József Gyurácz, Gábor Horváth, Tibor Csörgõ, László Bank and Sándor Palkó
Influence of macrosynoptic weather situation on the autumn migration of birds in Hungary
In the study we have examined the relation between the European macrosynoptic weather situation and the number of birds captured a day at four Hungarian ringing stations during the autumn migration. Along the research we examined the data of 32 809 individuals of 8 species using different migration strategies. Using the daily capture data at the four stations we constructed the migration diagrams for each year. We chose the migration peak days within ten-day periods and examined how these peak days or their preceding days are distributed over Péczely's macrosynoptic weather situations. Comparing the 8 bird species no significant difference in distribution of the peak days over the macrosynoptic weather situations was found (ANOVA: F7,376 = 1.81, p = 0.084). 85% of the migration peak days for all the species were connected with anticyclones, 10% with meridional cyclone / cold front situation and 5% with other cyclonic ones. The most frequent weather situation on the migration peak days was central anticyclone, which occurred in 61 cases.
László Bank, László Haraszthy, Adrienn Horváth and Győző F. Horváth
In this study, the results of a long-term nest box installation program of the Common Barn-owl Tyto alba (Scopoli, 1769) in Southern Hungary were evaluated, which program was conducted during a 24-year period (1995–2018). The percentages of occupied nest boxes ranged from 9.72 to 73.44% in the first breeding periods while this varied between 0 and 41.46% in the case of repeated clutches in the same nest boxes with second broods. A total of 1,265 breeding attempts were recorded including 1,020 (80.63%) in the first and 245 (19.36%) in the second breeding periods, from which a total of 210 (16.6%) clutches did not produce any fledglings. The modal clutch size was 7 eggs in both first and second annual clutches. However, the value of productivity was higher in the case of larger clutch sizes and we found significant linear relationship between initial clutch size and fledgling production per nesting attempt in both breeding periods. Significant variation of reproductive parameters was observed among the years. The proportion of egg loss showed significant decline, while the change of hatching success and the variation of annual productivity showed significant slight positive linear trend during the 24 years. Our results suggested that despite the outlier values of reproduction characteristics in the extreme years with negative effect, a relatively stable Common Barn-owl population can be maintained by the placement of nest boxes in the investigated region.