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In this study, we investigated fattening strategies of juvenile Sedge and Reed Warblers during their autumn migration. We analysed fat scores of birds captured at five ringing sites situated between the southern Baltic Sea coast and Asia Minor. In Eastern Europe these two species had similarly low fat reserves. Their fat load increased in the Balkans. Remarkable differences between the species were noted in Asia Minor, where fat reserves of Sedge Warblers were more than two-fold higher compared to Reed Warblers. As high as 90% of Sedge and only 30% of Reed Warblers captured in Asia Minor had the potential capability to cross the Mediterranean Sea in one non-stop flight. Moreover, two-thirds of those Sedge Warblers were able to continue their long flight without refuelling and reach the southern edge of the Sahara desert, while in Reed Warblers only 6% of individuals were potentially able to use the same strategy. The results of the study show clear differences in potential flight ranges of the studied species, revealing different fattening strategies of the Sedge and Reed Warbler in the Balkans and Asia Minor. Majority of Sedge Warblers refuel well before the Sahara desert indicating their potential for long non-refuelling steps while crossing two large ecological barriers, whereas the majority of Reed Warblers accumulate small fat reserves, which may indicate migration with short-steps through Cyprus and/or along the eastern coast of the Mediterranean Sea. Similar interspecific differences were reported from well-studied western European route and thus our results indicate consistent migration strategies of Sedge and Reed Warblers along these two migratory flyways in the Western Palearctic, the western and the eastern one. [ABSTRACT FROM AUTHOR]

So far discussions on the occurrence of polygyny have been conducted on an inter-specific or individual level. In this paper we analyse differences in polygyny rate between different populations of Eurasian Reed Warblers. We provide evidence that our study population in SW Poland, and also the nearby Slovak population, are purely monogamous in contrast to those from western Europe, and we discuss hypotheses regarding the occurrence of polygyny. We suggest that birds breeding in different parts of Europe may exhibit different strategies for optimising reproductive success. In richer habitats of western Europe, where solitary females are able to successfully rear their young, polygyny is more frequent and extra-pair copulations relatively rare. In contrast, in central Europe, where costs of rearing young unaided are high, males do not try to attract second females but engage more often in extra-pair copulations. [ABSTRACT FROM AUTHOR]

On their route to tropical Africa, European trans-Saharan migrants must cross two major geographical barriers, the Mediterranean Sea and the Sahara Desert, which necessitates the accumulation of large fuel loads. While northern Africa is the chief region where most migrants gain fuel for the Sahara crossing, Iberia is a target area to gain fuel before the sea crossing existing between Europe and Africa. Despite the large body of studies approaching the question of fuel accumulation before geographic barriers, it is still poorly known which factors apart from distance to a certain barrier shape the geographical pattern of fuel reserves. To investigate this question in detail we used data of first-year Reed Warblers from12 localities within Iberia during the autumn migration period of 2009. We run linear models to analyze the effects of location in Iberia, date, and body size on body mass variation at each migratory fly way (eastern, central and western Iberia). Flight ranges from each site were also calculated. Our results showed that Reed Warblers in Iberia had the necessary fuel needed to arrive in northern Africa but not to tropical Africa. However, body mass patterns varied depending on the geographical region (eastern, central orwestern Iberia). Date did not affect body mass in central and western Iberia, but in eastern Iberia heavier birds tended to pass later. Thus, the factors shaping body mass of Reed Warblers in Iberia before the sea crossing to Africa seemed to be more complex than just the distance to this geographical barrier, with underlying stop over quality-associated factors possibly playing a relevant role. [ABSTRACT FROM AUTHOR]

The article discusses a study on the organization of strophes and their possible function in the Great Reed Warbler (GRW). Short- and long-term changes in the size and composition of strophe repertoires and the relationship between strophe repertoire and male GRW age, philopatry and harem size are examined. The significant effects of male age and season on strophe repertoire size are addressed. GRW males' exchanging of more than half of their song types at three-year intervals is also cited.

The article discusses research done on predicting the sex of the Sedge Warbler, also known as Acrocephalus schoenobaenus, using discriminant analysis in Poland between 2008 and 2009. The Sedge Warblers used in the study were caught during autumn migration. Mist nets were used to catch the study subjects in the southern part of the Druzno Lake reserve. A wing-rule was applied for wing-length measurement while dial calipers were applied for the other measurements. Blood from the underwing vein of the birds was taken for molecular sexing.

The article presents a study that investigates the temporal characteristics of the introductory syllables of the song in the individual recognition capability of Great Reed Warbler songbird in Poland. The study was administered from 2003-2005 in 10 fish ponds wherein the recordings of male birds were collected and its variation and song function was identified. The study reveals that the initial syllables and characteristics of sound variation are more longer during breeding season which changes over the years. The study concludes that the introductory syllables of Great Reed Warbler provides sufficient information regarding the aggressiveness of birds during breeding and rival recognition.