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Avian eye colour changes with age, but many aspects of this transition are still insufficiently understood. We examined if an individual’s sex, age, species and body condition are related to the iris colour in common migratory passerines during their autumn passage through Central Europe. A total of 1,399 individuals from nine numerous species were ringed and examined in late autumn in northern Poland. Each individual was sexed by plumage (if possible) and assigned to one of three classes of the iris colour—typical for immatures, typical for adults and intermediate. We found that the iris was typical in 97.7% cases of immatures and in 75.8% cases of adults and this difference was significant. Species, sex and body mass index (BMI) had no significant influence on the iris colour. We show that iris colour in passerines in late autumn is strongly age-dependent and thus can serve as a reliable feature for ageing in field studies, especially in species difficult to age by plumage.

Stêpniewski K., White M.L.J., Megalli M. 2011. Autumn migration of passerines in BahariyaOasis in Egypt - where do they come from and where do they go? Ring 33, 1-2: 27-36. We present the results of studies on directional preferences of passerine migrants in Bahariya Oasis, Western Desert, Egypt. Fieldwork was conducted in August and September 2010. Birds were mist-netted, ringed and tested in Busse’s orientation cage; in total 66 tests were analysed. The most pronounced direction was W, which was surprising and remains unexplained. Southern directions were also prominent, particularly SW; among the northern directions NW were distinct and NE less so. Our results are in line with those at other ringing stations in Egypt, suggesting a common migration pattern in this region. They also allow for tracking probable migration routes through Bahariya. Birds may arrive at the oasis from the Nile Delta and Mediterranean coast, then the majority head SW towards Lake Chad, while others may fly directly S or SE towards the Nile Valley. Bahariya Oasis appears to be an important crossing point of passerine migration routes across the Sahara and it is important to continue further studies in this area.

1990-2002 and 2003-2005. The most numerous species caught at all the stations was the Reed Warbler, whereas the Aquatic Warbler was caught only sporadically. Long-term number dynamics from Bukowo-Kopañ and Mierzeja Wioelana showed considerable fluctuations for the first four species, which could have been influenced by weather or habitat changes, or they could have reflected long-term population cycles. Strong correlations between the numbers of species preferring reeds might indicate habitat basis of the fluctuations. Seasonal migration dynamics were also similar, with the peak of migration in mid-August. However, the dynamics from Dru¿no suggested that the real peak of migration occurred earlier. Median dates of the Reed Warbler migration at Bukowo-Kopañ showed marked fluctuations, whereas at Mierzeja Wioelana they were delayed significantly; these changes were probably connected with climate changes.

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