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The work was carried out in the villages of the Łomianki commune near Warsaw, Poland (52°20'N, 20°50'E) in 1994 and 1995. From among 315 clutches of Tree Sparrows studied, 20 exhibited one-day interruptions in the laying of first and second broods, while 2 were characterised by two-day interruptions. Amongst third broods, there was just a single one-day interruption noted in each year of the study. Interruptions did not occur immediately prior to the laying of the last egg in a clutch. Only in the case of the first brood in 1995 could a period of cold account for interruptions; in the remaining cases, the phenomenon must have been influenced by non-meteorological factors. The Tree Sparrow resembles the House Sparrow Passer domesticus in having far fewer interruptions to laying than other small hole-nesting birds, such as tits Parus spp. This is probably a reflection of the genus Passer having evolved in dry areas, where the accumulation of body reserves in the female prior to laying is an adaptation reducing the length of the breeding period to match the time associated with the rainy season, when food is abundant.
The dynamics of the biochemical parameters of the external mucus of carp Cyprinus carpio L. exposed to 1 μM concentrations of heavy metal salts (CuSO₄·5H₂O Pb(NO₃)₂ and ZnSO₄·7H₂O) were studied. The biochemical parameters of external mucus (specific weight, pH, total protein, hemoglobin, ketones) were measured during exposure at 1, 3, 6, 24 h and regularly during a 21-day post-exposure period. Significant changes in hemoglobin and total protein concentrations were determined during the period of exposure to heavy metals and after it. Correlations of changes in biochemical parameters of mucus with the intensity of some parameters of sun activity and radio radiation flow were found during the post-exposure period. It was concluded that it is necessary to assess the possible complex effects of various origin and the magnitude of environmental factors on fish.
The paper analyses the effect of egg dimensions (volume, breadth, and length) on the growth and development of Tree Sparrow nestlings on successive days of life. Egg size did not influence nestling mortality. It was found that for most days of nestling life, the mean volume and breadth of eggs were positively correlated with the mean mass of nestlings in the nest. Similarly, the deviation of the volume and breadth of a particular egg from the mean egg volume and breadth in the clutch was positively correlated with the deviation of nestling mass from the mean nestling mass in the nest. Nestling growth and development in terms of asymptotic mass (g), maximum growth rate (g/day), tarsus length, and longest remex length were also positively correlated with egg size. The effect of egg size was particularly pronounced in the period of termination of intensive growth rate, development of thermoregulation, and feather development. It is possible that larger eggs contain more microelements, hormones, antioxidants, and vitamins.
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