: A. ferina, A. fuligula, and A. marila. The nematodes, isolated from the intestines, were fixed in 75% ethyl alcohol and cleared in lactic acid. Among the 9668 helminth individuals found, 589 (6.1 %) represented the phylum Nematoda. They were found in 57 ducks (80.3% of all the ducks examined). The nematodes - belonged to the following 4 families: Amidostomatidae, Tetrameridae, Acuariidae, and Trichuridae. They were identified as representing 8 species, 2 genera (Amidostomoides sp. and Tetrameres sp.), and 1 subfamily (Capillariinae gen. sp.); in addition, 1 damaged individual could be identified as a nematode only. The highest prevalence (57 .8%), at mean intensity ( 4.8 inds), was typical of Amidostomoides petrovi (Shakhtahtinskaya, 1956) Lomakin, 1991, while Tetrameres fissispina (Diesing, 1861) Travassos, 1914 occurred with the highest intensity (15.1 inds) and 12.7% prevalence. Nematodes of the subfamily Capillariinae occurred with a fairly high intensity (averaging 10.0 inds) as well, although their prevalence was not high, either (4.2% of all ducks were infected). The nematofauna studied was clearly dominated by A. petrovi, T. fissispina, and Capillaria anatis (Schrank, 1790). The total frequency of occurrence of those species was close to 80%; their dominance indices exceeded the threshold value of 0.1 and amounted to 1.6 (the dominant A. petrovi), 0.2, and 0.5 (the subdominants T.fissispina and C. anatis, respectively). The three species listed occurred with the highest mean density (2.8; 1.9; and 1.8 nematode per duck examined). No age- (adult vs. immature) or sex- (males vs. females) related differences in the quantitative structure of the parasitic Aythyini nematodes were observed.
Specimens previously identified as Fimbriaria fasciolaris or Fimbriaria sp. from Poland, Ukraine and the Czech Republic were re-examined. The revision revealed Fimbriaria czaplinskii from naturally-infected Anas platyrhynchos dom., Anas acuta and Aythya fuligula (new host records) in Poland, Tadorna tadorna from the Black Sea coast and Aythya ferina from the coast of the Sea of Azov, Ukraine (new host records), Anas platyrhynchos, Aythya fuligula and Aythya ferina (the latter two being new host records) from Moravia, Czech Republic (new geographical record). The diagnostic characters of F. czaplinskii are commented and updated from an original erroneous description. The most reliable distinguishing character is the structure of the copulatory part of the vagina, which is funnel-shaped and usually has smooth internal surface. The characters associated with the cirrus size and armament and the number of genital primordia per segment are not considered reliable differentiating characters. A lectotype and paralectotypes of F. czaplinskii are designated.
A new cestode species from the genus Fimbriaria Froelich, 1802 is described. The parasites were found in the duodenum of Aythya fuligula L. and A. nyroca Güld. Described here new species differs from those previously recorded mainly by the mode of egg evacuation from gravid strobila: the Fimbriaria sarcinalis eggs leave the uterus in large irregular packets. Negative results of experimental infection of Acanthocyclops viridis and Macrocyclops albidus (Copepoda) considered as potential intermediate hosts of this new species of cestode are also described and discussed.
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Anomalie w ubarwieniu czernic /Aythya fuligula/

67%
Kulon
|
1997
|
tom 02
|
nr 1
53-55
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