Age Structure of the Long-Eared Owl ( Asio otus ) Migration at Bukowo-Kopań Station (Southern Baltic Coast) in Autumns 1996-2003 Over 2000 Long-eared Owls were caught (217 adult and 1827 immatures) at Bukowo-Kopań station (54°21'N, 16°17'E / 54°28'N, 16°25'E), in the central part of the Polish Baltic coast, during autumn seasons 1996-2003. Migration of this species had wave-like pattern with three distinguished passage waves. There were differences between young and adult birds passage in subsequent passage waves (statistically significant only in autumns 2000 and 2003, in other seasons they were non-significant. The value of X 2 -test calculated for all seasons together was high and differences were significant ( X 2 = 10.96, p < 0.01). Generally, very high variation must be stressed. Young birds dominated during autumn migration (on average they constituted 89%) but this number varied distinctly in different years. The immatures were the most numerous in the second and third wave (they were especially numerous in the third wave in years with the highest number of caught birds). Adult owls migrated a bit earlier - average passage data was earlier by 1 to 16 days in various seasons. All data point at very high variability of the Long-eared Owl migration and necessity of deeper studies on this phenomenon.

Autumn migration of the Goldcrest (Regulus regulus) in western Hungary At a site in Tömörd (W Hungary) in 2000-2001, numbers of Goldcrests peaked on the last days of October and the first days of November (24 Oct. - 10 Nov.). Migration of both sexes was somewhat differentiated - females migrated a little bit earlier than males. Goldcrests arriving in the peak migration periods stored significantly more fat than individuals ringed in the other periods (ANOVA: F4,305 = 28.6, p < 0.0001). The spatial occurrence of migrating Goldcrests revealed clumped distribution - 83% of the total captures took place in a dense scrubland, 17% in a grassland overgrown by bushes. During the migration there were more males - the average sex ratio in Tömörd was 1.61 : 1. These results are discussed in relation to the species' migration strategies and patterns of occurrence in northern Europe.

Variation of morphometric parameters within the Savi's Warbler (Locustella luscinioides) population in eastern Poland Characteristics of the intra-populational variation of morphological parameters in the Savi's Warbler is based on measurements of 512 individuals caught in the breeding seasons of 1989-1998 in the Bagno Ławki peatbog (the southern basin of the Biebrza river valley). In the studied population, adult Savi's Warblers had longer and more rounded wing, longer tail and larger body mass than young individuals. Moreover, significant differences in the length of allula and 1st primary were found between these age classes. The range of wing length noted in this population, with the maximum value of 78 mm, distinctly exceeded the range of this parameter described for European populations of the Savi's Warbler. The average lengths of wing, tail allula and tarsus were distinctly higher in males than in females. Sexes did not differ in body mass, Kipp's distance and wing pointedness index. In the studied population, a distinct long-term variability of tail length, Kipp's distance, wing-tip pointedness index and tarsus length was found in young birds. In adults such variability was found only in tarsus length. The paper discusses possible reasons for the long-term variability of studied parameters.